midterm 2- nervous system, sensory, endocrine

parts of outer ear (4)

helix, antihelix, lobule, tragus

external ear

includes auricle and external acoustic meatus

outer ear innervation

trigeminal (facial and vagus as well)

tympanic membrane separates what

outer and middle ear

middle ear

stapes

incus

malleus

inner ear

cochlea and semicircular canals

when stapes presses on inner ear, how does the fluid move?

begins at oval window, through the canal, ends at round window

the inner ear is embedded in what?

temporal bone (petrous part)

spiral organ

sensory organ within cochlea

contains the “hair cells” attached to the basilar membrane —> separates the

cochlear duct from the scala tympani

semicircular canals and cochlea are surrounded by what?

bony labyrinth

semicircular canals

3 tubes in inner ear

detect head rotation and help maintain balance

filled with endolymph

cochlea

spiral shaped, fluid filled

lined with hair cells allowing it to transduce sound into electrical impulses

perilymph location

scala tympani and scala vestibuli

endolymph location

cochlear duct

scala vestibuli and tympani

vestibuli- upper

tympani- lower

continous at helicotrema (apex)

spiral organ afferent neurons are

bipolar

what is in between the two scala in the inner ear?

cochlear nerve and spiral organ

in general cranial nerves are what?

collections of axons exiting or entering brain/brainstem

CN III-XII are similar to what?

spinal nerve

CN I and II are what?

outgrowths of the brain

CN I and II have their primary sensory neurons where?

within the sensory organs, CN I = Olfactory and CN II = optic

cranial nerves provide sensory input to the brain for what?

special senses- vision/hearing/smell

general senses- touch

Cranial nerves provide motor output how?

motor to skeletal muscles

autonomic motor to smooth muscles and glands

where are sensory CN bodies?

sensory ganglia

usually along nerve pathway a short distance from brain

where are motor CN bodies

within motor nuclei in brainstem

Pneumonic for CN names

Only One Of The Two Athletes Felt Very Good Victorious And Happy

Pneumonic for CN type (sensory, motor,both)

some say marry money but my brother says big brains matter more

which nerves have parasympathetic fibers

3,7,9,10

oculomotor, facial, glossopharyngeal, vagus

trigeminal nerve is split into what three branches

V1- opthalamic

V2- maxillary

V3- mandibular

CN V and VII both have what?

wide distribution in the head

CN V is largely

sensory

• Conveys nearly all general sensation from the skin of face

• Conveys general sensation from tongue, teeth, oral mucosa and gingiva, TMJ, palate, nasal cavity paranasal sinuses and the eyeball

• Motor for chewing muscles of mastication

CN VII is complicated how?

in function and its path as to where it gets around face

• Innervates: all muscles of facial expression, secretion at two of the three major salivary glands, taste of tongue

the ANS works at what level

subconscious level

ANS provides what?

involuntary control of functions that maintain body’s internal environment

ANS innervates what 3 things?

smooth muscle

cardiac muscle

glands

which are 2 neuron systems? which are 3?

2- motor, autonomic

3- sensory

the ANS synapses where?

in an autonomic ganglion

what three things help control ANS and which is most important?

cortex, brain stem, and hypothalamus

hypothalamus= most important

the hypothalamus controls visceral activity and is what?

the chief effector of the limbic system

What is the limbic system

functional system that has a big role in memory and behavior

limbic means

border

limbic neurons are found where?

deep in the brain

the limbic lobe borders what?

anterior brainstem

commissural fibers between L/R cerebral emispheres

where does the limbic system receive input from?

brainstem, prefrontal cortex, sensory association areas

4 main functions of limbic system

memory/learning

reward mechanisms

affective behavior (ex. craving food)

influence ANS

the hypothalamus has an important role in ____ and ___

self preservation and reproduction

control by the hypothalamus is mediated by what two systems?

nervous system (via ans) and circulatory system (via endocrine)

where are pre and post ganglionic neurons in autonomic system?

pre cell bodies in CNS

post cell bodies in autonomic ganglia (where synapse occurs)

2 major divisions of ANS

sympathetic

parasympathetic

sympathetic is aka

thoracolumbar

parasympathetic is aka

craniosacral

where are the preganglionic cell bodies for sympathetic and parasympathetic nerves

SYM- thoracic and upper lumbar spinal cord (lateral gray horn)

PARA- brain stem and sacral spinal cord

short preganglionic fiber, long postganglionic fiber

sympathetic

long preganglionic fiber, short postganglionic fiber

parasympathetic

paravertebral ganglia

sympathetic

peripheral ganglia

parasympathetic

duration sympathetic vs parasympathetic

SYM- diffuse, long duration

PARA- localized, short

neurotransmitters (pre and post) for sympathetic and parasympathetic

SYM: pre=acetylcholine, post=norepi and acetylcholine

PARA: pre and post are both acetylcholine

arterial baroreflex

sympathetic and parasympathetic responses to changes in blood pressure

detected by carotid and aortic baroreceptors

ascending is ___ while descending is ____

ascending= sensory

descending= motor

somatosensory includes what four things?

touch, proprioception, pain, temp

interoceptive

sensory receptors monitor internal events like BP

the primary neuron of sensory pathway is ____

unipolar with myelinated axon

primary sensory neuron cell bodies are found where?

spinal ganglion on the same side as sensation

axons of primary sensory neurons travel where?

in spinal and cranial nerves

general senses include what 5 things?

crude touch, tactile discrimination, proprioception, pain, temp

secondary sensory neuron cell bodies are found on what side of body?

same side of sensation

(location varies based on type of sensation)

pain and temp 2nd neurons are found where

dorsal horn

tactile sensation and proprioception 2nd neurons are found where?

medulla oblongata

crossover in sensory paths always involve what?

secondary neuron axon

tertiary sensory neurons are always found where?

in thalamus

contralateral to sensation

what are the two sensory pathways?

dorsal columns, lateral spinothalamic

pain and temp pathway

spinothalamic tract

the spinothalamic tract is where

on contralateral side of spinal cord

tactile discrimination and proprioception pathway

dorsal columns

dorsal columns are found where

ipsilateral (same side) as sensation

crossover in spinothalamic vs dorsal column

spinothalamic- in spinal cord

dorsal column- in medulla oblongata

tertiary fibers terminate where?

parts of postcentral gyrus associated with appropriate contralateral homonculus

postcentral gyrus has what?

primary sensory cortex, sensory cell bodies

somatosensory sensory receptive areas

postcentral gyrus (in parietal lobe)

visual sensory receptive areas

region of calcarine fissure (in occipital lob)

auditory sensory receptive areas

anterior transverse gyrus (in temporal lobe)

parietal association areas are located where?

between somatosensory and visual areas integrate info from both areas and convey signal to premotor and motor areas

prefrontal cortex space

anterior part of frontal lobe

anterior to motor and premotor regions

prefrontal cortex is attached to what

thalamus, limbic system, also to other lobes

the prefrontal cortex is highly responsive to what?

behavior importance of inputs

the prefrontal cortex is essential for what?

abstract thinking, foresight, mature judgement, tactfulness

• not intelligence!

prefrontal cortex has a role with pain in what regard?

modulation

persistent pain

how was chronic pain treated in past?

lobotomies

two types of pain

fast and slow

fast pain

sharp and pricking

well localized

slow pain

dull and burning

hard to localize

results from tissue damage

fast pain and temp travels where in brain?

from the thalamus to the postcentral gyrus

there is no perception of pain associated with what?

cortical tissue damage in postcentral gyrus

slow pain terminates where?

in frontal lobe and limbic system

when slow pain terminates what does it influence?

cortical arousal and affect

interneurons act to modulate secondary __

slow pain neurons

analgesia center

in brainstem

can inhibit transmission of ascending pain impulses