George test 1 Flashcards
what does grey matter consist of?
cell bodies, dendrites, unmyelinated axons, and glia in the CNS
what does white matter consist of?
myelinated axons and glia in the CNS
within white matter what does association refer to?
Within cerebral hemisphere
within white matter what does comissural refer to?
Between each hemisphere
within white matter what does projection refer to?
Connect cerebrum to other parts of the brain or spinal cord
basal ganglia, hippocampus and amygdala are located where?
referred to as allocortex
what is the function of the precentral gyrus?
Primary Motor Cortex (voluntary motor control)
Premotor & Supplementary Motor Cortex (motor planning)
what is the function of the superior frontal gyrus?
Frontal eye fields (eye tracking)
what is the function of the inferior frontal gyrus?
Broca’s Area (speech production)
Prefrontal Cortex* (Executive function, decision-making)
what is the function of the gyrus rectus/orbital frontal gyrus?
Olfactory Processing
where is the prefrontal cortex and what is its function?
Most of the area rostral to the primary, premotor and supplementary motor cortices is called “Prefrontal Cortex”. The PFC is responsible for cognition, metacognition, personality, executive function, decision-making.
what is brocca’s aplasia?
Distinct lesion in the left hemisphere, around the opercular and triangular parts of the inferior frontal gyrus leading to loss of ability to speak sometimes only saying one word
insula has what two functions?
limbic and gustatory (tasting)
what is the function of postcentral gyrus of the parietal lobe?
Primary somatosensory cortex (somato-sensation)
what is the function of the inferior parietal lobule/Supramarginal gyrus Angular gyrus?
Language comprehension (border with temporal & frontal lobes) Spatial orientation and preception Movment across visual fields (“dorsal stream”)
Patients with damage to the right parietal lobe tend to lose all attention to which space?
their left hemi-space.
what is the function of the superior temporal gyrus?
Primary auditory cortex
Wernicke’s Area (speech comprehension)
what is the function of the Middle temporal gyrus, Inferior temporal gyrus, and Fusiform gyrus?
High-order and visual processing (details, color, “ventral stream”)
where is there damage in wernicke’s aplasia and how does it present?
can produce words but cannot make sentences or comprehend. damage to the left superior temporal gyrus
what is the function of the Calcarine sulcus (and surrounding cortex of cuneus and lingual gyrus) of the occipital lobe?
Primary visual cortex (V1)
Area 17*
what is the function of the Rest of cuneus, lingual gyrus, and lateral occipital gyri of the occipital lobe?
Visual association cortex (V2)
Area 18*
how does cortical blindness present?
patients cannot consciously perceive any visual stimuli, but their eyes are working (somewhat) normally. must be bilateral damage to occipital lobe
what is the function of Parahippocampal gyrus/uncus areas thatbecome the amygdala and hippocampus, medially?
These areas are related to memory formation (both) and primitive emotions (amygdala)
where does the diencephalon “meet” the cerebral hemispheres, connecting the older brain areas to the newer?
the insula and basal ganglia
what is the basic function of thalamus?
Major sensory relay and gatekeeper for conscious perception
what is the basic function of subthalamus?
Works with basal ganglia to make fixed action patterns
what is the basic function of Epithalamus
(inc. pineal gland and habenula)?
Motivational drives (habenula) and melatonin secretion (pineal)
damage to what are my reduce motivational drive?
habenula
what is the function of the superior colliculus?
receives visual (and other sensory input) and coordinates eye, head and neck movements in response
what is the function of the inferior colliculus?
receives auditory information and is necessary for auditory perception
what is the function of the cerebellar hemisphere?
Largest part of cerebellum, coordinates complex movement, receive proprioceptive input
what cranial nerve is at the level of the cerebral hemisphere?
CN I
what cranial nerve is at the level of the diencephalon?
CN II
what cranial nerves are at the level of the midbrain?
CN III, CN IV
what cranial nerves are at the level of the pons?
CN V, CN VI
what cranial nerves are at the level of medulla?
CN VII-CN X maybe CN XI-XII ??? not on slide but says 6
what is the projectile bundle/tract called when it is in the cerebral hemisphere?
corona radiata
what is the projectile bundle/tract called when it is in the diencephelon?
internal capsule
what is the projectile bundle/tract called when it is in the midbrain?
Cerebral Peduncles/
Crus Cerebri
what is the projectile bundle/tract called when it is in the pons?
basal pons/ basal pontis
what is the projectile bundle/tract called when it is in the medulla?
medullary pyramids or just pyramids
Spinal cord reflexes, the simplest of the neural pathways, take place ipsilaterally or contralateraly?
ipsilateraly
in tactile sensation (touch or pain) when do the axons of the 2 degree nuerons decussate?
In the pain (and temperature) pathways, this decussation takes place in the spinal cord
-In basic touch pathways, this decussation takes place in the brainstem
-Therefore, all conscious, tactile sensory information that enters on one side of the body will be represented in the CNS contralaterally
where do basic pain and touch pathways converge in the brain?
thalamus 2nd synapse on 3rd
damage to the the spinal cord fibers (tract) of the pain pathway (which are 2˚ neurons) will cause symptoms to occur where?
contralateraly
Damage to the spinal cord fibers (tract) of the basic touch pathway (which are primary afferents) will cause symptoms to occur where?
ipsilateral symptoms
damage along the afferent unconscious proprioception pathway will have what sort of symptom presentation?
ipsilateral this info feeds into cerebellum/ no decussation
what is the pathway for efferent voluntary motor control?
Upper motor neurons (UMNs) originate in the primary motor cortex
This is also a 2-neuron chain
UMN axons descend through the corona, internal capsule, etc. and decussate in the pyramids
LMN’s synapse with the UMN’s in either the brainstem (cranial nerve nuclei) or the spinal cord (ventral horns)
if you have damage in your left motor cortex where would symptoms present for VMC?
right side contralateral to the damage because nuerons decussate in pyrmaids
if you damage the grey matter of the spinal cord how would symptoms present for VMC?
ipsilateral symptom presentation because neurons have already decussated in pyramids
If your left hand was numb to temperature and to basic touch, where might you suspect damage?
in the periphery but this would also be associated with motor loss or in the right brain stem also would probably have motor loss CORTEX MOST LIKLEY
when does the majority of neuronal production and migration occur?
Most neuronal production and migration occurs during the third through fifth months of development
what vitamin greatly reduces the risk of Neural tube defects?
folic acid
what is the embryological origin of CNS cells? (brain and spinal cord)
CNS cells differentiate from cells derived from neural tube (neuro-ectoderm)
when do rostral and caudal neurpores close?
around 24-26 days
what is the embryological origin of microglia cells?
*****
neuromesodermal or mesenchymal origin
what are PNS cells derived from?
PNS cells differentiate from neural crest cells
e.g., dorsal root ganglia, sympathetic chain, etc
what is the embryological origin of the pons and cerebellum?
metencephelon
what does the myencephalon become?
medulla
what does the telencephalon become?
Cerebral cortex Subcortical white matter Deep cerebral nuclei (Basal ganglia, Hippocampus, Amygdala) Olfactory bulb & tract Lateral ventricles The Cerebrum
what does the dyencephalon from?
Thalamus Hypothalamus Epithalamus (pineal) Optic cup 3rd ventricle
what does the mesencephalon become?
midbrain
what makes CSF and where is it located?
Choroid plexus is vascular tissue + pia + ependymal cells
Makes CSF
Not in aqueduct or central canal
found in later ventricle third and fourth ventricle
what is the cause of Holoprosencephaly?
Telencephalon fails to split into right and left hemispheres
(may also involve diencephalon) midline defects
what is a Schizencephaly and cause?
-characterized by abnormal slits or clefts in the cerebral hemispheres of the brain.
1st trimester infection, insufficient fetal blood supply, genetic mutation
what is Heterotopias?
-clumps of grey matter (ectopic nodules of neurons) located in the wrong part of the brain.
1st trimester infection, insufficient fetal blood supply, genetic mutation
what is Lissencephaly
-smooth braion absense of gyri
1st trimester infection, insufficient fetal blood supply, genetic mutation
how does the pontine flexure form?
the pontine flexure forms from the metencephalon fold over the myencephalon
where is sonic hedgehog
SHH ventrally initially secreted by notocord and floorplate
associated with motor neurons
where are Bone morphogenetic proteins secreted?
expressed in ectoderm (ECT) associated with sensory neurons
dorsal; expressed roofplate
what is the sulcas limitans?
division between ventral motor (Basal) and dorsal sensory plate (ala)
why are the lenticulostriate arteries referred to as the arteries of sudden death?
No anastomoses, They are much smaller than MCA
They have thin walls
Aneurysms difficult to detect
what is a lacunar stroke?
occlusion of small perferating artery leads to loss of small portion of brain tissue usually deep in white matter and asymptomatic
what is the significance of an internal capsule stroke?
A CVA in the internal capsule can mimic the effects of a MCA-ACA stroke
The internal capsule contains both ascending and descending fibers
CVA’s can be both sensory and motor
A small area damaged in the internal capsule carries diffuse fibers across the cortex
what artery does the posterior pituitary get?
inferior hypophyseal artery off of internal carotid
where does the insula get is blood supply from?
middle cerebral artery?
what does the posterior cerebral artery supply blood to?
Medial and inferior temporal and occipital lobes
Parahippocampal gyrus of limbic lobe
Perforating branches to hippocampus and thalamus
what structure connects the anterior and posterior blood supplies of the brain?
circle of willis connects middle cerebral artery to posterior cerebral artery through posterior communicating branch
the anterior inferior cerebral artery is a branch off what artery?
basilar artery
the posterior inferior cerebral artery is a branch off what artery?
vertebral artery
where do the superficial veins of the cerebrum drain?
drain into superior sagittal sinus
where do deep cerebral veins drain?
drain into straight sinus
what structure allows for transfer of motor commands from right and left sides?
corpus collosum
what vertebral level is the conus medualris at?
L1-L2
where would you want to do a lumbar puncture?
Within subarachnoid space
Inferior to conus medullaris
Between L4 & L5between L4-L5
at the dorsal horn of the spinal cord what cell bodies do you find?
cell bodies of sensory info 2nd neuron in chain
first neuron cell bodies of pseudounipolar neurons located in dorsal root ganglion
at the ventral horn of the spinal cord what cell bodies do you find?
cell bodies of motor neurons
what fibers does the lateral horn of the spinal cord contain and vertebral levels that contain these?
T1-L2 S2-S4, autonomic fibers
what dermatome are the nipples?
T4
what dermatome is the umbilicus?
T10
what dermatome is the pelvic rim?
L1
What dermatome is the big toe?
L5
what dermatome is the little toe and heel?
S1
what dermatome is the posterior thigh
S2
what myotome would be indicated for motor loss to most digital & wrist flexors?
median nerve c6-T1
what is the difference between fasciculus cuneatus and fasciculus gracilis?
FC located more laterally contains ascending fibers larger in cervical region.
FG located medilly on posterior side larger in thoracic region
where is the nucleus dorsalis present and what spinal tract is it a part of?
T1-L2 part of the dorsal spinocerebellar tract
also called clarkes nucleas
what diameter of neurons will you find in Lissauer’s Fasciculus
large more medially
What diameter fibers will you find in the Posterior Funiculus?
large
what is the function of renshaw cells?
Renshaw cells provide negative feedback on LMNs at level of spinal cord
Glycinergic
Large amounts in jaw and facial musculature
Blocked by strychnine
Convulsions
these are interneurons
what is found in the marginal zone of the rexed laminae?
Lamina I
pain and temperature afferent terminals, 2nd order cell bodies
some spinothalmic tracts
what is found in the Substantia Gelatinosa laminae 2 of the rexed laminae?
Interneurons that modulate activity of Pain and Temp Fibers
what is found in the nucleus proprius (laminae 3-4) of the rexed lamina?
Interneurons that receive input from non-nociceptive fibers
sensory processing
what is found in lamina V of the rexed lamina?
Terminals of GVAs, 2nd order cell bodies
what is found in laminae VI of the rexed lamina?
Terminals of proprioceptive afferents, 2nd order cell bodies
what is found in lamina VII
Contains both:
IML/Lateral horn (T1-L2, S2-S4)
Cell bodies of preganglionic autonomic cell bodies
Nucleus Dorsalis of Clarke (C8-L3)
Terminals of proprioceptive afferents, 2nd order cell bodies
T1-L2 posterior spinocerebellar tracts
T1-L3 preganglionic sympathetic neurons
what is found in lamina VIII
Interneurons and propriospinal neurons that receive input from UMN’s
what is found in lamina IX?
LMN’s that receive input from UMN’s
what is found in lamina X?
Mostly interneurons
where would you expect to find adult neural stem cells?
in the subventricular zone
how are layers 2 and 3 of the cortex connected between himispheres?
via the corpus collosum
what layer of the neocortex mostly recieves sensory info?
layer 4 thalomocortical synapes
what layer of the neocortex is the major output layer and contains large pyramidal neurons and corticocostriate fibers known as Betz cells?
layer 5
what cell types are cortical projection? (take info away from cortex)
pyramidal Betz fusiform
what cell types are cortical interneurons?
stellate (granular), chandelier, horizontal, basket, cell of mortinotti
how do cajal-retzius cells organize cortical migration and lamination?
through Reelin signals
what condition arises when there are mutations in the reelin signaling pathway?
Smooth brain or “lissencephaly” results when there are mutations in the reelin signaling pathways
what part of the cortex will have larger pyramidal neurons?
motor is larger sensory smaller
layers 2 and 3 of the neocortex have what function?
primarily send out commissural efferents
what will layer four of the neocortex have primarily?
cortical afferents primary sensory input
what will layers 5 and 6 of the neocortex primary have in them?
primarily Out: Basal ganglia, thalamus, brain stem, and spinal cord
what is the function and brodman area for precentral sulcus?
brodman area number four primary motor cortex
what brodman number is brochas?
44 45
what brodman number is the supplemental motor cortex and where is it located primarily?
posterior aspect of superior and middle frontal gyri as well as precentral gyri number 6
what brodman area is the primary somotosensory area?
postcentral gyri brodman number 3, 1, 2
what brodman area is the somoatosensory association area?
superior parietal lobule 5, 7
what brodman area is the angular gyrus?
39 inferior parietal lobe
Language comprehension (border with temporal & frontal lobes)
Spatial orientation and preception
Movment across visual fields (“dorsal stream”)
what brodman area is the supramarginal gyrus?
40 part if inferior parietal lobe
what is the function of the transverse temporal gyri and brodman number?
41 primary auditory cortex
what brodman area is the auditory association area?
42 transverse temporal gyri
what is the brodman number of wernickes area and location?
22 superior temporal gyri on left auditory association area
what brodman area is the primary visual area and name of area?
17 banks of calcarine sulcus
what is the brodman area for the visual association cortex?
18 19
what are considered left dominant traits?
Language
Calculation
Logic/Storytelling
what are considered right dominant traits?
Visuospatial Relationships
Music
Facial Recognition
what is the arcuate fasciculus?
a white matter bundle that connects brocca to wernick to the angular hyrus
what is apraxia?
Damage to different parts of LEFT frontal lobe result in an inability to willfully do a task
what is Alexia without agraphia
Able to write but unable to read
-Production of language and comprehension of speech intact
Caused by left PCA stroke
what is the function of Dorsolateral prefontal cortex (DLPFC):
Planning, solving problems, paying attention
what is the function of the Ventromedial prefontal cortex (?
Impulse control, processing of risk and fear, decision making
what is the superior colliculus associated with?
visual reflexes
what is the inferior colliculus associated with?
auditory reflexes
what aquaporin channels are important for CSF flow and regulating fluid homeostasis?
AQP 1 and AQP 4
what portions of the brain do not have trabelculae connecting the arachnoid matter to the dura matter?
Cisterna Magna
Pontine cistern
Lumbar cistern
how does csf access venous drainage?
csf drains into the venous system through the superior sagital sinus
what is a hydrocephalus and how do you get one?
a hydrocephalus is build up of CSF fluid in the brain pressure increases and ventricles get bigger usually caused by a blockage
hemispacial neglect is caused by what?
right superior parital lobule damage
function of lingual gyrus?
primary visual cortex
