ANS Flashcards
ANS
complex network of cells that controls body’s internal state
* regulates & supports many diff internal processes subconsciously
* only part of PNS
* collection of neurons that influence activities
Nervous System function
responsible for sensing info, integrating, & controlling response through signal transmission & transduction
anatomy of the major branches of NS
CNS: brain & spine
PNS: all neurons outside of brain & spine
PNS function
afferent & efferent fibers that relay signlas btwn the CNS & the periphery
CNS function
integrative & control centers
branches of PNS
afferent division: sensory
* conducts impulses from receptors to CNS
efferent division: motor
* conducts impulses from CNS to effectors
* effectors = muscles & glands
branches of efferent division
somatic NS (SNS): voluntary
* CNS to skeletal muscles through neuromuscular junctions
ANS: visceral (involuntary) motor nerve fibers
* conducts impulses from CNS to cardiac muscle, smooth muscle, & glands
branches of ANS
sympathetic: fight or flight
parasympathetic: rest & digest
* conserves energy
SNS
- sends signals through ANS nerves to adrenal glands
- adrenal glands respond by pumping epinephrine (adrenaline) into bloodstream
- both epinephrine & norepinephrine (NE) are neurotransmitters produced by SNS
pancreas
exocrine pancreas: secretion of digestive enzymes & ions & water into duodenum of GI tract
* makes up >95% of pancreatic tissue
endocrine pancreas: controls BG levels by secreting polypeptide hormones insulin & glucagon
stress pathway
hypothalamus ➞ secretes CRH ➞ activates pituitary gland ➞ secretes ACTH ➞ signals adrenal gland ➞ secretes gluticorcorticoids
stress response
inhibits parasympathetic neurons & activates sympathetic neurons
gluticocorticoids
- gluticocorticoid levels remain high with prolonged stress
- cortisol = main one in humans
- cortisol levels ↓ at night
- no sleep = cortisol levels remain high ➞ high BP
physiological reactions to gluticocorticoids
- ↑ BG from ↑ gluticocorticoids & ↓ glucose uptake into skeletal muscles
- ↑ likelihood of catecholamines ↑ lipolysis & ↑ BP
- inhibits protein synthesis & ↑ proteolysis
- is anti-inflammatory & immunosuppressive
which gland secretes gluticocorticoids
adrenal cortex of adrenal gland