Chapter 2: Basic Science Concepts

Question 1

Substrate (or Ligand)

Answer 1

A substance that creates a signal or produces an effect by binding to a receptor, enzyme, or transporter

Question 2

Endogenous

Answer 2

A substance that is produced by the body

Question 3

Exogenous

Answer 3

A substance that is produced outside of the body

Question 4

Agonist

Answer 4

A substrate that combines with a receptor to initiate a reaction

Question 5

Antagonist

Answer 5

A substance that reduces or blocks a reaction

Question 6

Induction

Answer 6

When a substance increases the activity of an enzyme

Question 7

Inhibition

Answer 7

When a substance decreases or blocks the activity of an enzyme

Question 8

The Central Nervous System (CNS) includes…

Answer 8

the brain and spinal cord

Question 9

the CNS controls the functions of the rest of the body by sending signals to the…

Answer 9

Peripheral nervous system (PNS)

Question 10

The PNS is comprised of two main systems:

Answer 10

Somatic nervous system
Autonomic nervous system

Question 11

Somatic nervous system

Answer 11

Voluntary
- controls muscle movement

Question 12

Autonomic nervous system

Answer 12

Involuntary
- digestion
- cardiac output
- blood pressure

Question 13

neurotransmitters

Answer 13

substrates that act as the body’s chemical messengers

Question 14

Acetylcholine (ACh)

Answer 14

The primary neurotransmitter in the somatic nervous system
- binds nicotinic receptors in skeletal muscle to affect muscle movement

Question 15

The two main divisions of the autonomic nervous system

Answer 15

Parasympathetic & Sympathetic

Question 16

Parasympathetic nervous system

Answer 16

• “rest and digest”
• Releases ACh -> binds muscarinic receptors
• triggers SLUDD

Question 17

SLUDD

Answer 17

• Salivation
• Lacrimation
• Urination
• Defication
• Digestion

Question 18

Sympathetic Nervous System

Answer 18

• “fight or flight”
• Releases Epi and NE
• bind adrenergic receptors (a1, b1, b2)
• causes increased HR, BP, bronchodilation, glucose production

Question 19

agonist

Answer 19

a substance that binds to and activates a receptor

Question 20

antagonist

Answer 20

a substance that binds to a receptor but does not produce a reaction

Question 21

Competitive inhibition

Answer 21

When an antagonist binds the same site as an agonist

Question 22

Noncompetitive inhibition

Answer 22

when an antagonist binds at a site other than the active site (called an allosteric site) which changes the shape of the active site and prevents the agonist from binding

Question 23

Muscarinic receptor

Answer 23

Endogenous substrate: ACh
Agonist action: inc SLUDD
Drug agonists: Pilocarpine, bethanechol
Drug antagonists: atropine, oxybutynin

Question 24

Nicotinic Receptor

Answer 24

Endogenous substrate: ACh
Agonist action: increased HR & BP
Drug agonists: Nicotine
Drug antagonists: neuromuscular blockers (ex rocuronium)

Question 25

Alpha 1 Receptor (mainly peripheral)

Answer 25

Endogenous substrate: Epi & NE Agonist action: Smooth muscle vasoconstriction & increased BP Drug agonists: Phenylephrine, dopamine Drug antagonists: doxazosin, carvedilol, phentolamine

Question 26

Alpha 2 receptor (mainly brain, central)

Answer 26

Endogenous substrate: Epi & NE Agonist action: decreased release of Epi & NE -> decreased BP and HR Drug agonists: Clonidine, brimonidine Drug antagonists: ergot alkaloids, yohimbine

Question 27

Beta 1 receptor (mainly heart)

Answer 27

Endogenous substrate: Epi & NE Agonist action: inc myocardial contractility, CO and HR Drug agonists: Dobutamine, Isoproterenol, dopamine Drug antagonists: Beta 1 selective BB (metoprolol) & non-selective BB (propranolol, carvedilol)

Question 28

Beta 2 receptor (mainly lungs)

Answer 28

Endogenous substrate: Epi Agonist action: Bronchodilation Drug agonists: albuterol, isoproterenol, terbutaline Drug antagonists: non-selective BB (propranolol, carvedilol)

Question 29

Dopamine receptor

Answer 29

Endogenous substrate: dopamine Agonist action: Lots o' stuff (inc renal, cardiac, & CNS effects) Drug agonists: levodopa, pramipexol Drug antagonists: first gen APS (haloperidol), metoclopramide

Question 30

Serotonin receptor

Answer 30

Endogenous substrate: Serotonin Agonist action: Lots o' stuff (inc platelet, GI, and psych effects) Drug agonists: Triptans (sumatriptan) Drug antagonists: ondansetron, second gen APS (quetiapine)

Question 31

Acetylcholinesterase

Answer 31

Action: Breaks down ACh Drug example: Acetylcholinesterase inhibitors (donepezil, rivastigmine, galantamine) -> block ACh-esterase -> inc ACh levels, used to treat Alzheimer's

Question 32

Angiotensin-converting enzyme (ACE)

Answer 32

Action: converts angiotensin 1 to angiotensin 2 (a potent vasoconstrictor) Drug example: ACE inhibitors (lisinopril, ramipril, etc) -> inhibit production of angiotensin 2 -> decreased vasoconstriction and aldosterone secretion * used to treat hypertension, HF, and kidney disease

Question 33

Catechol-O-methyltransferase (COMT)

Answer 33

action: breaks down levodopa drug example: COMT inhibitor (entacapone) -> blocks COMT enzyme -> prevents breakdown of levodopa -> treats Parkinsons

Question 34

Cyclooxygenase

Answer 34

Enzyme that converts arachidonic acid to prostaglandins (inflammation) and thromboxane A2 (platelet aggregation) Drug example: COX inhibitors (NSAIDS: aspirin, ibuprofen) -> decreased prostaglandins and thromboxane A2 -> treats pain and inflammation and decreases platelet activation

Question 35

Monoamine oxidase

Answer 35

Enzyme that breaks down catecholamines (DA, NE, Epi, 5-HT) Inhibitor examples: phenelzine, tranylcypromine, isocarboxazid, selegiline, rasagiline, methylene blue, linezolid -> block MAO -> inc catecholamine levels -> treats depression * if catecholamine levels are too high it can cause hypertensive crisis or serotonin syndrome

Question 36

Phosphodiesterase

Answer 36

Enzyme that breaks down cGMP (a smooth muscle relaxant) Inhibitor example: PDE-5 inhibitors (sildenafil, tadalafil) -> prevent breakdown of cGMP -> prolong smooth muscle relaxation -> treat erectile dysfunction

Question 37

Vitamin K epoxide reductase

Answer 37

enzyme that converts vitamin K to the active form required for production of select clotting factors inhibitor example: Warfarin -> decreases production of clotting factors for anticoagulant effect

Question 38

Xanthine oxidase

Answer 38

enzyme that breaks down hypoxanthine and xanthine into uric acid inhibitor example: allopurinol -> decreases uric acid production to prevent gout attacks