Section 2: Notes Flashcards
the lateral ventricle covers the ___ and ___
hypothalamus and thalamus
cognitive deficits signal what part of the brain?
forebrain
what is the striatum?
caudate, putamen
what is the basal gang.?
caudate, putamen, globus pallidus, substantia nigra, and subthalamus
what part of the brain is the basal gang. located in?
forebrain (gp, caudate, putamen are)
what structures are in the limbic system?
amygdala, anterior part of cingulate gyrus, orbital and medial prefrontal gyri, ventral parts of basal gang., hippocampus, parts of thalamus
what causes the cavity in the ventral lateral surface of the anterior horn of the lateral ventricle
head of the caudate
a hollow on the ventral medial surface of the inferior horn is produced by the____.
hippocampus.
the hole piercing the third ventricle made by the ____
massa intermedia
the “beak” of the third ventricle is surrounded by the ____
hypothalamus
he medial surface of the posterior horn normally abuts the ____.
calcarine sulcus
the _____ lies above the fourth ventricle
cerebellum
what forms the floor of the 4th ventricle?
the contiunation of the tegmentum into the pons
what does the blood brain barrier protect the brain from?
- sever flucations in ionic concentrantions - toxic compounds - circulating hormones and NT released in other parts of the body
The actual locus of the BBB is the capillary endothelium which is specialized by having what three things?
1) tight junctions between capillary endothelial cells 2) few endocytotic vesicles for intracellular transport 3) a high number of mitochondria indicative of high levels of oxidative metabolism.
what 3 methods is entry into the brain achieved?
- diffusion (lipid solube) 2. facilitative and energy depend. transport (water sol. like glucose and a.a.) 3. ion channels
how do molecules get to the blood from the brain
a reverse pump in astroglia transpots lipophilic molecules back out
how do some whole moelcules get into the blood brain barrier (like ymphocytes and macrophages)
a mechanism that opens tight junctions (implicated in disease with MS lymphocytes and HIV infected macrophages)
what are 3 examples in which the blood brain barrier breaks down
brain tumor, bacterial invasion, ischemia
ischemic directly damages cells ____ pumps
NA and K
what are some of the causes of edema with stroke?
ischemia alters na and k channels ionic influx causes cells to swell
csf is in equilibrium with
brain extracellular fluid
what is the total volume of csf? how much is made per day?
140 ml is total volume, 500 ml made per day so a lot of turn over (3-4x)
what secretes csf?
choroid plexus
choroid plexus consists of a specialized capillary network surrounded by a___ or ___ epithelium
cuboidal or columnar
what accounts for the continuous production of CSF and active transport of metabolites?
epithelial cells form a barrier that is responsible for carrier-mediated active transport that is bi-directional.
what is lower in blood plasma compared to CSF?
conentrations of K, Ca, bicarbonate, glucose, and protein
CSF is more ____ than blood plasma
acidic
what is the normal color of CSF?
clear; no rbcs and veyr few wbcs
where does most of the csf go after flowing through the 4th ventricle
exits via foramen magendie or formaina lusckha, not the spinal cord
CSF continues to flow over the whole brain and spinal cord beneath the arachnoid mater in the ___
subarachnoid space
CSF flows slowly over the convexities of the cerebral hemispheres until it reaches the___in the walls of the dural sinuses,
arachnoid villi
2 common spots for flow of csf to be obstructed are the
interventricular foramen or at the cereberal aqueduct
obstructiing hydrocephalus is also called ___
non communicating hydrocephalus
what is cause of communicating hydrocephalus
the arachnoid villi are diseased and absorption fails
with increase intercranil pressure ____ LOBE FUNCTION is often compromised
FRONTAL
papilledema is caused by swelling of the ___
optic nerve
what can cause increased protein content in csf?
changes in vascualr permeability or csf dynamics
assocaition fibers connect
different areas of cortex in the same hemisphere;
projection fibers connect
connect areas of cortex to lower areas of the neuraxis
where does the superior longitudinal fasiculus extent to?
from the frontal lobe to the temporal lobe to the occipial lobe
uncinate fasciculus runs deep to the
limen insulae
uncinate fasciculus interconnects orbital frontal cortex-based reward and punishment centers with
temporal lobe based memory representations
what does the cingulum connect?
structures of the limbic system
what deep white matter tract may be involved in the process to avoid painful stimuli
cingulum
The frontal lobes are connected through the
genu of the corpus callosum
parietal lobes are connected through the
body of the corpus callosum
occipital lobes (notably visual cortex) are connected via the ____
splenium of the corpus callosum
the ___ connects the anterior poles of the two temporal lobes
anterior commisure
the ___ connects the two fornices, connecting the two hippocampi
hippocampal comissure
the posterior commisure connects the two
sides of the rostral midbrain
what are the corona radiata
Projection fibers interconnect the cortex with nuclei at lower levels of the neuraxis.
As the axons of the corona radiata pass medial to the lenticulate nucleus they are called the
internal capsule.
Axons whose targets are in the ___ and ___ descend onto the anterior aspect of the midbrain as the crus cerebri.
rainstem and spinal cord
Then look at the roof of the anterior horn of the lateral ventricle and see the crossing fibers of the ___
corpus callosum.
what are the fibers going from the internal capsule to the temporal lobe called/
auditroy radiation
the INTERNAL CAPSULE is the neck of the funnel in which massive cables of axons (corona radiata) carry information from thalamus to cortex and from cortex to
thalamus, basal ganglia, brainstem and spinal cord.
anterior limb of the internal capsule carries informaiton to and from the
frontal lobes
what is the lenticular nucleus?
putamen and the globus pallidus
what does the crus cerebri carry?
motor functions going from the cortex to the brain stem and spinal cord
