19 D Special Senses

Question 1

Is the receptor for dynamic equilibrium
Is located in the ampulla of each semicircular canal
Responds to angular movements

Answer 1

crista ampullaris (or crista)

Question 2

Each crista has support cells and hair cells that extend into a gel-like mass called the

Answer 2

cupula

Question 3

Three canals that each define two-thirds of a circle and lie in the three planes of space
Membranous semicircular ducts line each canal and communicate with the utricle
The ampulla is the swollen end of each canal and it houses equilibrium receptors in a region called the crista ampullaris
These receptors respond to angular movements of the head

Answer 3

The Semicircular Canals

Question 4

jellylike mass studded with tiny CaCO3 stones called otoliths

Answer 4

Otolithic membrane

Question 5

The central egg-shaped cavity of the bony labyrinth
Suspended in its perilymph are two sacs: the saccule and utricle
1. Saccule extends into the cochlea
2. Utricle extends into the semicircular canals
These sacs:
House equilibrium receptors called maculae
Respond to gravity and changes in the position of the head

Answer 5

The Vestibule

Question 6

A spiral, conical, bony chamber that:
Extends from the anterior vestibule
Coils around a bony pillar called the modiolus
Contains the organ of Corti (hearing receptor)

Answer 6

The Cochlea

Question 7

The cochlea is divided into three chambers

Answer 7

1. Scala vestibuli
2. Scala media (cochlear duct)-contains the Organ of Corti
3. Scala tympani

Question 8

Series of membranous sacs within the bony labyrinth
Filled with a potassium-rich fluid

Answer 8

Membranous labyrinth

Question 9

Tortuous channels worming their way through the temporal bone
Contains:
Cochlea-hearing
Vestibule- head tilt and acceleration motion
Semicircular Canals-rotational and acceleration motion
Filled with perilymph

Answer 9

Bony labyrinth

Question 10

The tympanic cavity contains three small bones

Answer 10

Malleus
Incus
Stapes

Question 11

Loud sounds are dampened by two muscle

Answer 11

tensor tympani and stapedius muscles

Question 12

Thin connective tissue membrane that vibrates in response to sound
Transfers sound energy to the middle ear ossicles
Boundary between outer and middle ears

Answer 12

Tympanic membrane (eardrum)

Question 13

Short, curved tube filled with ceruminous glands

Answer 13

External auditory canal

Question 14

The auricle (pinna) is composed of:

Answer 14

The helix (rim)
The lobule (earlobe)

Question 15

Respond only in bright light
Have high-acuity color vision
Are found in the macula lutea
Are concentrated in the fovea centralis

Answer 15

Cones: (blue, red, green)

Question 16

Respond best in dim light
Are used for peripheral vision
Allow us to see black/white

Answer 16

Rods:

Question 17

contains:
Photoreceptors
a. Rods- allow you to see black/white and in dim light.
b. Cones- allow you to see color when you have bright light.( only works when plenty of light)

Answer 17

Neural layer

Question 18

the outer layer that absorbs light and prevents its scattering

Answer 18

Pigmented layer

Question 19

The colored part of the eye
Pupil – central opening of the iris
Regulates the amount of light entering the eye during:
Close vision and bright light – pupils constrict
Distant vision and dim light – pupils dilate
Changes in emotional state – pupils dilate when the subject matter is appealing or requires problem-solving skills (sympathetic stimulation)

Answer 19

Iris

Question 20

A thickened ring of tissue surrounding the lens
Composed of smooth muscle bundles (ciliary muscles)
Anchors the suspensory ligament that holds the lens in place

Answer 20

Ciliary Body

Question 21

A dark brown membrane that forms the posterior portion of the uvea
Supplies blood to all eye tunics

Answer 21

Choroid region

Question 22

2. Vascular Tunic (Uvea) Has three regions:

Answer 22

1. Choroid
2. Ciliary body
3. Iris

Question 23

clear(anteriorly)
-lets light enter the eye

Answer 23

Cornea

Question 24

opaque (posteriorly)
-protects the eye and anchors extrinsic muscles

Answer 24

Sclera

Question 25

Structure of the Eyeball

Answer 25

A slightly irregular hollow sphere with anterior and posterior poles The wall is composed of three tunics – 1. Fibrous-outer 2. Vascular -middle 3. Sensory-inner The internal cavity is filled with fluids called humors (Vitreous and Aqueous) The lens separates the internal cavity into anterior and posterior segments

Question 26

a. Enable the eye to follow moving objects b. Maintain the shape of the eyeball

Answer 26

Six straplike extrinsic eye muscles

Question 27

secrete tears Tears 1. Contain mucus, antibodies (defensin), and lysozyme 2. Enter the eye via superolateral excretory ducts 3. Exit the eye medially via the lacrimal punctum 4. Drain into the nasolacrimal duct

Answer 27

Lacrimal glands

Question 28

Transparent membrane that: Lines the eyelids as the palpebral conjunctiva Covers the whites of the eyes as the ocular conjunctiva Lubricates and protects the eye

Answer 28

Conjunctiva

Question 29

contains glands that secrete a whitish, oily secretion (Sandman’s eye sand)

Answer 29

Lacrimal caruncle

Question 30

Protect the eye anteriorly Palpebral fissure – separates eyelids Canthi – medial and lateral angles (commissures)

Answer 30

Palpebrae (Eyelids)

Question 31

move the eyebrows medially (What you talking about Willis?)

Answer 31

Corrugator muscles

Question 32

depresses the eyebrows (I’m sorry)

Answer 32

Orbicularis muscle

Question 33

Coarse hairs that overlie the supraorbital margins Functions include: 1. Shading the eye 2. Preventing perspiration from reaching the eye

Answer 33

Eyebrows

Question 34

70% of all sensory receptors are in the eye Most of the eye is protected by a cushion of fat and the bony orbit Accessory structures include

Answer 34

1. Eyebrows 2. Eyelids 3. Conjunctiva 4. Lacrimal apparatus 5. Extrinsic eye muscles

Question 35

send impulses to: The olfactory cortex just above the orbits. The hypothalamus, amygdala, and limbic system exhibit emotional response to smell) ex. Smoke , gas, or skunk –stimulate the sympathetic system where as appetizing odors stimulate para sympathetic (salivation)

Answer 35

Mitral cells

Question 36

Influence of Other Sensations on Taste

Answer 36

Taste is 80% smell Thermoreceptors, mechanoreceptors, nociceptors also influence tastes Temperature and texture enhance or detract from taste We can smell over 1000 different odors

Question 37

taste sensation elicited by the amino acid glutamate

Answer 37

Umami

Question 38

taste sensation alkaloids (base) such as quinine and nicotine

Answer 38

Bitter

Question 39

taste sensation- hydrogen ions (acid)

Answer 39

Sour

Question 40

taste sensation- metal ions

Answer 40

Salt

Question 41

taste sensation- sugars, saccharin, alcohol, and some amino acids

Answer 41

Sweet

Question 42

taste cells

Answer 42

Gustatory cells

Question 43

dynamic stem cells

Answer 43

Basal cells

Question 44

insulate the receptor

Answer 44

Supporting cells

Question 45

Taste buds are found in papillae of the tongue mucosa Papillae come in three types:

Answer 45

filiform, fungiform, foliate and circumvallate

Question 46

to substances dissolved in fluids of the nasal membranes

Answer 46

Smell

Question 47

to substances dissolved in saliva

Answer 47

Taste

Question 48

Chemical senses

Answer 48

gustation (taste) and olfaction (smell)