BY 32 – Fall 2000

Sections 6142/6143

 EXAM 1

 

NAME ___________________________________

Instructions:  Record your answers directly on this sheet by circling the correct response.  For each question, choose the single best response.

1.  Which of the following represent physiological variables that are maintained within relatively narrow limits as a result of regulatory mechanisms that contribute to homeostasis? (D)

a.      Body temperature

b.     The concentration of glucose in blood

c.      The concentration of Ca2+ in plasma

d.     All of the above

 

2.  In response to a fall in blood pressure due to hemorrhage, the heart begins to beat faster because: (B)

a.      the set point for blood pressure becomes altered.

b.     of an error signal generated by the central controller which in turn activates effectors.

c.      the baroreceptors stop sensing blood pressure.

d.     the baroreceptors become more sensitive to blood pressure.

 

3.  In a negative feedback system, the effectors cause changes in the physiological variable which tend to: (B)

a.      change the set point to lower values.

b.     oppose the initial disturbance.

c.      by-pass the central controller

d.     reinforce the initial disturbance.

 

4.  Of the various types of intercellular communication, all of the following involve receptors EXCEPT communication mediated by: (C)

a.      neurotransmitters.

b.     hormones.

c.      gap junctions.

d.     paracrine agents.

5.  Of the various types of intercellular communication, the one that operates on the shortest time frame is intercellular communication mediated by: (A)

a.      neurotransmitters.

b.     protein hormones.

c.      steroid hormones.

d.     thyroid hormones.

 

6.  Which of the following circulate in blood bound to carrier proteins? (D)

a.      Amine hormones

b.     Catecholamines

c.      Peptide hormones

d.     Steroid hormones

 

7.  All of the following hormones interact with a receptor located on the plasma membranes of target cells EXCEPT: (A)

a.      aldosterone.

b.     oxytocin.

c.      anti-diuretic hormone (ADH).

d.     parathyroid hormone (PTH).

 

8.  The portion of the pituitary gland where posterior pituitary hormones are released into the blood stream is called the: (A)

a.      pars nervosa.

b.     pars distalis.

c.      pars intermedia.

d.     pars tuberalis.

 

9.  Target cells for oxytocin include: (D)

a.      smooth muscle cells within the uterus.

b.     smooth muscle cells within blood vessels.

c.      smooth muscle cells within the mammary glands.

d.     both a and c.

 

10.  Under conditions of elevated ADH, (B)

a.      the amount of water lost in the urine increases compared to normal.

b.     the amount of water loss through perspiration decreases compared to normal.

c.      blood vessels relax (i.e., vasodilate) allowing fluid to leave the vasculature.

d.     both a and c.

 

11.  Prolactin is synthesized and secreted by: (D)

a.      hypothalamic neurons located in the supraoptic nucleus.

b.     hypothalamic neurons located in the paraventricular nucleus.

c.      corticotropes of the anterior pituitary.

d.     lactotropes of the anterior pituitary.

 

 

12.  Growth hormone (GH) production is stimulated by: (C)

a.      elevated levels of somatostatin.

b.     elevated levels of GH in blood.

c.      conditions of decreased blood sugar.

d.     conditions of elevated fatty acids in blood.

 

13.  Grave’s Disease is an autoimmune disease in which the body produces antibodies to thyroid stimulating hormone (TSH) receptors on follicular cells, and these antibodies stimulate these TSH receptors.  In a patient with Grave’s disease, you would expect: (A)

a.      elevated levels of thyroid hormones (T3 and T4) in blood.

b.     a low basal metabolic rate (BMR) and increased sensitivity to cold.

c.      elevated levels of TSH in blood.

d.     an increased tendency for weight gain.

 

14.  Parathyroid hormone (PTH) is synthesized and secreted by cells called: (A)

a.      chief cells.

b.     parafollicular cells.

c.      follicular cells.

d.     sommatotropes.

 

15.  A class of hormones called glucocorticoids is synthesized and secreted within the adrenal gland, mostly in a region called the: (B)

a.      zona glomerulosa.

b.     zona fasiculata.

c.      zona reticularis.

d.     adrenal medulla.

 

16.  Aldosterone secretion will be expected to increase in response to all of the following EXCEPT: (A)

a.      increased levels of atrial natriuretic peptide (ANP).

b.     increased levels of adrenocorticotropin hormone (ACTH).

c.      increased levels of angiotensin II.

d.     low blood concentrations of Na+ and high blood concentrations of K+.

 

17.  Glycogen breakdown is stimulated by: (B)

a.      insulin.

b.     glucagon.

c.      cortisol.

d.     all of the above.

 

18.  The process of breaking down food into simple nutrients that can be absorbed is called: (C)

a.      reabsorption.

b.     secretion.

c.      digestion.

d.     anabolism.

19.  All of the following organs form a portion of the gastrointestinal (GI) tract EXCEPT: (B)

a.      the esophagus.

b.     the pancreas.

c.      the oropharynx.

d.     the rectum.

 

20.  On the outer surface of the jejunum is found a single layer of mesothelial cells which form a structure called the: (A)

a.      visceral peritoneum.

b.     parietal peritoneum.

c.      mesentery.

d.     both a and c.

 

21.  Within the stomach, the component of the nervous system which controls mucosal secretion is called the: (C)

a.      muscularis mucosa.

b.     myenteric plexus.

c.      submucosal plexus.

d.     greater omentum.

 

22.  The vestibule is a space found: (A)

a.      between the cheeks & lips and the teeth & gums.

b.     between the teeth & gums and the pharynx.

c.      at the junction of the esophagus and the stomach.

d.     within the gallbladder.

 

23.  On the surface of the tongue are a number of mucosal specializations.  Of the various types, the specializations that are pointed and help to grasp food are called: (D)

a.      fungiform papillae.

b.     circumvallate papillae.

c.      lingual frenulums.

d.     none of the above.

 

24.  Which of the following portions of the GI tract is lined by an epithelium that is stratified squamous?  (C)

a.      The sigmoid colon

b.     The ileum

c.      The esophagus

d.     The stomach

 

25.  Of the four anatomical regions of the stomach, the two which are histologically indistinguishable are the: (C)

a.      cardiac and fundic regions.

b.     cardiac and pyloric regions.

c.      body and fundic regions.

d.     body and pyloric regions.

 

26.  The cell type responsible for secretion of pepsinogen is called the: (A)

a.      chief cell.

b.     parietal cell.

c.      paneth cell.

d.     pancreatic acinar cell.

 

27.  The duodenum receives exocrine secretions from the: (D)

a.      liver.

b.     parotid.

c.      pancreas.

d.     both a and c.

 

28.  Within the small intestine, which of the following cell types decreases in frequency as you move from the duodenum ® jejunum ® ileum? (A)

a.      Columnar absorptive cells

b.     Goblet cells

c.      Paneth cells

d.     Both a and c

 

29.  At the junction between the small and large intestines, there is a sphincter called the: (C)

a.      lower esophageal sphincter (LES).

b.     pyloric sphincter.

c.      ileocecal valve.

d.     internal anal sphincter.

 

30.  Within the large intestine, the longitudinal layer of the muscularis externa is organized into three longitudinal bands called: (D)

a.      haustra.

b.     plicae circulares.

c.      epiploic appendages.

d.     teniae coli.

 

31.  The portion of the large intestine situated between the ascending and descending colons is called the: (B)

a.      cecum.

b.     transverse colon.

c.      sigmoid colon.

d.     rectum.

 

32.  Within the salivary glands, the type of ducts that are lined by a simple cuboidal epithelium are called: (A)

a.      intercalated ducts.

b.     striated ducts.

c.      interlobular ducts.

d.     serous demilunes.

 

33.  You are given a histological slide which upon examination is seen to consist of a morphology consistent with an exocrine gland.  Closer examination reveals that ~75% of the acini are mucous and ~25% are serous.  Based on this information, you conclude that this tissue was most likely obtained from the: (C)

a.      parotid gland.

b.     submandibular gland.

c.      sublingual gland.

d.     pancreas.

 

34.  The common bile duct forms from a merger of the common hepatic duct and the: (B)

a.      main pancreatic duct.

b.     cystic duct.

c.      parotid duct.

d.     vermiform appendix.

 

35.  Which of the following are functions of saliva? (D)

a.      Chemical digestion of carbohydrates

b.     Protection of the oral mucosa against noxious foods and drink

c.      Prevention of infection within the oral cavity

d.     All of the above

 

36.  Salivary amylase is secreted mainly by: (A)

a.      serous cells.

b.     mucous cells.

c.      intercalated duct cells.

d.     striated duct cells.

 

37.  Within salivary glands, striated duct cells modify the composition of saliva by: (C)

a.      adding Na+ and Cl-.

b.     extracting K+.

c.      adding HCO3- (bicarbonate).

d.     both a and c.

 

38.  All of the following can increase the secretion rate of saliva EXCEPT: (D)

a.      nausea.

b.     parasympathetic stimulation.

c.      the sight and smell of food.

d.     vasoconstriction of blood vessels supplying the salivary glands.

 

39.  During swallowing, the upper esophageal sphincter (UES) is open during: (B)

a.      the oral phase.

b.     the pharyngeal phase.

c.      the esophageal phase.

d.     all of the above.

 

40.  Any condition that tends to relax the lower esophageal sphincter (LES) will predispose a person to: (B)

a.      an impaired ability to swallow.

b.     esophageal reflux (i.e., material passing from stomach to esophagus).

c.      an impaired ability to digest carbohydrates.

d.     both a and b.

 

41.  The ability of parietal cells to secrete stomach acid (HCl) is dependent on the action of: (C)

a.      pepsinogen.

b.     enterokinase.

c.      carbonic anhydrase.

d.     amylase.

 

42.  Within the gastric phase of gastric secretion, the vago-vagal reflex is initiated by: (A)

a.      distension of the stomach.

b.     distension of the duodenum.

c.      the presence of secretin.

d.     both b and c.

 

43.  Of the following, all will increase gastrin secretion EXCEPT: (D)

a.      acetylcholine (ACh).

b.     caffeine.

c.      the presence of partially digested proteins within the stomach.

d.     excessive acidity (pH < 2) within the stomach.

 

44.  Within the intestinal phase of gastric secretion, which of the following hormones is most effective at inhibiting gastric secretions? (B)

a.      Gastrin

b.     Secretin

c.      Cholecystokinin (CCK)

d.     Gastric inhibitory peptide (GIP)

 

45.  Receptive relaxation of the stomach is mostly due to local reflexes involving the release of nitric oxide which acts to: (C)

a.      stimulate gastric secretions.

b.     close the upper esophageal sphincter (UES).

c.      relax the smooth muscle of the stomach.

d.     open the pyloric sphincter.

 

46.  As chyme enters the duodenum from the stomach, the most potent stimulus for CCK secretion involves: (C)

a.      distension of the duodenum.

b.     the presence of acidic chyme in the duodenum.

c.      the presence of chyme containing amino acids and fatty acids.

d.     parasympathetic stimulation.

 

47.  The conversion of the inactive form (trypsinogen) to the active form, trypsin depends on the presence of: (D)

a.      chymotrypsin.

b.     acidic conditions within the duodenum.

c.      pepsin.

d.     enterokinase.

 

48.  CCK acts on the: (D)

a.      gallbladder to contract.

b.     sphincter of Oddi to relax.

c.      pancreas to increase enzyme secretion.

d.     all of above.

 

49.  Which of the following will enhance the duodenum’s ability to neutralize stomach acid? (B)

a.      Gastrin

b.     Secretin

c.      CCK

d.     GIP

 

50.  The final step of the defecation reflex involves: (C)

a.      stimulation of stretch receptors within the rectum.

b.     relaxation of the internal anal sphincter.

c.      relaxation of the external anal sphincter.

d.     the gastrocolic reflex.