Exam 3 practice questions

Question 1

Enterokinase is a key “brush border” enzyme in the small intestine. What consequences results from a mutation in the gene for enterokinase that renders it nonfunctional

Answer 1

Enterokinase digests trypsinogen from pancreatic juice into its active form trypsin. This allows trypsin to activate the other zymogens in pancreatic juice which are necessary for the complete digestion of food in the intestine.

Question 2

What happens to a developing embryo with a dysfunction mutation in the SRY gene?

Answer 2

The SRY-gene is also known as the sex determining region Y, or the testis-determining factor (TDF), and is the gene responsible for the initiation of male sex determination. TDF stimulates the wolffian system in males and leads to regression of the mullarian system (female). Early development of testes leads to production of testosterone which aids in brain development. If the SRY gene was mutated the female organization system would develop and the masculinization of brain would not occur. A phenotypic and behavioral female would result.

Question 3

Respiratory acidosis

Answer 3

decrease blood pH.

Compensation mechanisms (1) an increased respiratory rate (2) hemoglobin (Hb) buffering forming 
(3) increased renal ammonia acid excretions with reabsorption of bicarbonate 

acute: associated with pulmonary edema, aspiration of foreign body, overdose of sedatives/barbituate poisoning, smoke inhalation
chronic: emphysema, asthmabronchiectasis

Question 4

Respiratory acidosis

Answer 4

decrease blood pH.

Compensation mechanisms (1) an increased respiratory rate (2) hemoglobin (Hb) buffering forming 
(3) increased renal ammonia acid excretions with reabsorption of bicarbonate 

acute: associated with pulmonary edema, aspiration of foreign body, overdose of sedatives/barbituate poisoning, smoke inhalation
chronic: emphysema, asthmabronchiectasis

Question 5

Describe the overall organization of anterior pituitary hormone secretion. Draw a labeled diagram for one such hormone and its regulation.

Answer 5

Anterior pituitary is not innervated by nerves from the hypothalamus. so the release of anterior pituitary hormones is under the control of other hormones. ex: hypothalamus releases TRH thyrotropin releasing hormone which stimulates thyroid stimulating hormone from TSH from the thyroid which stimulates thyroxine which a build up of inhibits responsiveness of TRH from anterior pituitary and secretion of TRH

Question 6

What is the HPA Axis

Answer 6

hypothalamus releases CRH (corticotropin releasing hormone) which stimulates anterior pituitary to release ACTH (adrenocorticotropic hormone) which stimulates adrenal cortex to stimulate Cortisol which builds up and stimulates a negative feedback loop.

Controls reaction to stress, digestion, immune system, mood and emotions, sexuality, and energy

Question 7

What are the major activators of stomach activity (both mechanical and chemical)?

Answer 7

distension, vagus nerve stimulation (autonomic), enteric nervous system (myenteric + submucosal plexus), g cells–> gastrin, decreased pH, partially digested proteins (amino acids)

Question 8

How is the function of the colon different than that of the SI?

Answer 8

The colon absorbs water and vitamins and does little to no digestion. The colon is also involved in bacterial fermentation. The SI is the site of complete digestion of starch, protein, lipids and carbs and absorbs the monomers of these molecules through increased surface area provided by microvilli. . from the enzymes released from the pancreas

Question 9

What is the bottom-line message of Richards + Gumz’s review?

Circadian regulation of all body

Answer 9

Circadian regulation of all body systems
Important of down-time
Central/peripheral “clocks”

How are physiological systems regulated and coordinated to optimize overall functions
Heart and lungs would regulate with endocrine system, and nervous system, ex: hypothalamaic adrenal

Question 10

What is the bottom-line message of Richards + Gumz’s review?

Circadian regulation of all body

Answer 10

Circadian regulation of all body systems
Important of down-time
Central/peripheral “clocks”

How are physiological systems regulated and coordinated to optimize overall functions
Heart and lungs would regulate with endocrine system, and nervous system, ex: hypothalamaic adrenal

Question 11

Cholecystokinin (CCK) is a hormone that

Answer 11

stimulates contraction of the gallbladder, secreted by the duodenum in response to the presence of chyme, stimulates secretion of pancreatic enzymes into the dudoenum, inhibits gastric motility

Question 12

Stowhas et al

Answer 12

Effects of Acute Exposure to Moderate Altitude on
Vascular Function, Metabolism and Systemic
Inflammation

Conclusion: Short-term stay at moderate altitude is associated with increased blood pressure and heart rate likely due to
augmented sympathetic activity. Exposure to moderate altitude improves the lipid profile and systemic inflammation, but
seems to have no significant effect on glucose metabolism.

Question 13

Emerging themes

Answer 13

is the centrality of BALANCE
Includes mechanisms for homeostasis, pH, blood volume
Also includes appropriate amount of
Ability to be responsive to changing needs while maintaining a balance
Monitors and coordinators range from local like blood cardiovascular regulation at level of tissue and nervous system, endocrine regulators. This will lead to enacting changes to the body
All of the systems we have talked about exhibit autonomy and yet are interconnected

Question 14

Gilbert-Kawai et al 2014

Answer 14

King of the Mountains: Tibetan and Sherpa Physiological adaptations for life at high altitude. tolerance to hypobaric hypoxia at high altitude. These populations have successfully lived and reproduced at high
altitude for hundreds of generations with hypoxia as a constant evolutionary
pressure. Consequently, they are likely to have undergone natural selection
toward a genotype (and phenotype) tending to offer beneficial adaptation to
sustained hypoxia. With the advent of translational human hypoxic research, in
which genotype/phenotype studies of healthy individuals at high altitude may be
of benefit to hypoxemic critically ill patients in a hospital setting, high-altitude
natives may provide a valuable and intriguing model. The aim of this review is to
provide a comprehensive summary of the scientific literature encompassing Tibetan
and Sherpa physiological adaptations to a high-altitude residence. The
review demonstrates the extent to which evolutionary pressure has refined the
physiology of this high-altitude population. Furthermore, although many physiological
differences between highlanders and lowlanders have been found, it also
suggests many more potential avenues of investigation.

Question 15

Richard and Gumz

Answer 15

circadian rhythm

Question 16

true or false the esophagus is composed of smooth muscle that is responsible for rhythmic contrctions stimulated by the presence of partially digested carbohydrates

Answer 16

false

Question 17

Why is a sodium electrochemical gradient crucial for the fufnction of the SI epithelial cells?

Answer 17

The transport of free amino acids and monosaccharides from the lumen of the SI across the apical membrane of the epithelial cells (up their concentration gradient relies on utilizing energy obtained from the cotransprot sodium across the membrane down its electrochemical gradient. secondary active transport. The sodium electrochemical gradient is important so that the mvement of sodium into the epithelial cells will be downill and will generate enoguh energy to absorb glucose and proteins across the apical membrane. This process is crucual for main absorptiove.