Blood Brain Barrier

Question 1

The ________ barrier is the barrier between blood and extracellular fluid and is composed of ________.

Answer 1

Blood/brain, endothelium

Question 2

The ________ barrier is the barrier between blood and CSF and is composed of ________.

Answer 2

Blood/CSF, epithelium (tight ependyma)

Question 3

What separates endothelial cells from astrocytes?

Answer 3

Basement membrane

Question 4

Unlike in the dura mater, the blood vessels within the arachnoid mater and pia mater are _________ and have ________.

Answer 4

Nonfenestrated, tight junctions

Question 5

The specialized endothelial cells of the brain lack ________ vesicles.

Answer 5

Pinocytotic

Question 6

The ________ space allows for the circulation of CSF via the pulsatile nature of arterial vessels.

Answer 6

Perivascular (Virchow-Robin)

Question 7

The basal lamina supports the ________ surface of the endothelial cells and shares it with ________ and ________.

Answer 7

Abluminal, pericytes, astrocytes

Question 8

What transmembrane protein is involved in cell adhesion to the basil lamina?

Answer 8

Integrins

Question 9

________ are responsible for regulating endothelial cell proliferation, survival, migration, differentiation, and branching.

Answer 9

Pericytes

Question 10

How are pericytes in the brain distinguished from pericytes elsewhere in the body?

Answer 10

Lack α-actin (non contractile)

Question 11

Which cells envelop 99% of BBB endothelia and help determine BBB function, morphology, and protein expression?

Answer 11

Astrocytes

Question 12

What four things are restricted from passing through the BBB?

Answer 12

Large molecules

Low lipid soluble molecules

High electrically charged molecules

Toxins/drugs

Question 13

What is the difference in electrical resistance between pial vessels and cerebral microvessels?

Answer 13

Pial: 1500-2000 ohms cm^2

Cerebral microvessels: 8000 ohms cm^2

Question 14

________ are only a point of fusion of cell membranes and do not surround the entire cell. These types of tight junctions are found in ________ cells.

Answer 14

Macula occludens, ependymal

Question 15

________ proteins bring opposing cell membranes together.

Answer 15

Occludin

Question 16

________ proteins are what forms the primary seal for a tight junction.

Answer 16

Claudin

Question 17

Claudin is a ________ (size) phosphoprotein and has ________ transmembrane domains.

Answer 17

22kDa, 4

Question 18

Occludins are ________ (size) phosphoproteins and allow for binding to the ________.

Answer 18

65kDa, cytoskeleton

Question 19

Which adhesion molecules are members of the immunoglobulin superfamily?

Answer 19

Junctional adhesion molecules (JAM)

Question 20

Due to the BBB utilizing active transport, there are a greater number of ________ in cerebral endothelia as compared to the peripheral endothelia.

Answer 20

Mitochondria

Question 21

The BBB acts as an ________ by metabolizing drugs and nutrients coming from the blood. Some of these enzymes are ________ (3).

Answer 21

Enzymatic barrier

γ-glutamyl transpeptidase, alkaline phosphatase, aromatic acid decarboxylase

Question 22

The capillary wall thickness in the brain is ________ thinner than in peripheral capillaries.

Answer 22

40%

Question 23

The polarity between the luminal and abluminal surfaces of the BBB refers to having different ________ that perform different functions on each side.

Answer 23

Proteins

Question 24

The two major pathways of transport across the BBB are ________ and ________.

Answer 24

Lipid mediation - passive diffusion, catalysed transport

Question 25

Catalysed transport can be broken down into ________ and ________.

Answer 25

Carrier mediated, receptor mediated

Question 26

Carrier mediated transport occurs in ________ and can be either ________ or ________.

Answer 26

millisecs, facilitated diffusion (no ATP), active transport (ATP)

Question 27

Receptor mediated transport usually takes ________ to occur.

Answer 27

Minutes

Question 28

What are the two components of the Blood/CSF barrier?

Answer 28

Fenestrated choroidal capillaries and tight junctions between choroidal epithelium

Question 29

Brain structures that require contact with peripheral blood for monitoring and normal function are known as ________.

Answer 29

Circumventricular organs (CVOs)

Question 30

Circumventricular organs are in contact with walls of the ventricular system and is a functional interface between the ________ and ________ systems.

Answer 30

Nervous, endocrine

Question 31

What are some of the CVO’s?

Answer 31

Subfornical organ Lamina terminalis Median eminence Pineal gland Area postrema

Question 32

The ________ allows for hormones to pass quickly from the hypothalamus to the pituitary gland.

Answer 32

Median eminence

Question 33

The ________ monitors blood stream and can induce vomiting upon detection of toxins.

Answer 33

Area postrema

Question 34

Which drugs will the brain uptake 68% of in 30 sec?

Answer 34

Heroin, morphine

Question 35

________ is a drug that is able to cross the BBB and is used as a therapy for Parkinson’s disease.

Answer 35

L-dopa

Question 36

________ is used to decrease ICP by drawing fluid out of the subarachnoid space and back into circulation.

Answer 36

Hyperosmotic mannitol

Question 37

________ helps get chemotherapy drugs into the brain by using ________ that the BBB already has.

Answer 37

RMP-7, receptors

Question 38

________ can get across the BBB and can be paired with treatments for brain cancer.

Answer 38

Docosahexanoic acid (DHA)

Question 39

________ are highly lipophilic and are able to cross the BBB.

Answer 39

Flavonoids

Question 40

The ________ concept is the idea that you can link certain drugs to lipophilic molecules to get them across the BBB and then once the lipophilic molecule is broken down, the drug is released and can’t get back out.

Answer 40

Brain targetor