Chapter 24 - Digestive System

Symptoms of Hepatitis

1) Yellowish skin & eyes 2) Abdominal Pain

What are the 6 functions of the digestive system?

1. Ingestion 2. Mechanical processing 3. Digestion 4. Secretion 5. Absorption 6. Excretion "I'M Dead Sexy And Educated"

___________ pairs of salivary gland secrete into the oral cavity.

3 (the parotid, sublingual, and submandibular)

How many lobes does the human liver have?

4 right, left, caudate, quadrate

What happens after chyme arrives in the duodenum?

the intestinal phase begins: NEURAL RESPONSES - enterograstric reflex * inhibits gastrin production and gastric contractions * stimulates pyloric sphincter contraction to prevent further chyme discharge - local reflexes * stimulate mucus production HORMONAL RESPONSES - lipis and carbs stimulate secretion of CCK and GIP - pH below 4.5 stimulates secretion of secretin - partially digested proteins stimulate G cells to secrete gastrin

The dangling process that helps prevent food from entering the pharynx too soon is called

the uvula

Where is the appendix attached?

to the posteromedial surface of the cecum

The function of a lacteal is to

transport products of lipid digestion to the lymphatic system

At the hepatic flexure (aka right colic flexure), the colon becomes the

transverse colon

Enzymes secreted by the pancreas include

trypsin (as trypsinogen), amylase, lipase, nuclease, chymotrypsinogen

An obstruction of the common bile duct often results in _________.

undigested fat in the feces

Function of GIP

Exocrine = decreases gastric H+ secretion Endocrine = increases insulin release

An intestinal hormone that stimulates the release of insulin from the pancreatic islet cells is _________________.

GIP (gastric inhibitory peptide)

What are plicae circulares?

Plicae = folds, circulares = circular; thus, the circular folds of mucosa of the small intestine They are permanent features that do NOT disappear when the small intestine fills.

What are taeniae coli?

Three ribbon-like bands of longitudinal smooth muscle, running the length of the colon

A hepatic triad consists of

a bile ductule, a branch of the hepatic artery, and a branch of the hepatic portal vein

A drug that blocks the action of carbonic anhydrase in parietal cells would result in

a higher pH during gastric digestion

What are haustra and what is their function?

a series of pouches formed by the wall of the colon they permit the colon to expand and elongate

What is the function of pepsin?

an enzyme that digests proteins

What is the largest region of the stomach?

body

Which section of the stomach is known as the "mixing tank" for food and secretions?

body

What does the enzyme amylase digest?

carbohydrates

What part of the stomach connects to the esophagus?

cardia

What are the 4 regions of the stomach?

cardia, fundus, body, pylorus

An intestinal hormone that stimulates contraction of the gall bladder to release bile is ___________.

cholecystokinin (CCK)

The fusion of the hepatic duct and the cystic duct forms the

common bile duct

The duodenal ampulla receives secretions from the ___________.

common bile duct and the pancreatic duct

At the splenic flexure (aka left colic flexure), the colon becomes the

descending colon

Functions of the Kupffer cells of the liver

destroy damaged RBCs destroy bacteria present antigens are phagocytic

What stimulates the secretion of secretin?

drop of pH below 4.5 in the duodenum

Submucosal glands that secrete mucus are characteristic of which section of the small intestine?

duodenum

What part of the small intestine is most likely to develop an ulcer?

duodenum

Where is secretin produced?

duodenum

Which of these enhance the absorptive effectiveness of the small intestine? a) plicae circulares b) the villi c) microvilli d) intestinal movements e) all of the above

e) all of the above

The gastric phase of gastric secretion is triggered by the ________.

entry of food into the stomach

Which sections of the stomach secrete acid and enzymes?

fundus and body

Bile is STORED in the

gallbladder and is produced by the liver to help break down fats.

The hormone that stimulates secretion and contraction by the stomach is ___________.

gastrin

Peyer's Patches are found in the _____________ of the small intestine.

ileum

Where do G cells secrete?

in the pyloric gland

Functions of cholecytokinin

increase production and secretion of all digestive enzymes in the pancreas relax the hepatopancreatic sphincter and contract the gallbladder, ejecting bile and pancreatic juice into the duodenum

Functions of secretin

increase secretion of bile and buffers by the liver and pancreas inhibit secretions of chief and parietal cells

What is hepatitis?

inflammation of the liver

The endocrine function of the pancreas is to secrete what?

insulin and glucagon into the bloodstream to control blood sugar

The part of the digestive tract that plays the primary role in the digestion and absorption of nutrients is the

jejunum

The villi are most developed in the

jejunum

Where are plicae circulares found?

jejunum

Products of fata digestion are transported initially by

lacteals

The basic functional unit of the liver is the

lobule

Double sheets of peritoneum that provide support and stability for the organs of the peritoneal cavity are the

mesenteries

Carbohydrate digestion begins in the

mouth

What does the gastroileal reflex do?

moves some chyme to the colon in response to stretch receptors

Which layer of digestive tract contains the lamina propria and mucous epithelium?

mucosa

What layer of the digestive tract alters the shape of the intestinal lumen and moves epithelial pleats and folds?

muscularis mucosae of the lamina propria in the mucosa

What is between the layer of circular and longitudinal muscle in the muscularis externa?

myenteric plexus

The exocrine portion of the pancreas is composed of

pancreatic acini

How does the pancreas deliver digestive secretions to the duodenum?

pancreatic duct to the duodenal ampulla

Where is pepsin secreted?

pepsinogen is secreted by chief cells in the gastric glands which is converted to pepsin by HCl in the lumen of the stomach

What are the waves of muscular contractions that move the bolus along the digestive tract called?

peristalsis

Which structures enhance the absorptive effectiveness of the small intestine?

plicae circulares villi microvilli

What is the function of G cells?

produce gastrin which stimulates both parietal and chief cells, and contractions of the gastric walls

The pancreas produces __________-digesting enzymes in the form of proenzymes.

protein

The enzyme pepsin digests

proteins

What section of the stomach connects to the small intestine?

pylorus

What section of the stomach empties into the duodenum?

pylorus

Which section of the stomach secretes digestive hormones?

pylorus

Functions of the large intestine include

reabsorption of water and compaction of feces

Approximately the last 15cm of the digestive tract is the

rectum

In response to the hormone cholecystokinin, the pancreas secretes a fluid _________.

rich in enzymes

In response to the arrival of acid chyme in the duodenum, the blood levels of secretin ________________. rise or fall?

rise

What are the prominent ridges in the lining of the empty stomach called?

rugae

The intestinal hormone that stimulates the pancreas to release a watery, bicarbonate fluid is ___________.

secretin

Characteristics of the cardia include

smallest part of the stomach abundant mucus glands whose secretions coat the connection to the esophagus and protect it from stomach acid

Which salivary gland secretes a watery mixture rich in salivary amylase and bicarbonate ion?

submandibular

In which layer of the digestive tract are large blood vessels and lymphatics found in?

submucosa

In what layer of digestive tract are the sensory nerve cells, parasympathetic ganglia, and sympathetic postganglionic fibers located?

submucosal plexus of submucosa

Functions of the liver

synthesis and secretion of bile synthesis of plasma proteins inactivation of toxins storage of glycogen and iron reserves phagocytosis and antigen presentation removal of circulating hormones removal of antibodies

What is the saclike structure that joins the ileum at the ileocecal valve?

the cecum

What is the enormous pouch that extends inferiorly between the body wall and the anterior surface of the small intestine?

the greater omentum