Ch. 14 Digestive System Exam

Terms in this set (117)

breaking food into nutrient molecules

movement of nutrients into bloodstream

elimination of feces from the digestive tract through the anus (rid of waste)

alimentary canal (GI tract)

extends from mouth to anus

Accessory digestive organs

teeth, tongue, digestive organs (assist digestion)

Function of mouth

mastication, tongue initiates swallowing, and taste buds allow for taste

function of pharynx

passageway for foods, fluids, and air

Food passes posteriorly from the pharynx into the....

oropharynx and laryngopharynx

Function of esophagus

conducts food by peristalsis, passageway for food only

alternating contractions of the muscle layers

Function of the stomach

temporary storage of food, site of food breakdown, chemical breakdown of protein begins, delivers chyme to the small intestine

function of small intestine

nutrient absorption and chemical digestion

large intestine function

dries out the indigestible food residue by absorbing water and eliminating these residues as feces

opening for elimination of feces

What does the tongue do?

mixes food with saliva and initiates swallowing

lingual frenulum

anchors tongue to floor of mouth

What are the four layers of the alimentary canal?

mucosa, submucosa, muscularis externa, serosa

innermost moist membrane that is mostly simple columnar epithelium and has a scanty smooth muscle layer; lines LUMEN

soft connective tissue with blood vessels, nerve endings, lymphoid tissue, and lymphatic vessels

muscularis externa

smooth muscle; inner circular and outer longitudinal

outermost layer of the wall; contains fluid-producing cells

What are the sublayers of the serosa?

visceral and parietal peritoneum

visceral peritoneum

innermost layer that is continuous with the outermost layer

parietal peritoneum

the outer layer of the peritoneum that lines the interior of the abdominal wall

What are the two intrinsic nerve plexuses

submucosal and myenteric; they regulate mobility and secretory activity of the GI tract organs

cardioesophageal sphincter

where food enters the stomach from the esophagus

Pyloric sphincter

food empties into the small intestine at this location

cardia of stomach

body of stomach

pyloris of stomach

folds in the stomach that increase surface area

How does the stomach protect itself?

mucous cells produce alkaline mucus which protects wall from being damaged by acid and digestive enzymes

How does pepsinogen become pepsin?

When pepsinogen comes in contact with hydrochloric acid it breaks down into pepsin

helps with protein digestion

Where does protein digestion begin?

stomach (with pepsin)

regulates digestive activities of the stomach

Endocrine cells produce...

Stomach functions

food storage tank, site of food breakdown, chemical breakdown of protein begins, and delivers chyme to the small intestine

What are the three muscle layers of the stomach?

longitudinal, circular, oblique

Location from the pyloric sphincter to the ileocecal valve

small intestine

Subdivisions of small intestine

duodenum (5%), jejunum (35%), ileum (55%)

connective tissue that supports the small intestine and contains blood vessels to supply nutrients

What substance does the liver produce?

where is bile stores?

palatine tonsils

posterior end of oral cavity

lingual tonsils

hepatopancreatic ampulla

where the main pancreatic duct and bile ducts join;

Where do the liver, gallbladder, and pancreas release their secretions?

How does the small intestine increase surface area?

villi, microvilli, and circular folds

Finger-like extensions of the intestinal mucosa that increase the surface area

on top of the villi; tiny projections of plasma membrane (brush border enzymes)

deep folds of the mucosa and submucosa; less and less of these as you go through the small intestine

Peyer's patches

collections of lymphatic tissue; capture and destroy bacteria in submucosa

subdivisions of large intestine

cecum, appendix, ascending, transverse, descending, sigmoid (colon), rectum and anus

ascending colon

transverse colon

descending colon

external anal sphincter

skeletal muscle, voluntary

internal anal sphincter

smooth muscle, involuntary

accessory digestive organs

tongue, tonsils, teeth, liver, gallbladder, pancreas

How many permanent teeth are there?

incisors function

molars function

Two major regions of the tooth

process of chewing

visible part of tooth

enamel, dentin, pulp cavity, and root canal

hardest substance in the body; outer substance of the body

found deep to the enamel and forms the bulk of the tooth; surround pulp cavity

mixture of mucus and serous fluids

A soft mass of chewed food formed by saliva/mucus

salivary amylase

begins starch digestion

Where is the pancreas?

behind the stomach (posterior to peritoneum); extends across the abdomen from spleen to the duodenum

Functions of pancreas

produces insulin and glucagon; neutralizes acidic chyme coming from the abdomen

Largest gland in the body

What is the digestive role of the liver?

to produce bile

Where does bile leave the liver?

through the common hepatic duct and enters the duodenum through the bile duct

What do bile salts break down?

What happens when bile is in the gallbladder for too long?

the cholesterol it contains can crystalize and form gallstones

yellowing of the skin that occurs when bile is backed up in the liver and is in the bloodstream

chemical energy that drives cellular activities

substance used by the body for growth, maintenance, and repair

Major nutrients

carbohydrates, lipids, proteins, water

Minor nutrients

vitamins and minerals

fruits, vegetables, grains, dairy, protein

the starches and sugars present in foods; mostly derived from fruits and vegetables, lactose from milk and glycogens from meats

saturated fats from animal products

all of the chemical reactions necessary to maintain life

substances are BROKEN DOWN to simpler substances

larger molecules are built from smaller ones (proteins building up structures)

major breakdown product product of carbohydrate digestion; fuel used to make ATP

Cellular Respiration

as glucose is oxidized, carbon dioxide, water and ATP are formed

What are the steps of cellular respiration?

glycolysis, krebs cycle, electron transport chain

Occurs in cytosol; energizes a glucose molecule so it can be split into two pyruvic acid molecules and yield ATP

Krebs Cycle (Citric Acid Cycle)

occurs in mitochondria; produces all the carbon dioxide and water resulting from cellular respiration; yields a small amount of ATP

electron transport chain

hydrogen atoms are removed during glycolysis and krebs cycle and delivered to protein carriers; they are then split into hydrogen ions and electrons in the mitochondria; ELECTRONS give off tons of ATP

high blood sugar (glucose levels)

low blood sugar (glucose levels)

Functions of fat

insulate body, protect organs, build cell structures, and provide reserve energy

What role do fats have when carbohydrates are in limited supply?

Fats are oxidized to produce ATP

adidosis/ketoacidosis

when fat oxidation/breakdown causes the blood to become acidic (when too much fat is broken down); can be very dangerous

Aside from producing bile, what other digestive roles does the liver have?

detoxifies drugs and alcohol, degrades hormones, produces cholesterol

T o F; the liver can regenerate if part of it is damaged or removed

stores carbohydrates in the liver; glucose molecules are removed from blood and combined to form this

formation of glycogen from glucose

glucose is released from the liver after conversion from glycogen

Glyconeogenesis

making more glucose from fats and proteins

Is cholesterol used to make ATP?

functions of cholesterol

building block of plasma membranes; basis of steroid hormones and vitamin D

Most cholesterol in the body is...

manufactured by the liver

low-density lipoprotein (LDL)

"bad cholesterol"; transports cholesterol from the liver to the body tissues

High-density lipoprotein (HDL)

"good cholesterol" in the blood, which protects against cardiovascular disease

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