Anatomy exam 3 part 1

what are tactile receptors

(touch pressure vibration) - unencapsulated: free nerve endings, tactile disc, root hair plexus - encapsulated: tactile, bulbous, and pacinian corpuscle

dura mater

- 2 layers - periosteal: attaches skull - meningeal: covers brain and extends into vertebral canal - dural venous sinus: blood from vein empties

what are the brain ventricles

- CSF filled cavities - lateral: in cerebral hemisphere - third: in diencephalon - fourth: between pons and cerebellum - lateral and third communicate through interventricular foramen - third and fourth communicate to aqueduct - fourth communicates with cerebral canal

middle region of ear

- air filled cavity - inner tympanic membrane - auditory ossicles (MIS amplify sound waves) - opening to auditory tube: helps equalize pressure and connects inner ear to throat

what is receptive field?

- areas monitored by specific receptors - large or small - harder to localize stimuli in larger fields

temporal lobe

- auditory cortex - olfactory cortex - auditory association area

external region of ear

- auricle: elastic cartilage - external acoustic meatus: have ear wax glands and keeps out water - external tympanic membrane

subarachnoid space

- between arachnoid mater and pia mater - has CSF - cushions brain

what is the cerebrum?

- biggest part - gyrus: elevation increasing SA - sulcus: shallow depression - fissure: deep depression - longitudinal fissure separates R and L hemisphere - transverse fissure separates cerebellum and cerebrum - central sulcus separates frontal and parietal - parieto-occipital sulcus separates parietal and occipital - lateral sulcus - exterior surface is gray matter with many cell bodies - white matter has myelinated axons

protection and support of brain include

- bones of skull: brain is soft and needs extra protection - cranial meninges surround brain - CSF cushion and allows floating - blood brain barrier - rich blood supply

what are the 6 regions of the brain

- cerebrum - cerebellum - diencephalon (epithalamus, thalamus, hypothalamus) - mesencephalon - pons - medulla (makes link with brain and spinal cord)

vision

- detect by photoreceptors sensitive to photons - eyes have mostly structures for protection ex: eyelashes

what can chemoreceptors detect?

- detect change in oxygen levels - found in respiratory center of medulla oblongata, carotid bodies, aortic bodies

what are phasic receptors

- fast adapting - send signals at beginning and end - feeling dissipates over time

what are baroreceptors

- feel change of pressure - in bladder, lung, digestive tract, etc.

gustation

- gustatory cells in taste buds on dorsal surface - taste buds are epithelial cells w specialized gustatory cells responding to different stimuli - different taste buds - gustatory cells have microvilli that open up taste pores - taste info goes to the thalamus then to the gustatory cortex in the insula

insula

- gustatory cortex

vestibule

- has 2 membrane sacs: utricle and saccule (involved in gravitational pull and motion) - branching off is semicircular duct involved in rotational movement

anterior eye cavity of eye

- has anterior and posterior chambers - aqueous humor flows here - posterior has virtuous humor and keeps eye round

Cerebellar Punduncles

- how cerebellum and brain stem communicate - superior layer communicates mesencephalon, diencephalon, cerebrum - middle layer communicates pons - inferior layer communicate medulla oblongata

diencephalon

- in cerebellum - epithalamus: has pineal gland - thalamus: right and left divided by 3rd ventricle and all sensory info - hypothalamus: homeostasis

purkinje cells

- in cerebellum - molecular layer are dendrites - Purkinje layer are cell bodies - granular layer are axons and tightly packed neurons

choroid plexus

- in ventricles - bv network surrounded by ependymal cells that create CSF - take nutrients from blood and turn it to CSF - directionality due to ciliated movement of cells of CSF through ventricles - when CSF reaches the 4th ventricle it can leave through lateral and median aperture

cochlea

- involved in hearing - cells transduce sound waves to action potentials - have cochlear ducts between scala vestibuli and tympani

what are the two ways to classify general senses

- location on body - stimulus they respond to

brain stem

- mesencephalon (midbrain): movement of eyes, sight, sound, reflexes - pons: plays role in respiratory - medulla oblongata: connects brain and spinal cord (relay center)

what are proprioceptor

- monitor body position - integration with sensory information from inner ear conveys info of body position

olfaction

- nerve fibers in superior part of cavity which detect odor molecules - odor molecules bind receptors in nerve fibers - nerve fibers are specialized receptors, generate AP which travel up the cribriform plate, to the olfactory bulb, to the olfactory tract, and to the olfactory cortex

what purpose do eyelids have

- palpebral fissure between upper and lower palpebral - wash debris from eye - levator palpebral superioris helps open upper eyelid - orbicularis oculi closes - tarsal plates have tarsal glands that prevent sticking - orbital fat cushions eye

cerebral spinal fluid

- prevents contact of neural tissue with bones - provides support - transport nutrients to and waste away

frontal lobe

- primary motor cortex: (precentral gyrus) sends impulses down spine to muscle - premotor cortex: involved in motor movement - prefrontal cortex: thinking, problem solving, personality

parietal lobe

- primary somatosensory cortex (post central gyrus): consciously feel sensation - somatosensory association area: understanding of texture, size, and shape

what is the conjunctiva?

- protects and prevents debris from getting under eye - bulbar is anterior - palpebral lines the inner palpebrate

ciliary zonule

- pulls and controls lens shape - bends light - produces aqueous humor

blood brain barrier

- regulates substances between blood and brain tissue - made of capillary endothelial cells and astrocytes - nutrients in and CO2/waste out - no BBB in choroid plexus and hypothalamus

what are tonic receptors

- respond to every stimulus at same magnitude - all or none reaction - constant exposure

what are the layers of the skull

- scalp - epicranial aponeurosis - periosteum of cranium - cranium - meninges (separate soft tissue from bone) dura: toughest arachnoid: protects blood vessels pia: softest and attaches to brain (nourishes)

what is the cerebellum

- separated from brain due to 4th ventricle - 2nd largest - 2 hemispheres separated by vermis - anterior and posterior lobe separate by primary fissure - folia are folds in cerebellum - gray matter on surface - white matter is arbor vitae

folds of the dura mater

- support and limit brain movement - falx cerebri in cerebrum - falx cerebelli in cerebellum - tentorium along transverse cerebral tissue - crista galli: anchors brain, point of attachment for falx cerebri - sella turcica: enclosed by diaphragma sellae

inner region of ear

- vestibule apparatus - cochlea - membranous/bony labyrinth - space between labyrinths are filled with perilymph - endolymph is membranous labyrinth

occipital lobe

- visual association area: association of face with person - visual cortex

arachnoid mater

- weblike due to arachnoid tuberculae and anchors cerebral blood vessels)

cranial nerve 6

ABDUCES - abducts eye - motor

cranial nerve 11

ACCESSORY - motor - cranial and spinal root - innervates palate, pharynx, and larynx

cranial nerve 7

FACIAL - sensory and motor - carries sensory info from anterior 2/3 of tongue - motor controls face muscles, lacrimal gland, submandicular, and sublingual glands

cranial nerve 12

HYPOGLOSSAL - motor - goes to tongue

cranial nerve 3

OCULOMOTOR - motor function that helps move eye (not all extrinsic except superior oblique and lateral) - move upper eyelid, adjust amount of light, and lens

cranial nerve 1

OLFACTORY - most anterior - sensory function of smell

cranial nerve 2

OPTIC - sensory vision - only pair that comes together and separates in optic chiasm - simultaneous imaging

cranial nerve 5

TRIGEMINAL - motor and sensory - 3 branches - associated of all facial senses - ophthalmic and maxillary range are only sensory (upper teeth) - mandibular has both and innervates mastication

cranial nerve 4

TROCHLEAR - motor - only for superior oblique - innervated muscle goes through trochlea

cranial nerve 10

VAGUS - sensory and motor - goes to different regions - innervates respiratory, cardiovascular, and digestive organs - longest

cranial nerve 8

VESTIBULOCOCHLEAR - sensory - inner ear - info of equilibrium

what is receptor specificity

ability of sensory receptors to respond to one particular stimulus

what cells process visceral information

amacrine, bipolar, ganglion cells

what is the corpus callosum

bundle of axons connecting hemispheres - when combined with the anterior commissure they create commissural fibers

what are projection fibers?

connect brain stem to cerebral cortex

what are associated fibers?

connect regions of the same hemisphere ex: arcuate and longitudinal

arachnoid granulation

extensions where CSF reaches superior sagittal sinus

cranial nerve 9

glossopharyngeal sensory and motor swallowing, salivation, gag reflex, sensation form tongue and ear

chemoreceptors

monitor chemical composition of body fluid

iris

muscle that controls pupil

what is referred pain?

painful sensation from visceral organ is perceived as coming from another region

subdural space

potential space between dura mater and arachnoid mater

interoceptors

provide info of internal environment - in walls of digestive and respiratory system - detect oxygen levels and pressure - not aware

exteroceptors

provide information of external environment - usually superficial on skin and we are aware of it

lacrimal punctum

releases tears in lacrimal canaliculi, sac, and nasolacrimal duct

thermoreceptors

respond to change in temperature

nociceptors

respond to pain

mechanoreceptors

respond to physical distortion of cell membrane

proprioceptors

respond to stimuli in body position - we know where our limbs are

rods vs. cones

rod: black and white vision cones: color

sensation vs. perception

sensation: info arriving to CNS perception: conscious awareness of sensation

what are sensory receptors

specialized to respond to changes in environment - many receptors and stimuli specific

thermoreceptors vs. nociceptors

thermo: found in dermis, exist as free nerve ending, phasic noci: free nerve endings, large fields, tonic

what are the 3 eye layers

vascular - choroid (nourishes retina and cools eye) - ciliary body (controls lens shape) - iris fibrous - cornea - sclera retina - neural layer: senses light - pigmented layer: many melanocytes and prevents scattering

fornix

where lacrimal ducts open and tears are released