theresa maurer Flashcards
(51 cards)
All or none, recruitmen, motor units
All or none says a fiber fires or does not fire, motor units are responsible for a certain number of fibers that allow for bigger or small muscle movements. This creates gradation. When a bigger muscle movement is needed the motor units “recruit” other motor units to create the movement needed. Smaller movements less motor units are used
Motor unit
motor neuron and the fibers it controls
sliding filament theory
A bands-thick filaments myosin with microbridges small overlap of thin actin myofilaments
I bands- thin filaments inside Z line
I bands shortens
the myosin latch into the actin by microbridges and rachet to shorten and contract the muscle.
distinguish between non cardiac muscles
skeletal muscle- striated, vascularized, multinuclea, body movement, voluntary, very organized
smooth muscle- internal cover organs, involuntary, less organized
4 ways a target cell responds to hormone
changes cell division rate
changes permeability
changes protein activity
starts, stops or turns off
how are calcium blood levels regulated
thyroid hormone releases calcitonin when there is too much calcium in the blood and tells bones to absorb excess.
When there is not enough calcium in the blood the parathyroid releases parathyroid hormone PTH and tells the bone to release calcium, the kidneys to recover calcium and the GI tract to acquire more.
how are glucose levels regulated
too much glucose the Beta cells in the pancreas are prompted to make insulin to absorb excess glucose by and tell the liver to store it.
too little glucose the Alpha cells make glucagon and tells the liver to release glucose.
general mode of action of endocrine
Initial prompt- from nervous system(adrenal), cycle (reproductive), directly detecting chemical/hormone
gland releases staged hormone into blood stream goes to body
finds target cells in tissues and moves from blood to tissues
target cell changes- 4 ways
electrical synapse
2 cells are fused so EI passed directly through and the next cell always fires!
chemical synapse
Prompt EI
arrives at presynaptic membrane
neurotransmitters released to the synaptic cleft
receptors from the post synaptic cleft picks up the neurotransmitters and is
“influenced” whether or not to fire.
anterior pituitary location and hormone
grainy layer ACTH- adrenocorticotropic hormone- stimulates cortex of the adreno TSH Growth hormone FSH/LH -testes and ovaries prolactic All All The Fat guys like prolactin
posterior pituitary
oxytocin, ADH
located behind the nose in the brain in optic chasm
thyroid
thyroxin- increase metab
calcitonin- to reduce calcium levels
perifollicular cells make calcitonin and is stored as colloid in follicles
parathyroid
secretes Parathyroid hormone that increases calcium in the blood
tells bones to release calcium
tells kidneys to recover calcium
tells GI increase absorption of it
goiter
diseased thyroid too much colloid-enlarged
pineal
on cerebellum on back of 3rd ventricle
melatonin= regulates sleep
adrenal
zona glomerulosa
aldosterone- stabilized bp targets the kidneys- increase blood, hydration, solutes cortex
zona fasculata- cortisol, corticosterone, physio stress long term, anti-inflammatory
zona reticularis- androgen, estrogen, sex hormones, puberty
thymus
immunity- trains lymphocytes, Tcell maturation, tumor growth
neuron
basic functional unit
axon
takes info away
dendrites
take info somewhere else short and many
central nervous sysem CNS
brain, spinal cord
peripheral nervous system
sensory receptors and nerves
nerve
bundle of nerve fibers and connects to CNS, muscles, glands, packaged to go somewhere in the body
