Test 5 for old wrinkly ass peter

Olfactory CN

(I) Sensory; most anterior/w a sense of smell

Optic CN

(II) Sensory; sight/sense of seeing

Oculomotor CN

(III) Motor; movement of eye/ Intrinsic & Extrinsic

Trochlear CN

(IV) Motor; contains superior oblique eye muscle

Trigeminal CN

(V) BOTH sensory and motor.

sensory from face, sinuses, gum

motor to muscles of massification

Abducens CN

(VI) Motor; lateral rectus eye muscles

Facial CN

(VII) BOTH sensory and motor.

motor to muscles of facial expression & salivary/ lacrimal glands

sensory from anterior 2/3 of tongue

Vestibulocochlear CN

(VIII) Sensory; inner ear for balance & hearing of ear

Glossopharyngeal CN

(IX) BOTH sensory and Motor

sensory from posterior 1/3 of tongue/ tonsil/ pharynx/ middle ear

motor to upper pharynx & parotid gland (secretes saliva)

Vagus CN

(X) BOTH sensory and motor

motor to almost all viscera of thoracic/ abdominal cavity

sensory from almost all viscera of thoracic/ abdominal cavity

Accessory CN

(XI) Motor to sterneocleomastoid and trapezius muscles

Hypoglossal CN

(XII) Motor; to the muscles of the tongue

Cranial Nerve Zero

detects pheromones; sexual signals, social signals, dormitory syndrome (menstral cycles syncing)

All preganglionic neurons release:

Acetylcholine

Postganglionic neurons release:

Parasympathetic: release Acetylcholine

Sympathetic: most release Norepinephrine (adrenaline- like stimulant)

Somatic Senses /General:

-distributed throughout the body densely or sparsely

-Relay sensations of touch, pressure, temp, pain

Special Senses:

-Grouped in the tongue, nose, ear, eyes

-Produce sensations of taste, smell, sight, sound, and balance/imbalance

ALL sense organs & receptors:

initiate reflexes necessary for maintaining homeostasis

Sensory Adaption (in response to continuous stimulation):

• magnitude of the receptor potential decreases

• Sensory impulse conduction slows down & intensity of the sensation decreases

fast adapting

touch,temp,smell,light,sound,pressure,taste

slow adapting

pain,proprioceptors/stretch receptors

Mechanoreceptors:

• respond to mechanical force that in some way, moves or changes the shape/ position of receptors

• ex.) hearing & touch, pressure/blood vessels, skin: stretch/ muscles, tendons, lungs, balance

Chemoreceptors:

• Respond to pressure of chemicals; as in taste & smell

• also monitor blood levels of glucose, CO2, O2

Thermoreceptors:

found everywhere and respond to changes in temperature

Photoreceptors:

• located in the eyes only

• respond to light (if enough present)

Baroreceptors (Osmoreceptors):

• concentrated in the hypothalamus

• described as pressure sensors for detecting osmotic pressure or osmolarity

• Osmotic pressure: ionic concentration or concentration of electrolytes in body fluids

Nociceptors:

• pain receptors that respond to “noxious” stimuli

• Noxious stimuli: intense stimuli of any type that results in tissue damage due to intense light, sound, pressure, heat/cold, or toxic chemicals

Referred Pain:

• pain that originates from deep structures and is referred to surface areas

• Theory: somatic neurons & sensory automatic neurons share same interneurons/synapses in spinal cord

Free Nerve Endings:

• simplest, most common receptors

• respond to pain, itching, tickling, touch, temp, movement, stretch

Encapsulated Nerve Endings:

• are touch & pressure receptors

• ex.) meissner’s corpuscles: light touch; fingertips

• ex.) Pacinian corpuscles: deep pressure& stretch: deep dermis of skin

Stretch Receptors:

• Golgi Tendon Organ: Proprioceptor / prevents muscles& tendon injury

• Muscle Spindle: Proprioceptor/ prevents muscle& tendon injury

Olfactory receptors:

• chemoreceptors for our sense of smell

• ONLY neurons to regenerate throughout adult life

• also carry pain, touch, pressure & temp sensations to CN-V (Trigeminal)

Anosmia:

loss of sense from: infections, injury, smoking, cocaine use, zinc deficiency

Gustatory receptors:

• chemoreceptors for our sense of taste

• located in taste buds on superior surface of the tongue, throat, lining of mouth, and duodenum

Saliva does what?

• breaks food molecules into smaller chemicals called “Tastants”

• ciliary action moves tastants that are dissolved in saliva toward receptors

70%-75% of what we perceive as taste comes from:

smell

what are the 5 tastes:

• Sweet: sugars/salty

• Sour: acidic foods

• Unami/Savory: protein

• Bitter: high alkaline foods.

• Spicy Hot: not a taste but nerve damage

The Bitter Taste:

• has a high concentration of bitter sensing taste hairs on the posterior 1/3 of tongue

• connects to CN-IX (Glossopharyngeal)

• dangerous, elicits gag reflex

• only taste to adapt slowly

The Spicy Hot Taste:

• the sensations of pain, temp, touch are carried by taste fibers to CN-V (Trigeminal)

• CN-VII(Facial) carries taste sensations from anterior 2/3 of tongue

Hearing receptors:

• “Hair Cells”/ Mechanoreceptors

• Shape is changed by stimulus of sound waves, or movement of otoliths(Balance)

Mechanoreceptors mediate:

Both hearing(audition) and balance(equilibrium)

external ear

• auricle

• external auditory meatus

• tympanic membrane

auricle/pinna

outer ear

external auditory meatus

ear canal

tympanic membrane

eardrum

middle ear

• tympanic cavity

• ossicles

• auditory tube/Eustachian tube

ossicles

includes malleus,incus,stapes

auditory tube/Eustachian Tube

connects ear to throat and equalizes pressure around eardrum