Chapter 13- The Central Nervous System Flashcards
Caudal
Towards the tail (occipital lobe)
Rostral
Towards the snout; ex: cervical spinal cord more rostral than lumbar spinal cord
Cerebrum
largest part of brain: left and right hemispheres
Diencephalon
gives rise to thalamus, hypothalamus and epithalamus
Cerebellum
second largest part of brain
brain stem
Rostral continuation of the spinal cord, consists of the medulla oblongata, pons and midbrain
Brain ventricles
Spaces in the brain; continuous with each other and the central canal; contain CSF; lined with ependymal cells
Know everything on ventricle page…
fuck
protective coverings of the CNS
skull(protects brain); vertebrae( protects spinal cord); meninges (CT sheaths that encircle the brain and spinal cord; meninx=singular)
Layers of the meninges
Dura matter (strongest, most superficial); arachnoid matter (whispy and networked), pia matter (adheres directly to brain/spinal cord surface… outermost layer of brain and spinal cord)
Know picture of the meninges
:(
Falx Cerebri
separates the cerebral hemispheres
Dural Septa
holds brain in skull to prevent damage
Tentorum Cerebelli
separates the cerebellum from the cerebrum
Know anatomy of the cerebrum
:((((
Know cerebral cortex
lawrence, it’ll be ok
Know fissures and sulci
it’ll really be ok, lawrence
somatotopy
body mapping
Cerebral white matter
commissural fibers, associational fibers, and projection fibers
areas of greater cortical mass (somatotopy)
areas of greater sensitivity
Commissural fibers
between hemispheres; cross the midline; largest= corpus callosum
Associational Fibers
Intrahemispheric; can be long or short
projection fibers
cortexlower CNS regions; vertical fibers
Cerebral deep grey matter
basal ganglia
Basal ganglia
initiate and terminate body movements; suppresses unwanted movements
Diencephalon
Thalamus+hypothalamus+epithalamus
Thalamus
two egg shaped structures stuck together
Thalamus is a ___ station
Relay; every part of the brain that communicates with the cerebral cortex must relay its signal through a nucleus of the thalamus
there is ___ a paired nuclei in the thalamus
always
hypothalamus
controls homeostasis; inferior and rostral to the thalamus; many subnuclei; contains pituitary gland
3 parts of midbrain
cerebral peduncles; cerebral aqueduct; corporal quadrigemina
cerebral peduncles
composed mostly of the motor tracts from the cortex to the cerebellum and spinal cord (look like columns/pillars supporting the cerebrum; located ventrally)
Cerebral aqueduct
passes through center of the midbrain; 3rd->4th ventricle
Corporal quadrigemina
nuclei that form 4 bumps on the dorsal midbrain;superior colliculi= visual reflexes; inferior colliculi = auditory reflexes
Pons
bridge of fibers between brainstem and cerebellum; relay of motor information from cortex to the cerebellum
ventral brain structure
transversely running fibers in the pons
Medulla oblongata
continuous with superior aspect of the spinal cord; from the foramen magnum to inferior pontine border; pyramids (motor tracts that form bulges on the anterior surface of the medula) & olives (nuclei that form bulges lateral to the pyramids… sensory relay station)
Medulla is very important!!WHY?
motory and sensory tracts run through the medulla; descending motor tracts cross the midline in the medulla; very important nuclei housed in the medulla; cardiovascular center, respiratory center, vasomotor center, control of vomiting swallowing, sneezing, coughing
Arrangement of cerebellum
cerebellar cortex: grey matter w/ many folds called folia
Cerebellar white matter: tracts called arbor vitae deep grey matter nuclei
Major tract entering/exiting the cerebellum
middle cerebellar peduncle: only info in one direction, largest
Functions of cerebellum
coordinates and smooths motor movements equilibrium and balance; some cognition
Function of anterior and posterior lobes of cerebellum
motor coordination
Function of flocculonodular lobe of cerebellum
balance and equilibrium
Describe the spinal cord
- sensory and motor innervation of whole body (inferior to head)
- two way conduction pathway between the brain and the body (inferior to head)
- major integration center for reflexes (inferior to head)
Gross anatomy of the spinal cord
extends from the foramen magnum to L1 vertebra (conus medullaris; cauda equina; filum terminale); cervical enlargement; lumbar enlargement
Cauda equina
horses tail; spinal nerves
What does the filum terminale do?
holds the spinal cord in place
cervical spinal nerves?
8
spinal cord segments are typically located ___to where their corresponding spinal nerves emerge through the intervertebral foramina
superior
White matter is located ___ & grey matter is located ___
externally; internally
In the spinal cord…Dorsal=? Ventral= ?
dorsal = sensory
ventral=motor
Afferent
Dorsal roots carry info toward the CNS; Sensory
Efferent
Ventral roots carry info Away from the CNS; Motor
Somatic sensory neurons live in the
Dorsal root ganglion
Somatic motor neurons live in the
Ventral horn
White matter tracts name?
According to where the tract begins and where it ends
Spinal cord white matter is made up of
Both sensory and motor neurons
Ascending tracts =
traveling up the spinal chord, sensory
Descending tracts=
traveling down the spinal cord; motor
4 spinal cord segments
Cervical: largest amount of white matter and grey matter (cervical enlargement)
Thoracic: least amount of grey matter
Lumbar: large amount of grey matter (lumbar enlargement)
Sacral: least amount of white and grey matter
