Unit 4 Test Flashcards
endocrine system
communicates through hormones secreted into blood
nervous system
neurotransmitters are used to end messages from cell to cell
central nervous system (CNS)
brain and spinal cord
peripheral nervous system (PNS)
everything EXCEPT brain and spinal cord
(PNS) sensory division (afferent)
carries signals from receptors to CNS; visceral sensory and somatic sensory division
(PNS) motor division (efferent)
carries signals from CNS; visceral motor division and somatic motor division
(PNS) visceral motor division
cardiac, smooth muscle, glands
sympathetic division
fight or flight
parasympathetic division
rest and digest
(PNS) somatic motor division
skeletal muscle
3 properties of neurons
excitability, conductivity, secretion
classes of neurons
- sensory (afferent) neurons
- interneurons (association) neurons
- motor (efferent) neurons
structure of a neuron
- dendrites
- soma
- axon hillock
- singe axon
- synaptic knobs
multipolar neuron
1 axon, multiple dendrites; motor neuron; most common
bipolar neuron
1 axon, 1 dendrite; olfactory (smell), retina (eye), and inner ear
unipolar neuron
soma on side; sensory; skin and organs to spinal cord
anaxonic neuron
no axon, many dendrites; brain, retina, adrenal glands
anterograde axon transport
soma and synaptic knobs; proteins from soma are transported to axon and axon terminal
retrograde axon transport
soma and synaptic knobs; returns used synaptic vesicles to the soma
neuroglia cells
protect neurons and help them function; bind together neurons for nervous tissue;
(CNS) oligodendrocytes
form myelin sheaths that speed signal conduction
(CNS) ependymal cells
line central canal of the spinal cord and ventricles of the brain; secrete/circulate CSF
(CNS) microglia
macrophages, increased on area of injury
(CNS) astrocytes
blood brain barrier; largest and most numerou
(PNS) schwann cells
produce myeline sheath
(PNS) satellite cells
function = uncertain
myelin sheath
insulating layer around a nerve fiber; oligodendrocytes and schwann cells
gaps between myelin segments
nodes of ranvier
speed of nerve fibers
- type A (axons) (large diameter, myelinated, high speed)
- type B (axons) (medium diameter, myelinated, medium speed)
- type C (axons) (small diameter, unmyelinated, slow speed)
slow signals =
sent to stomach
fast signals =
sent to skeletal muscles
resting membrane potential
-70 mV (negative charge)
continuous propgation
unmyelinated axons; one segment of an axon at a time
saltatory propagation
myelinated axons; faster and uses less energy; myelin insulates the axon
1st neuron is…
presynaptic neuron; releases neurotransmitter
2nd neuron is..
postsynaptic neuron; responds to neurotransmitter
acetylcholine
neurotransmitter
amino acid neurotransmitter
GABA
monoamines
catecholamines
neuropeptides
2-40 amino acids
excitatory cholinergenic synapse =
ACh
excitatory adrengenic synapse =
NE