Lecture 7: Spinal Cord, CSF, and Cranial Nerves Flashcards
what is the spinal cord?
-a major organ of the CNS
-a downward extension of the medulla oblongotta
-ranges from 16.5 to 17.7” in adults
-carries motor info from the brain to the periphery
-carries sensory info from the periphery to the brain
**in reference to the spinal cord:
dorsal and ventral are used interchangeable with posterior and anterior respectively
-dorsal=posterior
-ventral=anterior
what are the segments of the spinal cord?
- cervical
- thoracic
- lumbar
- sacral
- coccygeal
how many pairs of nerves does each segment have?
- cervical - 8
- thoracic - 12
- lumbar - 5
- sacral - 5
- coccygeal - 1
how do you remember the nerve pairs for the segments
“breakfast at 7 (+1), lunch at 12, dinner at 5, a big drink and a small dessert”
what are the external landmarks of the spinal cord?
-enlargements (more gray matter) present in the cervical and lumbar regions
what is the cervical enlargement responsible for?
controls the skeletal muscles of the upper limbs
what is the lumbar enlargement responsible for?
controls skeletal muscles of the lower limbs
what is the Cauda equina?
-the “horses tail”
-distal lumbar and sacral nerves
what are the other external landmarks of the spinal cord
**make sure you can label :)
- conus medullaris:
-the terminal end of the spinal cord
-ends at about the 12th thoracic vertebrae/first lumbar - the lumbar cistern:
-has clinical relevance for puncture testing (taking cerebrospinal fluid) - filum terminale:
-“terminal thread”- connective tissue
-anchors the spinal cord inferiorly
what is cerebrospinal fluid (CSF)
-ultrafiltrate of blood plasma (clear and odorless)
-has more Na+ but less K+ than blood plasma, and less proteins
what are the functions of CSF?
- protection (shock absorber for the brain against the skull)
- nourishment
- waste removal
- helps regulate cerebral blood flow
where is CSF produced?
ependymal cells
where is CSF located?
-subarachnoid space around the brain and spinal cord
-ventricles of the brain
how much CSF is there?
150 ml at any given time
500ml produced per day
What are the internal landmarks of the spinal cord?
**make sure you can label :)
- posterior gray horn (sensory neurons)
- anterior gray horn (motor neurons)
- posterior median sulcus
4.anterior median sulcus - dorsal funiculus
- lateral funiculus
- ventral funiculus
make sure you know the directions of spinal tracts
:)
what happens to white matter as you go from the cervical segment down to the coccygeal segment
white matter decreases as you get lower
what happens to gray matter as you go from the cervical segment down to the coccygeal segment
I think it increases but I’m not really sure
what are spinal tracts?
-part of the PNS
-nerves arising from the spinal cord (8,12, 5, 5, 1 (31))
-distributed to the skin, sweat glands, mucosa, blood vessels, joints, and skeletal muscles
-can be sensory, motor, or inter
-involved in sensation, movement and sweating
sensory neurons travel in what direction and up what part of the spinal cord?
they are ascending and they travel up the dorsal root
motor neurons travel in what direction and down what part of the spinal cord?
they are descending and they travel down the ventral root
look at the spinal tract diagram :)
:)
cranial nerves (overview)
-part of the CNS
-nerves arising from the brain (12 pairs)
-distributed mainly to head and neck structures
-sensory motor and mixed neuron
“On Occassion Our Trusty Truck Acts Funny, Very Good Vehicle Any How”
what are the cranial nerves
I. olfactory nerve
II. optic nerve
III. oculomotor n.
IV. trochlear n.
V. trigeminal nerve
VI. abducens nerve
VII. facial nerve
VIII. vestibulocochlear nerve
IX. glossopharyngeal nerve
X. vagus nerve
XI. accessory nerve
XII. hypoglossal nerve
the olfactory nerve
I
smell
sensory
the optic nerve
II
vision
sensory
the oculomotor nerve
III
eyelid and eyeball movement
pupil size
motor
the trochlear nerve
IV
eye movement
motor
the trigeminal nerve
V
sensory (pain, temp, pressure, chewing)
both
the abducens nerve
Vi
abducts eye (lateral movement)
motor
the facial nerve
VII
facial expressions, eye and lip movement, taste
both
the vestibulocochlear nerve
VIII
hearing
balance
sensory
the glossopharyngeal nerve
IX
taste perception
swallowing
both
the vagus nerve
X
speech
digestion
respiration
cardiac activity
both
the accessory nerve
XI
head
neck
shoulder mvmt
motor
the hypoglossal nerve
XII
tongue movement
speech
motor
