Mini lectures 1-3
(no answer - 13 questions)
What tissue type lines internal hollow organs and external surfaces of the body, providing a barrier between the internal and external environment?A. muscle tissueB. epithelial tissueC. nervous tissueD. connective tissueE. reticular tissue
B
Organs of the body are defined as _______.A. collection of cells that perform similar functions.B. two or more tissues combined to form a structure that allows each tissue to function independently.C. collection of cells that function independently of one another.D. combination of two or more tissues that makes a structure which performs specific functions.E. collection of tissues that function independently of one another.
D
Total body water is composed of ________.A. intracellular fluid onlyB. extracellular fluid onlyC. intracellular and interstitial fluidD. intracellular and extracellular fluidE. plasma and intracellular fluid
D
Where is most of our total body water?A. in the lumen of the kidneysB. in the lumen of the gastrointestinal tractC. in bloodD. inside cellsE. surrounding the cells
D
Which of the following situations best represents a homeostatic mechanism?A. A person who becomes very nervous begins to sweat profusely.B. After going outside on a hot day, the core body temperature increases.C. Increasing the size of fast food restaurant portions causes body weight to increase.D. After eating a large batch of salty popcorn, levels of salt in the urine increase.E. As age increases, the amount of calcium in the bones tends to decrease.
D
If a person begins to sweat upon entering a hot room but continued sweating is able to keep the body temperature constant, which of these best describes her condition?A. She is in an equilibrium state.B. She is not using energy to maintain a constant temperature.C. She is in a steady stateD. She is using a positive feedback mechanism.
C
Which of the following statements about homeostasis is TRUE?A. The extracellular fluid is maintained in a state compatible for life.B. The primary mechanism to maintain homeostasis is negative feedback.C. The organ systems work together to maintain homeostasis.D. Homeostasis maintains the values of a number of variables, including pH and temperature, near a set point value.E. All of the above.
E
Which of the following is NOT an example of a homeostatic response?A. Body temperature increases, and sweating brings the body temperature down.B. The oxygen level in the blood falls, and breathing harder increases the oxygen level in the blood.C. Sweating leads to loss of body fluids, and urination increases the loss of body fluids.D. Glucose level in the blood falls, and eating increases the glucose level in the blood.
C
Describing a physiological variable as "homeostatic," means the variable:A. has varied from the normal value, and will remain constant at the new value.B. never varies from an exact set point value.C. is in a state of dynamic constancy that is regulated to remain near a stable set point value.D. is in an equilibrium state that requires no energy input to stay at the normal value.E. has no normal range, but will just change to match the outside environmental conditions.
C
The tissue type that generates mechanical force and movement, and whose activity is controlled both on a voluntary and involuntary level, is:A. muscle tissueB. epithelial tissueC. nervous tissueD. connective tissueE. skeletal tissue
A
Which of the following accurately represents the order of complexity for the components of the body, from least to most complex?A. organ systems, cells, tissues, organsB. tissues, cells, organs, organ systemsC. cells, tissues, organs, organ systemsD. cells, tissues, organ systems, organsE. organ systems, organs, tissues, cells
C
Extracellular fluid is composed of _________.A. interstitial fluid and plasmaB. plasma and intracellular fluidC. interstitial fluid onlyD. plasma onlyE. intracellular fluid only
A
Which of the following compartments contains most of the water found in the human body?A. intracellular fluidB. PlasmaC. interstitial fluidD. extracellular fluidE. lumen of the intestinal tract
A
Cell signaling Part 1
(no answer - 10 questions)
When a chemical messenger (also called a "ligand") reaches a target cell, it binds to a receptor. In general, a hydrophobic ligand binds to a(n) __________, whereas a hydrophilic ligand binds to a(n) __________.A. intracellular receptor; transmembrane receptorB. transmembrane receptor; intracellular receptorC. intracellular receptor; intracellular receptorD. transmembrane receptor; transmembrane receptorE. none of the above answers are correct.
A
Which characteristic do second messenger molecules share between them that also distinguish them from the rest of the molecules in a signal transduction pathway?A. they are all ionsB. they are all cyclic nucleotidesC. they are not proteinsD. they are all small peptidesE. they are all activated through G proteins
C
How does nitric oxide (NO) enter smooth muscle cells? NO:A. crosses the smooth muscle cell plasma membrane through ion channels.B. crosses the smooth muscle cell plasma membrane through channels called Aquaporins.C. diffuses directly across the smooth muscle cell plasma membrane.D. cannot enter smooth muscle cells.
C
A 59-year old man is brought to the emergency department with complaints of chest pain for the past hour. He says he is taking a drug for his blood pressure, but cannot remember the name. He recalls being told that the drug opens his blood vessels. Which of the following explains the mechanism of action of this medication?A. Inhibits the production of nitric oxide in endothelial cells.B. Activates the enzyme phosphodiesterase in smooth muscle cells.C. Stimulation of guanylyl cyclase activity in smooth muscle cells.D. Inhibits Acetylcholine receptors in endothelial cells.
C
Steroid hormones are lipid-soluble signal molecules that cross the plasma membrane. If these molecules can enter all cells, why do only specific cells respond to their presence?A. Nontarget cells lack the intracellular receptors that, when activated by the signal molecule, can interact with genes in the cell's nucleus.B. Nontarget cells possess enzymes that immediately degrade the molecules as they enter the cell.C. Nontarget cells lack the inactive enzymes that the signal molecules activate.D. In nontarget cells these signal molecules cross the membranes of the endoplasmic reticulum and are captured by vesicles.
A
Is the following statement regarding ion channel-linked receptors True or False?"Ion channel-linked receptors can rapidly alter the voltage across a plasma membrane in response to neurotransmitter binding."A. TrueB. False
A. True
Signal transduction pathways:A. are necessary for signals to cross the plasma membrane.B. include the intracellular events stimulated by an extracellular signaling molecule.C. include the extracellular events stimulated by an intracellular signaling molecule.D. are only found in cases where the signal can cross the plasma membrane.
B
Individuals possessing a mutation in the gene encoding the enzyme, Nitric Oxide Synthase (NOS) make this protein constitutively active, and overproduce the signaling molecule, Nitric Oxide (NO) resulting in low blood pressure. On a cellular level, which one of the following would be helpful in reducing the harmful effects of this NOS gene mutation?A. Increasing the amount of cyclic guanosine monophospate (cGMP) in smooth muscle cells.B. Increasing the activity of the enzyme phosphodiesterase in smooth muscle cells.C. Increasing the Acetylcholine signal sent to endothelial cells.D. Inhibiting activation of the Acetylcholine receptors in endothelial cells.E. Decreasing the activity of the enzyme phosphodiesterase in endothelial cells.
B
A 15-year-old male presents to your family practice complaining of delayed onset of puberty. He is 48 inches tall and shows no secondary sex characteristics. He requests testosterone injections. In general, testosterone mediates its effect by which of the following mechanisms?A. Activates a receptor that increases the permeability of the membrane to cations.B. Activates an intracellular enzyme when combined with a membrane receptor.C. Activates genes by binding with an intracellular receptor.D. Activates the phosphatidylinositol system.E. Increases cAMP levels by activating a second messenger.
C
Cell signaling Pt 2
(no answer - 12 questions)
Cholera toxin can affect cells by inhibiting the ability of the G protein α subunit to hydrolyze GTP to GDP.A. Increasing the amount of intracellular cAMP.B. Inhibiting the activity of adenylyl cyclase in the cell.C. Adding ligand for the G-protein coupled receptor in this pathway.D. Increasing the amount of protein kinase A activity in the cell.E. Inhibiting the activities of the β and γ G-protein subunits.
B
If a G protein were unable to release its bound nucleotide but could hydrolyze it, signal transduction would:A. not move beyond this point.B. be continuous beyond this point.C. be unaffected.D. be constantly switching on and off.E. be unpredictable.
A
Second messengers, like cAMP, are quickly degraded within cells because:A. The cell does not have enough space to hold a lot of second messengers.B. The cell must maintain sensitivity toward further extracellular signals.C. Too many second messengers in the cell are toxic.D. Second messengers accumulate at their source within the cell preventing the formation of further second messengers.
B
How does Diacylglycerol (DAG) function in a G-protein coupled receptor pathway? Diacylglycerol (DAG):A. activates phospholipase C.B. activates protein kinase G.C. on its own, recruits and activates Protein Kinase C (PKC).D. together with calcium, activates Protein Kinase C (PKC).E. binds to and opens calcium channels in the plasma membrane, allowing extracellular calcium to enter the cytosol.
D
Mutant Ras proteins, that are found in many cancer cells, can't hydrolyze their bound GTP to GDP, and therefore:A. can't turn themselves on.B. can't turn themselves off.C. can't be degraded.D. they are able to activate Mitogen-Activated Protein Kinase (MAPK) directly.
B
Which of the following statements is CORRECT about the chemical, caffeine? Caffeine:A. primarily inhibits phospholipase C.B. primarily activates phosphodiesterase.C. caffeine primarily inhibits adenylyl cyclase.D. caffeine primarily activates adenylyl cyclase.E. primarily inhibits phosphodiesterase.
E
If a G protein could release its bound nucleotide but was not able to hydrolyze it, signal transduction would:A. not move beyond this point.B. be continuous beyond this point.C. be unaffected.D. be constantly switching on and off.E. be unpredictable.
B
Following the binding of EGF, EGFR is activated by dimerization that allows:A. each monomer in the dimer to phosphorylate itself on specific tyrosine amino acids in its cytoplasmic tail.B. each monomer to phosphorylate the opposite monomer in the dimer on specific tyrosine amino acids in its cytoplasmic tail.C. the receptor to be internalized so that it can phosphorylate and activate various intracellular signaling proteins.D. none of the above answers are correct
B
The monomeric G-protein, Ras, is activated by a Ras-activating protein that:A. causes Ras to bind to a G-protein.B. phosphorylates Ras.C. dephosphorylates Ras.D. causes Ras to exchange GDP for GTP.E. causes Ras to exchange GTP for GDP.
D
Which of the following statements about G proteins is NOT correct?A. G proteins are involved in the signaling by lipid-soluble hormones such as steroidsB. G proteins can either stimulate or inhibit adenylyl cyclaseC. G proteins are involved in the signaling of a large class of receptors that have a similar general structure consisting of seven membrane-spanning domainsD. G proteins can couple a receptor to the opening of an ion channel
A
A mutation in the gene encoding the enzyme Mitogen Activated Protein Kinase Kinase (MAPKK) produces a constitutively activated form of MAPKK, leading to tumor formation.On a cellular level, which of the following would be helpful in reducing the harmful effect of the MAPKK gene mutation?A. Increasing the activity of Mitogen Activated Protein Kinase (MAPK) in the cell.B. Inhibiting the activity of Mitogen Activated Protein Kinase (MAPK) in the cell.C. Adding ligand for the Epidermal Growth Factor Receptor (EGFR).D. Inhibiting activity of the monomeric G-protein, RAS.E. Inhibiting the activity of Mitogen Activated Protein Kinase Kinase Kinase (MAPKKK).
B
The primary amino acid sequence of the Epidermal Growth Factor Receptor (EGFR) contains an invariant lysine amino acid essential for kinase activity. Substitution of this essential lysine by any other amino acid blocks the capacity of the receptor to phosphorylate targets. What stage of receptor activation is disrupted by substitution of the invariant lysine with another amino acid?When this lysine is replaced by another amino acid:A. EGFR is unable to activate an associated trimeric G-protein.B. the ligand Epidermal Growth Factor (EGF) is unable to bind to EGFR.C. docking sites for EGFR target proteins are not generated inside the cell.D. EGFR becomes constitutively activated, that is, EGFR is always on.E. enzymatically inactive EGFR monomers are unable to dimerize.
C
Endocrinology pt 1
(no Answer - 7 questions)
Which of the following statements regarding the endocrine system is true? The endocrine system:A. releases hormones into the bloodstream for circulation throughout the body.B. produces signals that have much longer delays and last for much greater lengths of time than nervous system signals.C. is composed of endocrine glands and hormone-producing cells located throughout the body.D. all of the above statements regarding the endocrine system are true.
D
The adrenal cortex produces only:A. steroid hormonesB. amine hormonesC. catecholamine hormonesD. peptide hormonesE. glycoprotein hormones
A
A simple goiter results from:A. lack of Thyroid Stimulating Hormone (TSH).B. lack of iodine.C. lack of iron.D. overproduction of the hormones thyroxine (T4) andE. triiodothyronine (T3).F. none of the above.
B
Is the following statement, True or False?"Thyroxine and triiodothyronine, the thyroid hormones, do not have a specific target organ; instead, they stimulate most of the cells of the body to metabolize at a faster rate."A. TrueB. False
A. True
Consider the thyroid hormones, triiodothyronine (T3) and thyroxine (T4). What do the numbers "3" and "4" refer to?A. The relative half-life of the hormones (3 or 4 hours).B. The number of thyrosine molecules linked together to form the hormones.C. The number of iodines found in each hormone.D. The number of enzymes required for synthesis of each hormone.E. None of the above.
C
Which of the following is an effect of thyroid hormones?A. increased basal metabolic rateB. increased body temperatureC. increased action of epinephrineD. All of the choices are correct.
D
An adult patient with a brain tumor that prevents the release of thyrotropin-releasing hormone (TRH) (but no other hormones) might experience which of these effects?A. decreased body temperatureB. increased heart rateC. increased blood pressureD. increased blood cholesterol
A
Endocrinology pt 2
(no answer - 13 questions)
The parathyroid hormone (PTH) is an 84 amino acid protein hormone that helps to maintain calcium levels in extracellular fluid by mobilizing calcium from bone.When PTH mRNA is transcribed from the PTH gene and translated on ribosomes, the ribosomes are found _________ and the translated PTH polypeptide formed is _________ the biologically active form of the PTH hormone.A. in the nucleus; larger thanB. in the cytoplasm; identical in size (84 amino acids) toC. attached to the rough endoplasmic reticulum; larger thanD. attached to the rough endoplasmic reticulum; smaller than
C
Which of the following approaches should be taken to stimulate steroid hormone synthesis and secretion in adrenal cortical cells lacking Protein Kinase A (PKA) expression?A. Increasing the activity of Cholesterol esterase in the adrenal cortical cells.B. Increasing the activity of Adenylyl cyclase in the adrenal cortical cells.C. Increasing the secretion of Adrenocorticotropic hormone (ACTH) from the anterior pituitary gland.D. Increasing the expression of Low-Density Lipoprotein (LDL) Receptors by the adrenal cortical cells.E. Inhibiting the activity of Adenylyl cyclase in the adrenal cortical cells.
A
Once a steroid hormone is synthesized, it is _________.A. stored in a vesicle until released.B. bound to albumin until released from the cell.C. immediately capable of diffusing across the membrane.D. stored in a unique protein structure that maintains steroids in the cell.E. bound to the mitochondria until released.
C
Is the following statement True or False?"Hormone that is bound up by transporter proteins in the blood is not part of the free fraction and is unavailable for cell signaling."A. TrueB. False
A. True
The half-life of a lipid-soluble hormone in blood is:A. directly proportional to its rate of secretion.B. directly proportional to the affinity of the hormone for its plasma protein carrierC. directly proportional to the number of hormone receptors present in target tissueD. inversely proportional to the concentration of the hormone's plasma protein carrierE. inversely proportional to the molecular weight of the hormone
B
What is the name of the stalk that connects the hypothalamus to the pituitary?A. sphenoid stalkB. nephronC. corpus callosumD. infundibulumE. cerebral cortex
D
Where are the posterior pituitary hormones manufactured? The posterior pituitary hormones are made by:A. endocrine cells located in the posterior pituitary.B. endocrine cells located in the anterior pituitary.C. endocrine cells located in the medulla of the adrenal gland.D. neurosecretory cells that originate in the hypothalamus.E. neurosecretory cells that originate in the thalamus.
D
You have consumed a six-pack of beer in the course of an evening. The combination of fluid intake and alcohol act to inhibit the secretion of:A. Adrenocorticotropic hormone (ACTH)B. Thyrotropin-releasing hormone (TRH)C. Vasopressin (ADH)D. InsulinE. Thyroid-stimulating hormone (TSH)F. Parathyroid hormoneG. OxytocinH. Corticotropin-releasing hormone (CRH)
C
Which of the following statements regarding the regulation of pituitary hormone secretion by the hypothalamus is CORRECT?A. All anterior and posterior pituitary hormones are regulated by tropic hormones from the hypothalamus.B. All anterior pituitary hormones are regulated by a releasing hormone and a release inhibiting hormone from the hypothalamus.C. All posterior pituitary hormones are regulated by a releasing hormone from the hypothalamus.D. All anterior pituitary hormones are tropic hormones.E. None of the above.
E
Which of the following statements concerning the hypothalamus and anterior pituitary gland is FALSE?A. Hypothalamic releasing hormones are synthesized and secreted by neurons.B. Blood flows from the anterior pituitary to the hypothalamus in portal vessels.C. The hypophysiotropic hormones produced by the hypothalamus typically act in a 3 hormone sequence to generate a response.D. Hypophysiotropic hormones are released into a capillary bed called the median eminance.
B
Is the following statement regarding short-loop feedback, True or False?"In a short negative feedback loop, a tropic hormone from the anterior pituitary inhibits the release of its own releasing hormone from the hypothalamus."A. TrueB. False
A. True
Neurons, Glia, and Brain structure
(no answer - 12 questions)
Neurons with highly branched dendrites:A. receive a great deal of input from other neurons.B. conduct action potentials more rapidly than neurons with less branching.C. exhibit extensive communication with the surrounding neuroglia.D. contain multiple nuclei, also called multinucleated.
A
Is the following statement True or False?"A myelinated axon is shielded from direct contact with the extracellular fluid all along its length."A. TrueB. False
B. False
What type of cell enhances the velocity of electrical transmission of an action potential along an axon in the central nervous systemA. Ependymal cellB. AstrocyteC. Schwann CellD. MicrogliaE. Oligodendrocyte
E
The middle layer of the three meninges is the:A. DuraB. Pia materC. Plasma membraneD. ArachnoidE. Plural membrane
D
What are the purposes of cerebrospinal fluid (CSF)? The CSF:A. reduces pressure at the base of the brain.B. cushions the brain to prevent damage caused by a blow to the head.C. provides a carefully regulated environment to support the electrical activity of neuronal cells.D. all of the above.
D
Cerebrospinal fluid is produced by theA. choroid plexus.B. pia mater.C. arachnoid villi.D. ventricles.E. frontal sinuses.
A
Which of the following statements is FALSE regarding the blood-brain barrier?A. Hydrophobic drugs pass through the blood-brain barrier more easily than hydrophilic drugs.B. Endothelial cells of the capillaries supplying the brain form tight junctions that restrict the passage of hydrophilic molecules into the extracellular fluid of the brain.C. Hydrophilic substances can be moved from the blood into the brain extracellular fluid via carrier proteins expressed by capillary endothelial cells.D. The walls of the capillaries supplying the brain are made up of several layers of cells, that act as a barrier to the release of drugs into the brain.
D
To help pay for medical school, you get a part-time job in the anatomy lab. In an examination of the respiratory control center found in the brainstem, you must separate the brainstem from the overlying forebrain for your students.In order to separate the brainstem from the forebrain, a cut must be made between the:A. medulla and ponsB. pons and midbrainC. midbrain and diencephalonD. diencephalon and cerebrumE. pons and cerebellum
C
Dr. Wilder Penfield (1891-1976) was the first to map functional areas of the human brain by electrically stimulating cortical regions (see https://www.youtube.com/watch?v=8uUvWmXUodE).In a similar cortical stimulation study, you expect to find a disproportionate amount of the motor cortex is devoted to the control of movements of the:A. fingersB. toesC. armsD. elbowE. eyebrows
A
Damage to the cerebellum will lead to which of the following symptoms?A. a complete inability to move (lack of execution)B. an inability to accurately plan a movementC. the generation of slow, fine movements onlyD. the generation of clumsy, poorly directed movementsE. the generation of movement of large muscle groups only
D
Which of the following is TRUE of the sensory homunculus? The sensory homunculus:A. represents the specific body muscle groups that are controlled by specific regions of the cortex.B. represents the specific body parts that send afferent (sensory) signals to a specific region of the cortex.C. is the only homunculus in the human brain.D. depicts motor information.
B
The mammalian cerebral cortex has _____ layers of cells.A. 2B. 3C. 5D. 6E. 10
D
What is the first event that must occur for a hydrophobic signaling molecule to initiate a cellular response?A) the chemical signal must diffuse through the plasma membrane.B) the chemical signal must bind to a receptor.C) the ligand-receptor complex must translocate to the nucleus.D) the ligand-receptor complex must be phosphorylated.E) a kinase enzyme must be phosphorylated.
A) the chemical signal must diffuse through the plasma membrane.
How can a target cell recognize a particular hormone and not respond to other hormones?A) target cells respond to whatever hormone is present in the largest concentration.B) the target cells are always located close to the source of the hormone, making it easy to respond to that hormone.C) protein receptors located on the surface of the target cell or in the cytoplasm match the hormone.D) carbohydrate tags on the surface of the target cell match the hormone.E) the hormone is only able to enter membrane channels on the correct target cell.
C) protein receptors located on the surface of the target cell or in the cytoplasm match the hormone.
Which of the following statements is TRUE about the drug, Viagra? Viagra:A) primarily inhibits nitric oxide production.B) primarily activates cGMP-specific phosphodiesterase.C) primarily activates adenylyl cyclase.D) facilitates the process of covalent modification of a protein.E) primarily inhibits cGMP-specific phosphodiesterase.
E) primarily inhibits cGMP-specific phosphodiesterase.
Which of the molecules below are not part of the GQ-protein linked receptor/Phospholipase C signaling pathway?A) diacylglycerol (DAG)B) adenylyl cyclaseC) Phosphatidyl inositol-bisphosphate (PIP2)D) Ca2+E) inositol triphosphate (IP3)
B) adenylyl cyclase
Each of the following hormones is an amino acid derivative EXCEPT one. Identify the EXCEPTION.A) EpinephrineB) NorepinephrineC) Thyroxine (T4)D) DopamineE) Cortisol
E) Cortisol
The thyroid gland secretes what hormone(s)?A) thyroid hormones onlyB) thymosin onlyC) calcitonin onlyD) both thyroid hormones and thymosinE) both thyroid hormones and calcitonin
E) both thyroid hormones and calcitonin
Which of the following statements regarding Phospholipase C (PLC) is true?A) PLC is an important enzyme in the Gi pathwayB) PLC is activated by IP3C) The cleavage of PLC leads to DAG and IP3D) The substrate of PLC is PIP2
D) The substrate of PLC is PIP2
Which of the following is true regarding the thyroid gland?A) It is located in the brain stemB) It is located next to the kidneyC) it requires stimulation by a pituitary hormone in order to function properlyD) It produces the hormone TSHE) it produces iodine
C) it requires stimulation by a pituitary hormone in order to function properly
Which of the following is NOT produced by the anterior lobe of the pituitary gland?A) VasopressinB) ProlactinC) Follicle-stimulating hormone (FSH)D) Thyroid-stimulating hormone (TSH)E) Adrenocorticotropic hormone (ACTH)
A) Vasopressin
A 30-year-old woman is breastfeeding her infant. During suckling, which hormonal response is expected in the woman?A ) Increased secretion of vasopressin (ADH) from the supraoptic nuclei.B) Increased secretion of vasopressin (ADH) from the paraventricular nuclei.C) Increased secretion of oxytocin from the paraventricular nuclei.D) Decreased secretion of oxytocin from the supraoptic nucleiE) ncreased plasma levels of both oxytocin and vasopressin (ADH).
C) Increased secretion of oxytocin from the paraventricular nuclei.