Chapters 17-18 Sense Organs: The Eye and Ear and Endocrine System

Pupil

Central opening of the eye, surrounded by the iris, through which light rays pass (appears dark)

Cornea

Fibrous transparent layer of clear tissue that extends over the anterior portion of the eyeball; protrudes outwards

Conjunctiva

Delicate membrane lining the undersurface of the eyelids and covering the anterior eyeball; up to cornea

Cone

Photoreceptor cell in the retina that transforms light energy into a nerve impulse; responsible for color & central vision

Retina

Light-sensitive nerve cell layer of the eye containing photoreceptor cells (rods & cones)

Iris

Pigmented (colored) layer that opens and closes to allow more or less light into the eye

Optic disc

Region at the back of the eye where the optic nerve meets the retina; blind spot of eye bc only has nerve fibers

Rods

Photoreceptor cell of the retina essential for vision in low light & for peripheral vision

Sclera

Tough, white outer coat of the eyeball

Macula

Yellowish region in the retina; contains the fovea centralis; small oval region on the retina near optic disc

Vestibule

central cavity of the labyrinth, connecting the semicircular canals & the cochlea; 2 structures to have equilibrium, saccule & utricle

Oval window

membrane between the middle ear & the inner ear

Semicircular canals

passages in the inner ear associated with maintaining equilibrium

Organ of Corti

sensitive auditory receptor area found in the cochlea of the inner ear

Cochlea

snail shell-shaped, spirally wound tube in the inner ear; has hearing-sensitive receptor cells

Auricle

the protruding part of the external ear, or pinna

Cerumen

Waxy substance secreted by the external ear; earwax

Labyrinth

maze-like series of canals of the inner ear; responsible for hearing and balance; includes the cochlea, vestibule, & semicircular canals

Incus

second ossicle (small bone) of the middle ear; incus means anvil

Malleolus

first ossicle of the middle ear; malleus means hammer

Stapes

third ossicle of the middle ear; stapes means stirrup

Strabismus

failure of the eyes to look in the same direction because of weakness of a muscle controlling the position of one eye; abnormal deviation of the eye

Acoustic neuroma

Benign tumor arising from the acoustic vestibulocochlear (eighth cranial nerve) nerve in the brain

Cholesteatoma

Collection of skin cells and cholesterol in a sac within the middle ear

Glaucoma

Increased intraocular pressure results in damage to the retina & optic nerve with loss of vision

Astigmatism

Defective curvature of the cornea or lens of the eye

Hyperopia

Farsightedness; eyeball is too short; see distance clearly, up close is blurry

Osteosclerosis

an abnormal hardening of bone

Presbyopia

Impairment of vision as a result of old age

Nystagmus

Repetitive rhythmic movements of one or both eyes

Chalazion

Small, hard, cystic mass on the eyelid

Parathyroid glands

Four small glands on the posterior of the thyroid gland; some ppl may have 3 or 5

Pituitary gland

Gland located at the base of the brain in the sella turcica; made of anterior lobe and posterior lobe

Thyroid gland

Gland located in the neck on either side of the trachea; secretes thyroxine, triiodothyronine, & calcitonin

Adrenaline (epinephrine)

Hormone secreted by the adrenal medulla that increases heart rate and blood pressure (epinephrine)

Luteinizing hormone

Hormone that stimulates ovulation in females and testosterone secretion in males; secreted by anterior lobe of pituitary gland

Adrenal medulla

Inner section of each adrenal gland; secretes epinephrine & norepinephrine

Electrolyte

Mineral salt found in the blood and tissues and necessary for proper functioning of cells; potass. sodium, calcium

Insulin

Secreted by beta islet cells of the pancreas; helps glucose pass into cells; promotes glucose to glycogen

Tetany

A condition of constant muscle contraction; muscle & nerve weakness

Myxedema

Advanced hypothyroidism in adulthood

Pheochromocytoma

Benign tumor of the adrenal medulla

Panhypopituitarism

Deficiency of all pituitary hormones

SIADH

Excessive secretion of antidiuretic hormone; syndrome of inappropriate ADH

Acromegaly

Hypersecretion of GH (growth hormone) leading to enlargement of extremities; after puberty

Cushing syndrome

Group of signs and symptoms produced by excess cortisol from the adrenal cortex

Addison disease

Hypofunctioning of the adrenal cortex

Diabetes mellitus

Lack of insulin secretion or resistance of insulin in promoting sugar, starch, and fat metabolism in cells

Graves disease

The most common form of hyperthyroidism; overactivity of the thyroid gland

Know some examples of steroids

Estrogens, androgens, and glucocorticoids; Corticosteroids, Anabolic Steroids, Oxandrolone, Progestogens

-opia

suffix for: vision (-opsia)

-acusis

suffix for: hearing (-cusis)

-meter

suffix for: instrument to measure

-otia

suffix for: ear condition

hypo-

prefix for: deficient

infra-

prefix for: below

sub-

prefix for: under

hypo-

prefix for: less than normal

hyper-

prefix for: excessive

hyper- & Supra- & Epi-

prefix for: above

Know another name for the tympanic membrane

also known as the eardrum

cor/o

comb form: pupil (pupill/o)

palpebr/o

comb form: eyelid

lacrim/o

comb form: tears

dacry/o

comb form: tears or tear duct

opt/o

comb form: eye/vision (optic/o)

corne/o

comb form: cornea (kerat/o)

phac/o & phak/o

comb form: lens of the eye

photo/o

comb form: light

ot/o

comb form: ear

staped/o

comb form: third bone of the middle ear

ossicul/o

comb form: three small bones of middle ear

acous/o

comb form: hearing (audi/o & audit/o)

myring/o

comb form: eardrum (tympan/o)

auricul/o & aur/o

comb form: ear

salping/o

comb form: eustachian tube

gluc/o

comb form: sugar (glyc/o)

estr/o

comb form: female

aden/o

comb form: gland

andr/o

comb form: male

kal/i

comb form: potassium

crin/o

comb form: secrete

gonad/o

comb form: sex glands (ovaries & tests)

natr/o

comb form: sodium

blephar/o

comb form: eyelid

Otosclerosis

hardening of the boney tissue of the middle ear

Adrenal cortex

Outer section of each adrenal gland