Exam 1 Flashcards
Short, course hairs overlying the supra orbital margins of the eye that shade the eyes and keep sweat out
Eyebrows
Help protect the eye from physical danger as well as drying out
Eyelids and eyelashes
Transparent mucous membrane that lines the eyelids and the whites of the eyes, produces lubricating mucous that prevents eye from drying out
Conjunctiva
Where tears fall from, opening edge on eyelid
Lacrimal punctum
Surrounds sides and back of eye, cushions eye, allows free movement, and protects blood vessels and nerves
Orbital fat
What are the 3 layers of the eye?
Tunica Fibrosa, Tunica Vasculosa, and Tunica Interna
What is the tunica Fibrosa made up of?
Sclera and cornea
What is the tunica Vasculosa made up of?
Choroid, ciliary body, and iris
What is the tunica Interna made up of?
Retina and optic nerve
Made up of two layers: pigmented layer and neural layer; pressed against back of eyeball by vitreous humor
Retina
Clouding of lens
Cataract
Elevated pressure within the eye due to obstruction of sleral venous sinus and improper drainage of aqueous humor
Glaucoma
Avascular, biconcave, transparent, flexible structure that can change shape to allow precise focusing of light on the retina
Lens
Occurs when light meets the surface of a different medium at an oblique angle rather than a right angle
Refraction
When is light bent?
- As it enters the cornea
- As it enters lens
- As it leaves lens
What must the eye do to see something close up?
Convergence of the eyes, constriction of pupil, and accommodation of lens
Occurs when objects focus in front of the retina and results in seeing close objects of the pupils and convergence of the eyeballs
Myopia (nearsightedness)
Occurs when objects are focused behind the retina and results in seeing distant objects clearly but close objects are blurred
Hyperopia
The process by which the eye detects light energy
Photoreception
Modified neurons that structurally resemble tall epithelial cells
Photoreceptors
Occurs when we move from darkness into bright light
Light adaption
When we go from a well-lit area into a dark one. The cones stop functioning and the rhodopsin starts to accumulate in the rods, increasing retinal sensitivity
Dark adaption
What are the receptors for taste and smell?
Chemorecepters
Organ of smell located in the roof of the nasal cavity
Olfactory Epithelium
Bipolar neurons with a thin apical dendrite that terminates in a knob with several olfactory cilia
Olfactory receptors
What are the sensory receptor organs for taste?
Taste buds
Olfactory disorders resulting from head injuries that tear the olfactory nerves, nasal cavity inflammation, or aging
Anosmias
Olfactory hallucinations
Uncinate fits
Small, air-filled, mucosa-lined, cavity in the petrous portion of the temporal bone
Tympanic Cavity (middle ear)
What are the two major divisions of the internal ear?
Bony labyrinth and the membranous labyrinth
The central cavity of the bony labyrinth with two membranous sacs suspended in the perilymph, the saccule and the utricle
Vestibule
Project from the posterior aspect of the vestibule, each containing an equilibrium receptor region called a crista ampullaris
Semicircular canals
A pressure disturbance produced by a vibrating object and propagated by the molecules of the medium
Sound
The number of waves that pass a given point in a given time
Frequency
Reveals a sounds intensity
Amplitude
Any hearing loss, no matter how slight
Deafness
A ringing or clicking sound in the ears in the absence of auditory stimuli
Tinnitus
Labyrinth disorder that causes a person to suffer repeated attacks of vertigo, nausea, and vomiting
Meniere’s syndrome
What are the sensory receptors for static equilibrium?
Maculae
What is the receptor for dynamic equilibrium?
Crista ampullaris
Why are people farsighted?
Eyeball is too short or lens cannot become round enough
What is Otitis Media?
A middle ear infection common in children where the auditory tube is short and horizontal; causes pain and impaired hearing
What is conductive deafness?
Conditions interfere with transmission of vibrations to inner ear
What is sensorineural deafness?
Death of hair cells or any nervous system elements concerned with hearing
What are the 4 principal mechanisms of communication between cells?
Gap junctions, neurotransmitters, paracrine hormones, and hormones
Glands, tissues, and cells that secrete hormones
Endocrine system
Organs that are traditional sources of hormones
Endocrine glands
Chemical messengers that are transported by the bloodstream and stimulate physiological responses in cells of another tissue or organ, often a considerable distance away
Hormones
Have ducts carry secretion to an epithelial surface or the mucosa of the digestive tract
Exocrine Glands
Do not have ducts; use internal secretions
Endocrine Glands
What hormones does the Hypothalamus produce?
ADH, Oxytocin, and regulatory hormones
What hormones does the Pituitary Gland produce?
ACTH, TSH, GH, PRL, FSH, LH, and MSH, oxytocin, and ADH
What hormones does the thyroid gland produce?
Thyroxine, Triiodothronine, Calcitonin
What hormones does the Pineal Gland produce?
Melatonin
What hormone does the parathyroid gland produce?
Parathyroid hormone
What hormones do the Adrenal glands produce?
Epinephrine, noepinephrine, cortisol, corticosterone, aldosterone, and androgens
What hormones does the pancreas produce?
Insulin and glucagon
Regulates primitive functions of the body from water balance and thermoregulation to sex drive and childbirth
Hypothalamus
What is acromegaly?
Thickening of bones and soft tissues in adults
What is goiter?
Any pathological enlargement of the thyroid gland
What is hyperparathyroidism?
Excess PTH secretion, causes tumor
Transmits light, supports the posterior surface of the lens, holds the retina firmly against the pigmented layer, and contributes to intraocular pressure
Vitreous humor
Supplies nutrients and oxygen to the lens and cornea while carrying away wastes
Aqueous humor
Highly sensitive and are best suited to night vision
Rods
Less sensitive to light and are best adapted to bright light and color vision
Cones
What do photoreceptors contain?
Retinal
