Organization of the Nervous System Flashcards
multipolar neurons
motor and interneurons; most of what we have
bipolar neuron
1 dendrite and 1 axon attached to cell body; found in hearing, balance, etc.
pseudounipolar neurons
usually sensory; (SA)
Cortical neurons
deal with (in additio to sensory and motor fxn) memory, calculation, mood, affect/behavior, feeding/watering, reasoning etc.
Vs. SC and brainstem which deal w/ somatic sens, motor and special sense
What term comes to mind when thinking about “the body”?
somatic
sensory nerve
aka AFFERENT; bring sensory info towards the brain or SC
Where does somatic sensation come from?
skin, joint receptors, etc. (touch, pressure, pain)
Visceral sensation
visceral meaning hollow organ; mostly not brought to level of consciousness
For what reasons would we be consciously aware of visceral sensation?
ischemia or distention
Motor nerves
EFFERENTS; transmit impulses away from the brain or spinal cord to induce movement
What functional component is responsible for moving skeletal muscles?
somatic efferents; AKA alpha motor neurons
What makes up the CNS?
cerebral cortex, cerebellum, brainstem, spinal cord
What makes up the PNS?
cranial nerves, spinal nerves, ANS
What are the 5 lobes of the brain and what is their function?
Frontal: motor/behavior Parietal: sensory/motor Occipital: hearing Temporal: smell/hearing/behavior Insula: behavior
Which portion of the SC house sensory components?
Dorsal
Which portion of the SC house motor components?
Ventral
What is the collection of cell bodies/perikarya outside the CNS called?
ganglia; (nucleus if w/i brainstem)
What gives sensory and motor supply to the 2in strip on either side of the spinal cord?
DPR
Where are ALL SA located from the mandible down?
DRG
Where are ALL of the cell bodies of alpha motor neurons located from the mandible down?
ventral horn of SC
What are the 4 cranial nerves that house parasympathetics?
CN III - oculomotor
CN VII - Facial
CN IX - glossopharyngeal
CN X - Vagus
What are the two exceptions to the rule of the ANS innervating only hollow organs?
arrector pili muscle and pupil
What indirectly effects rate of glandular secretion?
blood supply
summarize sympathetics
fight or flight; pupils dilate, HR increases, airways dilate, blood is shunted away from GI tract toward skeletal muscle; ejaculation
summarize parasympathetics
homeostasis; pupils constrict, HR decreases, GI blood and motility increase, blood to genitals increase
Where do parasympathetics only travel to?
head and neck, intra thoracic organs, etc.
which functional component requires 2 neurons to go from the spinal cord to the hollow organ target?
VE
What are the 3 possible areas that a VE will synapse?
sympathetic chain, anterior to the abdominal/pelvic arteries, or at/on/near/w/i the organ
SYMPATHETIC VEs travel from the SC to a ganglion how?
in the sympathetic chain OR anterior to abd/pelvis artery(pre aortic ganglia) - then follows an artery to target
PARASYMPATHETIC VEs travel from the cranial nerves/lower SC how?
to a ganglion at/on/near/or within the target organ
NO parasympathetics are found where?
no parasympathetics found in body wall or limbs - ONLY sympathetic efferent and associated afferent are found in spinal nerves
what structure drives the preganglionic sympathetics?
hypothalamus
Thoracic splanchnic nerves
primarily preganglionic; synapse in the pre aortic ganglion
Explain the parasympathetic innervation of the vagus n.
It comes out of SC, descends through neck as preganglionic, enters the thorax and synapses at cardiac ganglia (at/near/w/i target organ)
