Exam 3 review Flashcards
Define: responsiveness, conductivity, contractility, extensibility and elasticity. why are they signiificant?
begin e- signals. wave of e- signals. pull to create movement. stretch between contractions. recoil to beginning.
Define Nerve and Ganglion in PNS
Nerve: collection of nerve fibers (axons) Ganglion: collection of nerve bodies
what is the difference between the visceral and somatic divisions of the Sensory and Motor systems?
Visceral-Sensory: signals from viscera to brain. Visceral-Motor: signals from brain to viscera. Somatic Sensory: signals from skin, muscle, bone and joints to brain. Somatic-Motor: signals from brain to skin, muscle, bone and joint.
what is another name for visceral motor division? how is it divided?
ANS: sympathetic (fight or flight) parasympathetic (rest and digest)
Physiological characteristics of nerve cell (neuron)
excitability, conductivity and secretion
when a signal travels through the body, it travels through what THREE neurons?
sensory, inter- and motor
diameters of axons and somas
axons: 1-20 micrometers. Somas: 5-135 micrometers
fxn of nueroglia “oligodendrocytes”
myelinate axons only in CNS
fxn of ependymal cells
create CSF, appear to be epithelial cells only in CNF
fxn of microglia
only in CNF check brain tissue and consume foreign matter
fxn of astrocytes
Only in CNF many fxns of not already stated they do it
fxn of schwann cells
Only in PNS myelinate axons and regenerate nerve growth
fxn of satellite cells
provide e- insulation around somas
why are schwann cells and oligodendricytes necessary?
to increase rate of axn pot.
significance of Rita Levi-Montalcini
discovered Nerve Growth Factor which prevents apoptosis of growing nerves
GABA-ergic synapse
GABA is a NT that binds to ion channels (prompting changes in membrane potential) however, stimulates Cl- which LOWERS membrane potential. Inhibiting its ability to fire.
Cholinergic synapse
excitatory synapse using ACh as NT.
when Ulric decreases his appetite he is + what NT?
cholecystokin
when Ulric increases his endurance he is + what NT?
Beta-endorphin.
when feeling depressed, Ulric elevates his mood by + NT?
Dopamine
Ulric has a hard time controlling this homeostatic NT and this NT released by mast cells and basophiles
Serotonin and histamines
4 characteristics of Local potential
- graded 2. decremental- get weaker 3. reversible 4. either excitatory or inhibitory
what causes K+ to diffuse out of a resting cell? what attracts it into the cell?
K+ open more slowly than Na+. once rising pot hits peak K+ are repulsed by positive ICF and diffuse out.
what happens to Na+ when a neuron is +, why does movement of Na+ raise the voltage?
when neuron is + Na floods into cell quickly and increase in Na+ increases voltage
what makes and axn potential rasie to +35 mV? what makes it drop again?
increase of Na+. K+ leaving cell
what is RMP and what causes e- impulses in body?
resting membrane potential is -70mV and e- impulses are caused by the movement of Na+ and K+ through gated channels in plasma membrane
an example of IPSP is?
GABA ergic responces
an example of EPSP is?
Cholinergic synapses.
Temporal summation
one presynaptic neuron +ing quickly enough to induce a rxn
Spatial summation
several synapses add up to threshold at axon hillock
