2. Basic Science Concepts Flashcards
Define Substrate (or Ligand)
A substance that creates a signal or produces an effect by binding to a receptor, enzyme, or transporter
Define Endogenous
A substance that is produced by the body (such as a naturally-produced substrate)
Define Exogenous
A substance that is produced outside of a body (such as a drug or other chemical)
Define Agonist
A substance that combines with a receptor to initiate a reaction. Can be endogenous or exogenous (mimicking an endogenous substrate)
Define Antagonist
A substance that reduces or blocks a reaction. Can be endogenous or exogenous.
Define Induction
When a substance increases the activity of an enzyme
Define Inhibition
When a substance decreases or blocks the activity of an enzyme
The central nervous system (CNS) includes 2 parts: __ and ___
brain and the spinal cord
The peripheral nervous system includes 2 main systems. Explain both.
Somatic - voluntary (muscle)
Autonomic - involuntary (GI, CV)
____ is the primary neurotransmitter involved in the somatic nervous system. It is released in response to neuron signals and binds to __ receptors in ___ muscles to affect muscle movement.
ACh (acetylcholine)
Nicotinic receptors
Skeletal muscles
____ is known as the “rest and digest” system
Parasympathetic nervous system
How does the parasympathetic nervous system work?
Releases ACh, which binds to muscarinic receptors throughout the body
Results in physiologic response known as SLUDD (salivation, lacrimation, urination, defecation, and digestion)
What happens when parasympathetic nervous system is activated?
SLUDD = Salivation, lacrimation, urination, defecation, and digestion
____ is known as the “fight or flight” system
Sympathetic nervous system
How does the sympathetic nervous system work?
Releases Epi or NE which acts on adrenergic receptors (alpha-1, beta-1, and beta-2) in CV and respiratory systems
Results in increased BP, HR, and bronchodilation
What happens when sympathetic nervous system is activated?
Increased BP, HR, and bronchodilation
Stimulation of beta-2 receptors in GI tract = increased glucose production to provide muscles with oxygen and energy
Where do you typically find alpha-1 receptors? beta-1? beta-2?
Alpha-1 = smooth muscles, including blood vessels
Beta-1 = heart (1 = 1 heart)
Beta-2 = lungs (2 = 2 lungs)
Vasopressors, such as __ and ___, stimulate multiple receptors, including ___ and ___, leading to increased vasoconstriction, HR, and BP.
Epi, NE
alpha-1 and beta-1
Clonidine is a central acting ___ adrenergic agonists. What does it do?
alpha-2
Stimulates presynaptic alpha-2 receptors located in the brain, decrease in overall sympathetic output (NT release) –> vasodilation (decreased BP) and decrease in HR
Endogenous substrate of muscarinic receptors?
ACh
Endogenous substrate of nicotinic receptors?
ACh
Endogenous substrate of alpha-1 receptors (mainly peripheral)?
Epi, NE
Endogenous substrate of alpha-2 receptors (mainly brain; central)?
Epi, NE
Endogenous substrate of beta-1 receptors (mainly heart)?
Epi, NE
