test 3 Flashcards
differences between somatic and autonomic nervous system
somatic
- voluntary
- effector organ: skeletal muscle
- no N-N synapses
- well differentiates
autonomic
- involuntary
- visceral organs, smooth muscle, glands
- N-N synapse=ganglia
- tends to function as whole
cranial nerves (PNS)
12 pairs
3 sensory, 5 motor, 4 both
olfactory - sensory
optic - motor
trigeminal - both
- S touch from face; M mandibles
spinal nerves (PNS)
31 pairs
each have sensory and motor component (some have autonomic components)
8 cervical
12 thoracic
5 lumbar
5 sacral
1 coccygeal
sympathetic vs parasympathetic NS
sympathetic
- fight/flight
- catabolic (spending) system
- thoracolumbar system
- constrict blood vessels to GI tract/other viscera
- dilate blood vessels. to striated muscles and heart/brain
- liver releases glucose
parasympathetic
- rest and digest
- anabolic (saving/building) system
- craniosacral system
- dilate blood vessels to GI tracts/other viscera
- constrict blood vessels to striated muscles and heart/brain
stress response: sympathetic vs hormonal
sympathetic activation
neural path: fast
epinephrine release from adrenal medulla
hormonal
HPA (hypothalamic pituitary adrenal) axis: delayed but longer-lasting effects
CRH, then ACTH, then cortisol
cortisol released by adrenal cortex
primary motor cortex (SNS)
location - precentral gyrus of frontal lobe
function - controls voluntary motor movements
somatotopically mapped
larger areas devoted to regions requiring fine motor skills (ex fingers/face)
primary somatosensory cortex
location - postcentral gyrus of parietal lobe
function - receives and processes sensory input from body
somatotopically mapped
larger areas devoted to regions with greater sensory input (lips/hands)
somesthesis
touch, pain, temperature, proprioception (sense of body position), kinesthesia (sense of body movement)
general (crude) touch
protopathic pathway
poor localization - more diffusely
discriminative (fine) touch
epicritic pathway
well localized
specificity theory of pain
pain = nociception (sensory element)
amount of experienced pain should be directly related to tissue damage and extent of pain fibers activated
there is positive correlation between extent of injury and pain intensity but not a perfect one
bottom-up: all one direction
CAN’T explain phantom limb
gate control theory on pain
pain = nociception + other factors
an interaction of bottom-up and top-down factors
“other factors” often top-down processes to modulate ascending transmission of pain
examples: endorphin suppression of pain, phantom limb
direct pathway for pain
immediate
usually described as sharp/shooting pain
well localized
indirect pathway for pain
delayed; can be reactivated as reminder of injury
usually described as dull, aching, throbbing
diffuse effect
referred pain is type of indirect which is when a problem causes pain somewhere else (ex. heart attack)
visual pathway
- retina (rods/cones) convert light – electrical signals
- optic nerve (visual info from each eye)
- optic chiasm where nasal fibers cross (info from left visual field go to right brain vice versa; 1 and 4) or temporal fibers bring 2 and 3 straight back they don’t cross
- LGN (specific relay nucleus for sight) in thalamus make synapse
- optic radiation (bundles of axons) carry visual info from LGN; myers loop is part that juts forward
- striate cortex/primary visual cortex processes visual info
unilateral neglect
usually caused by damage to right parietal lobe
person ignore left side of space/body; impairment occurs in left visual field
attention problem
ex. draw only one side of an object
blindsight
caused by damage to primary visual cortex
subconscious awareness of movement by bypassing primary visual cortex
simultanagnosia
damage to dorsal stream
can only see one object at a time and can’t “paint the picture” (ex. if seeing table all set up reg person can assume having a dinner party they cannot)
visual agnosia
damage to ventral stream
give details of things they see but can’t identify the objects with a name
prosopagnosia
face blindness - inability to recognize familiar faces (including own)
