Digestive System Chapter 23

what is the digestive system responsible for?

processing food, absorbing nutrients, and eliminating waste.

what do carbohydrates for the body?

provide energy

what is protein essential for?

tissue repair and growth

what are fats important for in the body?

energy storage and cell membrane structure

What are vitamins and minerals required for in the body

various biochemical processes and overall health.

what is water critical for in the body?

every cellular process

Mechanical digestion involves the ______

physical breakdown of food

Chemical digestion involves _____ ______ that breakdown macromolecules

enzymatic reactions

what does chemical digestion turn carbohydrates into?

simple sugars

what does chemical digestion turn proteins into?

amino acids

what does chemical digestion turn fats into?

fatty acids and glycerol

what does chemical digestion turn mucleic acids into?

nucleotides

incisors are for _____

cutting food

canines are for____ ____

tearing food

molars are for _____ _____

grinding food

adults have how many teeth

32

what is stage one of digestion?

ingestion

what is stage two of digestion?

physical digestion (chewing)

what is stage three of digestion?

chemical digestion

whgat is stage four of digestion?

absorption of nutrients into the bloodstream

what is stage five of digestion?

elimination

the small intestine is responsible for majority of ______ _______ and ______ ______

chemical digestion; nutrient absorption

what are the intrinsic salivary glands?

lingual, labial, and buccal glands

what are the extrinsic salivary glands?

parotid, submandibular, and sublingual glands

Cholecystokinin increase _____ secretion when _____ arrive in the duodenum

enzyme; fats

Secretin stimulates ______ ______ secretion in response to acidic chyme

sodium bicarbonate

Acetylcholine stimulates secretion of _____ ______

digestive enzymes

Gallstones are _____ _____ in the gallbladder that can ______ _____ ______

hard masses: obstruct bile ducts

caused by a decline in lactase production leading to undigested lactose in the large intestine

Lactose intolerance

state the four tissue layers of the digestive tract from inner to outer

Mucosa , submucosa, muscularis, serosa

passage for food and air and connect the mouth to the esophagus

pharynx

The movement is primarily facilitated by muscular contractions of the pharyngeal walls, which push food toward the esophagus.

swallowing

musclular tube that transports food from the pharynx to the stomach

esophagus

wave like muscle contractions to push food toward stomach

peristalsis

A mass of chewed food that has been mixed with saliva in the mouth

bolus

Semi-fluid mass of partially digested food that is produced

chyme

What is the pH range of the stomach?

1.5 to 3.5

what is the acid produced by the stomach?

hydrochloric acid

why doesnt the acid in the stomach destroy the stomach wall?

is it lined with a thick layer of mucus

why does GERD occur?

the lower esophageal sphincter does not close properly allowing acid to escape

what is GERD?

where stomach acid or bile flows back into the esophagus irritating the lining

Esophageal stricture

narrowing of the esophagus due to scar tissue formation

What are gastric ulers?

sores that develop on the liming of the stomach due to erosion caused by stomach acid

what is the enzyme present in the stomach?

pepsin

The stomach primarily chemically digests

proteins

Produces hydrochloric acid and intrinsic factor, which is necessary for vitamin B12 absorption

parietal cells

Produces pepsinogen, which is activated into pepsin in the acidic environment of the stomach

chief cells

First part of the small intestine where most chemical digestion occurs

duodenum

middle part of the small intestine where nutrient absorption occurs

jejunum

last part of the small intestine where remaining nutrients are absorbed

ileum

near the esophagus

cardiac region

storage area for food

fundic region

main part for digestion

body

connects to the duodenum

pyloric region

folds in the stomach lining that allow for expansion and increase surface area for digestion

rugae

Digestive enzyme in the small intestine that breaks down carbohydrates

amylase

Digestive enzyme in the small intestine that breaks down proteins

proteases

Digestive enzyme in the small intestine that breaks down fats

lipase

Finger-like projections in the small intestine that increase surface area for absorption.

villi

Smaller projections on the surface of epithelial cells in the villi, further increasing absorption surface area.

microvilli