Autonomic Hypertension Flashcards
Review of ANS
ANS divided into:
- Sympathetic
- Parasympathetic
Sympathetic divided into:
- Adrenergic agonist (fight)
- Adrenergic antagonist (rest)
Parasympathetic divided into:
- cholinergic agonist
- anticholinergics
What are the neurotransmitters of parasympathetic?
What are the neurotransmitters of sympathetic?
- ACh
- Epinephrine and Norepinephrine
Where does parasympathetic come from in the spinal cord?
Where does sympathetic come from?
- Brain and Lower vertebrae
- Lumbar and Thoracic
What is sympathomimetic?
What drugs are involved with this?
- Promoting the stimulation of sympathetic nerves
- Adrenergic agonists
What is sympatholytic?
What drugs are involved with this?
- Inhibiting the transmission of sympathetic nerve impulses
- Adrenergic antagonists
What are adrenergic drugs used to treat?
- Cardiovascular conditions
- Respiratory conditions
- Common cold
How do most adrenergic drugs exert their effect?
Binding to postsynaptic receptor
What are the subtypes of adrenergic drugs?
What are each of their actions?
Alpha:
1- mainly vascular smooth muscle (vasoconstriction or dilation)
2- presynaptic junctions to influence NE release
Beta:
1- heart, kidney
2- lungs
3-adipose tissue
Is there a clinical use of B3?
No
What are the three catecholamines?
Catecholamines:
- Epinephrine
- Norepinephrine
- Dopamine
What are catecholamines?
- Hormones produced by adrenal glands.
- Usually released in response to physical or emotional stress.
- Released by sympathetic nervous system.
- Sympathomimetic
Catecholamines: Cardiac effects? Vascular effects? CNS effects? Nonvascular Smooth Muscle effects? Metabolic effects?
Cardiac effects: CO=SV*HR
- Positive inotropic effect (↑SV)
- Positive chronotropic effect (↑HR)
Vascular Effects:
- Epinephrine reduced peripheral vascular resistance at low dose, opposite at high dose
- NE elevates BP
CNS Effects:
-large doses can produce anxiety, tremors, HA
Nonvascular smooth muscle effects:
- relax smooth muscle of GI tract
- urinary retention
- dilation of bronchiole smooth muscle
Metabolic effects:
- increases blood glucose and fatty acid levels
- inhibits insulin secretion
- enhance glycogenolysis and gluconeogenesis
Does epinephrine effect all alpha and beta receptors?
Yes
What effect does it have on each receptor?
What is the net effect of all of this?
- B1- increases strength/ rate of cardiac contraction
- B2- relaxes bronchiole smooth muscle, activates glycogenolysis
- B3- activate lipolysis in fat cells
- A1- constricts vascular smooth muscle
- A2- (presynaptically)
Net effect= potent vasoconstrictor and cardiac stimulant
What can epinephrine be used for?
- Anaphylactic shock (epipen)
- Cardiogenic shock (cardiac arrest)
What receptors does norepinephrine act on?
- Acts on A1 receptors to a greater extent than A2 and B1.
- It has little effect on B2
What does norepinephrine mainly do?
Increase BP
What is norepinephrine used to treat?
- Severe hypotension
- Septic shock
What is septic shock?
When an organ is injured or damaged in response to an infection, leading to dangerously low BP
What is the precursor to norepinephrine?
What receptors does it activate?
- Dopamine
- Activates A1 and B1 receptors
What is dopamine used to treat?
- Shock in renal failure
- Cardiac decompensation
What are vasopressor drugs?
Cause vasoconstriction leading to increased BP and MAP
What are some examples of vasopressors?
- Norepinephrine
- Epinephrine
- Dopamine
- Vasopressin
Difference between Direct and Indirect Acting Adrenergic Drugs?
- Direct- directly stimulate alpha or beta receptors
- Indirect- Enhance effects of NE or Epi by inhibiting their reuptake or inhibiting their degredation, or increasing release of NE