Anatomy and Physiology Chpt 17+20

What are the main functions of the digestive system?

Ingest food, breaks it down my mechanical and chemical digestion, absorbs nutrients, and defecate unabsorbed materials

Between which two locations does the alimentary canal extend?

Mouth to anus

Which organs of the digestive system are not part of the gastrointestinal tract/alimentary

canal?

Salivary glands, liver, gallbladder, and pancreas

What is the difference between the digestive tract, gastrointestinal tract, GI tract, and the

alimentary canal?

Nothing they all mean the same thing

What is the correct sequence for the layers in the walls of the alimentary canal from

innermost to outermost?

Mucosa, Submucosa, Muscularis, Serosa

What is the outermost layer of the intestinal wall?

Serosa

Which layer of the alimentary canal wall absorbs nutrients

Mucosa

What is the major mixing movement of the small intestine?

Segmentation

What is peristalsis?

Squeezing motion that moves material forward

Where does peristalsis occur in the digestive tract?

The entire alimentary canal, from pharynx to anus

Which branch of the autonomic nervous system innervates the organs of the alimentary

canal?

Parasympathetic and the sympathetic nervous system

Which division of the nervous system increases activity in the digestive system?

Parasympathetic

Which branch of the autonomic nervous system increases movement in the small intestine?

Which branch decreases its movement?

Parasympathetic

Sympathetic

What is the technical term for mechanical breakup of food particles in the mouth?

Mastication

What chamber is located between the tongue and palate?

Oral cavity

Where is the vestibule of the mouth?

Between the gingiva and the lips/cheeks

What is the lingual frenulum?

connects tongue to floor of mouth

What is the uvula? What does it block during swallowing?

A projection of the soft palate

blocks the nasopharynx

Where are the palatine tonsils located? Which body processes might the palatine tonsils

interfere with if they are swollen?

They are on either side of the tongue on the back of the mouth

breathing and swallowing

How many primary teeth are there? How many secondary teeth?

20

32

What teeth are best adapted for biting off chunks of food?

Incisors

What is found in the root canal of a tooth?

Blood vessels and nerves

Why do bacteria in the mouth cause cavities (caries)?

Metabolizes carbohydrates in food producing acidic by-products that damage enamel and dentin

What are the functions of saliva?

Moisten food, ease swallowing, dissolves food, and begins the chemical digestion of carbohydrates

Which enzyme of the mouth breaks down starch into sugar?

Salivary amylase

Which enzyme is secreted by salivary glands? Which nutrient does it break down?

Amylase

Carbohydrates

How can the sight or smell of food affect salivation?

Triggers the parasympathetic NS to stimulate the release large amounts of watery saliva

Which salivary glands are the largest

Parotid

Where is the parotid gland located? What is its function?

Sides of the mouth

Secrete saliva

How is the secretion of the parotid gland different from that of the submandibular and

sublingual glands?

The parotid secretes watery saliva rich in salivary amylase and the other ones have thick mucus

What are the three parts of the pharynx from superior to inferior?

Nasopharynx, oropharynx, laryngopharynx

Which actions of swallowing are voluntary?

tongue rolls food into a bolus and pushes bolus into oropharynx

Why is it possible to swallow when upside down?

There is no gravity pushing the food down mouth

Describe the passageway created by the esophagus

Connect the pharynx to the stomach

What is the epiglottis attached to? What is its function?

Pharynx

create a passage for the food when you swallow

Where would a hiatal hernia occur?

Diaphragm

Describe the shape of the stomach.

J shaped pouch

Which two organs are connected to each other by the stomach?

Esophagus and duodenum

What are the four parts of the stomach? Which of these is the main part of the stomach?

Cadia, fundus, body, and pylorus

Body

What is the pyloric sphincter?

A valve that controls movement of chyme from stomach to duodenum

Which type of cell in the gastric glands would be affected by a drug that prevents the

secretion of the protective inner coating of the stomach?

Mucus

Mucus neck cells

What do parietal cells secrete? Which enzyme is activated by this secretion?

Hydrochloric acid

pepsin

If the stomach does not secrete enough HCl, which nutrient digestion is most affected?

Proteins

What is gastric juice composed of?

Pepsin, hydrochloric acid, mucus, and intrinsic factor

Which vitamin deficiency can be caused by lack of intrinsic factor?

B12

What is the function of gastrin?

Increase gastric juice secretion by gastric glands

What stimulates the secretion of cholecystokinin?

Proteins and fat enter the small intestine

What is the enterogastric reflex?

Stretching of the small intestine which sends a signal to the stomach to decrease peristalsis

What causes heartburn?

Gastric juice in the esophagus

What causes peptic ulcers?

Bacterial infections

Which accessory organ is attached to the duodenum and secretes fluid rich in digestive

enzymes?

Pancreas

Which cells of the pancreas secrete pancreatic juice?

Pancreatic acinar cells

How are all protein digesting enzymes secreted

In their inactive forms

Which protein-digesting enzyme is in pancreatic juice?

Trypsin

What often causes acute pancreatitis?

Conversion of trypsinogen to trypsin within the pancreas

What is the action of the hormone secretin?

stimulates the release of pancreatic juice

What is the function of secretin? When is it released?

release pancreatic juice high in bicarbonate ions to neutralize stomach acid

When acid chyme enters the duodenum

What regulates the secretion of digestive enzymes of the pancreas?

Cholecystokinin

Of all the many, many functions of the liver, which serves a role in digestion?

Secretes bile

How is hepatitis B transmitted?

By body fluids and sexual activity

How is hepatitis C transmitted?

blood contact

What is bile? Where is it produced? Where is it stored? What stimulates its secretion?

A yellowish-green liquid that emulsifies fat to aid digestion

The liver

Cholecystokinin

What are the constituents of bile? Which of these has a digestive function?

Water, bile salts, bile pigments, cholesterol, eletrolytes

Bile salts

If the liver was damaged which nutrient’s digestion would be most affected? Why

Lipids because bile is not secreted

What causes the yellowish tint of jaundice?

bile pigments

Which duct connects the gallbladder to the bile duct?

Cystic duct

Which larger duct forms from the union of the common hepatic duct and cystic duct?

Common bile duct

What is the usual cause of gallstones?

Bile becomes too concentrated

What is the major component of gallstones?

Cholesterol

What is the action of cholecystokinin on the gallbladder?

Causes the gall bladder to contract and release bile into the duodenum

What is the function of bile salts?

to emulsify lipids (separate large fat globules into small droplets

After leaving the stomach, what is the order food passes through the sections of the small

intestine?

Duodenum, jejunum, ilium

Which part of the digestive tract has the most lymph nodules and bacteria?

ileum

Which membrane composes the greater omentum?

peritoneal

Which body fluid transports most nutrients away from the intestine? Which body fluid

transports fat molecules away from the intestine?

blood

lymph

Describe the lifespan of epithelial cells lining the small intestine

They divide and are replaced every few days

What is a brush border enzyme?

one that completes final stages of digestion on the outer membrane of the intestinal cells

What occurs when nutrients are digested properly, but are not taken into the body and

intestinal blood supply?

malabsorption

In protein digestion, which enzyme breaks the last peptide bond between two amino acids?

dipeptidase

What suffix do most enzymes end with?

-ase

Where are nucleic acids chemically digested?

the small intestine

What is the sequence for the digestion and absorption of lipids?

Emulsification by bile, hydrolysis by pancreatic lipase, diffusion into intestinal epithelial cells, formation of chylomicrons, movement into lacteal ducts of lymphatic system

Where do chylomicrons in the blood transport dietary fats

to muscle and adipose cells

What is VLDL? Which organ produces VLDL

a lipoprotein that carries synthesized fats to adipose cells

liver

Which type of lipoprotein is removed from blood plasma by peripheral tissue cells using

receptor-mediated endocytosis?

LDL

What lipoprotein picks up cholesterol from the peripheral tissues and returns it to the liver?

HDL

What is stimulated by overdistention of the small intestine wall?

peristaltic rush

Where is the cecum located?

At the inferior end of the ascending colon

Which anal sphincter muscle is involuntary vs voluntary?

the internal sphincter is involuntary, the external sphincter is voluntary

What are enlarged blood vessels of the anal columns called

Hemorrhoids

How does the mucosa of the large intestine differ from the mucosa of the small intestine?

Large intestine does not have microvilli or villi, has more goblet cells that secret mucous, does not have circular golds

What are the functions of the large intestine?

Absorbs ingested water, four vitamins made by bacteria, and electrolytes

Which food molecules does the large intestine digest and absorb?

None

What chronic symptom occurs when the large intestine does not function properly?

Chronic diarrhea

Which vitamins are synthesized by bacteria in the large intestine and absorbed into the

blood?

Vitamin K, B12, thiamine, and riboflavin

What must occur during the defecation reflex?

Diaphragm lowers, abdominal wall muscles contract, internal abdominal pressure increases

About how much of feces is made up of water?

75%

What changes occur in the teeth with age?

shirinking gums, thinning enamel, thickening cementum, enlarging dentin, loosening

What is xerostomia? Why is it more common with age?

dry mouth

a side effect of many drugs taken by older persons

What happens to peristalsis in the elderly?

it slows