Practical 3

Unit 7

external ear

portion of the ear that funnels airborne vibration to the tympanic membrane; also consists of the pinna, external auditory canal, and ends with the tympanic membrane

pinna

earlobe part of the outermost portion of the ear

auricle

cartilaginous part of the outermost portion of the ear

external auditory canal

passage through the temporal bone leading to the tympanic membrane

tympanic membrane

closes the inner end of the auditory canal and separates it from the middle ear; suspended in a ring-shaped groove in the temporal bone; vibrates in response to sound

middle ear

an air-filled cavity lined with a mucous membrane, located within the petrous region of the temporal bone; contains auditory ossicles, oval window, round window, and auditory tube

tympanic cavity

another name for the middle ear

auditory ossicles

the smallest bones in the body; found in the middle ear

malleus

the auditory ossicle that has direct contact with the tympanic membrane; outermost ossicle; mallet-shaped with the handle attached to the membrane and head articulating with the incus

incus

the auditory ossicle connected to the malleus; has a roughly triangular body, a short limb suspended by a ligament, and a long limb articulating with the stapes

stapes

the auditory ossicle that attaches the other two ossicles to the membranous labyrinth of the inner ear; head articulates with the incus; has an arch and an elliptical base

oval window

upper opening in the middle ear that holds the base of the stapes; where the inner ear begins

round window

lower opening in the middle ear that is covered by a second tympanic membrane

auditory tube

connection between the middle ear and the nasopharynx

eustachian tube

another name for the auditory tube

inner ear

the portion of the ear located medial to the middle ear; consists of a bony labyrinth and a membranous labyrinth

bony labyrinth

a series of cavities within the petrous portion of the temporal bone; contains the vestibule, semicircular canals, and cochlea; filled with perilymph

perilymph

fluid that fills the bony labyrinth

petrous

the bony labyrinth is located within the _____ portion of the temporal bone

vestibule

ovoid chamber of the bony labyrinth that contains the utricle and saccule; proximal to the oval window

semicircular canals

somewhat circular structures arising superiorly from the vestibule; contain _____ ducts

cochlea

spiral tube arising medially from the vestibule; houses the _____ duct

membranous labyrinth

a series of membranous sacs and ducts contained within the bony labyrinth of the inner ear; includes the semicircular ducts, utricle, saccule, and cochlear duct; filled with endolymph

endolymph

fluid that fills the membranous labyrinth

semicircular ducts

fleshy loops that detect head rotation

utricle

an organ of balance housed within the vestibule; found at the bottom of the “U”’s of the semicircular ducts

saccule

an organ of balance housed within the vestibule; located at the end of the cochlear duct

cochlear duct

snail-shaped organ of hearing

internal acoustic meatus

passage for the vestibulocochlear nerve from the inner ear to the pons

palpebrae

eyelids (superior and inferior)

levator palpebrae superioris

muscle that lifts the upper eyelid

palpebral fissure

eye opening between the 2 palpebrae\`

lacrimal gland

tear duct gland found on the superior and lateral side of the eye; constantly producing tears

lacrimal caruncle

medial drainage for tears; found in the innermost corner of the eye

lacrimal punctum

holes in the drainage duct of the eye

lacrimal canaliculus

large canals found on either side (superior and inferior) of the caruncle

lacrimal sac

where the lacrimal canaliculus drains into; superior to and drains into the nasolacrimal duct

nasolacrimal duct

inferior duct that the lacrimal sac drains into

cornea

clear-coating over the top of the iris area

sclera

white portion of the eye

iris

colored portion of the eye

pupil

opening in the iris

lens

suspended behind the pupil by fibrous ring called a suspensory ligament

suspensory ligament

what suspends the lens

ciliary body

muscular ring around the lens for support; secretes aqueous humor; focuses/controls the lens

anterior segment

portion of the eye from the cornea to the ciliary bodies; filled with aqueous humor; has an anterior chamber and a posterior chamber

anterior chamber

portion of the anterior segment of the eye from the cornea to the lens

posterior chamber

portion of the anterior segment of the eye from the lens to the ciliary bodies

aqueous humor

watery fluid found in the anterior segment of the eye

posterior segment

portion of the eye from the ciliary bodies to the start of the optic nerve; filled with vitreous humor

vitreous humor

gel-like fluid found in the posterior segment of the eye

choroid

layer of the eye immediately deep to the sclera; brown in most 3D models

retina

layer of the eye immediately deep to the choroid; pink in most 3D models

fovea centralis

a small depression on the posterior end of the retina; responsible for high-acuity vision; yellow in most 3D models

optic disc

the “blindspot”; a raised disc on the retina around the point of entry of the optic nerve; white in most 3D models

optic nerve

nerve leading from the optic disc on the retina

macula lutea

area around the fovea centralis; region of keenest vision

extrinsic eye muscles

muscles responsible for moving the eyeball within the bony orbit

superior rectus

extrinsic eye muscle that turns the eye superiorly and medially

inferior rectus

extrinsic eye muscle that turns the eye inferiorly and medially

medial rectus

extrinsic eye muscle that turns the eye medially

III

the cranial nerve that innervates the superior rectus, inferior rectus, medial rectus, and inferior oblique

lateral rectus

extrinsic eye muscle that turns the eye laterally

VI

the cranial nerve that innervates the lateral rectus

superior oblique

extrinsic eye muscle that depresses the eye and turns the eye laterally

IV

the cranial nerve that innervates the superior oblique

inferior oblique

extrinsic eye muscle that elevates the eye and turns the eye laterally

C1-C4

nerve roots of the cervical plexus

C5-T1

nerve roots of the brachial plexus

T12-L4

nerve roots of the lumbar plexus

L4-S4

nerve roots of the sacral plexus

phrenic nerve

important nerve of the cervical plexus

musculocutaneous nerve

upper trunk, anterior division, lateral cord

axillary and radial nerves

all 3 trunks, posterior division, posterior cord; 2 nerves

median nerve

upper trunk, anterior division, lateral cord; lower trunk, anterior division, medial cord

ulnar nerve

lower trunk, anterior division, medial cord

iliohypogastric nerve

lumbar nerve from T12 and L1

ilioinguinal nerve

lumbar nerve from L1

lateral femoral cutaneous nerve

lumbar nerve from L2 and L3

femoral and obturator nerves

lumbar nerves from L2-L4; 2 nerves

sciatic nerve

important nerve of the sacral plexus

common fibular and tibial nerves

the 2 nerves that make up the sciatic nerve

musculocutaneous

innervates coracobrachialis

musculocutaneous

innervates biceps brachii

musculocutaneous

innervates brachialis

median

innervates pronator teres and pronator quadratus

median

innervates flexor carpi radialis

median

innervates palmaris longus

median

innervates flexor digitorum superficialis and profundus

median

innervates flexos pollicis longus

ulnar

innervates flexor carpi ulnaris

ulnar

innervates flexor digitorum profundus

ulnar

innervates dorsal interossei

ulnar

innervates lumbricals

axillary

innervates deltoid

axillary

innervates teres minor

radial

innervates triceps brachii

radial

innervates brachioradialis

radial

innervates extensors of the forearm

radial

innervates supinator and anconeus