Chapter 6

Question 1

What are psychoactive drugs?

Answer 1

substances that alter mood, thought, or behaviour, and used to manage neuropsychological illness

Question 2

What do we call the way a drug inters and passes through the body to reach its target?

Answer 2

Route of Administration

Question 3

Drugs injected into the bloodstream encounter the fewest barriers to the brain but must be ___________.

Answer 3

Hydrophilic

Question 4

Drugs that are prepared for inhalation or intravenous injections are much cheaper per dose, why?

Answer 4

Because the amount required is a lot sale than what’s needed for an oral dose

Question 5

Why is the passage of drugs across capillaries in the brain difficult?

Answer 5

Because of the blood-brain barrier

Question 6

What does the blood-brain barrier do?

Answer 6

it protects the brains ionic balance and denies neurochemicals passage in the brain. It also protects the brain for circulating hormones and toxic substances

Question 7

Capillaries are composed of a single layer of ___________ cells.

Answer 7

Endothelial cells

Question 8

Explain how Endothelial cells differ from in the brain and the rest of the body

Answer 8

Endothelial cells in capillary walls in the body are not joined, so substances can pass through. But in the brain, they are fused to form tight junctions, so most molecules can’t squeeze between them

Question 9

In brain capillaries, Astrocytes are attached to and cover most of the capillary wall, what exactly of they do here?

Answer 9

They provide a route for the exchange of food and waste between capillaries and the brains extracellular fluid

Question 10

The _________ is a source of many hormones secreted into the blood, and their release is triggered by other ________ carried to the _________ by the blood

Answer 10

Pituitary; hormones; pituitary

Question 11

The absence of a blood0brain barrier in the brainstems area allows toxic substances to enter from blood, how does our body react to this?

Answer 11

it triggers vomiting, so any ingested toxins in the stomach can come out

Question 12

What does the brain need to for fuel, and what does it need to build proteins

Answer 12

Oxygen and glucose, and amino acids

Question 13

What 2 ways do molecules cross the blood-brain barrier

Answer 13

1) Small molecules pass through the endothelial membranes (oxygen, carbon dioxide, lipid-soluble molecules)

2) Complex molecules are carried across the membrane by active transport systems or ion pumps (glucose, amino acids)

Question 14

When a drug enters the blood stream, the body begins to break it down through ________.

Answer 14

Catabolism

Question 15

Where does the body excrete drugs

Answer 15

urine, faces, sweat, breast milk, and exhaled air

Question 16

How does the liver play a part in eliminating drugs

Answer 16

to convert certain lipid-soluable molecules into a water-soluble form

Question 17

The liver houses a family of drug-catabolizing enzymes that break down different drugs into forms more easily excreted from the body, what is the drug?

Answer 17

Cytochrome P450 enzyme family

Question 18

What is the difference between antagonist drugs and agonists drugs

Answer 18

Agonists increase neurotransmission, and antagonists decrease neurotransmission

Question 19

All synapses on muscles are ___________, meaning they use ACh as their neurotransmitter

Answer 19

Cholinergic

Question 20

What are 2 drugs that influence ACh release from the axon terminal, explain what happens

Answer 20

Black widow spider venom = acts as an agonist by promoting the release of excessive amounts of ACh

Botulinum toxin = found in canned goods, and acts as an antagonist by blocking ACh release. The effects can lat for weeks and even months (can cause death)

Question 20

What happens when Botulinum toxin is injected into muscle?

Answer 20

It paralyzes the muscle, making it useful for blocking excessive and enduring muscular twitches.
Another word for Botulin is “botox,” commonly used for paralyzing facial muscles that cause wrinkling Nicotine

Question 21

Nicotine acts as an agonist to stimulate ___________ receptors. Nicotines molecular structure is similar enough to that of _____ to allow nicotine to fit into ____ receptors’ binding sights.

Answer 21

Cholinergic; ACh; ACh

Question 22

Early European explorers of South America discovered that the indigenous peoples living along the Amazon River killed small animals using arrowheads coated with curare prepared from the seeds of a plant. How were the indigenous not killed from ingesting curare?

Answer 22

Because curare cant pass from the gut into the body. This is why curare drugs have been synthesized

Question 23

What is an agonist for the enzyme acetylcholinesterase

Answer 23

physostigmine (obtained from an African bean)

Question 24

In small doses (because big doses disrupt movement and breathing), what can physostigmine be used to treat?

Answer 24

Myasthenia gravis, a condition of muscular weakness

Question 25

Organophosphates bind to AChE, allowing ACh to build up to toxic levels, where has Organophosphates been used?

Answer 25

As chemical weapons

Question 26

What are the 3 types of tolerance?

Answer 26

Metabolic tolerance, Cellular tolerance, and Learned tolerance

Question 27

What is metabolic tolerance?

Answer 27

when the number of enzymes needed to break down alcohol increases

Question 28

What is cellular tolerance?

Answer 28

where brain cell activities adjust to minimize the effects of alcohol in the blood

Question 29

What is learned tolerance?

Answer 29

A drop of visible signs of intoxication, people learn how to handle it

Question 30

What is sensitization?

Answer 30

the opposite of learned tolerance, its the increased reaction with continued drug use