The Digestive System

An increase in HCl (hydrochloric acid) secretion in the duodenum would stimulate which hormone that would help to counteract the effects of HCl?

B) secretin

What vitamin must be complexed with intrinsic factor in order to be absorbed?

B12

Where do chylomicrons go after they are transported out of the enterocyte and why do they go there?

lymphatic system, because they are too large to enter into the blood

In the small intestine, which of the following enzymes breaks down maltose?

maltase

Given the chemical nature of free fatty acids and monoglycerides, how are they absorbed across the epithelial border of the small intestine?

simple diffusion

organ where most digestion occurs

small intestine

GI contractions that are sustained for minutes or hours are called ________ contractions.

tonic

Which of the following structures are found within the chylomicron?

tryglycerides, protein, and cholesterol

Which of the following intestinal hormones stimulates bile from the gall bladder?

CCK (cholecystokinin)

The secretion in the large intestine consists of which of the following?

D) bicarbonate- and potassium-rich mucus

secreted by cells in the stomach

Gastrin

Powerful contractions that occur a few times each day in the colon are called

Mass Movements

The ________ is a significant site of absorption of water and electrolytes, but NOT of nutrients.

large intestine

goblet cells

Produce mucus, helps protect the intestinal mucosa.

parietal cells

Produces HCl

inhibits gastric emptying

Secretin

________ are short segments of intestine that alternately contract and relax. They are responsible for ________.

Segmental contractions, mixing

________ is a "housekeeping function" that sweeps food remnants and bacteria out of the upper GI tract and into the large intestine.

The migrating motor complex

Which of the following events does NOT occur when you swallow?

The upper esophageal sphincter closes.

Enteric interneurons that are inhibitory to smooth muscle use which of the following neurotransmitters?

VIP (vasoactive intestinal peptide)

What happens when slow wave action potentials reach threshold?

Voltage-gated calcium channels open in the muscularis externa.

What is the "migrating motor complex"?

a pattern of slow contractions sweeping along the GI tract

In response to a steak dinner, certain secretions are needed to aid digestion. What cells in the pancreas would provide these secretions?

acinar cells, in response to a high fat and protein meal, CCK (cholecystokinin) would be stimulated and in turn would stimulate an enzyme-rich secretion from the pancreas.

Which of the following structures can be found along the membrane of a micelle or within the micelle?

bile salts, diglycerides, free fatty acids, cholesterol, monoglycerides, and phospholipids

Merely anticipating that one is about to eat can trigger the ________ phase of digestion.

cephalic

HCl secretions convert pepsinogen to the active hormone pepsin. What cells in the gastric pits produce pepsinogen?

chief

Which is NOT classified as a member of the secretin family of GI hormones?

cholecystokinin (CCK)

stimulates bile release

cholecystrokinin

Decreased levels of bile salts in the bile would interfere with digestion of

fat

The breakdown products of which of the following are absorbed into lacteals?

fats

Salivation is controlled almost entirely by the nervous system. Which of the following stimuli would inhibit salivation?

fear, sleep, fatigue, and dehydration

What is the role of bile?

increases the surface area of fats so that they are easier to digest

During which phase in the control of the digestive system would bicarbonate and bile be stimulated?

intestinal phase

smooth muscle of duodenum is a target

motilin

The release of many GI tract hormones is stimulated by a particular food or substance. Which hormone is INCORRECTLY paired with its stimulus?

motilin-acid in the stomach

The four processes of the digestive system include digestion, absorption, secretion, and which other function?

motility

organ that adds exocrine secretions to the duodenum via a duct

pancreas

Which of the following enzymes is important for the digestion of fat?

pancreatic lipase is important for the digestion of fats. It is secreted by the pancreas and works in the small intestine.

Which of the following enzymes is important for breaking down protein?

pepsin

Enzymatic breakdown of which of the following compounds doesn't begin until it reaches the stomach?

proteins

location of the sphincter that prevents premature emptying of the stomach

pylorus

Which of the following GI hormones promotes a pancreatic juice rich in bicarbonate ions?

secretin

What type of contraction pattern allows the small intestines to churn and mix a chyme?

segmental

Slow waves are

spontaneous cycles of depolarization and repolarization.

Norepinephrine is the neurotransmitter released by which fibers?

sympathetic postganglionic fibers

In response to the arrival of acidic chyme in the duodenum, the blood levels of

the blood levels of secretin rise

A drug that blocks the action of the hormone cholecystokinin would affect

the composition of pancreatic secretions.

Mechanical digestion refers to

the effects of chewing, churning, and segmentation.

The gastric phase of gastric secretion is triggered by

the entry of food into the stomach.

Chemical digestion refers to

the enzymatic breakdown of food.