Pharm PNS I Flashcards
What does the autonomic system innervate?
Involuntary organs
What are two divisions of the autonomic nervous system?
Sympathetic (fight or flight) and parasympathetic (rest and digest)
What is the resting tone?
The resting level of activity in the normal animal
What does the somatic nervous system innervate?
organs under voluntary control (ex. skeletal muscles)
The fiber length for post ganglionic neurons in the PNS are…
Short
Neurotransmitters in the pre ganglions of the PNS are?
Acetylcholine (nicotinic)
Neurotransmitters in the post ganglions of the PNS are?
Acetylcholine (muscarinic)
PNS is in what region?
A. Craniosacral
B. Thoracolumbar
A. Craniosacral
SNS is in what region?
A. Craniosacral
B. Throacolumbar
B. Thoracolumbar
What is the fiber length of pre ganglions in the SNS?
short
What type of neurotransmitter is found in the pre ganglion of SNS?
acetylcholine
What type of neurotransmitter is found in the post ganglion of SNS?
norepinephrine
Where is acetylcholine released from?
Pre-synaptic neurons in:
- pre-ganglionic neurons (SNS, PNS)
- post-ganglionic terminal (PNS)
- somatic terminals (NMJ)
What breaks down acetylcholine?
Acetylcholinesterase (in synapse) and Pseudocholinesterase (plasma/other tissues)
Where is the neurotransmitter Norepinephrine released from?
Synaptic nerve endings of neurons
Where is the neurotransmitter Epinephrine released from?
Adrenal gland
What type of receptors are Cholinergic receptors?
Nicotinic and Muscarinic
What type of receptors are Adrenergic receptors?
Alpha and Beta
What kind of receptor is a nicotinic receptor?
Inotropic receptor
What kind of receptor is a muscarinic receptor?
metabotropic receptor
Which muscarinic receptors are stimulatory?
M1, M3, M5
Which muscarinic receptors are inhibitory?
M2 and M4
What does SLUDD stand for?
Salivation Lacrimation Urination Digestion Defication
Where do you normally find muscarinic (M1) receptor and what changes do they make?
- GI tract smooth muscles to increase gastric secretion
- smooth muscle contraction
- urinary bladder smooth muscle
- myocardium to decrease heart rate
- exocrine glands to increase exocrine secretions
What will a drug do in relation to the receptor?
Drug will act as an agonist and will bind to the receptors
What are some thangs about a-1?
- it is the most common adrenergic receptor
- found on vascular smooth muscle
- vasoconstriction
- increase blood pressure (MAP)
- Mydriasis (dilation of the pupil)
- sphincter contraction (urinary bladder and GI tract)
- glycogenolysis
What are some thangs about a-2?
- found in brain and spinal cord
- found in vascular endothelium
- found in endocrine organs
- decrease insulin
- decrease renin
- decrease Norepinephrine release
- decrease pancreatic secretion
What are some thangs about B-1?
- found in the myocardium to mediate HR
- found in adipose tissue
- increase heart rate
- increase cardiac contractility
- lipolysis
- smooth muscle relaxation
- increase renin to increase blood pressure
What are some thangs about B-2?
- airway smooth muscle (to open up airways)
- found in vascular smooth muscle
- bronchodilation
- vasodilation
- smooth muscle relaxation
- increase blood to skeletal muscle
- cycloplegia (paralysis of ciliary muscles in the eye)
- glycogenolysis
- increase in insulin
- increase in norepinephrine release
What are the main effects of the Vasopressin receptors?
- increases the amount of solute-free water reabsorbed back into the circulation by renal tubular cells –> main site of action is the collecting ducts
- arteriolar vasoconstriction –> increases peripheral vascular resistance (PVR) and mean arterial blood pressure (MAP)
Binding to V1 receptor does what to what structures?
- vascular smooth muscle
- vasoconstriction
- preferentially shunts blood to CNS and heart
- platelets
- aggregation
- juxtaglomerular cells
- inhibits renin release
Binding to V2 receptor does what to what structures?
- renal collecting ducts
- increase water permeability through aquaporins
- increase urea ports
- endothelial cells
- Von Williford Factor release
- platelets
- Aggregation
- vascular endothelium
- vasodilation
Binding to V3 receptor does what to what structures?
- Pituitary gland
- negative feed back for ADH (increase vasopressin will
cause a decrease in ADH release) - stimulates ACTH release
- negative feed back for ADH (increase vasopressin will
Autonomic drugs are classified as either MIMETICS or LYTICS. What does MIMETICS mean?
drugs that stimulate (mimic) autonomic input or effects
Autonomic drugs are classified as either MIMETICS or LYTICS. What does LYTIC mean?
drugs that block (lyse) autonomic input or effects
What does it mean if a drug is “direct-acting”?
They are agonists or antagonist and act directly on the receptor.
What does it mean if a drug is “indirect-acting”?
Non-receptor interactions
What are some sympathetic stuff about the eye?
- relaxation of ciliary muscle for far vision
- contraction of the iris radial muscle (mydriasis)
- decrease aqueous humor production
What are some parasympathetic stuff about the eye?
- contraction of ciliary muscle (lens accommodation for near vision)
- contraction of the iris sphincter muscle (miosis)
What are some sympathetic stuff about the heart?
- B-1
- increased heart rate (tachycardia, positive chronotropy)
- increased contractility (positive inotropy)
- increased automaticity and conduction of AV node (positive dromotropy)
What are some parasympathetic stuff about the heart?
- M1
- decreased heart rate (bradycardia, negative chronotropy)
- decreased contractility (negative inotropy)
- decreased AV node conduction (negative dromotropy)
What are some sympathetic stuff about the vasculature?
- a-1 and V-1
- vasoconstriction
- B-2 and V-2
- vasodilation
- a-2
- various (vasoconstriction or vasodilation)
What are some parasympathetic stuff about the vasculature?
indirect vasodilation through the release of nitric oxide (NO)
What are some sympathetic stuff about the lungs?
- B-2
- bronchodilator
- increase in cilia synchronicity
- B-1
- increase in pulmonary blood flow
What are some parasympathetic stuff about the lungs?
- bronchoconstriction
- increase respiratory secretions
What are some sympathetic stuff about the GI tract?
- a-1, B-1, B-2
- decrease motility
- closure of sphincters and increased tone
- inhibit secretions
What are some parasympathetic stuff about the GI tract?
- M1
- increased motility
- relaxation of sphincters and decreased tone
- stimulate secretion
What are some sympathetic stuff about the urinary bladder?
- B-2
- relaxation of detrusor muscle
- a-1
- contraction of internal urethral sphincter
What are some parasympathetic stuff about the urinary bladder?
- M1
- contraction of detrusor muscle
- relaxation of internal urethral sphincter
