Phys Exam 2 Parrish Mizzou

hormones

what allows for endocrine signalling

neurons

what allows for electrical signalling

CNS and PNS

what are the two regions of the nervous system

CNS

brain and spinal cord

PNS

nerves leaving from CNS: cranial, thoracic, lumbar, and sacral nerves or sensory nerves leading to CNS

neurons and glial cells

what are the two cell types within the nervous system

neurons

conduct electrical signals but generally cannot divide

glial cells

support the neurons and can divide but cannot conduct electrical signals

cell body

contains nucleus and other organelles

nuclei

clusters of cell bodies in the CNS

ganglia

clusters of cell bodies in the PNS

dendrites

receive chemical signals and conduct a graded impulse twoard the cell body

axon

conducts action potentials away from the cell body towards the terminal

sensory neurons

conduct impulses from sensory receptors to the CNS (afferent)

motor neurons

conduct impules from the CNS to target organs (muscles or glands) (efferent)

somatic motor neurons

responsible for reflexes and voluntary control of skeletal muscles, selective

autonomic motor neurons

innervate involuntary targets such as smooth muscle, cardiac muscle, and glands

parasympathetic and sympathetic

what are the two divisions of the autonomic nervous system

sympathetic

emergency situations “fight or flight”

parasympathetic

normal functions, “rest and digest”

support and protect neurons

what is the role of glial cells

schwann cells and satellite cells

what are the two types of glial cells found in the PNS

schwann cells

form myelin sheaths around peripheral axons

satellite cells

support cell bodies of neurons in the PNS

oligodendrocytes, microlgia, astrocytes, ependymal cells

what are the 4 types of glial cells found in the CNS

oligodendrocytes

form myelin sheaths around the axons of CNS neurons

microglia

migrate around CNS tissue and phagocytize foreign and degenerated material

astrocytes

regulate the external environment of the neurons and though to help from synapses, support tight junctions

ependymal cells

line the ventricles and secrete cerebrospinal fluid

tight junctions

what joins adjacent cells in the capillaries in the brain

not leaky

what is the effect of tight junctions in the brain capillaries

transcellular

does the blood brain barrier require transcellular or paracellular transport

into cell

which way is K+ pumped by Na+/K+ ATPase

out of cell

which way is Na+ pumped by Na+/K+ ATPase

K+ leak channel

what channel causes membrane potential

-70 mV

what is resting membrane potential

form concentration gradients

what is the purpose of the Na+/K+ ATPase

yes

are K+ leak channels always open

electrical gradient

why doesn’t K+ rush out of the leak channel?

no

can Na+ move at rest besides the Na+/K+ ATPase

K+

what ion has the greatest influence on membrane potential at rest

graded potential

a potential that changes based on ion permeability

depolarization

less negative, occurs when positive ions (usually Na+) enter the cell

hyperpolarization

more negative, occurs when positive ions (usually K+) leave the cell or negative ions (usually Cl-) enter the cell

depolarization

what excites cells

hyperpolarization

what inhibits cells

ligand gated channel

a channel that opens by something binding to a receptor

voltage gated channel

a channel that opens at a specific membrane potential

ligand gated Na+ channel gets bound

what happens first to intitiate an action potential

depolarization

what is the effect of the ligand gated Na+ channel opening

voltage gated Na+ channel opens

what happens due to depolarization due to ligand gated Na+ channel

rapid depolarization

what does the opening of voltage gated Na+ channels do

voltage gated Ca2+ channel

what channel opens at the terminal of an axon due to action potential

vesicle release into synapse

what does Ca2+ do at the terminal of an axon

closed, open, inactivated

what are the three states of a voltage gated Na+ channel

+30 mV

what membrane potential leads to voltage gated Na+ channel inactivation

-55mV

what membrane potential leads to voltage gated Na+ channel opening

no

can an action potential be fired when the voltage gated Na+ channel is inactivated

time

what regulates the inactivation gate after it has blocked the channel

voltage gated K+ channel

what channel opens at +30 mV

repolarization

what does the opening of a voltage gated K+ channel lead to

absolute refractory period

no new action potential can be fired, voltage gated Na+ channel is inactivated

relative refractory period

during hyperpolarization, harder to fire a new action potential, requires a larger stimulus

unidirectional

nerve impulses due to action potentials unidirectional or bidirectional

refractory periods

what allows for nerve impulses to be unidirectional

action potential

what kind of potential is all or none

no

will the size of stimulus affect the size of an individual action potential

slower action potential

what is the result of an unmyelinated axon

insulation

what does myelination provide that improves speed

nodes of ranvier

allows for leaping of action potentials due to concentrated ion channels

myelination, diameter

what are the two things that can increase action potential conduction speed

synapse

functional connection between a neuron terminal and the target cell

neuromuscular junction

synapse between neuron and muscle cell

electrical synapses

in smooth and cardiac muscle, require direct contact via gap junctions in the membrane

gap junctions

allow for direct contact for electrical signalling

chemical synapses

doesn’t require direct contact, using a neurotransmitter

1

how many neurotransmitters is a neuron able to make/release

voltage gated ca channel

what channels allow for neurotransmitter release

hyperpolarization

what needs to happen to a cell membrane for inhibition

depolarization

what needs to happen to a cell membrane for activation

reuptake, enzymatic digestion, diffusion

what are the 3 possible ways that a neurotransmitter can be removed from the synaptic cleft

reuptake

how is glutamate removed from the synaptic cleft

enzymatic digestion

how is acetylcholine removed from the synaptic cleft

excitatory

in all somatic motor neurons, what kind of neurotransmitter is acetylcholine

K+ or Cl-

what two channels would Ach need to open to be inhibitory

Na+ or Ca2+

what two channels would Ach need to open to be activating

nicotinic acetylcholine receptors

can be stimulated by nicotine, foundon the motor end plate of skeletal muscle cells and in autonomic ganglia

muscarinic acetylcholine receptors

can be stimulated by muscarine (from mushrooms), found in CNS and membrane of smooth and cardiac muscles and glands, innervated by autonomic motor neurons

muscarinic

what can of ach receptors can be inhibitory

acetylcholinesterase

what is the enzyme that breaks down ach

glutamate, norepinephrine, epinephrine

what are the three monoamines that we need to know

monoamine oxidase

what is the enzyme that can degrade monoamines after reuptake

skeletal muscle

striated and voluntary

cardiac muscle

striated and involuntary

smooth muscle

smooth and involuntary

muscle fiber

what is the cellular level of muscle

sarcomere

one contractile protein

lower motor neuron

what neuron innervated skeletal muscle

t tubule

extensions of the cell membrane that allow the action potential to travel into interior muscle fiber

sarcoplasmic reticulum

where is Ca stored in muscle