saliva - makes food wet and soft; starts breaking down food
tongue - manipulates food during chewing - rolls food into a ball and passes it down your throat
What does the esophagus do?
it's a muscular tube located behind the trachea which conducts food from pharynx to stomach
squeezes the ball of food down to the stomach in a synchronized wave of contractions called peristalsis
What does the stomach do?
produces hydrochloric acid and more enzymes to break down food
mashes and mixes food into a fine, runny paste
a ring-shaped muscle called the pyloric sphincter at the bottom of the stomach opens and closes to allow small amounts of food into the small intestine
What does the small intestine do?
18-20 ft long muscular tube lined with tiny hairlike projections called villi
absorbs the tiny particles of nutrients from food and passes them into the bloodstream
the liver and pancreas produce juices that help with digestion in the small intestine
What does the large intestine do (also called the colon)
shorter and wider than the small intestine
shaped like an upside-down U
where the small and large intestines meet, a finger-shaped pouch protrudes, called the appendix
the large intestine absorbs water from digested food into the bloodstream; only indigestible solids are left
the last part of the colon is called the rectum; it holds solid waste until it is pushed out through the anus
What do the kidneys do?
filters waste from blood
concentrates or dilutes the blood to keep it the right consistency
produces urine, about 16 cups a day
controls blood pressure
What do the ureters do?
transports urine from kidneys to bladder by peristalsis
What does the bladder do?
collects urine
can hold about 2 cups of urine for 2.5 hours
What does the urethra do?
lets out urine from bladder
What are some disorders/disease of the urinary system?
infection of the bladder or kidneys
cancer
kidney stones - when minerals in the urine crystalize inside the kidney and then work their way out
gout - crystals of uric acid form in the bloodstream and can lodge in the feet