Sense SystemSystem

Penabur Christian Junior High School

Jakarta

Pre Test• What are the sense organs?

• What is retina?

• What is the function of iris?

• What is the very sensitive part of retina (to light)?light)?

• What is cataract?

• What are part of ears?

• What is eustachian tube?

• Which part that play role in equilibrium?

A. Visual = Eye

Eyeball eye muscle and eyelids

Eyelid and Eyelash f: ?

Tear glands (lacrimal glands) Tear glands (lacrimal glands)

Part of Eye

• Anterior Cavity

– Between cornea and lens

– Aqueous fluid

• Posterior Cavity

– Between lens and retina

– Vitreous fluid

A. 1. Sclera

• Outer coat

• Protect inner structure & help to maintain the rigidity of eyeballof eyeball

• White, though, and fibre

• Front cornea as light regulator (transparant)

A.2. Choroid Layer

• Middle layer• Dark coloured• Dark coloured• A lot of blood vessels & pigment• Front part of choroid

– ciliary muscle to change thickness of lens– Iris regulates the size of light opening and give colour of

human eye

A.3. Iris

• control the amount of light that enters the eye and has pigment color

• In other words…..

A.4.Pupil

• opening in the middle of iris, place where light enters the eye

A.5.AQUEOUS HUMOR

aqueous liquid located between cornea and lens

Watery substance

A.6. Lens

• biconvex and transparent,

• F: to focusing image to retina

A.7. Viterous Humor

• jelly like substance

• lens and retina

A.8. Retina

• Inner layer

• Light ray receptor

• Consist of photoreceptor cells

– Rods: in dim light, shape and movement

– Cones: bright light, fine detail and colour vision

A.8.1. Fovea (Yellow Spot)

• center of eye’s sharpness vision

• location of most colour perception

• Very sensitive to light

Seeing Process

Light cornea pupil aqueous body lens vitreous body retina

photoreceptor optic nerve brainphotoreceptor optic nerve brain

DISFUNCTION AND ABNORMALITIES OF EYE

blurred vision due either to the irregular shape of blurred vision due either to the irregular shape of the cornea, light can not focused on the retina

• Glaucoma high pressure inside eyeball, can cause blindness

– Drainage ducts are blocked aqueous humor buid up high pressure blind

• Cataract fuzziness of lens

– Lens

– Aging and exposure to the sun

Color blind cones cells can’t receive light color heredity (genetic disorder)

• Nyctalopia the inability to see in dim light or at night

• Trachoma

– cornea inflammation caused by bacteria Chlamydia trachomatis

– causing mild irritation in the eyes and a discharge of pus and/or mucus

– 1st infection no prob

repeated inflammation of conjunctiva & scarring the cornea

B. THE EAR

• The human ear has two sensory functions:

– Hearing

– detecting positional changes

• Hearing ear can distinguish between • Hearing ear can distinguish between vibrations through air (sound)

B.1. OUTER EAR:

a. Pinna (external flaps) gathers sounds wave

b. Auditory canal transfers sounds to tympanic membrane Fine hair and sweat gland

c. Earwax glands protect from dirt (upper wall of canal) Against foreign materials

d. Tympanic membrane receives sounds Separate inner and middle

B.2. Middle ear:

a. Eustachian tube: connected to outside tube to sustain air pressure

b. Hearing bones (ossicles)

-maleus (hammer)

-incus (anvil)-incus (anvil)

-stapes (stirrup)

B.3. Inner ear:

a.Oval window:

Transmit vibrations from stapes

b. Round window:

Balance the vibrations

c. Cochlea: spiral shaped tube, consist of “corti organ”

d. Semicircular canal: filled with semicird. Semicircular canal: filled with liquid to maintain balance of the body

semicircular canals

cochlea

• Organ of corti

Contains hair

Cells very sensitive

to vibrations

organ of Corti

to vibrations

Transfer to auditory

Nerves brain

HEARING PROCESS

• Sound waves ear canal tympanic membrane hearing bones cochlea auditory nerves brain

DISFUNCTION AND ABNORMALITIES OF EAR

1. Deaf not able to hear, caused by pilling of ear wax, genetic factor, bacteria/fungi infection and damage to tympanic membrane

2. Otitis inflammation of middle ear caused by virus 2. Otitis inflammation of middle ear caused by virus or bacteria

3. Oterosklerosis stapes bone can’t vibrate deaf

4. Travel sickness abnormality of semicircular canal

THE NOSE

• Do you ever think how your nose can smell?

• What actually the substance that come to your nose and produce smell?

• Substances that produce smell is called as odor molecules

• generally light, volatile (easy to evaporate) chemicals that float through the air into your nose

• Odor molecules in the air enter the nose and hit roof of the nasal cavity

• At the roof of nasal cavity, there are olfactory nerves that receive the odor and that receive the odor and transfer it to the brain

SMELLING PROCESS

Odor molecules move into nostril dissolve in mucous membrane received by olfactory nerves send to brain

People are sensitive up to 10 000 odors

DISFUNCTION AND ABNORMALITIES OF NOSE

1. Anosmia abnormality of olfactory nerves, so can’t transmit smell to the brain

2. Influenza infection of virus in respiratory tract, so it will cause disfunction of nosetract, so it will cause disfunction of nose

THE TONGUE

• Detects taste from food

• Both smell and taste are involved in specific receptors cells called as chemoreceptor

PAPILLAThe small bumps or nodules

of tissue on your tongue

• Sense organs that detect taste taste buds located at surface of tounge (inside papillae)

taste process

Taste of food papillae taste pore taste bud taste nerves taste centre in the brain (parietal lobe) analyzed and answeredanswered

DISFUNCTION AND ABNORMALITIES OF TONGUE

Leucoplachia caused by fungi (spot white on tongue)

THE SKIN

• How does the body sense touch, temperature and pain?

• all regions of skin are sensitive to touch, so skin can be considered as your largest sense skin can be considered as your largest sense organ

DISFUNCTION AND ABNORMALITIES OF SKIN

• Allergic caused by food or chemical changes

• Melanoma (skin cancer) excessive ultra violet exposed

• Acne bacteria or disorder of sebaceous gland (oil gland)

• Seven year itch caused by saraoples scabei

• Exim inflammation in childhood• Exim inflammation in childhood