Chapter 8 vocab

Question 1

Special Senses

Answer 1

In medicine and anatomy, the special senses are the senses that have specialized organs devoted to them: vision (the eye) hearing and balance (the ear, which includes the auditory system and vestibular system) smell (the nose) taste (the tongue)

Question 2

Special Senses Receptors

Answer 2

respond to a stimulus by converting that stimulus into a nerve impulse

Question 3

Eyelids

Answer 3

each of the upper and lower folds of skin that cover the eye when closed.

Question 4

Eyelashes

Answer 4

each of the short curved hairs growing on the edges of the eyelids, serving to protect the eyes from dust particles.

Question 5

Meibomian Glands

Answer 5

are a holocrine type of exocrine glands, at the rim of the eyelids inside the tarsal plate, responsible for the supply of meibum, an oily substance that prevents evaporation of the eye’s tear film.

Question 6

Ciliary Glands

Answer 6

are modified apocrine sweat glands that are found on the margin of the eyelid

Question 7

conjunctva

Answer 7

the mucous membrane that covers the front of the eye and lines the inside of the eyelids.

Question 8

Lacrimal Apparatus

Answer 8

he physiological system containing the orbital structures for tear production and drainage.

Question 9

Lacrimal Glands

Answer 9

paired, almond-shaped exocrine glands, one for each eye, that secrete the aqueous layer of the tear film.

Question 10

Lacrimal Canals

Answer 10

he small channels in each eyelid that commence at minute orifices, termed puncta lacrimalia, on the summits of the papillae lacrimales, seen on the margins of the lids at the lateral extremity of the lacus lacrimalis.

Question 11

Lacrimal Sac

Answer 11

he dilated oval upper end of the nasolacrimal duct that is situated in a groove formed by the lacrimal bone and the frontal process of the maxilla, is closed at its upper end, and receives the lacrimal ducts.

Question 12

Nasolacrimal Duct

Answer 12

a membranous canal extending from the lacrimal sac to the nasal cavity, through which tears are discharged into the nose.

Question 13

Extrinsic/ External Eye Muscles

Answer 13

any of six small muscles that control the horizontal, vertical, and rotating movements of the eyeball.

Question 14

Eyeball

Answer 14

the round part of the eye of a vertebrate, within the eyelids and socket. In mammals it is typically a firm, mobile, spherical structure enclosed by the sclera and the cornea.

Question 15

Sclera

Answer 15

the white outer layer of the eyeball. At the front of the eye it is continuous with the cornea.

Question 16

Cornea

Answer 16

the transparent layer forming the front of the eye.

Question 17

Choroid

Answer 17

resembling the chorion, particularly in containing many blood vessels.

Question 18

Ciliary Body

Answer 18

the part of the eye that connects the iris to the choroid.

Question 19

Lens

Answer 19

an object or device that focuses or otherwise modifies the direction of movement of light, sound, electrons, etc.

Question 20

Iris

Answer 20

a flat, colored, ring-shaped membrane behind the cornea of the eye, with an adjustable circular opening (pupil) in the center.

Question 21

Pupil

Answer 21

The opening of the iris

Question 22

Retina

Answer 22

the nerve layer that lines the back of the eye, senses light, and creates impulses that travel through the optic nerve to the brain

Question 23

Rods

Answer 23

A type of specialized light-sensitive cell (photoreceptor) in the retina of the eye that provides side vision and the ability to see objects in dim light (night vision)

Question 24

Cones

Answer 24

type of specialized light-sensitive cell (photoreceptor) in the retina of the eye that provides color vision and sharp central vision.

Question 25

Photoreceptors

Answer 25

a specialized type of sensory neuron found in the retina that is capable of visual phototransduction

Question 26

Optic Nerve

Answer 26

each of the second pair of cranial nerves, transmitting impulses to the brain from the retina at the back of the eye.

Question 27

Optic Disc

Answer 27

the point of exit for ganglion cell axons leaving the eye.

Question 28

Blind Spot

Answer 28

mall portion of the visual field of each eye that corresponds to the position of the optic disk (also known as the optic nerve head) within the retina.

Question 29

Fovea Centralis

Answer 29

small, central pit composed of closely packed cones in the eye

Question 30

Color Blindness

Answer 30

abnormal condition characterized by the inability to clearly distinguish different colors of the spectrum

Question 31

Cataracts

Answer 31

A clouding or loss of transparency of the lens in the eye as a result of tissue breakdown and protein clumping

Question 32

Aqueous Humor

Answer 32

humor refers to a fluid (or semifluid) substance. Thus, the aqueous humor is the fluid normally present in the front and rear chambers of the eye

Question 33

Vitreous Humor

Answer 33

humor refers to a fluid (or semifluid) substance. Thus, the aqueous humor is the fluid normally present in the front and rear chambers of the eye

Question 34

Scleral Venous Sinus

Answer 34

circular channel in theeye that collects aqueous humor from the anterior chamber and delivers it into the bloodstream via the anterior ciliary veins

Question 35

Glaucoma

Answer 35

A common eye condition in which the fluid pressure inside the eye rises to a level higher than healthy for that eye

Question 36

Fundus

Answer 36

he bottom or base of an organ. For example, the fundus of the eye is the retina

Question 37

Refracted

Answer 37

the deflection from a straight path undergone by a light ray or a wave of energy in passing obliquely from one medium (as air) into another (as water or glass) in which its velocity is different

Question 38

Accommodaton

Answer 38

the ability of the eye to change its focus from distant to near objects (and vice versa)

Question 39

Optic Tracts

Answer 39

part of the visual system in the brain

Question 40

Optic Chiasma

Answer 40

the X-shaped partial decussation on the undersurface of the hypothalamus through which the optic nerves are continuous with the brain

Question 41

Optic Radiation

Answer 41

axons from the neurons in the lateral geniculate nucleus to the primary visual cortex.

Question 42

Binocular Vision

Answer 42

The ability to maintain visual focus on an object with both eyes, creating a single visual image

Question 43

Convergence

Answer 43

an embryonic movement that involves streaming of material from the dorsal and lateral surfaces of the gastrula toward the blastopore and concurrent shifting of lateral materials toward the middorsal line and that is a process fundamental to the establishment of the germ layers