Test 2 part 2 Flashcards
Schwann Cells
Myelin for neurons in peripheral nervous system
Glial cells of CNS
Astrocytes
Oligodendrocytes
Microglia
Ependymal Cells
10-50 times more glial cells than actual neurons in the CNS
Astrocytes
Star-shaped
Clean up brain debris
digest parts of dead neurons
transport nutrients to neurons
hold neurons in place
fill in extracellular space
help form the blood brain barrier
Fibrous Astrocytes
found in white matter
forms the blood brain barrier via perivascular feet
Protoplasmic astrocytes
found in gray matter
Oligodendrocytes
myelin of neuronal axons in the CNS
like schwan cells but in CNS instead of PNS
Small cells with processes
Microglia
Help eat up trash
Ependymal cells
look like little bags of sugar
line the cavities (ventricles) of the CNS
Superior Colliculi function
receive visual input that initiates a behavioral response.
Inferior colliculi function
auditory integration of sound
What makes up the Midbrain tectum?
4 corpora quadrigeminae which has 2 superior colliculi and 2 inferior colliculi
Cerebellar peduncles
axonal pathways that carry information to and from the brainstem and cerebellum
function of dorsal columns on the medulla?
(gracile tubercles & cuneate tubercles)
Carry tactile information upward to the thalamus
gracile tubercles - lower body and lower extremities
cuneate tubercles - upper body and upper extremities
What is the obex?
point where all sides of 4th ventricle converge
Area postrema
vomitting center
has chemoreceptors that stimulate vomitting when stimulated by toxins
Cerebral peduncles made of what?
fibers of the corticospinal motor system
Basal portion of pons (basis pontis) is formed by?
decussating fivers to the contralateral middle cerebellar peduncle
Cortico-spinal motor pathway
Precentral gyrus > internal capsule > midbrain > pons & medulla > pyramids > 85% cross to lateral cortico-spinal tract and the rest go to anterior corticospinal tract
Where does anterior cotricospinal tract cross over?
cervical spinal cord
folds of cerevellum
folia
biggest lobe of cerebellum?
posterior lobe
Ant. lobe of cerebellum (spinocerebellum) receives motor input from?
Spinal cord
Vermis of cerebelllum (vestibulocerebellum) receives motor input from?
Vestibular nuclei (brainstem)
Post. lobe of cerebellum (corticocerebellum) receives motor input from?
cerebral cortex
Spinocerebellar tract
sensory info from musclejoint > enter spinal cord through dorsal root ganglion > decussation to other side of spinal cord > up to medulla > up to pons > inferior cerebellar peduncle > back to other side > enters cerebellum > terminates in anterior lobe of cerebellum (spinocerebellum)
Vestibulocerebellar tract
vestibulocochlear nerve from vestibular apparatus > vestibular nuclei (medulla) > vermis of cerebelllum > projections from deep cerebellar nuclei back to the vestiblar nuclei > vestibulospinal tract projections to spinal cord
Corticocerebellar tract
motor portions of cerebral cortex > pontine nuclei > cerevbellum via contralateral middle cerebellar peduncles.
Cerebellum motor functions
muscle coordination and coordinated body movement
equilibrium and balance (vermis)
maintain muscle tone
Ataxia
Truncal and or limb instability
have broad based stance
unsteady gait (ataxic gait)
high fall risk
Dyskinesia
movement issue from basal ganglia
Dysnergia
movement issue from cerebellum
intention tremor
hard time performing rapidly alternating movements
(dysdiadochokinesia)
Dysdiadochokinesia
difficulty performing rapidly alternating movements
Dysmetria
past pointing (finger to nose test)
heel to shin test
Reticular formation
bilateral network of multi-synaptic neurons in the brainstem
Reticular formation functions
regulate level of consciousness
regulate breathing cycle
regulate muscle tone
Ascending portion of reticular activating system (RAS) function
regulate level of consciousness
Has cyclic activity
^ activity > arousal
decreased actvity > quiessence
Where does RAS receive input from?
skin, joints, muscles
visual system
auditory system
visceral system
General anestheisa affects what part of RAS?
ascending
Pathologies associated with RAS dysfunction
Schizophrenia
PTSD
parkinsons’s disease
REM behaviour disorder
narcolepsy
progressive supranuclear palsy
depression
autism
altzheimers disease
ADD/ADHD
Descending RAS function
regulates muscle tone
affected by LOC
Medulla function in breathing?
controls muscles involved in breathing
Pons function in breathing?
control rate of breathing
Parts of the Diencephalon
Thalamus
hypothalamus
epithalamus
sub-thalamus - 2 nuclei
How many lobes of thalamus?
2 lobes
Hypthalamus connected to?
pituitary stalk
Make up epithalamus?
pineal gland and habenula
Subthalamus function?
motor control (1 of several “basal ganglia”)
Internal capsule is what type of matter?
White matter
Thalamus
largest portion of diencephalon
has 2 lobes
80% of people have mass intermedia or thalamic adhesion
internal medullary lamina
seperate thalamus into nuclear regions
Nuclear regions of Thalamus?
lateral nuclear group
medial nuclear group
anterior nuclear group
