The Blood-Brain Barrier (BBB)

Pataasin ang iyong marka sa homework at exams ngayon gamit ang Quizwiz!

the BBB contains tight junctions. What are tight junctions?

intercellular junctions that are tight and don't freely allow diffusion

why is the modification of a drug of concern to physicians and pharmacists?

it can alter the drugs activities and physical properties

blood-brain barrier

semipermeable system that prevents some chemicals from passing from the blood stream to the brain

what is the principal energy source for brain cells?

glucose

what are the main functions of the blood brain barrier?

-help provide neurons with their exact nutritional requirement (glucose) -maintain the proper ion balance within the brain -isolate the brain from certain chemicals

name three methods pharmacist used to make drugs acceptable to the BBB:

-making it more soluble into lipids rather than water -make it look like natural substances that are actively transported through the BBB -inject highly concentrated sugar solutions into the arteries that supply the brain with blood so that the endothelial cells shrink to allow the drugs to diffuse

how is your blood glucose levels maintained?

A hormonal system including the hormones insulin and glucagon

what is the composition of the blood brain barrier?

A single layer of tile like endothelial cells that line the inner surface of capillaries in the brain; outside of the brain, the capillaries have large gaps but inside the brain they are tightly packed

of all the drugs prescribed and taken, how many actually into the brain?

A small amount

where does a second barrier similar to the BBB exist?

behind the retina

What is the main factor that determines whether a drug can pass the BBB? Why?

solubility in water and in lipids; cell membranes are composed partially from lipids so substances dissolved into lipids can pass through the membrane while substances that are dissolved in water cannot pass through the membrane because the lipids are hydrophobic

when does the BBB present a problem to physicians who are trying to treat a patient who is seriously ill and why?

when the disorders to be treated involve the brain and brain functions because the drugs are stopped by the blood brain barrier and cannot effectively treat it


Kaugnay na mga set ng pag-aaral

Self-Test 1-1: Business Process Cycles and Transactions

View Set

Chapter 5 - Elasticities of Demand and Supply

View Set

Oxygenation, Asthma RSV, Bronchiolitis and the Pediatric Airway

View Set

John Henry EXW COMBAT LOGISTICS FUNDAMENTALS

View Set

Chapter 1 - Introduction to Organizational Behavior

View Set

Social Psych. Chapter 4: Social Perception

View Set

AAPC Module 3 Fundamentals of Medicine

View Set