BBB And Cerebrospinal Spinal Fluid

Question 1

What is BBB formed by

Answer 1

Tight junctions between endothelial cells of brain capillaries
Astrocyte projection supporting and maintaining pressure
Basal BM

Question 2

Primary BBB function

Answer 2

Providing selective nutrient passage, controlling fluid movement, protecting from toxins, microbes

Question 3

BBB permeability

Answer 3

Can change due to inflammation, irradiation, tumours
Permeant molecules (lipid soluble)- steroid hormones; O, CO2, water, glucose, essential aa, certain electrocutes
Impermeant molecules- non- essential aa, waste products, microbes, toxins, proteins, K, water soluble drugs

Question 4

BBB in circumventricular - sensory organs

Answer 4

Sense plasma molecules, coordinate response to them
Area postrema/ vom senses harmful substance and vom
Subfornical organ
Vascular organ of laminated terminalis

Question 5

BBB in circumventricular organs- secretory organs

Answer 5

Receive stimuli, secrete substances directly in plasma
Post pit, median eminence of hypothalamus, pineal gland

Question 6

CSF circulates through

Answer 6

Ventricular system (lat, 3, 4, central canal of spinal cord)
Sub arachnoid space surrounding brain, spinal cord
Kept in motion by cilia of ependymal cells lining ventricle system

Question 7

Production of CSF

Answer 7

By choroid plexuses which is a network of capillaries, modified ependymal cells in ventricles also functions as blood CSF barrier
It’s regulated by hormones, bp, auto NS

Question 8

Lumbar puncture

Answer 8

Between L2 L3

Question 9

CSF function

Answer 9

Trauma absorbed mech energy
Buoyancy to weight
Decreases quantity to relieve intracranial pressure when is he is
Clears toxic metabolites
Transportation medium for chemical signals, nutrients