Chapter 15 Flashcards
somatic nervous system
-skeletal
-conscious/unconscious movement
-one synapse
autonomic nervous system
-smooth muscle/cardiac
-unconscious regulation
-2 synapse
-modifies effector activity rather than cause it
-motor nervous system
Properties of ANS
-carries out actions involuntary
-hypersensitivity
-maintain homeostasis
-motor nervous system
-biofeedback techniques
What are the divisions of the ANS?
sympathetic and parasympathetic
sympathetic
-fight or flight
-increases heart rate, BP, and blood flows to heart and muscle
parasympathetic
-rest and digest
-has a calming effect on many body functions
-waste elimination
-cranial nerves III, VII,IX, X
autonomic tone
balance of the 2 systems according to the bodys changing needs
parasympathetic tone
holds resting heart rate down to 70-80 beats
sympathetic tone
maintains BP and keeps most blood vessels partially constricted
hirschsprung disease
hereditary defect causing absense of enteric nervous system
adrenal glands
cortex-secrete steroid hormones
medulla- secrete neurotransmitters into blood and not onto other neurons
What cranial nerves are included in the parasympathetic NS?
oculomotor (III), facial (VII), vagus (X) and IX
visceral reflexes
smooth muscle, cardiac muscle, and glands
referred pain
visceral pain afferents travel along the same pathway as somatic pain fibers
-when having a heart attack, you might feel pain in left arm
neurotransmitters
the effects are determined by the types of neurotransmitters released and the types of receptors found on target cells
cholinergic
-type of neurotransmitter
-release acetylcholine
-come from preganglionic fibers of both systems
-come from postganglionic fibers of parasympathetic
adrenergic fibers
release norepinephrine
-released from postganglionic fibers of sympathetic
nicotinic receptors
occur on all ANS postganglionic neurons
-always excitatory
-curare binding site
adrenergic receptors (beta)
inhibitory
beta also excites the heart
adrenergic receptors (alpha)
excitatory
sympathetic tune
baseline firing frequency, provides partial constriction called vasomotor tone
sympathomimetics
enhance sympathetic activity
-cold medicines that dilate bronchioles or constrict nasal blood vessels
sympatholytics
suppress sympathetic activity
-beta-blockers that reduce BP
atropine
used to prevent salivation during surgery
neostigmine
treat myasthenia gravis
