NERVOUS SYSTEM Flashcards
Where is the central nervous system found?
inside the skull and vertebral column
What make up the CNS?
cerebral hemisphere
2 parts to the cerebral hemisphere
cerebrum
3 parts to brain stem
midbrain
found outside the skull and vertebral column
peripheral nervous sytem
make up the PNS
spinal and cranial nerves
number of spinal nerves
31 pair
cervical nerves
8
thoracic nerves
12
lumbar nerves
5
sacral nerves
5
coccygeal
1
number of cranial nerves
12 pair
cranial nerve VI
abducens nerve
collection of NERVE CELL BODIES associated w/peripheral nerves and located outside the CNS
ganglia
what do sensory ganglia consist of?
pseudounipolar
what do sensory ganglia in the cochlea consist of?
bipolar
what are cranial nerves associated with?
cerebral hemisphere
what are CN III to CN X and CN XII associated with?
brain stem
what is CN XI associated with?
spinal cord (upper)
2 types of sensory ganglia
spinal ganglia
2 types of autonomic, motor or visceral ganglia
sympathetic
what make up autonomic, motor, or visceral ganglia?
multipolar neurons
3 types of cranial nerves in the PNS
sensory
1 type of spinal nerve in the PNS
mixed sensory and motor
what does dorsal mean?
back, posterior
what does ventral mean?
front, anterior
3 parts of the cochlea ganglion
spiral ganglion - bipolar
what type of neurons are found in the spinal cord?
multipolar neurons
What matter contains the nerve cell bodies and synapses?
gray matter
what matter consists of axons which form tracts
white matter
3 columns in spinal cord
dorsal column/furniculus
T/F. Cord gets smaller caudally (towards tail).
TRUE
T/F. White matter increases at lower levels.
False. White matter decreases.
shape of cervical segments
large and oval
shape of lumbar and sacral segments
smaller, rounder
where is gray matter larger due to number of nerve cells associated with innervation of the limbs?
C4-T1
what contains the bodies of preganglionic sympathetic neruons
lateral horn
2 columns in the dorsal/posterior column
f. gracilis
what is the dorsal/postior horns function
sensory
sensory horn
involves the relay of sensory information (2nd order sensory neuron)
type of cell bodies in dorsal horn
mulitpolar neuron cell bodies
where do the sensory horns send their axons to?
higher levels in the CNS
part of the gray matter that contains preganglionic cell bodies of the sympathetic nervous system
lateral horn
column in the lateral horn
intermediolateral cell column
where is the lateral horn found
thoracic and upper lumbar spinal cord segments
what do the ventral or anterior horn contain?
motor horn
2 types of motor neurons in the motor horn
alpha motor neurons
alpha motor neurons
send axons to extrafusal skeletal msucles (lower motor neurons)
gamma motor neurons
innervate intrafusal muscle fibers/cells of the neuromuscular spindle
3 parts to white matter
dorsal column
what does the lateral column contain?
ascending sensory nerve fibers (tracts)
what does the dorsal column contain?
ascending nerve cell processes w/cell bodies located in dorsal root ganglia
what does the ventral column contain?
ascending sensory nerve fibers
somatic nerve fibers of the peripheral nerves
relation to body wall and limbs
where are somatic nerve fibers found?
cranial and spinal nerves
where are somatic sensory fiber nerve cell bodies located?
cranial and spinal sensory ganglia
what is the function of somatic sensory fiber?
carry sensory nerves to and from skin, skeletal muscle, and joints
what is the function of somatic motor fibers?
voluntary control of skeletal muscle
where are motor nerve cell bodies located?
central nervous system (brain stem and spinal cord)
what does visceral imply?
relation to the organs of body cavities - can include blood vessels and glands that lie outside the body cavities
where are visceral nerve fibers found?
crainal and spinal nerves
visceral sensory fibers…
sensory nerves from the viscera (heart, lungs, GI tract, urinary system, blood vessels)
visceral motor fibers..
make up the autonomic nervous system
what do visceral motor fibers do?
control involuntary regulation of smooth muscle, cardiac muscle, and glands
2 subdivisions of the ANS
sympathetic nervous system
where are visceral motor fiber cell bodies found
autonomic ganglia
contains sensory or afferenet nerve fibers relative to the spinal cord
dorsal (posterior) root aka sensory root
what type of neurons are found in dorsal roots?
pseudounipolar neurons
contain motor or efferent nerve fibers relative to the spinal cord
ventral (anterior) roots
where are cell bodies that send their axons through ventral roots found?
ventral and lateral horns of spinal cord
what forms the spinal nerve?
the ventral root joining the dorsal root
2 types of spinal nerves
dorsal (posterior) primary ramus
supplies muscular and cutaneous branches to the deep muscles and skin of back and posterior head
dorsal primary ramus
supplies muscular and cutaneous branches to the skin and skeletal muscles of the lateral and anterior aspects of the trunk, skin, and muscles of the limbs
ventral primary ramus
T/F. Cranial nerves have dorsal and ventral roots and dorsal/ventral rami.
False. only spinal nerves have them.
Five cranial nerves have ____
sensory ganglia
Tirgeminal:
CN V
facial
CN VII
Vestibulocochlear
CN VIII
Clossopharyngeal:
CN IX
Vagus
CN X
3 cranial nerves have ____
motor ganglia (parasympathetic ganglia)
3 cranial nerves w/motor ganglia
oculomotor
2 types of ganglia assocaited with cranial nerves
- sensory
What type of neurons do parasympathetic ganglia have?
multipolar
