Physiology of Autonomic Nervous System Flashcards Preview

CVPR: CV Unit I > Physiology of Autonomic Nervous System > Flashcards

Flashcards in Physiology of Autonomic Nervous System Deck (11):
1

Structures involved in central control of ANS

  • Spinal cord

  • Brain stem (medulla oblongata)

  • Hypothalamus

  • Cerebral cortex

2

Spinal cord role in ANS control

  • reflex changes in blood pressure
  • sweat production
  • micturition (urine production)

3

Brain stem role in ANS control

  • Medulla oblongata controls:
  • blood pressure
  • respiration.

4

Hypothalmus role in ANS control

  • principal locus of integration
  • body temperature
  • water balance
  • carbohydrate metabolism
  • sexual reflexes
  • autonomic emotional responses

5

Cerebral cortex role in ANS control

  • volitional changes
  • conditioned autonomic responses

6

Primary neurotransmitters (+roles) & receptors of the parasympathetic nervous system 

  • Acetylcholine (ACh)
  • Preganglionic neurons release ACh
  • In the ganglia Ach interacts with neuronal-type nicotinic cholinergic receptors (NNRs or neuronal-type nAChRs).
  • Postganglionic neurons release AChIn the end organs Ach interacts with muscarinic cholinergic receptors (MRs or mAChRs).

 

7

Primary neurotransmitters (+roles) & receptors of the sympathetic nervous system 

  • Acetylcholine (ACh)
    • Preganglionic neurons release ACh
    • In the ganglia and adrenal medulla ACh interacts with neuronal-type nicotinic cholinergic receptors(NNRs).
  • Norepinephrine (NE)
    • Postganglionic neurons generally release the catecholamine NE.
    • Exceptions: 
      • Adrenal medulla releases primarily epinephrine (EPI)
      • Postganglionic neurons innervating sweat glands release ACh.
      • Postganglionic neurons innervating renal vasculature release dopamine (DA).
    • @ end organs NE and EPI interact with a- and b-adrenergic receptors.

 

 

8

Major divisions (+general goals) of ANS

  • Parasympathetic nervous system (“rest and digest”): general goal—conserve and restore energy
  • Sympathetic nervous system (“fight or flight”): generally discharges as a unit in response to an acute stress.

9

General physiological response generated by parasympathetic nervous system (7)

  • ↑salivary gland secretion; ↑lacrimal gland secretion (tears); ↑bronchial gland secretion
  • miosis (constriction of the pupil; iris circular muscle) and accommodation (focusing for near vision; ciliary muscles)
  • ↓heart rate (bradycardia)
    • ↓conduction at the S-A node indirectly ↓blood pressure.
  • Constriction of bronchioles
  • ↑GI absorption; ↑GI motility; relaxation of sphincters; ↑GI secretions.
  • ↑urinary tract motility; relaxation of sphincters; bladder contraction.

 

10

General physiological response generated by sympathetic nervous system (6)

  • ↑Heart rate (tachycardia); ↑force of cardiac contractility
  • ↑total peripheral resistance (vasoconstriction) resulting in ↑blood pressure.
  • ↑blood glucose; ↑lipolysis
  • Mydriasis (dilation of the pupil; iris radial muscle)
  • Dilation of bronchioles
  • controls of tone in blood vessels

11

Mechanisms by which drugs alter activity of ANS (5)

  • Mimicking the neurotransmitter action
  • Blocking the neurotransmitter action
  • Changing the normal action of the neurotransmitter by altering:
    • Synthesis of the neurotransmitter
    • Release of the neurotransmitter
    • Inactivation of the neurotransmitter following release