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Biol 353 Final Exam 2011
Part I.
1. Chorionic gonadotropin
a.
Is the basis for at-home pregnancy tests
b.
Sustains the corpus luteum during the first trimester of human pregnancy
c.
Stimulates testicular function in male fetuses
d.
All of the above
2. The luteal phase of the ovarian cycle corresponds most closely in time to the _________
phase of the uterine cycle
a.
menstrual
b.
proliferative
c.
secretory
d.
decidual
3. Reaching a threshold body fat content is believed to be an important requirement for the
onset of menarche. Which of the following hormones is important in transmitting
information about fat mass to the brain?
a.
Ghrelin
b.
Somatomammotropin
c.
Cortisol
d.
Leptin
4. The role of hypothalamic neurons in sustaining menstrual cycling in women is to
a.
Emit a spike of GnRH that causes ovulation at midcycle
b.
Deliver pulses of GnRH to the anterior pituitary at correct, regular time
intervals
c.
Inhibit GnRH secretion by secreting dopamine
d.
Secrete GnRH at a steady, high level during the follicular phase of the cycle
and at a steady, low level during the luteal phase
5. Loss-of-function mutation of the enzyme 5α reductase, which converts testosterone to
dihydrotestosterone
a. Would prevent elimination of the Műllerian structures in the case of an embryo
with the XY sex genotype
b. Would result in pseudohermaphroditism in the case of a fetus with the XY
sex genotype
c. Would prevent the brain from developing “male” behavior in the case of a fetus
with the XY sex genotype
d. All of the above are correct
6. In our current understanding of the onset of labor contractions,
a.
Uterine contractility is suppressed by prolactin until near the end of the
gestation period
b.
The anterior pituitary releases oxytocin in response to cervical pressure
c.
The uterus itself is an important source of oxytocin and prostaglandin F2α,
which increase uterine contractility
d.
All of the above are true
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7.
In the 3rd world generally, the most important means of contraception is
a. Barrier methods, such as condoms and diaphragms
b. Vasectomy
c. Herbal remedies
d. Lactation
8.
The pressure experienced by the neonate during vaginal delivery results in a surge of
catecholamines that is usually beneficial because it
a. Increases alertness
b. Raises systemic loop pressures, helping to close the foramen ovale
c. Stimulates removal of fluid from the lungs
d. All of the above
9.
Fertilization normally occurs in the
a. Uterus
b. Fallopian tubes
c. Vagina
d. Abdominal cavity
10. During the phase of follicle maturation,
a. Theca cells export androstenedione to granulosa cells
b. Granulosa cells convert androstenedione to estradiol
c. Both of the above are true
d. Neither of the above is true
11. At the onset of menopause
a. The ovaries seem to have exhausted their supply of primary follicles
b. Plasma levels of LH and FSH increase, suggesting that menopause is not
initiated by the hypothalamus
c. The risk of osteoporosis increases, because estrogen favors maintenance of
bone mass
d. All of the above are true
12. Which of the following statements about the effect of estrogen is correct?
a. Gonadotropin secretion is inhibited if estrogen levels are high throughout the
cycle
b. Rising levels of estradiol during the follicular phase bring about a shift from
negative to positive feedback with respect to gonadotropin secretion
c. Gonadotropin secretion is inhibited during the luteal phase because the
corpus luteum secretes estrogen at a steady, high rate.
d. All of the above are true.
13. For a woman who has Type I diabetes mellitus, the severity of the disease is likely to
increase during pregnancy in large part due to secretion of _____________ by the
_________________.
a. Estrogen; corpus luteum
b. Insulin; placenta
c. Chorionic somatomammotropin; placenta
d. Cortisol; fetal adrenal
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14. In the following spaces, list the six major anterior pituitary hormones (full names, not
abbreviations):
a.
_thyroid-stimulating hormone_____________
b.
__growth hormone______________________
c.
___adrenocorticotrophic hormone___________
d.
___luteinizing hormone____________________
e.
____follicle-stimulating hormone___________
f.
____prolactin_____________________________
15. Hemoglobin mutants are identified according to the city or hospital where they were
discovered. Hemoglobins Rainier and Yakima are the result of a single amino acid
substitution in the beta chain that results in an increased oxygen affinity. Which of the
following would be expected for a person homozygous for these recessive genes?
a. exercise intolerance
b. resistance to acute mountain sickness
c. reduced blood oxygen saturation in individuals breathing room air at sea level,
compared to individuals with wild-type hemoglobin
d. resistance to chronic mountain sickness
16. Individuals homozygous for the Hb Rainier gene also have elevated hematocrits. You
might expect them to have elevated levels of the hormone _erythropoietin_, which
regulates red cell production and is secreted by the kidney in response to___ hypoxia_.
17. Target tissues convert thyroxine to T3 at a rate that in humans is most sensitive to
a. Consuming a carbohydrate meal
b. Cold exposure
c. Plasma catecholamine levels
d. Plasma cortisol levels
18. In the fetal-placental circulation before birth, the highest PO2 values are usually found in
the
a. Umbilical arteries
b. Pulmonary arteries and ductus arteriosus
c. Right atrium
d. Umbilical vein
19. Which of the following statements about fetal hemoglobin is true?
a. It is fully saturated at the PO2 of the blood in placental blood sinuses.
b. It consists of 2 beta and 2 gamma subunits, in contrast to adult Hb, which
consists of 2 alpha and 2 gamma subunits
c. It has a lower oxygen affinity than adult Hb
d. It is less than fully saturated at the PO2 it encounters in placental capillaries.
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20. When the zygote arrives in the uterus,
a. It implants in the uterine endometrium immediately
b. Implantation may be delayed for days to months, depending on the
mammalian species
c. It is in the form of a hollow ball of cells called a gastroblast
d. It is still arrested at the 2nd meiotic metaphase
21. Within a few minutes after ovulation, the ovum
a. Begins to secrete chorionic gonadotropin
b. Completes the 1st meiotic division and emits a 1st polar body
c. Completes the 2nd meiotic division and emits a 2nd polar body
d. Enters the uterus
22. Engorgement of the penis and clitoris with blood in the course of the first stage of sexual
response is the result of
a. constriction of outflow vessels by increased sympathetic input
b. constriction of arterioles by increased parasympathetic input
c. dilation of arterioles by parasympathetic efferents that release nitric oxide
d. dilation of arterioles by sympathetic cholinergic fibers
23. The male scrotum is developmentally homologous to the female
a. scrotum
b. labia minora
c. clitoris
d. labia majora
Part II Some questions about renal physiology
1. For a person under maximum hypovolemic stress without access to fresh water (lost in
the desert or adrift in a lifeboat at sea, for example), urine can be at most (circle one) 6X
12X 20X 100X more concentrated than plasma.
2. The actual anatomical site where energy is spent as ATP to achieve urine concentration
is the:
a. proximal convoluted tubule
b. descending thin limb of the Loop of Henle
c. thin ascending limb of the Loop of Henle
d. thick ascending limb of the Loop of Henle
3. For a person under maximum hypovolemic stress as described in Question 1,
a. lost volume will come from the extracellular compartment only
b. plasma ADH levels will be maximal
c. plasma aldosterone levels will be maximal
d. all of the above are correct
4. For the person described in Question 1, the GFR will be less than normal due to
a. The fact that reduced plasma volume will decrease renal plasma flow
b. The fact that reduced blood volume will decrease filtration pressure
c. The effect of decreased secretion of atrial natriuretic peptide
d. All of the above
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On the graph at
right, plot the
normal values for
plasma HCO3- and
pH and the
patient’s values.
Draw in
reasonable isobars
for the PCo2 values
associated with
each point. (3
points)
bicarbonate concentration
Part III Consider the following case data:
A 23-year old woman was brought to the acute care unit with nausea, vomiting and malaise.
Her weight on admission was 111 lbs. She had a 4-month history of weight loss (5.5 lb),
fatigue and anorexia. Skin hyperpigmentation was evident, particularly on her face, shoulders
and hands. She reported noticing increased growth of dark hair (a condition called hirsutism)
on her face and forearms in the past year. Her blood pressure was 110/85 while supine but
dropped to 92/60 when she sat up. Her heart rate while sitting was 104. Blood chemistry
values on admission were:
Na+: 111 mEq/L
K+ :
5.5
Cl- :
78
HCO3-: 23
Total plasma osmolarity: 234 mOsM
Pco2: 28 mmHg
pH: 7.31
glucose: 55 mg% (normal fasting value 75 mg%)
30
25
20
15
10
5
0
6
7
8
arterial pH
Please answer the following questions about this case.
1.
a.
b.
c.
d.
The acid-base status of this patient is best described as
Normal
Simple metabolic acidosis
Simple respiratory acidosis
Primary metabolic acidosis with partial compensation
2.
The numerical value of the anion gap in this patient is ___10___mEq/liter.
3.
This value is
a. larger than normal
b. smaller than normal
c. about normal
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4.
The patient’s plasma was found to contain antibodies to the enzyme 21hydroxylase. Autoimmune elimination of the 21-hydroxylase enzyme of the adrenal
would tend to block synthesis of
a.
Mineralocorticoid and glucocorticoid, but not androgen
b.
Glucocorticoid only
c.
Mineralocorticoid only
d.
Mineralocorticoids, glucocorticoids and androgens
5.
A piece of evidence that supports a diagnosis of primary adrenal disease
versus secondary or hypopituitary hypoadrenalism is the patient’s
__hyperpigmentation_______.
6.
The patient’s depressed plasma glucose value is the result of the fact that in
the absence of the permissive effect of cortisol, the hormones __epinephrine____
and _____glucagon____ become ineffective.
7.
For each of the following, mark “elevated”, “depressed” “normal” or “can’t be
sure” to indicate the plasma levels of the factor that you would expect in this patient,
as compared to values from a healthy person.
a. Renin:
_elevated___________
b. Antidiuretic hormone __elevated_____
c. Atrial Natriuretic Peptide ___depressed_____
Part IV. List four enzymatic components of pancreatic secretion (at least 7 were mentioned in
lecture) and characterize the function of each one, following the example below. (2 points
each response)
Chymotrypsin: endopeptidase that cleaves some peptide bonds
1. trypsin – endopeptidase that cleaves some peptide bonds________
2. amylase – converts polysaccharides to oligosaccharides___
3. lipase- cleaves triacyglycerols to FFA and monoglycerides_
4. carboxypeptidase – detaches single AAs from carboxy ends of polypeptides __
Pancreatic enzymes are secreted in inactive forms; the first step in activating them all is
activation of the protease __trypsin _______by the enzyme _ enterokinase __ located
on the intestinal surface.
List 2 major duodenal hormones and for each, give two specific effects
1st duodenal hormone ___secretin________
major effect 1____stimulates bicarbonate secretion by pancreas and liver___
major effect 2___inhibits gastric acid secretion__
2nd duodenal hormone __cholecystokinin____
major effect 1 ____stimulates bile secretion_____
major effect 2_____inhibits stomach emptying____
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Part V Some of these questions should also look familiar.
1. Intestinal motility has two basic functional modes; these are
_segmentation__contractions that result in mixing of chime and _peristaltic___
contractions that result in movement of food along the length of the intestine.
2. The enzyme __pepsin___, secreted by gastric __chief_ cells, is an endopeptidase that
converts dietary proteins to _oligopeptides__.
3. Nutrients that have entered the intestinal venous blood during the intestinal phase of a
meal pass to the liver via the __hepatic portal vein___.
4. The temporary rise in urine pH that typically follows breakfast has historically been called
the __alkaline tide___.
5. Peptic ulcers were treated with bland diet and antacids until pharmacological inhibitors of
gastric acid secretion were commercialized. However, currently, the correct treatment for
peptic ulcers is usually __antibiotics_____.
6. The most important physiological role of gastric acid secretion is to prevent bacterial
infection. In this, it is assisted by the chemical __nitric oxide___ formed in the stomach
from nitrites. In turn, these nitrites are formed from dietary nitrates by symbiontic denitrifying
_bacteria___ that reside in the pharynx.
Part VI Some Questions About The Visual System
1. Primary visual photoreceptors could be best described as
a. photon detectors
b. spot detectors
c. orientation detectors
d. shape detectors
2. In the human visual system, axons of ganglion cells with receptive fields in the lateral
halves of the retinas
a. Decussate in the lateral geniculate nucleus of the thalamus
b. Decussate at the optic chiasm
c. Decussate in the corpus callosum
d. Don’t decussate at all
3. Ganglion cells of the retina could best be described as
a. Spot detectors
b. Orientation detectors
c. Photon detectors
d. Motion detectors
4. Columns of the primary visual cortex contain cells that are
a. responsive to single orientations
b. equally responsive to inputs from either eye
c. spontaneously active
d. all of the above
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Part VII The EKG shown is from a 37-year-old man who has a congenital pulmonary
stenosis – a narrowing of the pulmonary valve.
I
II
III
1. Plot this patient’s vectorcardiogram (3 points)
2. This patient has a (circle one)
Left axis deviation
Right axis deviation
Normal cardiac axis
3. Mark each of the following with less than, greater than or no difference to indicate how this
patient’s cardiovascular system variables will compare with those of a normal healthy person.
a. central venous pressure __greater than_________________
b. left atrial pressure __less than_________________
c. pulmonary arterial pressure ____less than_____________
d. maximum cardiac output during exercise __less than______
e. oxygen saturation of pulmonary venous blood ___no difference____
4. This patient was given Lasix (furosemide). This drug
a. Inhibits Na+ reabsorption in the distal convoluted tubule
b. Inhibits carbonic anhydrase in the proximal convoluted tubule
c. Strengthens cardiac contractions
d. Would benefit the patient by reducing the workload of the right ventricle.
5. This patient has a cardiac murmur that is audible during
a. systole
b. diastole
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6. Fill in the blank spaces in the following paragraph with the most appropriate words or
phrases:
The heart’s pacemaker is located in the __SA___________ node of the __right_____
atrium. Impulses arising in this structure spread through the two atria, causing the _P_
wave of the EKG. The wave of excitation then arrives at the __AV____ node and
spreads from there into the Bundle of His, which branches to excite both ventricles.
Ventricular contraction causes the closure of the __AV_________ valves and the
opening of the __pulmonary_____ and ____aortic________ valves, leading to blood
ejection into the aorta and pulmonary arteries. The closure of these valves causes the
2nd ____heart sound__. Repolarization of the ventricles leads to the __T_____ wave
of the EKG.
Part VIII. Normal physiological values
1. For each of the following, circle the value that correctly represents the order of
magnitude of the fluid movement in each system in a healthy adult human (12 points)
a. The total volume of blood that flows through the systemic loop each day is about 100
1,000
10,000
100,000 liters.
b. The total volume of blood that flows through the pulmonary loop each day is about 100
1,000
10,000
100,000 liters
c. The total net volume of fluid that cycles through the interstitial fluid compartment each
day is about 2
20
200
2,000 liters
d. The volume of fluid that flows through the lymphatic system each day is about
2
20
200
2,000
e. The glomerular filtration rate is about 1
10 100
1,000 liters/day
2. Fill in correct normal numerical values for each of the following:
a. PO2 systemic arterial blood at 1 atm.___100_________mmHg
b. PCO2 systemic arterial blood at 1 atm __40_________mmHg
c. PO2 mixed venous blood __40______________mmHg
d. PCO2 mixed venous blood__46______________mmHg
e. HCO3- concentration arterial plasma __24_______mEq/L
f. Na+ concentration plasma _____140_________mEq/L
g. K+ concentration plasma ______4_________mEq/L
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Part IX. Another question set that should seem familiar. Consider the following scenario: Four
workers lift a square table, one worker holding each corner.
1. When the workers activate motor programs that result in lifting,
a. alpha motorneurons will be activated by the central commands, but gamma motor neurons
will not
b. gamma motor neurons will be activated by the program but alpha motor neurons will not
c. both alpha and gamma motor neurons will be recruited simultaneously by
descending impulses
d. gamma motor neurons will not be activated unless the table is too heavy for the workers to
lift.
2. If one of the workers should drop her corner, the other three workers may still be able to
support their increased loads because their stretch reflexes will respond to the change in the
load. Which of the following statements about this is/are correct?
a. the stretch reflex will result in an increase in the number of active gamma motorneurons
serving arm flexors
b. the stretch reflex will result in recruitment of alpha motorneurons innervating arm
flexors
c. Each motorneuron that is recruited by the stretch reflex will activate only some of the
muscle fibers that it synapses on.
d. All of the above are true.
3. Considering the situation in the above question, which of the following is a true statement?
a. according to the principle of negative feedback regulation, the stretch reflex will
compensate for the increased load and return the lengths of the flexors exactly to the lengths
for which they were set before the load was increased.
b. according to the principle of negative feedback, the stretch reflex will return the length of the
flexor muscles to a length that is somewhat longer than the setpoint length.
c. we could calculate the gain of the reflex by the ratio of Δ flexor length/ Δ load.
d. both b and c are true
4. If the table drops on the toe of one of the workers, a rapid withdrawal of the injured
appendage will result. Which of the following is a true statement about this response?
a. it is a monosynaptic reflex in which nociceptors synapse directly on spinal motorneurons.
b. it is a polysynaptic reflex that allows for excitatory input to ipsilateral flexors and
inhibitory input to ipsilateral extensors
c. input from pain receptors in the injured appendage will also activate flexors and inhibit
extensors on the corresponding contralateral appendage
d. all of the above are true.
5. The emotional response of the worker whose toe is injured will involve mainly
a. The hypothalamus
b. The hippocampus
c. The limbic system
d. The somatosensory association area of the cortex
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Part X. The following passage is about fat digestion and fat metabolism. Fill in the blanks with
answers chosen from the answer bank at the end of the passage
As fat enters the intestine it is in the form of droplets. Interaction with __bile salts____
secreted by the liver causes the large droplets to be converted to small ones, a process called
emulsification. The secretion of the ___pancreas__ contains three enzymes that, acting
together, can convert the triacylglycerol into free fatty acids and monoglycerides. The action of
__phospholipase_______ cleaves phospholipids at the surface of fat droplets and clears the
way for __colipase __to attach to the surface and act as an anchor for attachment of
__lipase___, the enzyme that actually converts triacylglycerol to FFA and monoglyceride. In
the aqueous medium of the intestinal contents, the FFA and monoglyceride associate to form
structures called __micelles__ that can approach the surfaces of intestinal epithelial cells.
Once taken up into the cells, the FFA and monoglyceride are resynthesized into triacylglycerol
and ejected from the intestinal cells as __chylomicrons___. These enter the general blood
circulation by way of the lymphatic system, and ultimately may be converted to FFA and
glycerol when they contact the enzyme __lipoprotein (capillary) lipase___located on the
surfaces of capillaries in adipose tissues. Fat and cholesterol that have been synthesized in
the liver travel in the bloodstream to other tissues in the form of _low-density
lipoproteins____ which are tagged with specific destination labels called _apoproteins_.
Fat deposition, along with most of the other metabolic processes of the absorptive state, can
be accounted for by the effects of the hormone _insulin__. Mobilization of fat during
starvation is the result of stimulation of the enzyme __hormone-sensitive lipase_ by the
hormones ___epinephrine__ from the adrenal medulla and _glucagon__ from the pancreas.
These hormones require the hormone _cortisol____ from the adrenal cortex for full
effectiveness.
Lipoprotein lipase
Bile salts
Chylomicrons
Insulin
Leptin
Amylase
Colipase
Cortisol
Pancreatic lipase
Phospholipase
Invertase
Liver
Pancreas
Glucagon
Ghrelin
HDL
LDL
Apoproteins
Micelles
Epinephrine
Hormone-sensitive lipase
Lipoprotein lipase
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Part XI Consider the following case data: A 34 year old woman who had a history of
intravenous drug use was hospitalized for exercise-related dyspnea (e.g. she felt out of breath
after climbing a single flight of stairs). A sample of arterial blood, drawn while the patient was
breathing air, showed a PaO2 of 65 mmHg, a PaCO2 of 37 mmHg, and a pH of 7.44. Her
respiratory rate while at rest was 22/min. A test of her pulmonary diffusing capacity showed
that it was 36% of the expected value, whereas her FEV1 and VC were within normal ranges.
A biopsy of lung tissue revealed deposits of talc associated with pulmonary capillaries, the
result of intravenous injection of street drugs cut with talcum powder.
1. You could characterize this patient as
a. hypercapnic
b. hypoxic
c. both hypercapnic and hypoxic
d. none of the above
2. This patient’s acid base status is
a. respiratory acidosis
b. respiratory alkalosis
c. metabolic acidosis
d. within a normal range
3. The main source of respiratory drive in healthy people breathing air at sea level is
arterial
a. PCO2, acting on central chemoreceptors
b. pH, acting on peripheral chemoreceptors
c. PO2, acting on central chemoreceptors
d. PO2, acting on carotid and aortic bodies
4. In this patient, the main source of respiratory drive is arterial
a. PCO2, acting on central chemoreceptors
b. pH, acting on peripheral chemoreceptors
c. PO2, acting on central chemoreceptors
d. PO2, acting on carotid and aortic bodies
5. Which of the following statements is the most likely explanation for the arterial gas values of
this patient?
a. The lung damage imposes about the same limitation on the exchange of both O2 and
CO2.
b. The lung damage is making it more difficult to gain oxygen than to lose carbon
dioxide.
c. At this level of lung damage, O2 diffusion is limiting but CO2 diffusion is not.
d. The patient’s discomfort and anxiety are causing her to hyperventilate
6. Particles that are inhaled can result in fibrotic lung disease. If this patient had fibrotic
lung disease as a result of the particles deposited in her pulmonary vasculature, lung
compliance would decrease, and you would expect that
a. Functional residual capacity would decrease
b. FEV1 as a fraction of vital capacity would increase
c. Elastic work of breathing would increase
d. All of the above would occur
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Part XII. Consider the following case data: A 23 year old woman was hospitalized because of
primary amenorrhea (i.e. she had never menstruated) and bilateral inguinal (low pelvic)
masses. Her doctor made the following observations:
The vagina is short and a uterine cervix is not visible; a uterus is not palpable by rectal
examination. There is no pubic or axillary (underarm) hair.
The patient underwent an unremarkable feminizing puberty with breast development
beginning at 16 years. She is unmarried and has never been sexually active.
The hormonal profile of patient’s plasma shows levels of estrogens and testosterone within
the normal ranges for adult males.
1. A uterus and proximal vagina are not present because
a. the patient expressed Mullerian inhibitory factor
b. the patient lacked estrogen receptors
c. differentiation of the uterus was suppressed by testosterone
d. differentiation of the uterus was inhibited by Woffian inhibitory factor
2. The feminizing puberty was the result of
a. estrogen and progesterone from the patient’s ovaries
b. estrogen from the patient’s testes
c. estrogen from the patient’s adrenals
d. conversion of testosterone to estrogen by brain aromatase
3. Laparoscopy is a procedure in which a fiberoptic device is inserted into the abdomen to
view internal structures. In this patient, laparoscopy would show that she has
a. both testes and ovaries
b. a male accessory gland-duct system, but no testes
c. ovaries
d. testes but no male gland-duct system
4. The sex genotype of this person is
a. XX
b. XY
c. XYY
d. XXO
5. In a normal female, sexual interest is believed to be maintained mostly by
a. estrogen
b. progesterone
c. adrenal androgen
d. gonadotropins
6. Individuals with Turner’s syndrome (XO sex genotype) also have a female body plan and
do not menstruate, but they differ from this patient in that they
a. do not undergo a feminizing puberty
b. have pubic and axillary hair
c. do not undergo a growth spurt at puberty
d. all of the above
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Part XIII Some More FITB
1. Enter one of acetylcholine, norepinephrine, epinephrine, muscarinic, nicotinic, alpha
adrenergic, or beta adrenergic for each of the following blanks:
a. Transmitter released at the somatic neuromuscular junction___Ach______________
b. Transmitter released in sympathetic chain ganglia____Ach_____________
c. Transmitter released by sympathetic postganglionic neurons___NE _____________
d. Transmitter released by parasympathetic postganglionic neurons__Ach_____
e. Transmitter released by the brain’s reticular activating system____NE___________
f. Receptor type that can be blocked by atropine____muscarinic________________
g. Receptor type at somatic neuromuscular junctions___nicotinic____
h. Hormone released by the adrenal medulla __E_________________
i. Dominant receptor of systemic arterioles___alpha adrenergic___________________
j. Receptor type that results in positive chronotropic effect___beta adrenergic_________
k. Transmitter that activates thermogenesis in brown fat __beta adrenergic_________
2. Fill in each of the following blanks with either N for “neurons” or E for “epithelial cells” as
appropriate.
Primary photoreceptors are ____E______
Primary gustatory receptors are _E_________
Primary auditory receptors are __E_______
Primary olfactory receptors are __N_______