digestive system

digestive tract

tubular path that extends through the body from the lips of the mouth to anos where food travels

digestive glands

located outside walls of the digestive tract and secrete chemical enzymes of digestion and emulsifying salts into the lumen

mouth

site of mechanical and chemical digestion, begins digestion by chewing and mixing with saliva

esophagus

transports

stomach

site of chemical digestion and absorption (digests proteins, fats, carbohydrates; absorbs nutrients and water)

large intestine

absorbs water and forms feces; contains symbiotic bacteria

appendix

contains immune tissue; harbors symbiotic bacteria

anus

eliminates feces

pancreas

secretes enzymes and other materials into small intestine

gallbladder

stores secretions from liver; empties into small intestine

liver

secretes molecules that aid in fat digestion

salivary glands

secrete enzymes that digest carbohydrates; supplying lubricating mucus

tongue

moves food, connects to floor of mouth via fernulum

fernulum

tongue

palate

forms roof of oral cavity

uvula

back of the mouth, closes so that food doesnt go up to nasal region

amylase

enzyme that breaks down starch into sugars

bicuspids + 1st, 2nd, 3rd molars

crushing and grinding food

incisors

slicing and cutting food

cuspids

tearing food

pharynx

throat

esophageal hiatus

where it penetrates the diaphragm

cardiac esophageal

sphincter at entrance to stomach

peristalsis

pushes food down the tube by using contractions

mucus

prevents stomach from digesting itself

pepsin

digestive enzyme for breaking down food

chyme

paste released then into the duodenum

rugae

wrinkles within the lining

acid reflux

occurs when stomach acid splashes back into the esophagus, causing a burning sensation

small intestine function

absorption of nutrients

mesentery

supports coils of small intestine and contains blood vessels, keeps abdominal organs in place

villi

finger-like projections covered in microvilli vastly increase the surface area available for absorption

cecum

start of large intestine, has an attached appendix

colon

4 section, ascending, transverse, descending, sigmoid

rectum

stores waste before it is expelled from the body

anus

muscular sphincter which controls the exit of waste

mass movements (defacation)

removes undigested food

large intestine function

main job is water reabsorption

kidneys

filters blood and produce urine

ureters

transport urine from the kidneys to the bladder

urinary bladder

stores urine

urethra

transports urine outside the body

renal medulla

inner area

renal cortex

outer shell

diffusion

removes substances from the blood and collects into a filtrate

renal pyramids

each kidney has 7-18 containing thousands of nephrons

nephrons

filtering units

detrusor muscle

forms the bladder walls to allow distension, when the muscle contracts it compresses the urinary bladder and expels urine into the urethra

trigone

at its base is formed by the entry of the ureters and the internal urethral orifice