FREE AND STUDY GAMES ABOUT BRAIN BARRIER SYSTEM

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FREE AND STUDY GAMES ABOUT BRAIN BARRIER SYSTEM

EXAM QUESTIONS

Actual Qs and Ans Expert-Verified Explanation

This Exam contains:

-Guarantee passing score -13 Questions and Answers -format set of multiple-choice -Expert-Verified Explanation Question 1: why are tight junctions only present in specialized ependymal cells?

Answer:

tight junctions r absent from ependymal cells everywhere else b/c it is important to allow xchanges of nutrients/wastes b/w brain tissue and CSF (no brain-CSF barrier) Question 2: how do we compensate for it being hard to deliver drugs to brain area

Answer:

we can give precursors or nasal sprays: (that bypass BBB and get in through nasal area)

Question 3: example of giving a precursor to bypass the BBB

Answer:

parkinson's disease (problem w voluntary control). need dopamine, but DA cannot cross BBB, so give the precursor to DA= L-dopa (it CAN cross BBB and body uses it to make DA)

Question 4: how much 02 does the brain consume at rest?

Answer:

20%

Question 5: when do you become unconscious from lack of oxygen or blood flow?

Answer:

1-2 minutes

Question 6: when do you become brain dead from lack of oxygen or blood flow?

Answer:

• min

Question 7: BBB is highly permeable to? (9 things)

Answer:

water, glucose, lipid-soluble substances like 02, CO2, alcohol, caffeine, nicotine, anesthetics, heroin Question 8: what are the two potential points of entry that must be guarded and what is each barrier subsequently called at those points?

Answer:

1)blood capillaries throughout the brain tissue (blood-brain-barrier or BBB) 2)capillaries of the choroid plexuses (blood-CSF barrier) Question 9: Blood-CSF Barrier: definition location and what is it composed of?

Answer:

barrier between bloodstream and CSF, located at choroid plexuses. It protects CSF from harmful substances. Formed from the specialized ependymal cells and the tight junctions between them.Question 10: Blood Brain Barrier (BBB): definition and what does it consist of?

Answer:

barrier between the bloodstream and brain tissue: protects brain from harmful substances. formed by capillary endothelium (including the endothelial cells and the tight jxns in between them), basement membr of endoth. and perivascular feet of astrocytes

Question 11: BBB is NOT permeable to? 2 things. what does this mean?

Answer:

proteins and antibiotics, which means its harder to deliver drugs to brain area (like antibiotics or cancer drugs).

Question 12: how do astrocytes function in terms of BBB?

*ensures that anything leaving blood must pass through cells and not between them

Answer:

astrocytes secrete a chem that is somehow resp 4 maintaining the special permeability char of the endoth cells. thru contact w their P feet, induce endo cells 2 form T jxns that completely seal off gaps bw them, = B capillaries "less leaky" (ensures that*

Question 13: brain barrier system

Answer:

strictly regulates which substances can get from the bloodstream into the tissue fluid of brain.