chapter 13 Flashcards
CNS
brain and spinal cord
PNS catergories
-afferent
-efferent
afferent PNS
sensory information TOWARDS CNS
-somatic and visceral
efferent PNS
motor commands AWAY from CNS
-somatic nerves
-automatic nerves
afferent sensory
-monitor skeletal muscles and joints
afferent visceral
-monitor smooth muscle, cardiac muscle and internal organs
efferent somatic nerves
-control skeletal muscle contraction
efferent autonomic nerves
-control internal organ activity
-2 types
-parasympathetic nerve
-sympathetic nerve
parasympathetic nerve
PNS autonomic nerve
-pupil constriction, heart rate decrease, increase digestive movement (REST AND DIGEST)
sympathetic nerve
PNS autonomic nerve
-pupil dilation, increase heart rate, slow down digestion (FIGHT OR FLIGHT)
neural tissue
-neurons
-neuroglia
neurons
nerve cells that transfer and process information in the nervous system
-conduct impulses (on test)
-soma, axon, dendrites
neuroglia
-supporting cells
-protect neuron
-do not conduct impulses (on test)
-maintain intercellular environment
-act as phagocytes
-100 billion, 5x more than neuron
-
neuroglia
-supporting cells
-protect neuron
-do not conduct impulses (on test)
-maintain intercellular environment
-act as phagocytes
-100 billion, 5x more than neuron
-CAN REPRODUCE/ MITOSIS past childhood (on test)
Neuroglia in the CNS
-astrocytes
-oligodendrocytes
-microglia
-epidymal
oligodendrocytes
-form myelin sheath around neurons
-contact soma or axon
-cytoplasmic extension tie axons together
-make the myelin sheath
astrocyte
-scar tissue (strokes)
-maintain blood brain barrier
-isolate neurons from general circulation
microglia
-phagocytes cells (debris and microbes)
-remove waste
ependymal
-make CSF
-line ventricles (hollow chambers of the brain)
-line central canal
-circulate CSF
neuroglia PNS
-satellite
-schwann cells
satellite cells
-support neuron, at the neuron cell bodies
-regulate exchange btwn cell body and environment
-surround cell bodies of PNS neurons in clusters (ganglia)
Schwann cells
-form myelin sheath (speed ups impulse)
-repair damages neurons in PNS
(oligodendrocytes of the PNS)
soma
-nissl bodies (give gray color)
-lack centrosomes (bc they dont mitosis)
white matter
myelin
-made of fat so white
axon
-axon hillock (cell body turns to axon)
-axoplasm (cytoplasm of the neuron)
-axollema (plasma membrane of the axon)
-terminal buttons (may be where neurotransmitters are)
neuron structural classification
-placement in body
-processes extending from cell body
functional classification
-sensory
-motor
-interneuron (both sensory and motor)
anaxonic
has many rpocesses but cannot differentiate btwn axons and dendrites
bipolar
cell body is btwn the 2 axons
pseudounipolar
the cell body is off to one side of the axon
multipolar
has a single axon and multiple dendrites
sensory
sends information from pns to cns
-SOMATIC SENSORY AND VISCERAL SENSORY NEURONS
-pick up information from pns receptors
motor
send information from the cns to periphery
-SOMATIC MOTOR AND AUTONOMIC MOTOR NEURONS
-send information to the effectors of the periphery (muscles. glands organs etc)
interneurons
-are betwn motor and sensory neurons
-alayze sensory input and coordinate motor output
-excitatory or inhibitory
exteroceptors and proprioceptors
-go to the somatic neurons
-go to the muscle
exteroceptors
information abt the external environment (touch, temp, smell, vision etc)
propioceptors
position and movement of the body in muscles and joints (tell you brain that your arms are raised)
interoceptors
monitor internal organ activity
neural regeneration (ON TEST)
neural regeneration process does not happen in the CNS
-astrocytes form scar tissue at the sites of damages neurons
neural regeneration PNS
limited ability to repair PNS
-schwann cells grow into the cut area
-axons begin to grow into the schwann cells
-cell bodies must be alive for this to happen
nerve impulse
action potential of the nerve
action potential
caused by an exchange of ions across the membrane (sodium and potassium)
ability to conduce an impulse
excitability
stimulus
anything that can cause an action potential
threshold level
stimulus must overcome the threshold of particular neuron to fire the action potential/ impulse
What is the thresholD level?
The amount of stimuli needed to create action potential/ impulse
what affects the speed of the impulse? ON TEST
-myelin (speeds it up)
-diameter of axon (larger= faster)
what is a synapse
a junction
-axodendritic
-axosomatic
-axoaxonic
-neuromuscular synapse or junction
-neuroglandular synapse
axodendritic synapse
axone of one neuron and dendrite of another neurons
axosomatic
axon of one neuron and soma of another neuron
axoaxonic
axon of one neuron and axon of another
neuromuscular
axon of a neuron and a muscle
neuroglandular
axon of a neuron and a gland
vesicular synapses
-a chemical synapse
-involved neurotransmitter release from the terminal bouton
neuronal pools
organized groups of neurons identified by neural circuitry
-divergence
-convergence
-serial processing
-parallel processing
-reverberation
divergence
-info from one neuron to several
-info enters the CNS and spreads to brain and spinal cord at the same time
-broad distribution of inputed information
convergence
-information from several neurons to a single neuron
-ex: 10 million rods and cones in the eye that make contact with 1 million neurons
serial processing
-info going from one neuron to the next and the next and the next…
-info going from one part of the brain tot he net and the next…
-sequence of neurons
parallel processing
-several enurons process info at the same time
-step on a nail move your foot and dance a lil
reverbration
-collateral axons extend back to the origin of the impulse to cause an enhancement or a continuation of the impulse via feedback
nuclei/ cortex cns
-collection of cell bodies in one area
-gray matter
white matter
bundles of axons/ myelin
-fatty
-called tracts/ columns
cell bodies in pns
ganglia/ gray matter
-axons form spinal nerves and cranial nerves
-can be myelinated or unmyelinated
