Podcast reviews Flashcards
Brain Capillaries have what kind of polarity?
Endothelial:
Basal and Apical
Route of transport in brain
tight junctions: keeps cellular route intracellular
Three components to BBB
basal lamina
pericytes
astrocyte foot processes
cover abluminal surface (surface that faces away from capillary lumen or towards the brain)
astrocyte foot processes
Cells that have sm. muscle properties
pericytes
Tight junctions limits mvmt of what type of agents
Tight jnx limit movment of water soluble agents
What pathway allows O2, CO2 and drugs and other lipophilic molecules?
Transcellular
Receptor mediated transcytosis use __________ and ________
insulin and transferrin
What is the process of transcytosis?
Plasma proteins (albumin) get surrounded by Cations
Can glucose move against the conc gradient?
No: its is non-E dependent
What is the metabolic barrier in the brain?
Enz system specific to BBB regulate composistion of brain interstial fluid
Astrocyte foot processes surround which surface?
Albuminal
What are the 3 functions of astrocytes?
- Regulate tight jnx (physical)
- Influence expression and polarization of transporters (transporter)
- Influence expression of enZ systems (metabolic)
How can you disrupt the BBB?
Down regulate proteins in tight jnx, break down basil lamina, influence secretion of proteins
What pathology is the BBB absent from?
brain tumors–thus amendable to chemotherapy
Methods to disrupt BBB
Stroke/trauma/infection/MS/HIV/Alzeihmers disease/Parkinsons/Epilepsy/Tumor/Pain
What organs lack a BBB
Circumventricular organs
Sensory receptors here require access to blood to monitor blood so it can send signal to ant. Pit for homeostasis purpose
Median eminense
6 Circumventricular Organs
area postrima pineal gland Choroid plexus of third ventricle Subfornical organ vascular organ of lamina terminalis Median Eminense
BBB have less/more pinocytotic vesicles
less
BBB has ________ and capilary has _________
tight…. gap
Veins of the Cerebrum have valves/no valves and are in how many groups?
No valves, 2 groups
What drains superolateral and medial surfaces of cerebral hemis?
Superficial Superior Vein
Where does the superficial superior vein empty into?
Superior Sagittal Sinus
What veins join the superior sagittal sinus at right angles?
Anterior superficials
What is the direction of blood flow?
angles are significant; blood flow it anterior→posterior
What keeps posterior veins from collapsing?
pressure keeps posterior veins from collapsing
Where is the superficial middle vein located?
In the Sylvian fissure
What does the superficial middle vein drain?
Lateral surface of cerebral hemisphere
Where does the superficial middle vein empty into?
Cavernous sinus
Where is the Superficial inferior vein located?
on Orbital surface of Frontal lobe + Inferior surface of temporal lobe
What two veins does the Superficial inferior vein turn into?
Orbital vv
Temporal vv
Orbital vv empties to :
Superior Sagittal Sinus
Temporal vv empties into:
Cavernous sinus (via middle cerebral veins)
Superior Anastomotic Veins connects what to what?
-Connect Superficial Middle Cerebral w/ Superior Sagittal Sinus
Called veins of Trolard
Inferior Anastomotic Veins (of Labbe) connects:
Connect Superficial Middle to Transverse sinus
Inferior Anastomotic Veins (of Labbe) runs over
runs over temporal lobe
Basal vein is made up of what two veins?
Anterior cerebral vein (drains medial aspect of cerebral hemis) + deep middle cerebral vein (drains insula and surrounding gyri)
-drains medial aspect of cerebral hemis
