TEAS 7 (Digestive Sys)

mouth

the first organ of digestion, where food is chewed and mixed with saliva to begin carb digestion

salivary glands

produce saliva containing amylase to begin breaking down carbs

saliva

a fluid that moistens food and contains amylase, the enzyme that starts carb digestion

amylase

an enzyme that breaks down carbohydrates into simpler sugars

bolus

a small ball of chewed food mixed with saliva that is swallowed

pharynx

the throat; passageway that moves food from the mouth to the esophagus

epiglottis

flap of cartilage that closes over the trachea during swallowing to prevent food from entering the airway

esophagus

a muscular tube that transports food from the throat to the stomach by peristalsis

peristalsis

wave-like muscle contractions that move food through the digestive tract

lower esophageal sphincter

a ring of muscle that prevents stomach acid from flowing back into the esophagus

stomach

organ that stores food, mixes it with acid and enzymes and begins protein digestion

hydrochloric acid (HCl)

acid in stomach that activates pepsin and helps kill bacteria

pepsin

an enzyme in the stomach that begins the digestion of proteins

chyme

semi-liquid mixture of partially digested food and stomach juices that leaves the stomach

liver

largest organ that prod. bile, detoxifies blood, stores glycogen, and processes nutrients

bile

a digestive fluid produced by the liver that emulsifies fats to aid digestion

gallbladder

organ beneath liver that stores and concentrates bile before releasing it into small intestine

pancreas

gland that produces digestive enzymes, bicarbonate, insulin, and glucagon

bicarbonate

substance released by the pancreas that neutralizes acidic chyme entering the small intestine

small intestine

primary site of digestion and nutrient absorption

duodenum

first section of the small intestine; where chyme mixes with bile and pancreatic enzymes

jejunum

middle section of small intestine; where most nutrient absorption occurs

ileum

final section of the small intestine that absorbs vitamin B12, bile salts, and remaining nutrients

villi

tiny finger like projections lining the small intestine; increase surface area for nutrient absorption

microvilli

microscopic projections on villi that further increase the surface area for absorption

large intestine (colon)

portion of the digestive tract that absorbs water and electrolytes while forming feces

cecum

first part of the large intestine; where material enters from the small intestine

ascending colon

the section of the large intestine that travels upward along the ride side of the abdomen

• absorbs water and salts

• solidify waste into formed stool

transverse colon

the middle part of the large intestine; passing across the abdomen from right to left below the stomach

• storage site for digested food

• more absorption of water and salts

descending colon

the section of the large intestine; that travels downward along the left side of the abdomen

• carries solid waste toward the rectum

• more absorption of water and minerals

• store feces until defecation

sigmoid colon

the S-shaped portion of the large intestine that connects the descending colon to the rectum

rectum

final portion of the large intestine that stores feces before elimination

anus

opening at the end of the digestive tract where feces exit the body

lipase

enzyme that breaks down fats into fatty acids and glycerol

trypsin

a pancreatic enzyme that digests proteins in the small intestine

chemical digestion

breakdown of food using enzymes into molecules that can be absorbed

mechanical digestion

physical breakdown of food through chewing and stomach churning

carbohydrates

body’s primary source of energy, broken down by amylase into simple sugars

Proteins

nutrients made of amino acids that are digested by pepsin and trypsin

lipids (fats)

nutrients that provide long term energy and are emulsified by bile before being digested by lipase

insulin

hormone prod. by pancreas that lowers blood glucose by helping cells absorb glucose

glucagon

hormone prod. by the pancreas that raises blood glucose by stimulating glycogen breakdown

digestion

process of breaking down food into smaller molecules that the body can absorb and use

absorption

the movement of digested nutrients from the digestive tract into the bloodstream

emulsification

process in while bile breaks large fat droplets into smaller droplets, making them easier for lipase to digest

nutrient absorption

process by which digested nutrients pass through the walls of the small intestine into the bloodstream

feces

solid waste formed in large intestine after water has been absorbed

gastrin

found in the G cells of the stomach; stimulate gastric glands to secrete pepsinogen and HCl

cholecystokinin

found in the I cells of the duodenum and jejunum; digesting fats and proteins and stimulating the gallbladder to release bile

secretin

found in the S cells of the duodenum; regulates pH by inhibiting gastric acid secretion and stimulating bicarb production

pyloric sphincter

seperates the stomach from the small intestine

• control passage of partially digested food into small intestine

lower esophageal sphincter

separates the esophagus from the stomach

• open and allow foods into stomach and makes sure acid does not go up