Which of the following is an important characteristic of lipids?
They can be linked into long chains.
They dissolve in water.
They can be converted to hormones.
They are nonpolar.
They are nonpolar. pg33
What is a substance that can moderate the change in pH of a solution?
An enzyme
A polar compound
A buffer
Peptide
A buffer pg 49
Which compound is hydrophobic?
Potassium ions (K+)
Sugar
Butter
Table salt
Butter
Lemon juice has a pH of about 2.0, compared to a pH of about 1.0 for stomach acid. Therefore, the concentration of H+ in stomach juice is ________ than that of lemon juice.
10 times higher
2 times lower
2 times higher
10 times lower
10 times higher pg48
Define interstitial fluid, indicating if it is inside or outside cells (intracellular or extracellular).
Interstitial fluid is the intracellular fluid found in all cell types.
Interstitial fluid is the extracellular fluid inside the circulatory system.
In
Interstitial fluid is extracellular fluid outside the circulatory system and the cells.
Functions of the cell membrane include physical isolation of the cell from its surroundings, regulation of exchange, structural support, and which other function?
Communication between the cell and its environment
Radiation of heat to prevent protein dena
Communication between the cell and its environment 65
Cell membranes are mainly constructed from ________.
lipids and carbohydrates
lipids and proteins
nucleic acid and proteins
carbohydrates and proteins
lipids and proteins 66
Mitochondria are unique organelles in several ways. They contain a specific genome that allows them to produce their own proteins. They can undergo replication to create more mitochondria within a cell. What other characteristic make mitochondria unique f
They have a double wall creating two separate compartments. 71?
Which tissues would likely have cells with the greatest number of gap junctions?
Epidermis
Mucosal layer of the GI tract
Bone
Cardiac muscle
Cardiac muscle 79
***
GAP JUNCTIONS ARE USED FOR CELL-CELL COMMUNICATION. These junctions are ideal for cardiac muscle. Cardiac muscle requires a lot of communication because each cell must contract simultaneously each time the heart beats
***
Which two fluid compartments make up the extracellular fluid?
Plasma and interstitial fluid
Cytosol and plasma
Intracellular fluid and plasma
Interstitial fluid and intracellular fluid
Plasma and interstitial fluid 65
In a system that includes a ball and a ramp, when would potential energy be greatest?
When the ball comes to rest at the bottom of the ramp
When the ball was at rest at the top of the ramp
When the ball is at its maximal velocity
When the ball first begin
When the ball was at rest at the top of the ramp 101
What type of reaction releases energy?
An exergonic reaction
A reversible reaction
An endergonic reaction
A thermodynamic reaction
An exergonic reaction 103
A kinase moves which functional group or molecule?
Amino groups
Phosphate
Hydroxyl
H2O
Phosphate 108
Enzymes ________.
are altered in structure as a result of chemical reactions
allow for chemical reactions to occur, which would otherwise not be possible
increase the rate of chemical reactions
determine the direction of the chemical reaction (i.e., wheth
increase the rate of chemical reactions 105
What is the definition of "metabolism?"
It is the reaction in an organism that uses energy.
It is the total of all the chemical reactions in an organism.
It is the reaction in an organism that releases energy.
It is the reaction in an organism that takes
It is the total of all the chemical reactions in an organism. 109
What is the simplest way for a human cell to acquire the activation energy necessary for metabolic reactions?
Couple an exergonic reaction with an endergonic reaction.
Allow more water to flow across the cell membrane and use the kinetic energy to drive r
Couple an exergonic reaction with an endergonic reaction. 104
During aerobic metabolism of glucose, most ATP is produced during which group of chemical reactions?
Conversion of pyruvate to acetyl CoA
Citric acid cycle
Electron transport (yielding 26-28 molecules of ATP per molecule of glucose)
Glycolysis
Electron transport (yielding 26-28 molecules of ATP per molecule of glucose) 111-115?
Which of the following best describes the function of enzymes?
Enzymes slow down chemical reactions so they don't proceed too fast, thus causing problems.
Enzymes will turn into specific molecules as needed by the body, such as ATP.
Most reactions are due
Enzymes lower the activation energy level of a chemical reaction, thus making it so the reaction will proceed. 107
How does the intracellular fluid compartment differ from the extracellular fluid compartment?
Sodium ions are more concentrated inside cells than in the plasma.
Proteins are more concentrated in the interstitial fluid than in cells.
Bicarbonate ions (HCO3
Potassium ions are more concentrated inside cells than in the extracellular space. 172
(Answers Box #2)
If a swimmer cuts his foot on a seashell while wading in the ocean and bleeds into the seawater, his red blood cells (erythrocytes) will shrink. What does this tell us about seawater?
The seawater is hypotonic to the erythrocytes.
The erythrocyte cell mem
The seawater is hypertonic to the erythrocytes. 134
How can a solution be hyperosmotic but hypotonic?
If the concentration of nonpenetrating solutes is less in the solution than in a cell
If the concentration of penetrating solutes is higher in the solution than in a cell
If the total concentration of solu
If the concentration of nonpenetrating solutes is less in the solution than in a cell 135
What is the mechanism of action of the cystic fibrosis transmembrane conductance regulator (CFTR)?
It allows for the active pumping of chloride from the extracellular fluid to the intracellular fluid.
It allows for the diffusion of sodium across the epith
It allows for the diffusion of chloride across the epithelium of a cell.
How is the function of the CFTR altered in someone with cystic fibrosis?
The CFTR channel is absent.
The CFTR functions in reverse.
The CFTR channel does not respond to ATP.
There is excessive functionality of the CFTR channel.
The CFTR channel is absent. Paragraph 3
Why is the thick mucus in Daniel's lungs a sign that he might have cystic fibrosis?
Without the CFTR, mucus cannot be thinned.
The CFTR is needed to produce a thick mucus.
When not working properly, the CFTR pulls liquids out of the mucus causing it to th
Without the CFTR, mucus cannot be thinned.
Why would tasting salty sweat on the foreheads of babies lead a midwife to assume that the baby might be afflicted with cystic fibrosis?
The CFTR allows for chloride to leave the sweat and re-enter the cells, creating a hypotonic sweat.
The CFTR channel a
The CFTR allows for chloride to leave the sweat and re-enter the cells, creating a hypotonic sweat.
What is the most important distinction between the membrane transporters known as channel proteins and those known as carrier proteins?
Channel proteins transport water-soluble molecules. Carrier proteins transport water-insoluble molecules.
Channel prote
Channel proteins create water-filled passages for small molecules that do not bind to the protein. Carrier proteins transport larger molecules by binding to them. 146
What properties must a molecule have to pass through a cell membrane by simple diffusion?
They must be polar and ionic.
They must be small and/or lipophilic.
The temperature must be high enough to increase the speed of the molecule so it has ample force t
They must be small and/or lipophilic. 165
Which of the following statements correctly describes the relationship between intracellular fluid (ICF) and extracellular fluid (ECF)?
All of the contents within the ICF are readily exchanged with the contents of the ECF.
Total solute concentration diffe
The types of solutes and their distribution between the ICF and ECF are not the same. 130
A solution containing:
Which of the following conditions below has the highest osmolarity?
5 mOsm of potassium (K+) and 3 mOsm of sodium (Na+)
3 mOsm of sodium (Na+) and 4 mOsm of chloride (Cl-)
2 mOsm of chloride (Cl-)
7 mOsm of sodium (Na+)
5 mOsm of potassium (K+) and 3 mOsm of sodium (Na+)
Solute/Volume = Concentration
You have prepared a beaker containing two membranes that are permeable only to water. This beaker has three separate compartments each containing the following osmolarities:How would you describe the osmolarity of compartment
Compartment A is hyposomotic to compartment B.
Using the same scenario as Part E, how would you describe the osmolarity of compartment B relative to compartment C?
A. 10 Osmol/L
B. 13 Osmol/L
C. 7 Osmol/L.
Compartment B is hyposomotic to compartment C.
Compartment B is isosmotic to compartment C.
Comp
Compartment B is hyperosmotic to compartment C.
You have a total body concentration of 900 mosmol dissolved in 3 liters of solution. If you added 0.5 liters of a solution with 150 mosmol of NaCl to the body, what would the new total body concentration be?
450 mOsM
300 mOsM
350 mOsM
700 mOsM
300 mOsM
The Breakdown:
900mosmol / 3L = 300mOsM
150 mosmol / 0.5L = 300mOsM
Channel proteins that can be opened or closed are called ____ channels.
receptor-mediated
carrier
Gated
signal
Gated 147
Membrane receptors are involved in various types of cell signaling. Some membrane receptors function as _____ channels.
chemically gated
mechanically gated
voltage-gated
open
chemically gated
Cell membranes are primarily made of _____ molecules.
cholesterol
Phospholipid
carbohydrate
protein
Phospholipid
What type of membrane transporter would be activated by an action potential?
A voltage-gated channel
A chemically-gated channel
A carrier protein
An open channel
A voltage-gated channel
What will happen to the cells of a patient who is provided with an intravenous solution that is isosmotic to intracellular fluids?
The question cannot be answered with certainty without knowing the identity of the solutes present in the IV solution.
The c
The question cannot be answered with certainty without knowing the identity of the solutes present in the IV solution.
The membrane potential of most cells ________.
determined primarily by sodium
results in a net negative electrical charge in the body
is negative, except when there is a change in membrane permeability to ions.
is negative at all times
is negative, except when there is a change in membrane permeability to ions.
What will occur if solution A (500ml solution containing 400mosmol/L nonpenetrating solute) is separated by a biological membrane from solution B (4L solution containing 600mosmol/L nonpenetrating solute)?
The volume of B will increase.
The volume of A wi
The volume of B will increase.
Which type of membrane transport generally requires that the transported molecule dissolve in the lipid membrane?
Phagocytosis
Active transport
Facilitated diffusion
Simple diffusion
Simple diffusion
The permeability of a membrane to a particular molecule is related to two variables. Which two variables is it related to and what is the relationship?
It is directly proportional to both lipid solubility and molecular speed.
It is indirectly proportional
It is directly proportional to lipid solubility and inversely proportional to the size of the molecule.
Which membrane proteins bind ligands and trigger another membrane event?
Receptors
Structural proteins
Transporters
Enzymes
Receptors 156
Where is most of the water in the body located?
Interstitial fluid
Intracellular fluid
Lumen of the digestive and urinary tracts
Plasma
Intracellular fluid 132
Which of the following statements makes an accurate distinction between type 1 and type 2 diabetes?
Both are characterized by an inability to make insulin.
Type 1 diabetes is characterized by high levels of insulin while type 2 diabetes is characterized b
Type 1 diabetes occurs when cells of the pancreas stop making insulin while type 2 diabetes occurs when the cells are no longer sensitive to insulin.
If you give a patient who recently developed diabetes a shot of insulin and blood glucose levels do not change, what type of diabetes does he or she most likely have?
type 2
type 1
It is possible that they could have either.
There is not enough informatio
type 2
Is Marvin's high blood glucose level the direct cause for concern expressed by the nurse?
Yes. The body should never have a high level of glucose in the blood.
No. Blood glucose levels are always high in the body and should therefore not be a cause for co
No. Blood glucose normally spikes after a meal; it is the fact that it is high under a fasted state that suggests a problem with homeostatic controls.
If glucose levels are low, how would you predict activation of the beta cell and insulin release to change?
increase; decrease
decrease; increase
decrease; decrease
increase; increase
decrease; decrease
A given hormone affects ________.
only specific target cells, because nontarget cells lack the appropriate receptors
all cells in the body, but different types of cells produce different responses to the hormone
all cells in the body, because hormones are
only specific target cells, because nontarget cells lack the appropriate receptors
Extracellular signal molecules are also called
neurotransmitters.
ligands.
receptors.
hormones.
ligands.
Conversion of an extracellular signal into an intracellular one is called
signal transduction.
transmogrification.
translation.
transcription.
signal transduction.
Amplifier enzymes produce
kinases.
second messengers.
phosphorylated proteins.
ATP.
second messengers.
Administration of ibuprofen can decrease pain. Why would this COX-2 inhibitor have this effect?
It blocks production of prostaglandins.
It enhances the production of thromboxanes.
It would inhibit lipoxygenase activity.
It blocks production of the leukotr
It blocks production of prostaglandins.
What are Prostaglandins?
Eicosanoid family. Molecules that regulate physiological systems.
The neurotransmitter norepinephrine ________.
causes some blood vessels to dilate and others to constrict, because different vessels have different receptors for norepinephrine
has effects that are opposite those of the neurohormone epinephrine
affects al
causes some blood vessels to dilate and others to constrict, because different vessels have different receptors for norepinephrine
Which of the following is NOT a means by which cell signal pathways are normally halted?
The signal is halted by the binding of an inactivator molecule to the signal molecule.
The extracellular signal molecule may be transported away from the receptor.
Th
The signal is halted by the binding of an inactivator molecule to the signal molecule.
Alpha-adrenergic receptors have a higher affinity for norepinephrine than for epinephrine. Beta-adrenergic receptors have a higher affinity for epinephrine than for norepinephrine. Which concept about receptor function do these statements reflect?
Specifi
Specificity
Which of the following is the best example of an antagonist?
Atenolol is a drug that binds to ?1-adrenergic receptors reducing blood pressure.
Epinephrine and norepinephrine each bind to ?- and ?-adrenergic receptors, but with different affinities.
Glucag
Atenolol is a drug that binds to ?1-adrenergic receptors reducing blood pressure
What are the 6 basic components of a reflex pathway?
S.I.I.E.O.R
Sensor
Input Signal
Integrator
Effector
Output Signal
Response
Name the 7 stages of a Reflex Pathway
S.S.A.I.E.E.R
1. Stimulus
2. Sensor
3. Afferent Signal
4. Integrator
5. Efferent Signal
6. Effector
7. Response
Describe the function of an afferent neuron.
to release neurohormones into the circulatory system
to deliver information about the physiological variable to the integrator
to release neurotransmitters onto an organ
to deliver information to the target tis
to deliver information about the physiological variable to the integrator
A simple endocrine pathway will include which of the following?
endocrine organ
efferent neuron
afferent neuron
sensor
neurotransmitter
circulatory system
classic hormone
neurohormone
brain
target tissue
endocrine organ
classic hormone
target tissue
sensor
Which of the following best describes the role of endocrine organs in both simple and complex reflex pathways?
to function as a sensor and integrator
to deliver information about the stimulus to the brain
to release neurohormones into the circulatory syst
to function as a sensor and integrator
Specialized neurons in the brain respond to changes in blood osmolarity (solute concentration). When blood osmolairty strays outside of homeostatic range, these neurons release a neurotransmitter that acts upon neurons in the posterior pituitary. When sti
neurohormone
In order to prevent damage due to overstretching, skeletal muscles contain specialized sensors. As a muscle stretches, information from these sensors is sent via afferent neurons to the spinal cord where the information is integrated. After integration is
simple neural
Arrange in order:
1. Gastrin stimulates parietal cell
2. Parietal cell releases HCL
3. Effernt neurons stimulate the G cell
4. Meal containing protein enters the stomach
5. G-cell releases gastrin into circulation
6. Afferent Neurons send info to nervous
4, 6, 3, 5, 1, 2
Identify the role of the G cell in the gut lining.
integrator
generates response
sensor
target organ
integrator
In the sequence of events mapped out in Part I, what is response?
release of gastrin from the G cell
delivery of sensory information to the nervous system of the gut
entry of food containing protein into the stomach
release of hydrochloric acid by the par
release of hydrochloric acid by the parietal cell
What is the best example of a first messenger?
Na+, which binds to the Na+/K+ATP pump and is actively transported out of a cell in exchange for K+.
Dystrophin, which associates with costameres to transmit the force of muscle contraction to the extracellul
Insulin, which causes the target cell to take up glucose from the blood.
What determines which cells act as targets for endocrine signals?
Those with receptors specific for the signaling molecule.
Those in the same area as the cells that release the hormone.
Those cells that are derived from the same embryonic tissue as the en
Those with receptors specific for the signaling molecule.
Which form of cell-to-cell communication uses the direct transfer of electrical and chemical signals?
Contact dependent signaling
Autocrine signaling
Gap junction signaling
Endocrine signaling
Gap junction signaling
The most rapid intracellular responses to signals result from activation of receptors that are also ________.
second messengers
ion channels
amplifiers
enzymes
ion channels
Which gas is also a paracrine signaling molecule?
Nitrous oxide
Sulphur dioxide
Carbon dioxide
Nitric oxide
Nitric oxide
Compared to endocrine reflexes, neural reflexes ________.
respond rapidly and are longer-lasting
respond slowly and are very brief
respond slowly, but are longer-lasting
respond rapidly, but are very brief
respond rapidly, but are very brief
Which molecule of the GPCR-adenylyl cyclase signal transduction system phosphorylates proteins to create the cellular response?
Inositol triphosphate
Protein kinase C
Protein kinase A
Phosphatase
Protein kinase A
The hypothalamus senses the temperature of the blood via thermoreceptors. When blood temperature begins to drop, the hypothalamus releases a hormone, TRH, that stimulates the release of TSH from the anterior pituitary gland. TSH causes the thyroid gland t
The hypothalamus
Active transport of molecules across membranes requires ATP because ________.
the molecules are moved against the concentration gradient (uphill)
more than one molecule is transported at a time
the transport protein moves or has moving gates
the transport
the molecules are moved against the concentration gradient (uphill)
The time required for molecules in a solution to move from A to B is proportional to the square of the distance from A to B. What property of diffusion does this principle explain?
Diffusion is rapid over short distances but slow over longer distances.
Di
Diffusion is rapid over short distances but slow over longer distances.
Ion channels can be opened or closed via three signal transduction mechanisms. Two of them are extracellular signals and second messengers. What is the third mechanism for opening or closing ion channels?
Altered membrane permeability to Ca2+
Electrical s
G protein action
Which specific characteristic must a signaling molecule have in order to bind to a cytosolic or nuclear receptor?
It must be a gene activator.
It must be actively transported across the membrane.
It must be lipophilic and able to diffuse across the plasma
It must be lipophilic and able to diffuse across the plasma membrane.
Why is the resting membrane potential (Vm) approximately - 70 mV for most cells?
Most membranes are 40 times more permeable to K+ than to Na+.
Most membranes are 10 times more permeable to Na+ than to K+.
The large concentration of proteins in the interst
Most membranes are 40 times more permeable to K+ than to Na+.
The membrane potential of most cells ________.
determined primarily by sodium
is negative at all times
results in a net negative electrical charge in the body
is negative, except when there is a change in membrane permeability to ions
is negative, except when there is a change in membrane permeability to ions
Negative feedback in reflex loops ________.
is "negative" because it opposes homeostasis
is responsible for triggering the response to the stimulus
is rare compared to positive feedback
is common because it promotes homeostasis
is common because it promotes homeostasis
The ion that controls the widest variety of intracellular activities is ________.
chloride
potassium
sodium
calcium
calcium
Signal molecules that degrade most rapidly, resulting in very brief effects, are ________.
hormones
paracrines
ions
gases such as nitric oxide
gases such as nitric oxide
What are the second messengers in the GPCR-phospholipase C signal transduction system?
Ca2+and calmodulin
cAMP and cGMP
Inositol triphosphate and diacylglycerol
ATP and NADH
Inositol triphosphate and diacylglycerol
Which of the following hormones has intracellular receptors?
insulin
epinephrine
Cortisol
Cortisol
What is the mechanism of action of lipid-soluble hormones?
increasing protein kinases
phosphorylation of intracellular proteins
activation of genes, which increases protein synthesis in the cell
activation of genes, which increases protein synthesis in the cell 215
After a lipid-soluble hormone is bound to its intracellular receptor, what does the hormone complex do?
activates a protein kinase
directly alters protein synthesis at the ribosome
acts as a transcription factor and binds to DNA, activating a gene
phospho
acts as a transcription factor and binds to DNA, activating a gene
Which hormone's receptor is always bound to DNA, even when the receptor is empty?
thyroid hormone
insulin
cortisol
thyroid hormone
What keeps intracellular receptors from binding to DNA before a hormone binds to the receptor?
Receptors can't enter the nucleus until the hormone is bound to it.
transcription factors
chaperone proteins
chaperone proteins (chaperonins)
What distinguishes a hormone from other signaling molecules such as cytokines, or paracrine or autocrine signaling molecules?
Hormones are secreted into the bloodstream.
Hormones act when they are in high concentrations.
Hormones are nucleotides while oth
Hormones are secreted into the bloodstream.
Hormones act when they are in high concentrations.
***No, they act at low [ ]
Hormones are nucleotides while other signals are peptides or lipids.
***NO - most hormones are peptides and proteins
Hormones bind to
A new hormone is discovered. Analysis of its synthesis suggests that it is synthesized on demand and has a long half-life in the bloodstream once it is released. It seems to activate gene transcription in its target cells though no cell surface receptors
A catecholamine
***Catecholamines are neurohormones. They bind to membrane recepts like peptide hormones do. Also have short half-life
A thyroid hormone
***Also behave like steroid hormones but have short half life
A peptide
***Peptide hormones need membr
When might negative feedback fail to regulate hormone production, and how would this affect hormone secretion?
A pathology in the endocrine gland could prevent negative feedback from working, resulting in hyposecretion.
Negative feedback may cause down-re
A pathology in the endocrine gland could prevent negative feedback from working, resulting in hypersecretion.
Norepinephrine and epinephrine cause an increase in heart rate (HR) and stroke volume (SV), which is the amount of blood pumped out during each heart beat, but the effect is enhanced when thyroid hormone (TH) is also present. Oddly, TH has little effect o
Permissiveness
Most amine hormones are derived from which source?
Freely circulating amine groups
Tyrosine
Cholesterol
An iodinated peptide
Tyrosine 216
What is the role of the hypothalamus with regard to hormone release and endocrine function?
to release trophic hormones that stimulate the anterior pituitary
to release classic hormones for delivery to the systemic tissues
to release trophic hormones that
to release trophic hormones that stimulate the anterior pituitary 223
Which loss of function would occur if you were to sever the connection between the hypothalamus and the anterior pituitary?
There would be no loss of function.
The portal system would carry tropic hormones from the hypothalamus to the anterior pituitary a
The anterior pituitary would not release hormones in response to trophic hormone stimulation.
How would you classify the type of chemical released by the posterior pituitary (e.g., classic hormone, neurotransmitter etc.)?
Choose the best answer.
classic hormone
trophic hormone
neurotransmitter
Neurohormone
Neurohormone 221
Which of the following are released by the posterior pituitary?
Select all that apply.
Vasopressin
Oxytocin
prolactin
luteinizing hormone
Vasopressin 219
Oxytocin 219
Where are the neurohormones released by the posterior pituitary produced?
by neuroglia located at the end of the posterior pituitary
in the axon terminal of the neurons that project from the hypothalamus through to the infundibulum
by the endocrine cells
in the neuronal cell bodies found in the hypothalamus 219
Mrs. Johnson does goes in to visit her doctor because of some health issues that she has been having. One of the many tests that were run on Mrs. Johnson revealed that she had no circulating concentrations of vasopressin. The doctor does a further analysi
The neuronal cell bodies in the hypothalamus are damaged.
Which of the following statements regarding the anterior and posterior pituitary is correct?
Anterior pituitary is composed of endocrine tissue while the posterior pituitary is composed of neural tissue.
Both are composed of endocrine tissue.
Anterior pit
Anterior pituitary is composed of endocrine tissue while the posterior pituitary is composed of neural tissue.
What tropic hormone stimulates cortisol from the adrenal gland?
thyroid stimulating hormone (TSH)
growth hormone (GH)
luteinizing hormone (LH) and follicle stimulating hormone (FSH)
adrenocorticotropic hormone (ACTH)
adrenocorticotropic hormone (ACTH)
What is the function of the ventral hypothalamic neurons?
control secretion of thyroid stimulating hormone (TSH)
control secretion of oxytocin
control secretion of antidiuretic hormone (ADH)
control secretion of thyroid hormones
control secretion of thyroid stimulating hormone (TSH)
Insulin-like growth factors (IGFs) are intermediary hormones stimulated by which of the following hormones?
thyroid hormones
GH (growth hormone)
prolactin (PRL)
oxytocin
GH (growth hormone)
**
GH stimulates liver to release IGF-1
**
Which of the following hormones is regulated by a neuroendocrine ("letdown") reflex?
cortisol
antidiuretic hormone (ADH)
Oxytocin
Oxytocin
Where is antidiuretic hormone (ADH), also known as vasopressin, synthesized?
posterior pituitary
Hypothalamus
kidney
anterior pituitary
Hypothalamus
What is the most important regulatory factor controlling the circulating levels of thyroid hormone?
negative feedback
thyroid-stimulating hormone (TSH)
thyrotropin-releasing hormone (TRH)
a circadian rhythm of release
negative feedback
If the release of thyroid hormone (TH) was regulated by a long-loop negative feedback system, where would the target cells be located to which TH would bind to inhibit the pathway?
The posterior pituitary
The hypothalamus
The anterior pituitary
The thyroi
The hypothalamus
What type of hormones bind to receptors located on the cell membrane?
lipid-soluble hormones, such as thyroid hormones and cortisol
water-soluble hormones, such as insulin and epinephrine
water-soluble hormones, such as insulin and epinephrine
Which intracellular substance degrades cAMP, thus inactivating the response to a hormone?
Phosphodiesterase
protein kinase C
phospholipase C
adenylate cyclase
Phosphodiesterase
Growth factor hormones, such as insulin, bind to which type of receptor?
G proteins
tyrosine kinase receptors
intracellular receptors
tyrosine kinase receptors
Which is the correct order of events for hormones activating Gs proteins?
activation of G protein, binding of GTP, activation of adenylate cyclase, conversion of ATP to cAMP
activation of G protein, binding of GTP, activation of phospholipase C, activatio
activation of G protein, binding of GTP, activation of adenylate cyclase, conversion of ATP to cAMP
Which second messenger causes the release of calcium from the endoplasmic reticulum?
tyrosine kinase
IP3
cAMP
DAG
IP3
Which of the following adrenergic receptors increase cAMP levels?
? receptors
?1 receptors
?2 receptors
? receptors
The membrane potential of most cells ________.
is negative at all times
determined primarily by sodium
results in a net negative electrical charge in the body
is negative, except when there is a change in membrane permeability to ions
is negative, except when there is a change in membrane permeability to ions
Why is the resting membrane potential (Vm) approximately - 70 mV for most cells?
Most membranes are 10 times more permeable to Na+ than to K+.
The large concentration of proteins in the interstitial space draws Na+ out of the cell making it negatively cha
Most membranes are 40 times more permeable to K+ than to Na+.
The sympathetic and parasympathetic nervous systems are divisions of which system?
Somatic motor nervous system
Sensory nervous system
Central nervous system
Autonomic nervous system
Autonomic nervous system
The part of the neuron that receives most of the incoming signals is the ________.
dendrite
cell body
soma
axon
dendrite
Which glial cell produces myelin in the central nervous system?
Oligodendrocytes
Ependymal cells
Astrocytes
Schwann cells
Oligodendrocytes
Ions are unequally distributed across the plasma membrane of all cells. This ion distribution creates an electrical potential difference across the membrane. What is the name given to this potential difference?
Resting membrane potential (RMP)
Action pote
Resting membrane potential (RMP)
Sodium and potassium ions can diffuse across the plasma membranes of all cells because of the presence of what type of channel?
Voltage-gated channels
Sodium-potassium ATPases
Ligand-gated channels
Leak channels
Leak channels
On average, the resting membrane potential is -70 mV. What does the sign and magnitude of this value tell you?
The outside surface of the plasma membrane is much more negatively charged than the inside surface.
The inside surface of the plasma membrane is
The inside surface of the plasma membrane is much more negatively charged than the outside surface.
The plasma membrane is much more permeable to K+ than to Na+. Why?
There are many more K+ leak channels than Na+ leak channels in the plasma membrane.
Ligand-gated cation channels favor a greater influx of Na+ than K+.
The Na+-K+ pumps transport more K+ i
There are many more K+ leak channels than Na+ leak channels in the plasma membrane.
The resting membrane potential depends on two factors that influence the magnitude and direction of Na+ and K+ diffusion across the plasma membrane. Identify these two factors.
The presence of a resting membrane potential and leak channels
The presence of
The presence of concentration gradients and leak channels
What prevents the Na+ and K+ gradients from dissipating?
H+-K+ ATPase
Na+ cotransporter
Na+-K+ ATPase
Na+ and K+ leaks
Na+-K+ ATPase
The membranes of neurons at rest are very permeable to _____ but only slightly permeable to _____.
Na+; K+
K+; Na+
K+; Cl-
Na+; Cl-
K+; Na+
During depolarization, which gradient(s) move(s) Na+ into the cell?
only the chemical gradient
only the electrical gradient
both the electrical and chemical gradients
Na+ does not move into the cell. Na+ moves out of the cell.
both the electrical and chemical gradients
What is the value for the resting membrane potential for most neurons?
-90 mV
+30 mV
-70 mV
-70 mV
The Na+-K+ pump actively transports both sodium and potassium ions across the membrane to compensate for their constant leakage. In which direction is each ion pumped?
K+ is pumped out of the cell and Na+ is pumped into the cell.
Both Na+ and K+ are pumpe
Na+ is pumped out of the cell and K+ is pumped into the cell.
The concentrations of which two ions are highest outside the cell.
Na+ and A- (negatively charged proteins)
K+ and Cl-
K+ and A- (negatively charged proteins)
Na+ and Cl-
Na+ and Cl-
Which of the following neurons or groups of neurons are NOT considered to be a part of the efferent pathway?
somatic motor
sensory
parasympathetic
sympathetic
sensory
The part of the neuron that receives most of the incoming signals is the ________.
dendrite
cell body
soma
axon
dendrite
What did Dr. McKhann observe in the children in Beijing and why did this observation lead him to question the original diagnosis of Guillain-Barré syndrome?
Hint 1.
Think about both efferent and afferent pathways.
Children were not able to move but they
Children were not able to move but they did have sensory function.
Why would the conduction velocity of a neuron be used to diagnose demyelinating diseases?
Hint 1.
Myelin surrounds the axon of large somatic motor neurons.
In a demyelinating disease, myelin production increases, which leads to an increase in conduction v
In a demyelination disease, myelin is degraded, which will decrease conduction velocity.
If the children from Beijing did in fact have a demyelinating disease, what would have been the result of Dr. McKhann's conduction velocity test?
Hint 1.
Demyelination will cause a loss of myelin.
increased conduction velocity
decreased conduction velocit
decreased conduction velocity
Why is the diminished strength of the action potential observed by Dr. McKhann a problem with axons and not myelination?
Hint 1.
Axons propagate action potentials to their targets.
There is no known link between the axon and the action potential.
Because
Because the axonal membrane contains the ion channels necessary to conduct the action potential.
What would happen to the membrane potential if a cell suddenly becomes more permeable to Na+?
Hyperpolarize
It would reverse polarity.
Repolarize
Depolarize
Depolarize
What happens if a graded stimulus is of sufficient strength to reach threshold at the trigger zone?
An action potential occurs.
The membrane is hyperpolarized.
The cell becomes more permeable to Cl-.
The graded stimulus moves through the cell more quickly
An action potential occurs.
Which two properties determine the conduction velocity in a mammalian neuron?
The leak resistance of the membrane and myelination
Axon diameter and the leak resistance of the membrane
The voltage-gated K+ ion channel concentration and axon diameter.
Myeli
Axon diameter and the leak resistance of the membrane
Which type of receptor would bind acetylcholine and be found in skeletal muscle?
�-adrenergic
NMDA receptors
Nicotinic cholinergic
Muscarinic cholinergic
Nicotinic cholinergic
Which of the following would NOT cause the membrane potential to change from -70 mV to +30 mV?
Sodium ions entering the cell.
Calcium ions entering the cell.
Chloride ions leaving the cell.
Potassium ions leaving the cell.
Potassium ions leaving the cell.
Where do most action potentials originate?
Hint 1. Parts of a neuron
Most input to a neuron is to the cell body and dendrites. If a neuron is excited to threshold, an action potential will be generated in the first part of the axon. Identify this part.
Ax
Initial segment
What opens first in response to a threshold stimulus?
Hint 1. Voltage-gated channels
Action potentials occur in areas of the plasma membrane that are densely populated with voltage-gated, or voltage-sensitive, ion channels. Which type of voltage-gated cha
Voltage-gated Na+ channels
What characterizes depolarization, the first phase of the action potential?
Hint 1. Resting membrane potential
A resting membrane potential (RMP) is exhibited by all cells, and it is caused by an unequal distribution of ions across the plasma membrane. To
The membrane potential changes from a negative value to a positive value.
What characterizes repolarization, the second phase of the action potential?
Once the membrane depolarizes to a threshold value of approximately -55 mV, it repolarizes to its resting value of -70 mV.
As the membrane repolarizes to a negative value, it goe
Once the membrane depolarizes to a peak value of +30 mV, it repolarizes to its negative resting value of -70 mV.
Hint 1. Resting membrane potential
A resting membrane potential (RMP) is exhibited by all cells, and it is caused by an unequal distribution o
What event triggers the generation of an action potential?
The membrane potential must depolarize from the resting voltage of -70 mV to its peak value of +30 mV.
The membrane potential must hyperpolarize from the resting voltage of -70 mV to the more nega
The membrane potential must depolarize from the resting voltage of -70 mV to a threshold value of -55 mV.
Hint 1. Voltage-gated channels
Action potentials occur in areas of the plasma membrane that are densely populated with voltage-gated, or voltage-sens
What is the first change to occur in response to a threshold stimulus?
Voltage-gated Ca2+ channels change shape, and their activation gates open.
Voltage-gated K+ channels change shape, and their activation gates open.
Voltage-gated Na+ channels change sh
Voltage-gated Na+ channels change shape, and their activation gates open.
Correct
Yes! The activation gates of voltage-gated Na+ channels open very rapidly in response to threshold stimuli. The activation gates of voltage-gated K+ channels are comparative
The sympathetic and parasympathetic nervous systems are divisions of which system?
Central nervous system
Somatic motor nervous system
Sensory nervous system
Autonomic nervous system
Autonomic nervous system
Most neurons have at least two processes extending from the soma, or cell body. Which type of neuron only has one process extending from the cell body?
An efferent neuron
A pseudounipolar neuron
An interneuron
A unipolar neuron
A pseudounipolar neuron
Which glial cell produces myelin in the central nervous system?
Schwann cells
Ependymal cells
Oligodendrocytes
Astrocytes
Oligodendrocytes
Which of the following statements best describes the concept of permeability?
whether or not a molecule moves across the cell via passive or active mechanisms
the surface area of a cell and its relationship to the diffusion of water
the ability of a molec
the ability of a molecule to cross the cell membrane
Hint 1. The plasma membrane
The plasma membrane is defined as a semipermeable membrane. This means that the membrane is permeable to some substances but not others. The chemical nature of the plasma mem
The two cells below are hypothetical cells with a concentration of 100 mOsm of K+ inside the cells and containing only leak channels for K+ within the membrane. Each cell is placed into a different solution containing different concentrations of K+ in the
B, because it has more ion leak channels for K+ than A.
Hint 1. Ions and the plasma membrane
The plasma membrane is impermeable to ions due to their charges. In order for an ion to cross the plasma membrane, it would have to travel through a pore. These p
Which of the following statements best describes the resting membrane potential?
the differences that exist between excitable cells and nonexcitable cells
a concentration gradient that exists between the intracellular and extracellular fluids
an osmotic p
an electrical gradient that exists between the intracellular and extracellular fluids
Hint 1. What are excitable versus nonexcitable cells?
Excitable cells are those that are capable of changing their membrane potentials in order to cause the release of a
Concentration Gradients
Note:
In order for an ion to passively move across a cell membrane, not only does there have to be a channel for that ion to move, but there has to be a concentration gradient as well. Concentration gradients are a form of potentia
...
Indicate whether Membrane Potential Becomes More + or -
Increasing [Na+] in ECF
Increasing [K+] in ECF
Inserting more K+ leak channels
Removing Na+ leak hannels
Decreasing [K+] in ECF
Increasing [Na+] in ECF (+)
Increasing [K+] in ECF (+)
Inserting more K+ leak channels (-)
Removing Na+ leak hannels (-)
Decreasing [K+] in ECF (-)
Hint 1. Changing permeability
You can change a cell's permeability to an ion by either inserting more ion channels or opening up channels for a particular ion that is normally closed. This would result in either an increased influx or increased efflux of
Hint 2. Changing concentration gradients
Membrane potential can be calculated by using the Goldman-Hodgkin-Katz equation. This equation (see below) takes in to account the concentrations as well as permeabilities of various ions between the extracellular
Hint 1. Changes in permeability
Changes in permeability can occur when a cell opens up more channels associated with a particular ion. This increase in permeability will allow for the diffusion rate of an ion to increase. As long as there is a potential e
Hint 2. Concentrations of Na+ and K+
Na+ is an ion that will be more concentrated in the extracellular fluid, while K+ is an ion that is more concentrated in the intracellular fluid. These differences create concentration gradients for each ion in opposit
Hint 1. Rising phase of the action potential
During the rising phase of the action potential, the membrane potential starts to become more positive. This is due to the changing permeability of the cell to Na+. It begins with a stimulus that increases the
Hint 2. After-hyperpolarization phase
The after-hyperpolarization phase occurs due to the functionality of the voltage-gated K+ channels. These channels are slow to close, which will result in an excess leakage of K+. This will usually result in a membran
Hint 1. Cause and effect of channels, permeability, and ion flow
The opening and closing of ion channels will directly affect the permeability of the cell to that ion. This event must come first in order for permeability to change. Take, for example, a ce
Hint 2. What are graded potentials?
Graded potentials are produced when the cell body of a neuron receives a stimulus from either a receptor or another neuron. These stimuli cause changes in the membrane potential of the cell body which then diffuse like
Hint 1. Changes in Ca2+ permeability
We have not worked at all with changes in Ca2+ permeability but instead have only looked at the effects of Na+ and K+ permeability. The cells found in the heart as well as the axon terminal of neurons rely on the diffu
Hint 2. Shape of the action potential
All action potentials will not look the same. This is due to differences in the types of ion channels present. Although this might be the case, the relationship between the ion channel and the changes in permeability
Why are Na+, K+, and Cl- the only ions considered in the GK equation when calculating resting membrane potential (Vm)?
These are the only ions to which cell membranes are permeable at rest.
These ions bind to receptors that increase the charge on the memb
These are the only ions to which cell membranes are permeable at rest.
What would happen to a patient's cellular EK+ if a nurse accidentally administered a potassium solution that caused the patient's extracellular potassium ion concentration to rise to 6.01 mM? Assume a body temperature of 37 �C.
It would become positive, 8
It would become less negative, -85 mV.
During an action potential, activation of voltage-gated sodium and potassium channels occurs at different rates. What is the effect of this difference on ion flow across an axon membrane?
At first there is no change in ion movement, then sodium ions flow
Initially, Na+ flows into the cell followed by K+ flowing out of the cell.
In a graded potential, what is the effect of cytoplasmic resistance and current leak?
More K+ is able to enter the cell, off-setting the depolarizing effects of Na+.
Fewer Na+ can cross the membrane in response to the stimulus.
The outer membrane surface
The strength of the signal inside the cell decreases over distance.
Why is an action potential conducted in only one direction, from an axon hillock to an axon terminal?
The channels are progressively easier to open down the length of the axon.
The number of voltage-gated ion channels increases along the length of the axo
The membrane channels upstream are refractory and cannot open.
What is the definition of an ionotropic receptor?
A receptor that acts through a G-protein to activate a second messenger when bound to its ligand.
A receptor that can bind ions as ligands.
A receptor that alters ion flow when it binds with its ligand.
Re
A receptor that alters ion flow when it binds with its ligand.
A stronger stimulus to a neuron results in ________.
larger voltage changes in graded potentials and greater frequency of action potentials produced in response
larger voltage changes in the graded potentials, but no changes in action potentials
larger vo
larger voltage changes in graded potentials and greater frequency of action potentials produced in response
Hint 1. Conduction speed
Recall that axons may be myelinated or unmyelinated. The speed of action potential conduction is increased with myelin, as action potentials are regenerated at nodes of Ranvier only. In contrast, action potentials are regenerated
...
What type of conduction takes place in unmyelinated axons?
Synaptic transmission
Saltatory conduction
Electrical conduction
Continuous conduction
Continuous conduction
Yes! An action potential is conducted continuously along an unmyelinated axon from its initial segment to the axon terminals. The term continuous refers to the fact that the action potential is regenerated when voltage-gated Na+ chan
An action potential is self-regenerating because __________.
repolarizing currents established by the efflux of Na+ flow down the axon and trigger an action potential at the next segment
depolarizing currents established by the influx of Na+ flow down the
depolarizing currents established by the influx of Na+ flow down the axon and trigger an action potential at the next segment
Yes! The Na+ diffusing into the axon during the first phase of the action potential creates a depolarizing current that brings th
Why does regeneration of the action potential occur in one direction, rather than in two directions?
The inactivation gates of voltage-gated Na+ channels close in the node, or segment, that has just fired an action potential.
The activation gates of volta
The inactivation gates of voltage-gated Na+ channels close in the node, or segment, that has just fired an action potential.
Yes! At the peak of the depolarization phase of the action potential, the inactivation gates close. Thus, the voltage-gated Na+ ch
What is the function of the myelin sheath?
The myelin sheath increases the speed of action potential conduction from the initial segment to the axon terminals.
The myelin sheath decreases the speed of action potential conduction from the initial segment t
The myelin sheath increases the speed of action potential conduction from the initial segment to the axon terminals.
Yes! The myelin sheath increases the velocity of conduction by two mechanisms. First, myelin insulates the axon, reducing the loss of depo
What changes occur to voltage-gated Na+ and K+ channels at the peak of depolarization?
Inactivation gates of voltage-gated Na+ channels close, while activation gates of voltage-gated K+ channels open.
Inactivation gates of voltage-gated Na+ channels close
Inactivation gates of voltage-gated Na+ channels close, while activation gates of voltage-gated K+ channels open.
Correct
Yes! Closing of voltage-gated channels is time dependent. Typically, the inactivation gates of voltage-gated Na+ channels close about
In which type of axon will velocity of action potential conduction be the fastest?
Myelinated axons with the largest diameter
Unmyelinated axons with the largest diameter
Myelinated axons with the smallest diameters
Unmyelinated axons of the shortest leng
Myelinated axons with the largest diameter
Correct
Yes! The large diameter facilitates the flow of depolarizing current through the cytoplasm. The myelin sheath insulates the axons and prevents current from leaking across the plasma membrane.
Hint 1. Axon
How is an action potential propagated along an axon?
Stimuli from the graded (local) potentials from the soma and dendrites depolarize the entire axon.
An efflux of potassium from the current action potential depolarizes the adjacent area.
An influx of so
An influx of sodium ions from the current action potential depolarizes the adjacent area.
Yes, the influx of sodium ions depolarizes adjacent areas, causing the membrane to reach threshold and cause an action potential. Thus, the action potential is regen
Why does the action potential only move away from the cell body?
Hint 1.
What would stop the action potential from going back towards the cell body?
The flow of the sodium ions only goes in one direction�away from the cell body
The areas that have had the
The areas that have had the action potential are refractory to a new action potential.
Yes, sodium channels are inactivated in the area that just had the action potential.
The velocity of the action potential is fastest in which of the following axons?
a small unmyelinated axon
a large unmyelinated axon
a small myelinated axon
Correct
Yes, the myelination acts as insulation and the action potential is generated only at the
a small myelinated axon
Yes, the myelination acts as insulation and the action potential is generated only at the nodes of Ranvier. Propagation along myelinated axons is known as saltatory conduction.
What factor does not contribute to the rate of transmembrane transport of glucose?
a. the number of glucose transporters in the plasma membrane
b. the ambient temperature
c. the difference in glucose concentration on the two sides of the plasma membrane
d
d. the amount of ATP available in the cytosol
A cell removed from the body and placed in pure water will:
a. shrink due to a net flux of water out of the cell
b. shrink due to a net flux of ions out of the cell
c. expand due to a net flux of water into the cell
d. expand due to a net flux of ions int
c. expand due to a net flux of water into the cell
Net diffusion of CO2 across a plasma membrane requires:
a. no energy at all
b. the kinetic energy contained in CO2 molecules
c. ATP
d. a transport protein
b. the kinetic energy contained in CO2 molecules
Which solution has the greatest osmolarity? Assume complete ionization of salts.
a. 150 millimoles of NaCl in 1.0 L of H2O
b. 150 millimoles of albumin (plasma protein) in 1.0 L of H2O
c. 75 millimoles of NaCl and 75 millimoles of KCl in 1.0 L of H2O
d. 1
d. 150 millimoles of MgCl2 in 1.0 L of H2O
The neighbor's dog ran away and was too inexperienced to find water for a couple of days. As she lost water, she became increasingly dehydrated. What's going on physiologically? Dogs don't sweat much, so assume there is no loss of salt via sweat.
a. she i
d. the average size of most cells in much of her body is decreasing as H2O diffuses out of cells via aquaporins
The plasma membrane of axon terminals is, of course, composed of an amphipathic lipid bilayer that acts as a barrier to the influx or efflux (flux out of cell) of most molecules. What would be the most pronounced change in K+ movement if the membrane resi
b. there would be an increase in net efflux of K+ across the terminal plasma membrane
Which is most likely to cross a plasma membrane by simple diffusion?
a. fatty acid
b. protein
c. glucose
d. Na+
a. fatty acid
Which of the following comparisons is accurate?
a. primary active transport requires a transport protein but facilitated diffusion does not
b. primary active transport displays saturation with higher concentrations of substrate but facilitated diffusion d
c. primary active transport requires the hydrolysis of ATP for energy whereas facilitated diffusion requires only the energy stored in a concentration gradient
9. Examine the transport process across the plasma membrane in the diagram. What can you conclude?
Line A = linear
Line B = exponential logistic curve
a. line "a" probably represents facilitated diffusion
b. line "b" might represent facilitated diffusion,
b. line "b" might represent facilitated diffusion, 1� active transport, or 2� active transport
Did you know there are no reports of anyone dying of dehydration while running a marathon? On the other hand, a number of people have died from water intoxication after drinking excessive amounts of water during or after a marathon run. Several years ago,
e. both b and c
Which body fluid compartment has the smallest total volume?
a. plasma
b. intracellular
c. extracellular
d. interstitial
a. plasma
Which of the following is NOT a good example of physiological homeostasis in a strict sense:
a. the hormones insulin and glucagon act together to closely regulate glucose concentrations in our plasma
b. if body temperature drops, we will attempt to restor
d. euryhaline fish can live in H2O with varying salinities; they are osmoconformers, meaning that their plasma levels of salt vary directly with their external environment
A receptor for a small, non-polar, hormone is likely to be located in the:
a. Plasma membrane
b. Cytoplasm
c. Extracellular matrix
d. Mitochondria
b. Cytoplasm
What would happen to transport via secondary active transporters if a cell were depleted of ATP?
a. Transport would continue for a while until concentration gradients run down
b. Transport would stop immediately
c. Nothing would change because these trans
a. Transport would continue for a while until concentration gradients run down
In the Na+/K+ ATPase activity cycle, when is the affinity for Na+ highest?
a. When the transporter binding sites are exposed to the cytosol
b. When the transporter binding sites are exposed to the extracellular fluid
c. When GTP binds to the transporter
d
a. When the transporter binding sites are exposed to the cytosol
Which of the following would NOT decrease a target cell's sensitivity to a particular hormone?
a. down-regulate the number of hormone receptors
b. decrease the amount of hormone released from endocrine cells
c. receptor phosphorylation leading to desensit
b. decrease the amount of hormone released from endocrine cells
Caffeine is an antagonist at adenosine A1 receptors. When adenosine target cells are repeatedly exposed to the adenosine receptor antagonist, the cells are likely to increase the synthesis of adenosine A1 receptors and insertion in plasma membranes. Which
f. both a and d
Sarah ran the New York City Marathon on an 85� day. She lost 4 liters of fluid during the race, mostly in the form of sweat, some from breathing. Sweat contains H2O and NaCl. During the marathon, she drank 4 liters of pure H2O to replace the H2O she lost.
d. it would probably be better to drink fluids that contained electrolytes (NaCl particularly) than pure water
What would happen to K+ flux in a typical cell if membrane resistance to K+ flux suddenly decreased?
a. there would be a decrease in net efflux of K+ across the plasma membrane
b. there would be an increase in net efflux of K+ across the plasma membrane
c
b. there would be an increase in net efflux of K+ across the plasma membrane
What is the final common pathway for nearly all 2nd messenger-mediated intracellular signaling?
a. change in [cAMP]
b. change in phosphorylation state of specific cellular proteins
c. change in gene expression
d. change in the number of receptors in the p
b. change in phosphorylation state of specific cellular proteins
Sartans are a class of drugs used to treat hypertension (high blood pressure). Sartans can lower blood pressure by acting as antagonists at Angiotensin II receptors. Predict/explain how sartans can produce vasodilation (increased diameter of blood vessels
e. b and c
Take a look at the two cartoons below representing hormone signaling via G protein-coupled receptors. Which statement about the pathways is FALSE?
a. in both cases the activated receptor activates a G protein
b. in both cases the activated G protein disso
g. in both cases, the end result is the production of cAMP
What kind of cells are Na+/K+ ATPases found in?
a. animal but not plant cells
b. only neurons and muscle cells
c. virtually all cells
d. only neurons
c. virtually all cells
Ions do NOT cross the plasma membrane of cells by which process?
a. simple diffusion
b. voltage-gated ion channels
c. ligand-gated ion channels
d. active transport
e. carrier-mediated transport
a. simple diffusion
Look at this diagram of ligand binding to a receptor. What can you say from looking at this?
(A & B are both logistic exponential curves. A has a slightly higher curve than B.)
a. Ligand A has a higher affinity for the receptor than ligand B does
b. Ligan
a. Ligand A has a higher affinity for the receptor than ligand B does
Examine this equation. Which statement is FALSE?
W=RTln [X]outside/[X]inside
a. The energy stored in a concentration gradient depends upon temperature
b. If [X]outside = [X]inside the cell, there is no driving force for diffusion
c. A concentration gradie
d. If the [X]inside is greater than [X]outside the cell, there's no energy for diffusion
Death by injection in many states involves administration of a lethal dose of an anesthetic, followed by a lethal dose of a paralyzing agent, followed by a lethal dose of KCl. In the unlikely event that a subject was still alive after the first two inject
b. 0 mV
Which of the following is the major contributor to the membrane potential of kidney cells?
a. K+ diffusion across the plasma membrane into the intracellular fluid
b. K+ efflux through leaky K+ channels into the extracellular fluid
c. pumping K+ out of cel
b. K+ efflux through leaky K+ channels into the extracellular fluid
What conditions are necessary for cells to have a membrane potential (Vm)?
a. the semipermeable plasma membrane must be permeable to an ion
b. the lipid bilayer can separate and store charge across the plasma membrane
c. the concentration of anions is gre
f. a and b
Which of the following statements about Na+ / K+ ATPases is FALSE?
a. they generate and maintain concentration gradients for K+ and Na+ in all cells
b. the energy stored in Na+ concentration gradients created by Na+ / K+ ATPases is used to transport other
d. the movement of ions via Na+ / K+ ATPases create the negative resting potential of neurons
Which of the following is NOT a signaling pathway used by peptides hormone or neurotransmitter receptors? (Some molecules in pathway may not be listed.)
a. activate Gq, phospholipase C, production of IP3 and diacylglycerol, and activation of protein kinas
d. activate Gs protein, adenylyl cyclase, and phospholipase C with production of cAMP and IP3
How does a single hormone, like epinephrine (EPI), produce different responses in different cells?
a. EPI binds to adrenergic receptors in some cells but binds to G proteins in other cell membranes
b. Binding to different adrenergic receptor subtypes may
b. Binding to different adrenergic receptor subtypes may activate different G proteins in the plasma membranes of different cells
At the resting membrane potential for a typical neuron:
a. there is no net diffusion of K+ or Na+
b. there is net diffusion of K+ but no net diffusion of Na+
c. there is a greater driving force for diffusion of K+ than for Na+
d. the plasma membrane is mo
d. the plasma membrane is more permeable to K+ than Na+
What differentiates peptide hormones from steroid hormones?
a. Steroid hormones are synthesized 'on demand' but peptide hormones can be stored for release in vesicles.
b. Steroid hormones are made from cholesterol but peptide hormones are made from amino
d. All of the answers are correct
Binding of oxytocin to the oxytocin receptor leads activation of Gq and subsequent activation of phospholipase C land production of second messengers. Which mechanism would normally contribute to the termination of oxytocin signaling?
a. phosphodiesterase
e. both b and d
Oxytocin is:
a. Synthesized in the neurohypothesis (posterior pituitary)
b. Released from the neurohypophysis
c. Released from the anterior pituitary
d. Released in response to oxytocin-releasing hormone
e. Synthesized in the hypothalamus and released fro
a. Synthesized in the neurohypothesis (posterior pituitary)
Cortisol is:
a. A peptide hormone that binds to receptors in plasma membrane
b. Released from the anterior pituitary gland
c. Released from the adrenal cortex
d. Released from the adrenal medulla
c. Released from the adrenal cortex
Dr O just did a month of treatment with prednisone, a synthetic cortisol-like drug. Prednisone binds to cortisol receptors and pretty much just acts like cortisol....but it's not. When Dr O was taking prednisone:
a. the concentration of corticotropin-rele
b. the concentration of corticotropin-releasing hormone in his hypothalamic-pituitary blood portal vessels was low
Which of the following scenarios would make the resting membrane voltage across the plasma membrane more positive?
a. Up-regulate the number of leaky K+ channels
b. Increase the concentration of K+ on the inside of the cell relative to outside
c. Increase
c. Increase the number of Na+ passive leak channels in the plasma membrane
As part of an undergrad research project, Amanda impaled a rat neuron with a intracellular electrode and recorded the membrane potential. You go, girl! She then added drugs to the buffer bathing the cells to block all ion channels except leaky K+ channels
c. around - 90 mV
Groups of cells performing related tasks are known as ________.
organisms
organs
organ systems
tissues
tissues
Which is the best example of integration in physiology?
The interaction of nervous and endocrine signals to regulate blood flow to the small intestines
Air is carried into alveoli in the lungs where oxygen can diffuse through the respiratory membrane into
The interaction of nervous and endocrine signals to regulate blood flow to the small intestines
Which of the following is the best example of a mechanistic understanding of a function?
We are self-aware so that we can recognize ourselves and distinguish ourselves from others.
Skeletal muscle cells contract when myosin heads attach to actin filaments
Skeletal muscle cells contract when myosin heads attach to actin filaments and rotate, producing force.
What is a good reason to consider using mapping to learn physiological concepts?
It is easier to memorize things when they are written in a memorable way such as mapping.
Mapping is a way of forcing students to spend time with the material so they will st
Creating a map requires thinking about and understanding the relationships between facts.
Select the most accurate definition of homeostasis.
The ability of an organism to maintain relatively constant internal conditions despite variability in external conditions.
The ability of an organism to maintain relatively constant internal conditions a
The ability of an organism to maintain relatively constant internal conditions despite variability in external conditions.
What is the primary mechanism allowing a molecule like an enzyme to perform a particular function?
Its specific structure
The need for that function
The color of the molecule
The location of the molecule
Its specific structure
What is the main difference between the concepts of "steady-state" and "equilibrium?"
A steady-state system is dynamic, whereas a system in equilibrium is not.
There is no movement of materials within a steady-state system, but materials move freely in an
A steady-state system is dynamic, whereas a system in equilibrium is not.
Which component of a control system initiates an appropriate response to a stimulus?
Receptor
Stimulation receiver
Integrating center
Response center
Integrating center
What does it mean if an article has been peer reviewed?
The work has been read by an anonymous panel of researchers in a different field than that represented by the article.
The work has been read by an anonymous panel of doctors.
The work has been read
The work has been read by an anonymous panel of scientists qualified to judge the science.
What is a review article and why might it be beneficial for a novice in a subject matter to read?
It is a technical paper based on a single research project; because it is written as a summary paper that can be understood by a novice.
It contains a synops
It contains a synopsis of recent research on a particular topic; because it gives a general summary of several technical papers, making it easier for a novice to
understand.
Which of the following search combinations would render in the most accurate results if you wanted to know if there was a link between the consumption of high fructose corn
syrup and the incidence of type II diabetes?
high fructose corn syrup
corn syrup A
high fructose corn syrup AND the incidence of type II diabetes
Which of the following websites would be best if you wanted to learn about the effectiveness of hormone replacement therapy on reducing the symptoms associated with
menopause?
www.mayoclinic.com
www.webmd.com
www.estroven.com
www.nlm.nih.gov/medlineplus
www.nlm.nih.gov/medlineplus
You want to obtain information from organizations that are part of the scientific community. These types of websites will contain reliable information intended to educate the
public on the subject matter.
Processes that cannot be predicted simply from understanding the functions of the individual components of the system are known as ________ properties.
gradient
emergent
retrospective
variable
emergent
Hint 1. Cause and effect relationships
When considering a physiological process, we have to be careful with cause and effect. Let's take a non-physiological process for example. If you fill a pot with water and
place it on a burner, the conduction between
Hint 2. Homeostatic regulation
Cause and effect in physiology is made evident when considering changes to a homeostatic variable and how those changes are corrected for. Consider blood pressure
for example. A high blood volume can cause blood pressure to
Hint 1. Scatter plots
Scatter plots will typically be used if you want to see the effects that one variable has on the other.
Hint 2. Histograms vs. bar graphs
A histogram is a type of bar graph that could tell you how many people in a class received an 85% on exam 1.
Which of the following would best describe the concept of negative feedback as it relates to homeostasis?
A negative feedback response is one where the setpoint is maintained and is not altered.
A negative feedback response demonstrates a fluctuation arou
A negative feedback response demonstrates a fluctuation around a setpoint.
Heating an area of the skin can cause sweat glands in that area to begin producing and releasing sweat. This is an example of what type of control system.
Local control system
Feed-forward control system
Reflex control system
Positive feedback loop contro
Local control system
What is an independent variable?
The value that is measured.
The thing held constant to ensure that the effect is due to the variable of interest and not due to some unanticipated cause.
The thing that is manipulated to test an effect.
A model that is sup
The thing that is manipulated to test an effect.