science B3 Flashcards
what are enzymes? (or what do they do)
chemically digests large starch molecules into smaller sugar molecules. (found in saliva)… Enzymes are biological molecules (typically proteins) that significantly speed up the rate of virtually all of the chemical reactions that take place within cells. They are vital for life and serve a wide range of important functions in the body, such as aiding in digestion and metabolism
Chemical digestion
the breakdown of large particles into
smaller particles by substances called enzymes
Mechanical digestion
physical breakdown of food into very small pieces
digestive system
is in charge of breaking down the food you eat into parts small enough to be used by your cells. OR Digestion is the breakdown of food into small molecules, which are then absorbed into the body
peristalsis
a wave of motion caused by contraction and relaxation of muscle tissue. (Such as in the esophagus.)
epiglottis
As you swallow, a flap of skin called the epiglottis moves across your windpipe, and food is funneled into the esophagus.
esophagus
the stretchy tube that food travels down from the back of the throat to the stomach.
stomach
stores food that arrives from the esophagus. breaks down the food with acid and physical churning. empties into small intestine.
Gastric Juice
is made of mucus, hydrochloric acid and enzymes
to chemically break down food.
villi
small, finger‐like projections that increase
the surface area (in the small intestine) to aid in absorbing nutrients. (nutrients are absorbed into the bloodstream by special structures called villi)
microvilli
The cells of the epithelial tissue have modified cell membranes that form more finger‐like projections called microvilli. Microvilli further increase the surface area of the
small intestine to help absorb nutrients. (located on the outside of the villi)
small intestine
breaks down food into even smaller parts using enzymes from the pancreas and bile from the liver. most nutrients are absorbed here
large intestine
removes waste from the small intestine. It absorbs any remaining water. transmits waste for eliminations. removes solid waste in ES
excretion
the job of waste removal in ES
excretory system
different organ systems interact to get rid of wastes.
urea
the body’s breakdown of proteins and ammonia. It can also be chemically composed into a liquid or a solid using ammonia and carbon dioxide.
liver in ES
takes the highly toxic ammonia produced by the body’s
cells out of the bloodstream and converts it into a less
harmful substance called urea
kidney in ES
are the main organs of excretion
they act as filters to the blood, straining out the unwanted
urea, water, and other salts, and they produce urine.
the skin in es
the skin functions by eliminating excess water and salt through sweat glands
sweat glands
in addition to producing sweat to keep you cool, these glands remove excess salt from your blood.
formation of urine
- Blood enters the kidney by the renal artery. 2. The artery branches into smaller and smaller vessels.
- These capillaries enter filtering units called nephrons.
- These microscopic nephron units remove wastes from the blood and produce urine.
- The “clean” filtered blood returns to the body through the renal vein. 6. The urine flows out a separate vessel and into the ureter to leave the body.
nephrons
nephron units remove wastes and produce urine.
Ureters
Ureters are long tubes that connect the kidneys to the
bladder.
urethra
When bladder is full, the bladder
muscles contract and push the
urine out through the urethra.
