Lecture Outline #16: Cranial nerves & endocrine system Flashcards
5 types of cranial nerves
somatic afferent
somatic efferent
visceral afferent
visceral efferent
special sensory afferent
somatic afferent
skin, skeletal muscles, joints to the CNS
somatic efferent
CNS to skin, skeletal muscles, joints
visceral afferent
BVs, gut, lungs to the CNS
visceral efferent
CNS to BVs, gut, lungs
special sensory afferent
ears, eyes, nose, tongue
CNs I, II,VIII
CN I source
up superior & middle conchae through olfactory epithelium
CN V trigeminal neuralgia
neuropathic disorder, pressure on the nerve
CN VII Bells palsy
injury/infection within facial canal, regional paralysis, tears and smell stop working on that side
CN X dural sinus & type of nerve
sigmoid sinus leads to this nerve around jugular foramen, parasympathetic nerve
ANS Organ function
balance between sym & para-sym stimulation, only one can be elevated
ANS motor fiber
pre-ganglionic fiber - synapse onto autonomic ganglia throughout body
post-ganglionic fiber - synapse onto target organ
sym - fight/flight response
mental alertness, increased metabolic, respiratory, and heart rate, stops UG/GI functions and blood supply
sym - thoracolumbar division
pre-gang fibers exit from T1-L2 & have NAVLs with them
pre & post gang fibers are similar in length
sympathetic chain ganglia - para-vertebral ganglia
segmental autonomic ganglia
located along posterior body wall T1-L2
integrates spinal levels - C6-Co1
MOST pre-gang fibers pass thru chain ganglia
SOME pre-gang fibers synapse @ chain ganglia
SOME post-gang fibers synapse @ chain ganglia
SOME post-gang gibers synapse @ collateral ganglia
collateral ganglia - pre-vertebral ganglia
adjunct to chain ganglia, often travel w/gut vasculature
sympathetic neurotransmitters
pre-gang acetylcholine (AcH) - short-acting, para-sym responses are of short duration, system easily turned off
post-gang norepinephrine (NE) - long-acting, sym responses may be of long duration, system not easily turned off, CN III(pupil size increase), VII, IX (dry mouth)
para-sym rest/digest response
decreases metabolism, respiratory, & heart rate, activates salivary/digestive glands, increases activity & blood supply of/to UG/GI organs & defecation
para-sym - craniosacral division
MOST pre-gang fibers bundled w/ CNS III (pupil decrease), VII, IX (increase salivation), X (pudendal n)
SOME pre-gang fibers bundled with S2-4
Pre-gang fibers are longer than post
parasympathetic ganglia
located at/near targets
para
sym - neurotransmitters
both pre & post gang fibers utilize AcH
time - nt
AcH - fast (millisec)
NE - slower (more millisec)
duration - nt
AcH - short (sec)
NE - long (min)
bv - nt
AcH - contrict
NE - dilate
pupils - nt
AcH - contrict
NE - dilate
gut - nt
AcH - increase activity
NE - decrease activity
sympathetic reflexes
cardiac, vasomotor, pupil size increase, orgasm
parasympathetic reflexes
gut motility, defecation, vomiting, swallowing, urination, pupil size decrease, coughing, baroreceptors
what effects does AcH have on the heart
decrease the rate of contractions
homeostasis
maintain the status quo - hormone, temp, ph levels constantly go up and down
ns instruction to target organ
via cranial/peripheral n.s
localized effects on target
short-term effects w/ immediate recovery
endocrine s instruction to target organ
via chemical messages - hormone via blood supply
widespread, systemic affects
long term effects w/ slow recovery
hormone activity
endocrine glands have capillary glands
hormones enter blood stream and circulate through body
- broken down in liver or enzymes in blood
- filtered by kidneys - lost thru urine
how do hormone alter cellular function
- penetrate cell & enter nucleus
- attach to specific DNA segments
- stimulate new protein/enzyme synthesis
