Ch 12 Human Physiology Flashcards
two functions of digestive system
breaking down large molecules of food and absorbing smaller molecules
fats get digested into ___ and ____
glycerol and fatty acids
starch gets digested into ______ and _____
monosaccharides ad thats it
vitamins are digested into _____ and ______
ridiculous question, they are small enough to go by without being digested
peristalsis
process that pushes food along digestive tract
muscles of digestive tract are controlled by _____ nervous system
autonomic
salivary amylase
enzyme in saliva, begins STARCH digestion
where does mechanical digestion occur
mouth
where does chemical digestion occur
mouth
what digestion occurs in esophagus
none
epiglottis
flap of cartilage in back of throat (pharynx)
what kind of digestion occurs in stomach
mechanical and chemical
digestion of _____ begin in stomach
proteins
mechanical digestion in stomach?
done by churning of its thick muscular walls
pepsinogen
activated by hydrochloric acid and digests proteins in stomach
cause of ulcers? treatable?
bacterium Heliobacter pylori; yes
pH of small intenstine
6-8
duodenum
first 10 inches of small intestine, completes all digestion.
enzymes in small intestine
amylases, proteases, lipases, nucleases.
villi
millions of fingerlike projections from small itestine, absorb all nutrients previously released from digested food.
structure of villus
contains capillaries which absorb amino acids, vitamins, and monosaccharides directly into bloodstream. Lacteal absorbs fatty acids and glycerol into lymp system
kidneys produce ____ that emulsify _____
bile; fats
pH of bile
11
role of bile
neutralize acidified food from the stomach in small intestine
gallbladder
keeps bile from lover until released into small intestine. body does not actually need it
other functions of liver
breaks down red blood cells, detoxifies blood, produces cholesterol for cell membranes, produces urea
pancreas
secretes peptidases into small instestines; protein digesting
what kind of digestion occurs in large intestine
none
3 functions of large intestine
egestion, vitamin production, reabsorption of water
egestion
removal of undigested waste
constipation
too much water is reabsorbed from intestine into body
diarrhea
not enough water is reabsorbed into body
rectum
egestion - removal of undigested waste
where does diffusion of gas occur
alveoli
what happens when rib cage expands
forces diaphragm to contract, move down; expands chest cavity and decreases internal pressure
why is air drawn into lungs
negative pressure - air inside the chest cavity is lower than air pressure surrounding the body
medulla
in brain, sets breathing rhythm by monitoring CO2 levels in blood and sensing pH
hemoglobin
carries oxygen; combines to form oxyhemoglobin
carbonic acid-bicarbonate ion system
maintains the blood at a constant pH of 7.4
plasma
liquid matrix in blood that suspends several cell types. 90% water
____ is necessary for normal blood clotting
calcium
pathway of normal blood clotting
thromboplastin + Ca++ stimulates prothrombin (inactive) to thrombin (active) which stimulates fibrinogen (inactive) to fibrin (active) which does the clotting.
erythrocytes
red blood cells; carry hemoglobin and oxygen, no nucleus, formed in bone marrow
leukocytes
white blood cells, fight infection, formed in bone marrow
trombocytes
platelets, clot blood, cell fragments
SA Node
sinoatrial node, heart’s pacemaker, sets the timings of the contraction of the heart.
factors that influence the hearts pacemaker
nervous system, hormones, and body temperature
average blood pressure
120/80
systolic nuymber
number on top, measurement of pressure when ventricles contract
diastolic number
number on bottom, measurement of pressure when the heart relaxes
pathway of blood starting from right atrium go!
RA, RV, pulmonary artery, lungs, pulmonary vein, LA, LV, aorta, body cells, vena cava
pulmonary artery carries _______ blood, and pulmonary vein carries ______ blood
deoxygenated, oxygenated
two systems that work together to maintain homeostasis
endocrine and nervous
endocrine system secretes ____, nervous secretes
hormones; neurotransmitters
ductless glands
produce hormones
short lived response EX
adrenaline causing fight or flight response
long term response EX
edcysone controls metamorphosis in insects
tropic hormones
stimulate other glands to release hormones; far reaching effect
hypothalamus
in brain; bridge between the endocrine and nervous systems
hypothalamus role in nervous system
sends electrical signals to adrenal gland to release adrenaline
hypothalamus role in endocrine
produces oxytocin and antidiuretic hormones thats stored in posterior pituitary
other roles of hypothalamus
thermostat and hunger/thirst regulator
hormones in anterior pituitary
growth, luteinizing, thyroid stimulating, follice stimulating
hormones in posterior pituitary
oxytocin and ADH
wtf are pituitaries
different glands that secrete hormones
two types of hormoes
steroid and nonsteroidal
steroid hormones
lipid, diffuse directly through plasma membrane and bind to receptor inside cell that triggers response
non steroidal hormones
protein; cannot dissolve in membrane, so they bind to receptor on surface, triggers secondary messenger (like c AMP)
positive feedback
enhances an already existing response. like childbirth contraction pressure stimulating more contractions.
negative feedback
maintains homeostasis, when something too low, it gets higher and vice versa
central nervous system consists of ____ and ___
brain and spinal cord
peripheral nervous system consists of ______
all nerves outside central system
somatic system
part of peripheral nervous system and controls the voluntary muscles
aotonomic system
part of the peripheral nervous system and controls the involuntary muscles
sensory
conveys info from sensory receptors or nerve endings
motor
stimulates voluntary and involuntary muscles. consist of somatic and autonomic systems
neuron
basic unit of nervous system. has two cytoplasmic extensions: dendrite and axons
dendrites
sensory, 100s can be in neuron
axons
transmit impulse from cell body to another cell. only one per neuron.
reflex arc
simplest nerve response. knee jerk reflex.
neuron at resting potential
its polarized, membrane potential of -70 mV. maintained by sodium potassium pump.
the larger the membrane potential, the _____ the stimulus must be to cause the nerve to fire
stronger
action potential
impulse, can only be generated in the axon when it overcomes the threshold. sodium channels open, floods into cell, potassium out of cell,
wave of depolarization
rapid movement of sodium ions in to cell and potassium ions out of cell
repolarization
sodium pump restores membrane to original position. causes refractory period
refractory period
when graph of neuron dips below resting potential; neuron can’t respond to another stimulus.
impulse travels along axon ______, it crosses a synapse ________ through the use of ______
electrically, chemically, neurotransmitters
cones
photoreceptors in retina that distinguish colors
cornea
tough and clear; protects the eye
humor
fluids that maintain eye’s shape
iris
colored part of eye, controls how much light gets in
lens
focuses light on retina
retina
converts light into nerve impulses to brain
rods
very sensistive photoreceptors, but no color distinction
auditory canal
ear canal where sound enters
cochlea
fluid filled art of inner ear, sends nerve impulses to brain
ear bones
hammer, anvil, and strrup. transmit vibrations from eardrum to oval window
eustachian tube
equalizes pressure between environment and inner ear
oval window
sends waves of pressure to cochlea
semicircular canals
fluid filled, helps maintain balance
tympanum
ear drum, vibrates as sound hits it
excretion
removal of metabolic wastes; skin, lunds, liver, and kineys are organs involved
renal artery
supplies blood to kidney to filter
antidiuretic hormone
released by posterior pituitary, targets collecting tube of nephron. regulates blood pressure by controlling how much water is reabsorbed by the kidneys.
nephron
basic funcitonal unit of kidney. consists of glomerulus, bowmans capsule, tubule, and loop of henle.
four steps of nephron
filtration, secretion, reabsorption, and excretion
glomerulus
sluster of capillaries in nephron that sits inside bowmans capsule
bowmans capsule
contains glomerulus
tubule
long narrow tube in nephron
filtration (kidney)
occurs by diffusion, passive and nonselective. filtrate goes into bowmans capsule, goes through loop of henle, and then collecting duct. trickles to ureter, urethra, and out of body
secretion (kidney)
active, selective uptake of molecules that didnt get filtered into bowmans capsule.
reabsorption (kidney)
water and solutes that initially entered tubule during filtration are transported back into body
excretion (kidney)
removal of metabolic wastes.
smooth muscle
involuntary, walls of blood vessels, and digestive tract. not striated. autonomic
cardiac muscle
found in heart, not striated, generates its own action potential (will beat even outside body).
skeletal muscles
voluntary. large. work in pairs
sliding filament theory
how muscles work; actin and myosin proteins
