Anatomy : Special Senses

Front 1

Receptor cells

Back 1

Not free endings of sensory neurons ; described as neuron like epithelial cells or small peripheral neurons . Receptor is a protein molecule that receives chemical signals from outside a cell.

Front 2

Complex sensory organs

Back 2

Eyes and ears

Front 3

Distinctive epithelial structures

Back 3

Taste buds and olfactory epithelium

Front 4

Cranial nerves

Back 4

Some receive sensory information from sensory receptors

Front 5

Olfactory nerve / cranial nerve 1

Back 5

Smell

Front 6

Optic nerve/ CN 2

Back 6

Sight

Front 7

Vestibule cochlear/ auditory nerve / CN 8

Back 7

Hearing and equilibrium

Front 8

Facial nerve (CN 7), glosspharyngeal (9) nerve/vagus Nerve (10)

Back 8

Involved with taste

Front 9

Taste buds

Back 9

Taste receptors are found with taste buds

Front 10

Mucosa of mouth and pharynx

Back 10

Location of taste buds

Front 11

How many taste buds

Back 11

10,000

Front 12

Taste buds

Back 12

The majority of taste buds are found on the tongue, but not all of them

Front 13

Two types of papillae

Back 13

Fungiform papillae & Vallate Papillae

Front 14

Fungiform papillae

Back 14

Relatively small: located over the entire surface of the tongue; most NUMEROUS

Front 15

Vallate Papillae

Back 15

Relatively large, located near the back of the tongue, least numerous , forms a V-SHAPE

Front 16

How many epithelial cells make up an individual taste bud

Back 16

50 to 100 epithelial cells make up ONE taste bud

Front 17

Gustatory cells (epithelial cells)

Back 17

Receptor cells

Front 18

Supporting cells (epithelial cells)

Back 18

Insulate/protect gustatory cells: very numerous

Front 19

Basal cells ( undifferentiated )

Back 19

Will replace gustatory cells or supporting cells

Front 20

Taste pore

Back 20

Near the center of the taste bud. Where Microvilli from gustatory cells absorb taste molecules

Front 21

Tastes

Back 21

Sweet, sour, salty, bitter, umami (deliciousness / savory )

Front 22

Sensory pathway

Back 22

Taste buds (sensory receptors) > sensory fibers of CRANIAL NERVES 7, 9, 10 >> solitary nuclei of medulla oblongata > thalamus > gustatory area of cerebral cortex

Front 23

Olfactory epithelium (SMELL)

Back 23

Olfactory receptors are located within the epithelia that cover the super nasal Conchae and superior nasal septum

Front 24

Sniffing

Back 24

Draws more air and intensifies the smell

Front 25

Pseudostratified columnar epithelium

Back 25

Olfactory epithelium (SMELL)

Front 26

Olfactory receptors cells

Back 26

Bipolar neurons

Front 27

Olfactory cilia

Back 27

Apical (bottom) dendrite projections act as receptors and largely immotile

Front 28

Supporting cells

Back 28

Secrete mucus

Front 29

Mucus

Back 29

Captures and dissolves scent molecules

Front 30

Basal cells (undifferentiated)

Back 30

Form new olfactory (SMELL) receptor cells

Front 31

Olfactory glands

Back 31

Also secrete mucus

Front 32

Filaments of olfactory nerve

Back 32

Axons of cranial nerve 1 = olfactory

Front 33

Olfactory bulb

Back 33

Part of the forebrain

Front 34

Mitral cells

Back 34

Neurons that synapse with CN 1 AXONS

Front 35

Glomeruli

Back 35

Present between CN 1 filaments and Mitral cells( where synapses occur)

Front 36

Sight/vision

Back 36

Dominant special sense in humans ; accounts for 70% of sensory receptors and 40% of cerebral cortex

Front 37

Eyebrows

Back 37

Shade the eyes and prevent sweat from the forehead from reaching the eyes

Front 38

Eyelids/palpbrae

Back 38

Upper and lower lids; close to protect the eyes

Front 39

Eyelashes

Back 39

Help to protect the eyes as a filter and through reflexive blinking

Front 40

Conjunctiva

Back 40

Conjunctiva Is a transparent mucus membrane that covers the inner surfaces of the eyelids and anterior surface of the eyes; forms the white scleara ; blood vessels are present within, responsible for bloodshot eyes

Front 41

Lacrimal apparatus

Back 41

Keeps the surface of the eye moist with tears/lacrimal fluid

Front 42

Extrinsic eye muscles

Back 42

6 skeletal muscles that move the eye

Front 43

Eye

Back 43

The eye has anterior and posterior poles

Front 44

Tunics

Back 44

Three layers

Front 45

3 types of tunics

Back 45

Fibrous, vascular, and sensory tunic

Front 46

Fibrous tunic

Back 46

Outer layer; corresponds to the dura mater of the brain

Front 47

Sclera- outer layer

Back 47

White

Front 48

Cornea- outer layer

Back 48

Transparent / Clear

Front 49

Vascular tunic

Back 49

Middle layer

Front 50

Choroid - middle layer

Back 50

Highly vascular, dark pigmented membrane, corresponds To arachnoid mater and pia mater

Front 51

Ciliary body - middle layer

Back 51

Thickened ring of tissue continuous with the choroid anteriorly( in the front of eye), encircles the lens .

Front 52

Iris - middle layer

Back 52

Iris is the Visible colored part of the eye located between the cornea and lens

Front 53

Sensory tunic

Back 53

Inner layer

Front 54

Retina - inner layer

Back 54

Retina - where photo receptors are found

Front 55

Cavities / chambers

Back 55

Anterior and posterior

Front 56

Two types of humors

Back 56

Vitreous and aqueous humor

Front 57

Aqueous humor

Back 57

Watery fluid found within the anterior( front) chamber of the eye

Front 58

Vitreous humor

Back 58

Relatively viscous fluid found with the posterior (back) chamber of the eye, gel consistency

Front 59

Lens

Back 59

Focuses light on the retina, is capable of changing shape

Front 60

Layers of retina

Back 60

The retina is composed of two layers

Front 61

Layers of retina

Back 61

Pigmented and neural layer

Front 62

Pigmented layer

Back 62

Outer layer, lies against the choroid, composed of melanocytes

Front 63

Melanocytes - pigmented layer

Back 63

Produce melanin, which absorbs incoming light to prevent scattering

Front 64

Neural layer

Back 64

The inner layer of the retina, relatively thick, contains photoreceptors

Front 65

Photoceptor cells

Back 65

Rods, cones, and ganglion cells

Front 66

Rods

Back 66

The most numerous, very sensitive to the light, allow vision in dim light

Front 67

Cones

Back 67

Bright light, color vision, three types of cones

Front 68

Three types of cones

Back 68

Blue, red, green

Front 69

Blue, red, green cones

Back 69

These cones are sensitive to different wavelengths of light

Front 70

Ganglion cells

Back 70

Axons of which form optic nerve (CN 2)

Front 71

Ora serrata retinae

Back 71

Location where the neural layer of the retina ends anteriorly ( in the front)

Front 72

Macula lutea

Back 72

Located at the posterior (back) pole ; appears yellow : lots of cones ; central vision best

Front 73

Fovea centralis

Back 73

Located in the center of the macula lutea, contains only cones, maximum visual acuity (sharpest daylight images)

Front 74

Optic disc / Papilla

Back 74

Where the axons of the ganglion cells Converge to form optic nerve / CN 2 : blind spot

Front 75

Main visual pathway

Back 75

Photoreceptors ( retina) >> optic nerve >~> optic chiasma > optic tract > thalamus > visual cortex of the occipital lobe of cerebrum

Front 76

Superior colliculi

Back 76

Reflex nuclei controlling extrinsic eye muscles

Front 77

Pretectal nuclei

Back 77

Pupillary light reflex

Front 78

Pupillary light reflex

Back 78

Change diameter of pupil

Front 79

Suprachiasmatic nucleus of hypothalamus

Back 79

Timer that runs daily biorhythms associated with daylight/ dark cycles

Front 80

Development of eyes

Back 80

Eyes form as outpocketings of brain( optic vesicles > optic cups)

Front 81

Outer / external ear

Back 81

Auricle / pinna

Front 82

External Acoustic Meatus

Back 82

External Acoustic/Auditory Meatus – canal through which sound waves travel.

Front 83

Elastic cartilage - ear

Back 83

Elastic Cartilage – flexible cartilage.

Front 84

Cerumen/earwax

Back 84

Cerumen/Earwax – produced by ceruminous glands.

Front 85

Tympanic Membrane

Back 85

Tympanic Membrane – “ear drum”; medial boundary of external ear; lateral boundary of middle ear.

Front 86

Pharyngptympanic/auditory/eustachian tube

Back 86

Pharyngotympanic/Auditory/Eustachian Tube – connects middle ear to pharynx.

Front 87

Middle ear ossicles

Back 87

Middle Ear Ossicles – transmit vibrations to inner ear.

Front 88

Types of ossicles

Back 88

Mallelous, incus, Stapes

Front 89

Malleus, incus, Stapes

Back 89

Malleus, Incus, Stapes – from most lateral to most medial.

Front 90

Inner ear / labyrinth

Back 90

Inner Ear/Labyrinth – sometime referred to as the “maze”.

Front 91

Bony labyrinth

Back 91

Bony Labyrinth – three parts composed of bone.

Front 92

Semicircular Canals

Back 92

Semicircular Canals – house semicircular ducts.

Front 93

Vestibule

Back 93

Vestibule – houses utricle & saccule.

Front 94

Vestibular Nerve

Back 94

Vestibular Nerve – innervates vestibule; balance.

Front 95

Cochlea

Back 95

C

C

Cochlea – houses cochlear duct.

Front 96

Cochlear Nerve

Back 96

Cochlear Nerve – innervates cochlea; hearing.

Front 97

Semicircular ducts

Back 97

Semicircular Ducts – sense rotational acceleration.

Front 98

Cupula

Back 98

Cupula – hairs of epithelial cells form a cap-like structure that bends.

Front 99

Utricle & Saccule

Back 99

Utricle & Saccule – senses static equilibrium and linear acceleration.

Front 100

Macula

Back 100

Macula – sensory epithelium within utricle and saccule; monitors static equilibrium and linear acceleration.

Front 101

Otoliths

Back 101

Otoliths – “ear stones”.

Front 102

Cochlear duct

Back 102

C

C

Cochlear Duct – senses sound/hearing.

Front 103

Hair Cells

Back 103

H

H

Hair Cells – act as receptors; bent by vibrations.

Front 104

Auditory pathway

Back 104

Auditory Pathway Cochlear Nerve => Medulla => Midbrain => Cerebral Cortex (Primary Auditory Cortex)

Front 105

Equilibrium Pathway

Back 105

Equilibrium Pathway Vestibular Nerve => Brain Stem (Medulla & Cerebellum) Also, Minor Equilibrium Pathway to Cerebrum