The Senses

Front 1

General senses organs

Back 1

Often exist as individual cells or receptor units. Widely distributed throughout the body.

Front 2

Special sense organs

Back 2

Large and complex organs. Localized grouping of specialized receptors

Front 3

Classification of sense organs

Back 3

Either encapsulated or unencapsulated (bare). Also what type of stimulus is required to activate them

Front 4

Conversion of stimulus into a sensation

Back 4

A particular stimulus is detected, it’s turned into a nurse impulse, and the CNS perceives that sensation to determine what it is

Front 5

General sense organs

Back 5

Widespread single cell receptors. Common.

Front 6

Skin receptors (general sense)

Back 6

Free nerve endings (several types)-pain, discriminative touch, tickle and temp. Tactile (Meissner) corpuscle-fine touch and vibration. Bulbous (Ruffini) corpuscle-touch and pressure. Lamellar (pacini)- pressure and vibration. Bulboid (Krause)-touch

Front 7

Muscle receptors (general sense)

Back 7

Golgi tendon receptor-proprioception (position of body parts). Muscle spindle-proprioception

Front 8

Deep receptors (general sense)

Back 8

Stretch pressure receptors in hollow organs like stomach and intestines, arteries, vagina (birth canal), and urinary bladder. Chemical receptors-detect pH, carbon dioxide, and other chemicals.

Front 9

The eye

Back 9

Special sense organ

Front 10

Sclera

Back 10

Tough outer coat. White if the eye. Cornea is transparent part of the sclera over iris

Front 11

Choroid

Back 11

Pigmented vascular layer prevents scattering of light. Front part is made of ciliary muscle and iris. Pupil is the hole in center of iris. Contraction of iris muscle dilated or constricts pupil

Front 12

Retina

Back 12

Innermost layer of eye. Contains rods (monochrome receptors for night vision and cones (color receptors for day vision)

Front 13

Conjunctiva

Back 13

Mucous membrane covering front surface of the sclera and lining the eyelid.

Front 14

Lens

Back 14

Transparent body behind the pupil, focuses light rays on retina

Front 15

Aqueous humor

Back 15

In the anterior cavity in front of lens, watery fluid

Front 16

Vitreous humor

Back 16

In the posterior cavity behind the lens. Jellylike mass

Front 17

Visual pathway

Back 17

Innermost layer contains rods and cones. Impulse travels from the rods and cones through the bipolar and ganglionic layers of retina. Nerve impulses leave the eye through the optic nerve, the point of exit is free of receptors and therefore called the blind spot. Visual interpretation occurs in the visual cortex of the cerebrum

Front 18

Macula

Back 18

Highest density of photoreceptors for the best resolution

Front 19

Fovea

Back 19

Overall region of highest acuity

Front 20

Sty

Back 20

Infection of eyelash follicle, very painful and should solve on their own

Front 21

Cataract

Back 21

Cloudiness of the eye. Common cause is long term exposure to ultraviolet light. Becomes hard and losses transparency. Can have cloudy resolution or complete blindness

Front 22

Myopia (refraction disorder)

Back 22

Nearsightedness often caused by elongation of the eyeball

Front 23

Hyperopia (refraction disorder)

Back 23

Farsightedness often caused by a shortened eyeball

Front 24

Astigmatism (refraction disorder)

Back 24

Distortion caused by an irregularity of the cornea or lens

Front 25

Conjunctivitis (refraction disorder)

Back 25

Inflammation of the conjunctiva. Trachoma-chronic chlamydial infection. Acute bacterial conjunctivitis-highly contagious infection producing a discharge of mucous pus. Can be caused by allergies

Front 26

Strabismus

Back 26

Improper alignment of eyes. Eye can converge (cross) or diverge. If not corrected can cause blindness

Front 27

Retinal detachment (disorder of retina)

Back 27

Part of the retina detached form the other structures. Bright flashing lights and an abundance of eye floaties

Front 28

Diabetic retinopathy

Back 28

May cause retinal detachment; one of the leading causes of blindness in the US

Front 29

Nyctalopia

Back 29

Night blindness or the inability to see in dim light is caused by retinal detachment or lack of vitamin A

Front 30

Age related mascular degeneration (AMD)

Back 30

Affects part of retina most essential to good vision (macula). Idiopathic, risk increases after 50, genetics, and smoking

Front 31

Color blindness

Back 31

Inherited; abnormality in the cones photopigments. Red, green, and blue cones affected. Green sensitive pigment can be missing or deficient, red sensitive pigment can be abnormal

Front 32

Glaucoma

Back 32

Overbuild up of aqueous humor by not allowing drainage and filling up, putting pressure on the retinal layer

Front 33

Scotoma (disorder of visual pathway)

Back 33

The loss of only the central visual field when only certain nerve pathways are damaged

Front 34

Cerebrovascular accidents (CVA)

Back 34

Can damage visual processing centers. Cortical color blindness-Difficulty in distinguishing any color (not just one or two in color blindness

Front 35

The ear

Back 35

Sense organ in hearing and also of equilibrium and balance

Front 36

Divisions of the ear

Back 36

External ear, middle ear, inner (internal) ear

Front 37

External ear

Back 37

Auricle (pinna)-appendage on side of head. External acoustic canal (meatus)-Curving tube 1 inch in length, Contains ceruminous (earwax) glands. Ends at tympanic membrane

Front 38

Middle ear

Back 38

Epithelium-lined cavity that houses the ear ossicles-malleus (hammer), incus (anvil), and stapes (stirrup). Ends in oval window-separates middle ear from inner ear.

Front 39

Auditory (eustachian) tube

Back 39

Connects the middle ear to the throat-one continuous membrane.

Front 40

Otis media

Back 40

Infection causing sore throat may spread to produce ear infection

Front 41

Inner ear

Back 41

Bony labyrinth filled with perilymph. Subdivided-vestibule, semicircular canals, and cochlea. Filled with endolymph. Receptors for balance are cristae ampullaris.

Front 42

Sound pathway in inner ear

Back 42

Sensory hair cells in the organ of Corti (spiral organ) respond when bent by the movement of surrounding endolymph set in motion by sound waves

Front 43

Hearing disorder

Back 43

Conduction impairments-can be caused by blockage of the external or middle ear

Front 44

Otosclerosis

Back 44

Inherited bone disorder involving irregularity of shapes; first appears as tinnitus (ringing) then progresses to hearing loss

Front 45

Otitis

Back 45

Ear inflammation caused by infection; can produce swelling and fluids that block sound conduction

Front 46

Presbycusis (nerve impairment)

Back 46

Progressive nerve deafness associated with aging

Front 47

Meniere disease

Back 47

Chronic inner ear disorder characterized by tinnitus; nerve deafness; and vertigo

Front 48

Taste receptors

Back 48

Taste buds-chemoreceptors. Cranial nerves VII and IX carry gustatory impulses. Four taste sensations-sweet, sour, bitter, salty. Gustatory and olfactory senses work together

Front 49

Smell receptors

Back 49

Receptors for fibers lie in olfactory mucosa of nasal cavity. Olfactory receptors are extremely sensitive but easily fatigued.

Front 50

Pathway of smell

Back 50

Odor causing chemicals initiate a nervous signal that is interpreted as a specific odor by the brain.