Neuroanatomy 3

Question 1

what are the three layers of the meninges

Answer 1

dura mater, arachnoid, pia mater

Question 2

what are the two layers of the dura mater and what do they do

Answer 2

periosteum - anchors dura mater to skull meningeal dura - mechanical support and strength to brain

Question 3

which layer of the dura mater is in the vertebral column

Answer 3

meningeal dura

Question 4

where are the venous sinuses found

Answer 4

between the layers of dura mater and separate left and right hemispheres, as well as occipital lobe from the cerebellum

Question 5

what are the venous sinuses filled with

Answer 5

venous blood

Question 6

where are the potential spaces and what kind of blood vessel can fill it

Answer 6

epidural space (superficial to peristeom) - meningeal artery subdural space (deep to meningeal layer) - bridging veins

Question 7

where are the real spaces

Answer 7

-between periosteal and meningeal layer - sagittal fissure - transverse fissure (separates occipital and cerebellum) - venous sinuses

Question 8

describe the pathway of cerebral spinal fluid

Answer 8

made in lateral ventricle interventricular foramina of Monro 3rd ventricle cerebral aquaduct 4th ventricle foramina magendie –> cisterna magna foramina luschka –> pontine cistern subarachnoid space arachnoid granulations dural venous sinuses

Question 9

where are the other areas that CSF goes in the body besides the cortex

Answer 9

superior cistern, interpeduncular, pontomedullary, cisterna magna, and lumbar (see lecture for picture)

Question 10

what is non-communicating hydrocephalus

Answer 10

when flow of CSF is obstructed in the ventricular system

Question 11

what is a communicating hydrocephalus

Answer 11

when the absorption of CSF is not sufficient to remove fluid being produced

Question 12

what are arachnoid granulations. what kind if pressure is needed

Answer 12

protrusion of arachnoid into the venous sinus where the CSF in the subarachnoid space can drain into the venous sinuses. CSF pressure must be greater than venous pressure

Question 13

what are the three most common brain herniations

Answer 13

subfalcine, uncal, tonsilar

Question 14

what is this

Answer 14

epidural hematoma

Question 15

what is this

Answer 15

subdural hematoma

Question 16

what is this

Answer 16

subarachnoid hemorrhage

Question 17

describe the full layers from the scalp to the pia mater

Answer 17

Question 18

a subfalcine herniation compresses which part of the brain

Answer 18

limbic cortex and comissural

Question 19

an uncal herniation compresses which brain structures

Answer 19

temporal lobe and midbrain

Question 20

what are the three layers of the blood brain barrier

Answer 20

arachnoid barrier, choroid/blood CSF barrier, and actual BBB

Question 21

how does the arachnoid barrier work

Answer 21

arachnoid granulations are considered one-way valves to prevent venous blood from subarachnoid space

Question 22

how does the blood-CSF barrier

Answer 22

choroidal blood capillaries have fenestrations but tight junctions at the choroid epithelium that prevents blood from entering ventricles

Question 23

how does the blood brain barrier proper work

Answer 23

tight junctions at the capillary level with astrocytes to help

Question 24

where is an area where there is no BBB

Answer 24

pineal gland

Question 25

what are the two arterial supply of the brain (and is it anterior or posterior)

Answer 25

internal carotid (anterior) and vertebral (posterior) artery

Question 26

what is the venous drainage of the brain

Answer 26

internal jugular vein

Question 27

the signal from the basal ganglia to the thalamus is (excitatory/inhibitory)

Answer 27

inhibitory

Question 28

what are the two structures in the red? what is the called overall

Answer 28

Putamen and globus pallidus. Lentiform Nucleus

Question 29

what are the two structures in blue? what are they called overall

Answer 29

caudate and putamen. Striatum

Question 30

what is this? what does it do

Answer 30

nucleus accumbens - connection between limbic system and basal ganglia

Question 31

what is the top blue arrow

Answer 31

subthalamic nucleus

Question 32

what is the bottom blue arrow

Answer 32

substantia nigra

Question 33

what are the inputs to the basal ganglia

Answer 33

cerebral cortex, substantia nigra pars compacta, centromedian cortex

Question 34

what structures outputs the info from the basal ganglia

Answer 34

substantia nigra pars reticulata and globus pallidus internus

Question 35

what is the effect of the direct pathway on the thalamus (movement, inhibition?, thalamocortical activity)

Answer 35

selective facilitation of movement, disinhibits thalamus, increased thalamocortical activity

Question 36

what is the effect of the indirect pathway on the thalamus (movement, inhibition?, thalamocortical activity)

Answer 36

selective suppression of movement, inhibits thalamus, decreased thalamocortical activity

Question 37

what is the pathophysiology of parkinsons

Answer 37

loss dopaminergic neurons of the substantia nigra pars compacta, so there is no dopamine influence on the striatum. leads to a net inhibitory effect on the thalamus

Question 38

what is the pathophysiology of huntington's disease

Answer 38

- polyglutamine expansion in the huntingtin protein which leads to the STRIATAL degeneration - indirect-pathway selectively vulnerable - loss of OUTPUT STRIATAL NEURONS removes the inhibitory effect on the thalamus ​

Question 39

what is the dysfunction of the cerebellum

Answer 39

ataxia

Question 40

what are the three functional areas of the cerebellum

Answer 40

1) Flocculonodular lobe/vernis 2) intermediate hemispheres 3) lateral hemispheres

Question 41

what is the function of the flocculonodular lobe and vernis

Answer 41

coordination of the proximal limb and trunk muscles (like the fasciculus cuneatus) (vermis) balance (FN) vestibular-ocular reflex (FN)

Question 42

what is the function of the intermediate hemisphere

Answer 42

coordinate distal limb muscles and modulate ongoing movement

Question 43

what is the function of the lateral hemisphere

Answer 43

motor planning

Question 44

what are the three pairs of peduncles in the cerebellum and do they have afferent or efferent nerves

Answer 44

inferior - afferent and efferent middle - afferent only superior - efferent primarily

Question 45

what are the sources of afferent nerves to the cerebellar peduncles and what information do they bring

Answer 45

vestibular system (balance and head position) spinal cord (proprioceptive) pons (cortical info)

Question 46

what are the three pairs of deep cerebellar nuclei

Answer 46

- fastigial nucleus - interposed nucleus - dentate nucleus

Question 47

where are the dentate and interposed nuclei found

Answer 47

superior penduncle

Question 48

what intermediate targets does dentate and interposed nuclei send efferent information to

Answer 48

thalamus (VA, VL) and red nucleus

Question 49

what motor system does the dentate and interposed nuclei modulate

Answer 49

lateral

Question 50

where is the fastigial nucleus found

Answer 50

inferior peduncle

Question 51

what intermediate targets do the fastigial nucleus send efferent info to

Answer 51

vestibular, reticular formation, MLF

Question 52

which motor system does the fastigial nucleus modulate

Answer 52

medial

Question 53

what kind of muscle coordination is the fastigial nucleus in charge of

Answer 53

eye movements, posture, balance

Question 54

what kind of muscle coordination is the interposed nucleus in charge of

Answer 54

limb movements (pose for a funny picture!)

Question 55

what kind of muscle coordination is the dentate nucleus in charge of

Answer 55

skilled learned movements (like how a dentist needs to be skilled)

Question 56

what is the general pathway to determine cerebellar motor pathways

Answer 56

sensory --\> cerebellar functional structure --\> cerebellar deep nuclei --\> target nuclei --\> target

Question 57

what is the cerebellar pathway for eye movement

Answer 57

vestibular flocculonodular lobe fastigial nuclei vestibular nuclei MLF

Question 58

what are the symptoms of impaired cerebellar function of eye movement

Answer 58

impaired vestibulo-ocular reflex impaired nystagmus ocular dysmetria (overshoot and undershoot saccades)

Question 59

what is the cerebellar pathway for postural control

Answer 59

proprioceptive and vestibular cerebellar vermis fastigial nucleus vestibular nucleus medial motor system (vestibulospinal)

Question 60

what are the symptoms of impaired cerebellar postural control

Answer 60

impaired ability to sit and stand without support vertigo

Question 61

what is the cerebellar pathway for truncal balance

Answer 61

proprioceptive and vestibular cerebellar vermis fastigial nucleus vestibular and reticular formation medial motor system (vestibulospinal and reticulospinal)

Question 62

what is the cerebellar pathway for appendicular movement

Answer 62

proprioceptive intermediate hemisphere interposed nucleus VA/VL lateral motor system

Question 63

what are the symptoms of cerebellar dysfunction of appendicular movement (ataxia)

Answer 63

- impaired on finger-nose-finger task - impaired on heel-shin test - impaired rapid alternating movements - incoordination during limb movement

Question 64

what is the cerebellar pathway for learned skilled movements

Answer 64

pontocerebellar lateral hemisphere dentate nucleus VA/VL nuclei lateral motor system

Question 65

what are the symptoms of cerebellar dysfunction of learned skilled movements

Answer 65

- impaired rapidity & precision of performing skilled movements (e.g.playing piano) - impaired ability to learn new skilled motor tasks