Intracellular calcium comes from
extracellular fluid and intracellular storage
Lipophilic hormones
bind to receptors inside the cytoplasm or nucleus
The pituitary hormone that controls the release of glucocorticoids from the adrenal cortex is
ACTH
A placebo is
a drug or treatment that is expected to have no pharmacological effect
When adenylyl cyclase is activated,
cAMP is formed
If a 30% sucrose solution is separated from a 40% sucrose solution by a membrane impermeable to sucrose, in which direction will net movement of water occur?
from the 30% sucrose solution to the 40% sucrose solution only
The following statements describe peptide hormones. Which one is true?
peptide hormones in the bloodstream are always bound to carrier proteins
The pituitary hormone that stimulates cell growth and metabolism in many tissues is
somatotropin
Signal molecule receptors exhibit
specificity, competition, and saturation
Which of the following is NOT involved in creating the resting potential of a neuron?
resting membrane permeability for sodium ions greater than potassium ions
A distinguishing characteristic of cell membranes is that some substances pass through them but not all substances. For this reason, cell membranes are classified as _________
selectively permeable
Transcription occurs in the _________ of the cell
nucleus
Neurotransmitters and neurohormones both
are released by neurons and affect only cells with specific receptors
Microscopically, an organ shows a lining of several layers of cells -- a lining that does not contain any blood vessels. One surface of these cells is on the same side as the lumen of the organ. This tissue is probably
epithelium
Plasma has the same relationship to blood as which of the following does to cytoplasm?
cytosol
What type of epithelia is made up of flattened cells that facilitate the fast passage of oxygen and carbon dioxide in and out of the lungs and certain blood vessels?
exchange
Of the following, which describe differences between endocrine and neural control systems?
All of the answers are correct; specificity, speed, nature of the signal, duration of action
In a neuron, as the potential difference across the membrane proceed from -55 mV to 0 mV, the cell is
only depolarizing
In what type of study is a given subject treated with the test drug for half of the trial and the placebo in the other half of the trial?
crossover
When glucose is metabolized in aerobic conditions, which of the following acts as the final electron acceptor?
oxygen
True or false: only totipotent stem cells are capable of producing new cells in an adult.
False
Centrioles are absent in neurons of the adult central nervous system. This should tell you what about those neurons?
they don't replicate themselves
________ are held within normal values by control mechanisms which are employed if the variable wanders too far from its ________
independent variables, steady state
How do cells typically regulate how fast an enzymatic reaction occurs? By
changing the concentration of an enzyme
What typically happens to a hormone after it has interacted with its target cells? It:
is inactivated or removed from the blood
When a steroid hormone (which is lipophilic) is bound to its receptors, what event typically takes place?
gene transcription
ATP synthase transfers the _________ energy of the H+ ions to the high-energy phosphate bond of _________
kinetic, ATP
Typically, the concentration of calcium inside a cell is .3% while the concentration of calcium outside the cell is .1%. By what process would the cell then transport calcium from the outside to the inside?
active transport
Which of the following body systems does NOT perform an exchange with the external and internal environments?
circulatory system
The pancreas is an exocrine and endocrine organ whose exocrine digestive enzymes are secreted into the duodenum. Therefore, in exocrine pancreatic cells, you would expect to find a very well-developed:
rough endoplasmic reticulum
The endoplasmic reticulum is considered which of the following?
membranous organelle
The rate of diffusion across the membrane of a cell would be increased by
a decrease in membrane thickness
Cyclic AMP activates
protein kinase A
How can enzymes be useful as clinical tools for diagnostic purposes?
damaged cells release enzymes into the blood that can be detected
When glucose enters the ECF from the gastrointestinal lumen, ALL of it is then taken up into the nearby cells. Since absorption of a substance usually results in only 50% of the substance entering the cell (the point in which equilibrium is reached), how is that ALL of the glucose is taken into cells?
Insulin forces glucose into the cell against a concentration gradient
Which of the following is the correct sequence of events in a typical process of scientific inquiry?
observation, hypothesis, experimental data, replication, model, theory
The link between a first messenger and a second messenger in a cell that responds to peptide hormones is usually
a G protein
The following statements are about diffusion. Which of them is NOT true with regard to biological systems?
Smaller molecules take longer to diffuse than larger ones
What is the group of triplet bases in the transfer RNA molecule referred to as?
anticodon
The following statements describe important aspects of the process of diffusion. Which statement most accurately explains why organisms with more than one cell require a circulatory system?
Diffusion is rapid over short distances but much slower over long distances
Assuming water can move across a membrane, water will always move from the _________ side of the membrane to the ________ side.
hyposmotic, hyperosmotic
The most complex endocrine responses involve the
hypothalamus
Suppose you have a cell whose membrane is permeable to solute A is placed into solution containing a higher concentration of Solute A. Assume that diffusion is allowed until equilibrium is reached. At this time,
Both of the statements are correct.
An exergonic chemical reaction
releases energy as the reaction progresses
Typically, when steroid hormones bind to their receptors,
gene transcription may increase or decrease
In the cellular breakdown of glucose, which of the following is a key intermediate between glycolysis and the citric acid cycle?
pyruvate
Homeostasis involves the ability of the living organism to
quickly restore changed conditions to normal
What is the result of alternative splicing of mRNA?
izoenzymes are produced from a single gene
People with Type I diabetes do not make enough insulin. Which of the following would be a mechanistic explanation of how insulin is used by the body?
insulin binds to its receptor which triggers the movement of glucose transporters to the cell membrane
The environment of our planet is terrestrial, dry, and highly variable. To maintain a constant internal environment, our bodies use very large amounts of energy in order to maintain a constant internal environment. Why our bodies do this is what kind of scientific endeavor?
teleological
(A) distinction(s) between graded potentials and action potentials is(are)
graded potentials can undergo summation and the rate of action potentials is limited by the refractory period
What is the correct description for an alteration in the force of a smooth muscle cell when there is NO alteration of the membrane electrical potential?
pharmacomechanical coupling
The following events occur in the formation of an action potential:1. inactivation of sodium channels2. a larger number of voltage-gated potassium channels open; followed by the movement of potassium out of the cell and the start of repolarization3. sodium channels return to their normal configuration4. a graded depolarization brings an area of an excitable membrane to threshold5. a temporary hyper-polarization occurs6. sodium channel activation occurs7. sodium ions enter the cell and further depolarization occursThe proper sequence of these events is
4, 6, 7, 1, 2, 5, 3
Which of the following sections of the brain is an important integrating center for homeostatic events?
hypothalamus
A child is taken to the emergency room with hypotension, and difficulty in breathing with wheezing upon exhalation. The parents suspect that the child took one of his grandfather's blood pressure medications. Which class of drugs did the child most likely take?
beta blocker
Which statement about the hypothalamus is NOT true?
it receives sensory fibers from the optic tract, ears, and spinal cord
Sound waves that are lower in frequency result in the greatest displacement of the basilar membrane _________, which is the place where the basilar membrane is ________.
near the helicotrema, flexible
When an action potential travels along the t-tubule in a muscle, it is first detected by the
dihydropyridine (DHP) receptor (L-type calcium channel)
Sound waves are initially converted into mechanical activity (vibrations) by the
tympanic membrane
What ionic event leads to the cessation of the rising phase of the action potential?
The Na+ activation gate opens
A key distinction between single-unit smooth muscle and multiunit smooth muscle is the
numerous gap junctions in single-unit smooth muscle, which allow many cells to work together as a sheet
High-volume sounds are coded in the ear by action potentials in the sensory neuron that are
more frequent
Signs and symptoms of the fight-or-flight response include all of the following with the EXCEPTION of
hunger
What do the intrafusal fibers of a muscle spindle synapse with?
gamma motor neurons
________ postganglionic sympathetic neurons secrete _________ onto the target cells
Most, norepinephrine
Graded potentials
act as signals over short distances and cause or prevent an action potential
The importance of the adrenal medulla includes the fact(s) that
it is a source of catecholamines, it is considered a modified sympathetic ganglion, and it releases epinephrine and norepinephrine directly into the blood
Identify the FALSE statement.
The amplitude of the action potential depends on the amplitude of the graded potential that precedes it
Which part of the brain is involved in the control of movement?
basal nuclei only
What would you expect to find in the pathway of a polysynaptic reflex?
two synapses and three neurons
Puffer fish toxin inhibits voltage-gated sodium channels. What would be the resulting effect on neuronal function?
the neuron is not able to propagate action potentials
In comparison to skeletal muscle, smooth muscle
uses less energy to generate a given amount of force, can sustain contractile force without fatigue and uses calcium from the sarcoplasmic reticulum and extracellular space
With people who are right-handed, what hemisphere of the brain would you expect to find language and verbal skills?
concentrated on the left
When contrasted with unfused muscle tetany, what is the most accurate statement?
complete tetanus involves development of maximum tension
In the inner ear, the transduction of fluid vibration into graded potentials occurs via channels that allow ion passage which are located on the
stereocilia
If a patient's cornea is more flat than normal, the result would be that the patient is
hyperopic
In the middle ear, the main purpose of the ossicles is to
amplify the vibration as it conducts to the cochlea
Which of the following is considered to be the mechanism at the synapse for memory and learning?
long-term potentiation
Cell bodies of sensory neurons are located in
dorsal root ganglia
Interneurons in the spine keep opposing muscle pairs from interfering with a desired movement by
the process of reciprocal inhibition
Of the following descriptions as they pertain to the nervous system, which one best applies to parasympathetic activity?
it is dominant during "resting and digesting" and its ganglia are nearby, on or near their target organs
Place the following in the correct order:1. end-plate potentials result in action potentials2. t-tubules conduct electrical potentials into the inside of the cell3. acetylcholine binds to receptors on the motor end plate.4. calcium leaves the sarcoplasmic reticulum
3, 1, 2, 4
When a dog is told "No!" each time he chews on your shoelaces, eventually he learns to not exhibit this behavior. This type of learning is called
associative
Which of the following is activated by the calcium-calmodulin complex to phosphorylate the myosin light chain protein?
myosin light chain kinase
For an individual muscle cell, the intensity of the tension in the course of a twitch is dependent on the
length of the sarcomeres prior to contraction
With the type II cells for taste in the tongue, signal transduction utilizes the G protein
gustducin
What kind of neurons are used to bring impulses TO the central nervous system?
afferent and sensory
Subsequent to stretching a muscle spindle, the next step is
an increase in action potentials along the associated sensory neuron
When the concentration of potassium in the ECF is higher than normal, the result is that
neurons are hyper-excitable because their resting potential is closer to threshold and neurons respond too quickly to smaller graded potentials
When an organ exhibits "dual innervation" this means that it receives
both sympathetic and parasympathetic nerves
The process of visual accommodation results in converging light onto the retina by changing
the shape of the lens
The two divisions of the efferent side of the peripheral nervous system are
somatic motor neurons and autonomic neurons
A patient has a stroke that results in partial paralysis on one side of the body. What type of glial cell do you think would see more of in the area of the brain that is affected by the stroke?
astrocytes
In the transduction of odorants, something that inhibits adenyl cyclase in the sensory neurons would
reduce the sensitivity of these receptors
The motor end plate is
a folded area of muscle cell membrane with ACh receptors clustered at the top of each fold
When someone slips and loses their balance, in an attempt to break the fall, the person extends the arms. What type of reflex is this?
crossed extensor reflex
The part of the brain whose abnormal function can lead to Parkinson's disease is the
basal ganglia
Increasing the stimulation of the parasympathetic division
increases gastric motility
For the bicep muscle to become shorter, what must be true about the force generated by the muscle? It must be:
greater than the load applied at the hand
In the dark, the rods of the eye have a high cytosolic amount of
cGMP
Which of the following blood pressures would lead to a mean arterial pressure of 108?
130/97
The velocity of blood flow through the capillaries is _________ when contrasted to that of arteries.
much slower
Which of the following would NOT make peripheral RESISTANCE greater?
vasodilation
What is the correct term to describe the percentage of anti-coagulated blood that is made up of red blood cells?
hematocrit
When the volume of blood in the body has been lowered, compensation includes increases in
sympathetic stimulation to blood vessels, sympathetic stimulation of the heart, and water conservation by the kidneys
Monocytes that have migrated from the peripheral blood and reside in the tissues are known as
macrophages
The process by which material in the peritubular capillaries is transported into the convoluted tubules is
secretion
Hemoglobin is a blood protein that has what structure?
four protein chains and four heme groups
Chronic low plasma protein levels could lead to ________ as a result of ________ colloid osmotic (oncotic) pressure
ascites; lower
The lymphatic system
empties the lymph vessels into the veins near the clavicles
Agent that inhibits carbonic anhydrase would
cause an increase in blood pH
Measurements in a nephron reveal a glomerular hydraulic pressure of 71 mm Hg, and a fluid pressure in the Bowman's capsule of 14 mm Hg. Assuming that the plasma osmotic pressure is 30 mm Hg, and that essentially no plasma proteins are filtered by the glomerulus, what is the net glomerular filtration pressure in this case?
27 mm Hg
In the kidney, there is an anatomical structure that is also observable in at least two other organs. What is it?
portal system
The force for glomerular filtration is the
blood pressure in the glomerular capillaries
A graph of the relationship between oxygen tension in the tissues versus the percent saturation of hemoglobin is S-shaped. Which of the following would make this curve shift to the right?
none of the answers are correct
If the type II alveolar cells were to be injured, this would lead to
decreased alveolar compliance
A person suffering from a severe liver disease would probably show what symptoms?
all answers are correct; accumulation of fluid in the tissue spaces of the extremities, increased levels of bilirubin in the blood, decreased clotting ability, decreased blood osmotic pressure
In the renal filtrate at the glomerulus and in Bowman's Capsule, everything listed here will normally end up in the filtrate with the exception of
erythrocytes
Tissue factor is released in the
extrinsic pathway
Of the following, which will lead to a faster heart rate?
both sympathetic stimulation and application of epinephrine to the SA node
The alveolar sacs in the lungs allow for optimal gas diffusion primarily because of which of the following?
they are made of a single layer of simple squamous epithelium
Because cardiac muscle cells exhibit a refractory period that is longer than that of skeletal muscle cells, which of the following is NOT seen in cardiac muscle cells?
tetany
Assume the baroreceptor reflex has been stimulated by a decrease in blood pressure. What would the compensatory response entail?
sympathetic activity increases and cardiac output increases
Air flow
is directly proportional to a pressure gradient, and flow decreases as the resistance of the system increases
The chloride shift
occurs when bicarbonate ions leave the red blood cells
The growth and development of megakaryocytes is controlled by:
thrombopoietin
Reactive hyperemia
is triggered by local accumulation of paracrines due to reduced blood flow
If the partial pressure of carbon dioxide in the blood is higher than normal, this would lead to
decreased parasympathetic stimulation of the heart
If the rate of alveolar ventilation increases, this will
increase the partial pressure of oxygen in the alveoli
Of the following changes in the blood or a blood vessel, which would have the most influence on vascular resistance?
doubling the diameter of a vessel
An increase in the flow of blood through the afferent arteriole relative to the flow in the efferent arteriole would result in which of the following?
stretch reflexes trigger afferent vasoconstriction to reduce the flow
Several factors have an effect on the diffusion of oxygen and carbon dioxide in the lungs and in the tissues. Of these, the most important consideration is the
concentration gradient
Regarding the process of external respiration, the neurons responsible for expiration exert an effect on the ________ muscles, and the neurons responsible for inspiration exert an effect on the ________ muscles
abdominal and internal intercostal, diaphragm and external intercostal
During a physical examination, a cardiologist listens to the chest of a patient and hears a whistling sound that occurs after heart sound S1 and before S2. This is most probably indicative of
a stenotic semilunar valve
Because carbon dioxide is more soluble in water than oxygen, it would be necessary to ____________ in order to get the equivalent amount of oxygen to dissolve in plasma
increase the partial pressure of oxygen
If the end diastolic volume is 139 mL, which of the following values are likely to be seen in a healthy patient?
the ESV could be 69 mL and the SV could be 70 mL
The following structures propagate electrical signals through the heart. Arrange them into the proper sequence.1. bundle of His2. internodal pathway3. Purkinje fibers4. atrioventricular node5. sinoatrial nodes6. left and right bundle branches
5, 2, 4, 1, 6, 3
In which of the following scenarios would you expect the stroke volume to be the highest?
when venous return is increased
If a blockage occurs between the atrioventricular node and the atrioventricular bundle, what effect will this have on the ECG?
There will be more P waves than QRS complexes
Vessels that effect blood flow in the nephron are shown. Order them in the proper sequence.1. afferent arteriole2. efferent arteriole3. glomerulus4. peritubular capillary
1, 3, 2, 4
Place the following stages of the cardiac cycle in the proper sequence.1. the SL valves open2. isovolumetric contraction3. start of atrial systole4. the atrioventricular valves close5. end of ventricular filling6. beginning of ventricular systole7. ventricular relaxation8. ventricular ejection
3, 5, 6, 4, 2, 1, 8, 7
What effect would low blood iron have on hemostasis?
there would be no effect
Cystic fibrosis is a disease that will frequently lead to periods where the patient has great difficulty breathing. This is due to
thick secretions that exceed the ability of the mucus elevator to transport them
Dalton's law
states that in a mixture of gases like air, the total pressure is the sum of the individual partial pressures of the gases in the mixture
A patient has an abscessed tooth (a bacterial infection). In a differential count of the peripheral blood white cells, what type of cell would you see in increased percentage?
neutrophils
Fibrinolysis
dissolves clots
Under what conditions would the end-systolic volume be the largest?
when parasympathetic stimulation of the heart is increased
In the process of normal expiration,
elastic recoil of stretched muscles helps return the thorax to its resting volume
When a patient inhales maximally and then exhales maximally, the volume of air leaving the patient is the
vital capacity
The hemoglobin molecule is exquisitely suited to the function as a transporter of oxygen. Which of the following is responsible for this?
each hemoglobin molecule can bind four oxygen molecules
If you were in a desert without a food source, which nutrient would you like to have stored in your body in a large amount?
fat
Which of the following events does NOT occur when you swallow?
the upper esophageal sphincter closes
Maltose is broken down by maltase into two molecules of
glucose
Saliva secretion is primarily a result of
increased parasympathetic stimulation
The C cells of the thyroid gland produce
only calicitonin
In response to a rapid increase of organic acid in the body, you would expect to observe
increased alveolar ventilation
If growth hormone is secreted into the blood in high amounts after epiphyseal plates close, this will result in
acromegaly
A decrease in which population of lymphocytes would impair all aspects of immune response?
helper T cells
A patient comes down with severe diarrhea while in a foreign country. Because he can't consume much food, his body compensates by using energy sources other than carbohydrates. This would result in
All of these answers are correct; increased gluconeogenesis in the liver, ketosis, a decreased blood pH, increased levels of urea in the blood
The hormone primarily responsible for milk synthesis is
prolactin
In response to the hormone secretin, the pancreas secretes a fluid that contains
bicarbonate
In an experimental situation, a virus is injected into a rabbit and the rabbit is allowed to make antibodies for the viral antigen. These antibodies are then removed from the rabbit plasma and injected into a human to help combat the same viral disease. This is an example of
passive immunization
Order the events of fertilization and implantation in the appropriate order.1. implantation of the developing embryo2. the developing embryo becomes a blastocyst which consists of a hollow ball of cells3. mitosis occurs in the fallopian tube4. the cortical reaction occurs, preventing polyspermy5. the egg is fertilized by the sperm
5, 4, 3, 2, 1
AQP2 water pores are added to the cell membrane by ________ and withdrawn by _________ in a process known as __________
exocytosis, endocytosis, membrane recycling
Which of the following symptoms would you expect to observe in a person suffering from type I diabetes mellitus?
All of these answers are correct; thirst and polydipsia, glucosuria, ketoacidosis, hyperglycemia
Somatostatin is another name for
growth hormone-inhibiting hormone
During the first 15 seconds of intense exercise, such as sprinting or power lifting, most of the energy is provided by
ATP in muscle fiber and phosphocreatine
_______, produced by ovarian follicles during the first part of the ovarian cycle, prevents too many follicles from developing at one time.
Anti-Mullerian hormone
Excess growth hormone prior to puberty would result in
giantism
An agent that interferes with the activity of cholecystokinin would
affect the pancreatic secretions
If the levels of angiotensin II were elevated, this would lead to increased
all of these effects; blood pressure, blood volume, retention of sodium ions at the kidney, water retention
An overweight middle-aged taxicab driver exhibits the following symptoms: blurry vision, tingling sensation in the extremities, frequent urination and thirst. Laboratory tests reveal an elevated fasting blood glucose level and oral glucose tolerance test, higher than normal glycosylated hemoglobin, and a blood pH of 7.38. The probable diagnosis is
type II diabetes mellitus
__________ cells produce testosterone while __________ cells regulate sperm development
interstitial, sertoli
Dehydration can result from
heat exhaustion and diabetes
Redistribution of blood flow during exercise results from
vasodilation in skeletal muscle and vasoconstriction in viscera
When the pH of body fluids begins to fall, proteins will
lose three-dimensional structure
Vitamin _______ must be bound to _________ to be absorbed from the small intestine
B12, intrinsic factor
If a person with dehydration experiences marked hyperkalemia, you could probably see
abnormal cardiac rhythms
The mechanism by which iodine enters thyroid cells utilizes symport with
sodium
A drug that blocks the action of carbonic anhydrase in parietal cells would result in
a higher pH during gastric digestion
The synthesis of glucose from a noncarbohydrate precursor is referred to as
gluconeogenesis
Bile is
secreted by hepatocytes
The designation for the renal arrangement of structures that facilitates the movement of solutes between blood vessels is called the
countercurrent exchange system
If the levels of calcium in the blood were to increase, this would lead to increased
secretion of calcitonin
The precursor chemical for ACTH synthesis is
POMC
Swelling and soreness of the lymph nodes indicate that
immune cells are fighting infection
The Atkins and South Beach diets are considered ketogenic because
they caused the body to burn calories from non-carbohydrate sources
If sodium increases in the ECF, water will move from
cells to the ECF, and cells will shrink
The process of disassembling fatty acids into two-carbon units inside mitochondria is called
beta-oxidation
A person has not had water to drink for two days. You would see with this person
elevated vasopressin levels
In order for a lymphocyte to respond to an antigen, the antigen must
bind to specific receptors on the lymphocyte membrane
________ are pacemakers for slow wave activity
interstitial cells of Cajal
A fluid sample contains a large amount of IgA type antibody. This fluid is probably
tears
A male body builder starts taking injections of testosterone (an anabolic steroid) on a daily basis. After three weeks, which of the following would you expect to observe?
all of the above observations; decreased levels of GnRH, decreased levels of FSH, decreased levels of LH, increased sex drive
In the postabsorptive state, which of the following statements is NOT TRUE?
skeletal muscle will increase gluconeogenesis
Cholesterol is a precursor for the synthesis of
progesterone, aldosterone, and estradiol
Opsonins function by
marking or tagging pathogens so phagocytes can find and ingest them
Lymphocytes that attack foreign cells or body cells infected with viruses are
cytotoxic T cells
During exercise, skeletal muscle
vasodilation decreases peripheral resistance to blood flow
In an experimental situation focused on the development of a new vaccine, mice were injected with a viral antigen. Their plasma was removed in order to detect the presence of antibodies. This is an example of
active immunization