A&P2 Exam2 Ch17.6

These flashcards cover key terms and concepts related to the digestive system, focusing on the pancreas, liver, gallbladder, small intestine, and large intestine.

Pancreas

A gland (organ) that produces pancreatic juice containing digestive enzymes

gallbladder & small intestine

What 2 organs are connected to pancrease?

Pancreatic Juice

A fluid secreted by the pancreas containing digestive enzymes.

1. pancreatic amylase

2. pancreatic lipase

3. trypsin

4. chymotrypsin

5. carboxypeptidase

6. nucleases

7. bicarbonate ions

What are the 7 components of pancreatic juice?

Pancreatic Amylase

An enzyme of pancreatic juice that splits starch and glycogen into disaccharides.

Pancreatic Lipase

An enzyme of pancreatic juice that breaks down triglycerides into fatty acids.

Trypsin

An enzyme of pancreatic juice that digests proteins; released as inactive trypsinogen.

Chymotrypsin

An enzyme of pancreatic juice that digests proteins; released as inactive, but activated by trypsin.

Carboxypeptidase

A digestive enzyme of pancreatic juice that digests proteins; released as inactive, but activated by trypsin.

Nucleases

Enzymes of pancreatic juice that digest nucleic acids.

Bicarbonate Ions

Ions of pancreatic juice that make pancreatic juice alkaline and buffer stomach acid

trypsin, chymotrypsin, carboxypeptidase

What are the 3 proteinases contained in pancreatic juice?

secretin & CCK

What are the 2 hormones that help to release digestive enzymes?

Secretin

A hormone released by intestinal mucosa that stimulates pancreatic secretion.

Cholecystokinin (CCK)

A hormone that stimulates gallbladder contraction and bile release.

1. Acidic chyme enters duodenum

2. Intestinal mucosa releases secretin into bloodstream

3. Secretin stimulates pancreatic duct cells to secrete bicarbonate ions

4. acidic chyme enters duodenum

What are the steps of regulation of pancreatic secretion? (4)

liver: produces bile

gallbladder: storage of bile

What is the main difference in function b/t the liver and gallbladder?

right lobe, left lobe, quadrate lobe, caudate lobe

What are the 4 lobes of the liver?

right lobe

largest lobe of the liver

left lobe

smaller than right lobe of liver

quadrate lobe

minor lobe of liver, near gallbladder

caudate lobe

minor lobe of liver, near inferior vena cava

hepatic lobules

consisted in lobes, functional units of liver

hepatocytes

contained in hepatic lobules; the liver cells around central vein

hepatic sinusoids

liver channels for blood, between plates of cells

hepatic portal vein

brings absorbed nutrients to sinusoids in liver

The liver has blood from other organs flowing through it

What is so different about the blood flow through the liver?

Hepatopancreatic Ampulla

The junction where the bile duct and pancreatic duct meet.

carbohydrate metabolism, lipid metabolism, protein metabolism, secretion & production of bile

What are the 4 main liver functions?

bile

yellowish-greenish liquid that hepatic cells continuously secrete; crucial for digesting fats

water, bile salts, bile pigments, cholesterol, electrolytes

What are the 5 components of bile?

bile salts

component of bile; produced from cholesterol; emulsify fats; only bile component that has a digestive function

bile pigments

component of bile that is bilirubin and biliverdin, derived from hemoglobin breakdown

1. inflammation of liver

2. at first, symptoms resemble the flu; symptoms progress to rash, pain in right upper qaudrant, dark urine, pale feces, & jaundice

3. most common cause is a type of virus

4. can be blood-borne or transmitted by contact with food, body fluids, or objects contaminated with feces that contain virus

What are the 4 main points of hepatitis? (clinical application)

transmitted by contact with food or objects contaminated with feces containing the virus

how is hepatitis A transmitted?

transmitted by contact with body fluids containing the virus

how is hepatitis B transmitted?

transmitted through blood contact; half of all known cases; newer medications successfully treating hepatitis

how is hepatitis C transmitted?

hepatitis D, hepatitis E, hepatitis G

What are the other 3 forms of hepatitis

because it is viral

Why are antibiotics not effective against hepatitis?

hepatitis A & B

which types of hepatitis are there effective vaccines to prevent now?

Gallbladder

An organ that stores bile and releases it into the small intestine; connected ot cystic duct & hepatic duct; holds 30-50 mL of bile

Cystic Duct

A duct that connects the gallbladder to the common bile duct.

Common Bile Duct

The duct formed from the union of the cystic duct and common hepatic duct.

hepatopancreatic sphincter

guards the exit of common bile duct & regulates release of bile into duodenum

1. chyme with fat enters duodenum

2. cells of the intestinal mucosa secrete the hormone cholecystokinin (CCK) into bloodstream

3. CCK stimulates muscular layer of the gallbladder wall to contract

4. bile passes down the cystic duct and bile duct to the duodenum

5. the hepatopancreatic sphincter relaxes and bile enters the duodenum

What are the 5 steps of the regulation of bile release?

emulsification and forming micelles to aid in absorption of fatty acids

What are the 2 functions of bile salts?

micelles

formed by bile salts; soluble in chyme and easier to absorb by epithelial cells

Emulsification

The process of breaking down fat globules into smaller droplets.

1. pain in right upper abdominal quadrant, back and right shoulder

2. perhaps nausea and sweating

What are 2 main symptoms of gallbladder disease? (clinical application)

Gallstones

Solid particles that form in the gallbladder and can block ducts.

1. ultrasonography of gallbladder/ X-ray called a cholecystogram

2. gallstones found in gallbladder, cystic duct, hepatic ducts, or the common bile duct

What are the 2 types of tests to observe the gallbladder?

1. cholecystectomy: surgical removal of gallbladder

2. endoscopy to find stones or remove them from certain areas

What are the 2 treatments for gallbladder disease?

small intestine

receives secretions from pancreas & liver; complete digestion of nutrients; absorbs products of digestion; transports residues to large intestine

1. duodenum

2. ileum

3. jejunum

What are the 3 parts of the small intestine in order?

Intestinal Villi

Tiny projections of the mucosa in the intestinal wall that increase surface area for absorption.

lacteal

lymphatic capillary that absorbs large fats

simple columnar epithelium with connective tissue core w/ blood vessels, a lacteal, nerve fibers

What are 3 things each villus of the small intestinal wall consists of?

microvilli (increase surface area for absorption)

What do the free surfaces of epithelial cells on the small intestinal wall contain?

located b/t the bases of villi in stem cells

Where are the small intestinal glands located?

plicae curculares

circular folds of mucosa in small intestinal wall, which also increase surface area

mucus, watery fluid, enzymes, chemical messengers, antimicrobial substances

What are the 5 secretions of the small intestine?

mucus

secreted by goblet cells and by specialized Brunner’s glands; secreted in response to stimuli

watery fluid

secreted by intestinal glands; picks up digestion products and transports them into villi; doesn’t contain digestive enzymes

1. peptidases

2. sucrase, maltase, lactase

3. lipase

What enzymes do the small intestine secrete? (5) from the membranes of microvilli

1. mucus secretions increase in response to mechanical stimulation and presence of irritants

2. distention of intestinal wall triggers release of secretions

How is the small intestinal secretions regulated? (2 ways)

1. monosaccharides

2. amino acids

3. fatty acids & glycerol

4. electrolytes

5. water

What kinds of nutrients are absorbed in the small intestine? (5)

1. (most) resynthesized into triglycerides & incorporated into chylomicrons (lymph)

2. relatively short ones are absorbed into blood capillaries

What are the 2 ways that fatty acids are diffused back into body?

1. fatty acids resulting from triglyceride digestion enter epithelial cell

2. fatty acids are used to synthesize triglycerides in endoplasmic reticulum

3. triglycerides collect in clusters encased in protein to form chylomicrons

4. chylomicrons leave epithelial cell and enter lacteal

5. lymph in lacteal transports chylomicrons away from intestine

What are the 5 steps of triglyceride absorption?

peristalsis

wave-like movements that propel chyme in proper direction down the small intestine

segmentation

ring-like contractions that move chyme back and forth (mixing movements); place chyme in contact with digestive enzymes in brush order and aids in absorption

parasympathetic impulses

stimulate both mixing and peristaltic movements, and sympathetic impulses inhibit them

sweeping of contents quickly into large intestine after small intestine becomes over distended or irritated, resulting in diarrhea

ileocecal sphincter

joins ileum of small intestine to cecum of large intestine and helps regulate flow of chyme

large intestine

opens to outside of body through anus at distal end; absorbs some water and electrolytes; forms and stores feces

cecum

pouch that forms beginning of large intestine; attached to appendix

colon

ascending, transverse, descending, and sigmoid portions; contains hepatic and splenic flexures

rectum

extends from sigmoid colon to anal canal; lies next to sacrum

anal canal

last portion of large intestine; opens to outside as anus; internal and external anal sphincters guard anus

internal sphincter

anal sphincter with involuntary control

external sphincter

anal sphincter with voluntary control

taenia

muscle of large intestine

haustra

pouches of large intestine

1. little to no digestive function

2. absorbs water

3. houses intestinal flora

4. forms and excretes feces

functions of the large intestine (4)

similar to, but slower and less frequent than small

how does the movements of the large intestine compare to movements of the small?

mass movements

movement of the large intestine that is peristaltic waves 2-3 times a day, usually following meals

defecation reflex

pooping