PHYS Block A

The flashcards below were created by user dfusel2 on FreezingBlue Flashcards.

  1. ANS
    • automatic, involuntary system that serves to maintain homeostasis
    • effectors: cardiac, smooth muscle & glands
    • afferent sensory neurons respond to stretch, glucose, PCO2, PO2, osmolarity & pH, temperature
    • efferent motor neurons: innervate viscera & involuntary muscle
    • sympathetic & parasympathetic systems
  2. functional units of SNS & PSNS
    • two neuron pathway
    • pathway leading from the CNS (preganglionic neuron) to a peripheral ganglion (postganglionic neuron) to the target tissue
  3. sympathetic nervous system
    • short preganglionic neurons from thoracolumbar spinal cord (T1-L3) are cholinergic (release ACh)
    • long postganglionic neurons from paravertebral or prevertebral ganglia are adrenergic (release NE)
  4. enteric nervous system
    • part of peripheral nervous system (operates largely independently of CNS)
    • 3 neuron system: sensory neuron, interneuron, motor neuron
    • function: coordinates GI function, monitors state of lumen & gut wall, respons appropriately
    • networks: myenteric (motility) & submucous (secretions)
  5. nicotinic receptor
    • N2 receptor
    • binds ACh on postganglionic (adrenergic) neuron
  6. adrenergic receptor
    • binds NE on target cell
    • a1: vasculature
    • a2: presynaptic
    • B1: heart, adipose
    • B2: bronchioles, vasculature
    • B3: adipose (thermogenic)
  7. exceptions of SNS neurotransmitter release
    postganglionic neuron releases ACh that binds to muscarinic receptors in sweat glands & vessels
  8. specific responses of adrenergic receptors
    • a1q: vascular smooth muscle contraction, skin, GI tract, kidney
    • a2i: decrease neurotransmitter release; SM contraction (GI sphincters), decrease insulin release
    • Bs: increase heart rate, SM relaxation (bronchi, uterus), glycogenolysis, lipolysis
  9. parasympathetic nervous system
    • long preganglionic neurons from brainstem (CN III, VII, IX, X) and sacral spinal cord
    • short postganglionic neurons from parasympathetic ganglia near or in wall of target organ
    • both neurons are cholinergic (release ACh)
    • preganglionic ACh binds to nicotinic receptors
    • postganglionic ACh binds to muscarinic receptors
  10. somatic nervous system
    • effectors: skeletal muscles
    • efferent: heavily myelinated axons from CNS to muscle
    • NT effects: ACh excitatory effect in nicotinic receptors
  11. cholinergic receptors
    • nicotinic: ligand gated ion channel
    • muscarinic: G protein coupled; ACh binds to receptor & triggers signaling cascade
  12. neurotransmitters
    • acetylcholine
    • norepinephrine
    • ATP
    • nitric oxide
  13. neurotransmitters of enteric nervous system
    • acetylcholine: increase motility, increase intestinal secretions, increased enteric hormone release
    • norepinephrine: decrease effects of acetylcholine
    • others: VIP, opiods, 5-HT, substance P, NO, etc.
  14. function of SNS
    • "fight or flight"
    • exercise, excitement, embarrassment
    • dilation of pupils
    • increase HR, contractility & BP
    • blood flow decreased to non-essential organs
    • increased bronchial dilation
    • increased respiratory rate
    • increase fuel mobilization (glucose & FFA)
  15. function of PSNS
    • "rest & digest" - conserve & restore energy
    • normally PSNS tone > SNS
    • digestion, defecation, diuresis
    • SLUDD response: salivation, lacrimation, urination, digestion & defecation
    • decreases: HR, airway & pupil diameter
  16. SNS/PSNS dual control
    • GI
    • cardiovascular: sensory input - chemo & stretch receptors at carotid sinus & aortic arch
  17. exclusive SNS control
    • adrenal medulla
    • sweat glands
    • erector pili muscles
    • kidneys (renin-angiotensis system)
    • most blood vessels
  18. exclusive PSNS control
    erectile tissue
  19. cardiovascular response to increased pressure
    • decrease SNS activity (decrease BP)
    • increase PSNS activity (decrease HR)
  20. cardiovascular response to decreased pressure
    increase SNS activity (increase HR & BP)
  21. SNS & PSNS modulation of GI function
    • PSNS favors digestive processes: increased gut motility, acid & enzyme secretions; relaxation of sphincters
    • SNS inhibits digestive processes: contraction of sphincters (pyloric, ileocecal, & internal anal); inhibition of motor neurons throughout gut
  22. thermoregulation
    exclusive SNS modulation of internal body temp
  23. SNS response to increased environmental temp
    • sweat gland activation
    • skin vasodilation (bring warm blood to surface)
  24. SNS response to decreased environmental temp
    • skin vasoconstriction (blood retained in vital organs)
    • shivering
    • piloerection
    • no sweating
  25. SNS/PSNS control of sexual function
    • erection: PSNS (vasodilation of erectile tissue); SNS (decreased tone during erection)
    • ejaculation: SNS (smooth muscle contraction at distal epididymis)
Card Set:
PHYS Block A
2013-01-26 04:28:44
physiology cardiovascular

Physiology Block A Cardiovascular
Show Answers: