1. Chapter 7 Personal Health
Health Science
Mr. Otteson

2. Function of the Skin
The skin is the single largest organ in the human body.
Integumentary system- includes your hair, skin, and nails.
The skin is your first line of defense.
Helps cushion your internal organs.
Helps regulate body temperature.

3. Integumentary System
Sweat glands- structures within the skin that secrete perspiration through pores onto your skin.
Sweat cools your body
Skin has an enormous supply of tiny blood vessels.
Internal heat is circulated through the vessels and is lost through the process of radiation. When you perspire your skin cools.

4. Healthy Skin
Every morning and every evening you should wash your face with facial soap, pat your skin with a clean towel, and apply moisturizer when finished.
Eat a well-balanced diet.
Vitamin A helps promote healthy skin.
A good source of Vitamin A is milk, egg yolks, liver, green leafy and yellow vegetables, and yellow fruits.

5. Skin and Sun UV rays-light rays from the sun Two types of UV sun rays:
1. shorter rays-are most intense in middle of the day and are main cause of sunburn.
2. longer rays-in the morning and late afternoon, best for tanning.
80 percent of UV can penetrate haze, light clouds or fog.
Snow, sand, and water are reflectors of UV rays, sending back >85% of the rays.

6. Protecting Your Skin Use SUNSCREEN!!!!!
SPF 15 or higher. SPF 30 is best.
Avoid long term exposure to the sun.
Reapply sunscreen throughout the day when you are in the sun frequently.
Eat a healthy diet filled with lots of Vitamin A.

7. Your Hair You have between 100,000-200,000 hairs on your head.
The roots of hair are made of cells and grow out of tiny pits called follicles.
Proper care includes daily washing, & conditioning.
Brushing daily helps prevent dirt build up on the scalp and also distributes natural oils evenly.

8. Hair Problems
Dandruff- condition in which the outer layer of dead skin cells is shed from the scalp.
Can be prevented with regular washing and dandruff control shampoos.

9. Your Nails
Fingernails and toenails are dead cells that grow from the outer layer of your skin.
Living cells die and are replaced. They are pushed up and out from the rest of the nail.
Proper care includes cleaning, & trimming your nails regularly.

10. Healthy Teeth & Mouth
Good regular oral health care is essential for clean, healthy teeth.
Regular brushing and flossing helps prevent diseases such as Periodontal Disease.
Gingivitis-swelling or bleeding
Halitosis-bad breath
Plaque- a sticky, colorless film that acts on sugar to form acids that destroy tooth enamel and irritate gums.

11. Healthy Eyes
Your eyes have > a million electrical connections and can distinguish nearly 8 million differences in color.
Protective structures around the eyes include eyebrows, eyelids, and eyelashes.
Lacrimal gland- produces tears.
The salt in tears gives them an antiseptic effect, which helps fight pathogens.

12. Parts of the Eye Sclera-tough, white outer coat of the eye.
Cornea-main lens that performs most of the eye’s focusing.
Choroid- midlle layer of the eyball wall.
Iris- color portion of the eye.
Retina- light-sensitive membrane on which images are cast by the cornea and lens.
Aqueous humor- watery fluid btwn cornea and lens.
Vitreous humor-clear jelly behind the lens that keeps the eyeball firm.

13. Healthy Eyes Have yearly checkups Wear your glasses or contacts
Take breaks when working at computers
Read and watch T.V. in a well lit room
Avoid rubbing your eyes
Wear sunglasses
Wear protective glasses or goggles for athletics

14. Eye Problems Two types: Vision problems and diseases
Nearsightedness (myopia)- close up objects are seen clearly, but distant objects are blurred.
Farsightedness (hyperopia)- distant objects are seen clearly, but close objects are blurred.

15. Diseases of the Eye
Cataracts- clouding of the lens causing blurred or hazy vision and problems with night vision.
Glaucoma- pressure of the fluid in the eye is so high that it damages the optic nerve and may result in blindness.
Detached Retina- the retina may become separated from the outer layers of the eye, resulting degeneration or wearing out of the tissue.

16. Parts of the Ear
Outer ear-curved part attached to each side of the head. Made of fatty tissue and cartilage. Collects sounds and directs them into the ear.
External auditory canal-a passageway that leads to the eardrum.
Middle Ear- three small bones linked together that connect the eardrum with the inner ear. Malleus, Incus, Stapes

17. Parts of the Ear
Inner Ear (labyrinth)-maze of winding passages divided into three parts.
Cochlea-outermost part of inner ear, turns sound vibrations into nerve impulses.
Vestibule & semicircular canals-contain structures critical to the sense of balance.

18. Hearing
Your ears transform sound waves into nerve impulses that your brain interprets as sounds. Sound waves entering the external auditory canal cause the eardrum to vibrate. These vibrations are carried across the middle ear by the ossicles and into the inner ear. They are converted into nerve impulses that are then sent to the brain.

19. Balance
Semicircular canals provide balance. At one end of each canal is an organ called crista. The crista contains many tiny hairs bathed in a fluid. As the head moves, the fluid shifts, bending the hairs and stimulating nerve impulses. Nerve fibers send information about changes in position to the brain. The brain signals the muscles to make the necessary adjustments to maintain balance.

20. Healthy Ears Clean them regularly
Clean the outer ears with a cotton swab
Do NOT push anything into the ear.
Avoid loud noises, gunshots and music.
Wear ear protectors when operating loud machinery
Take regular hearing tests. Early diagnosis of hearing problems is important.

21. Problems of the Ear
Deafness is a complete or partial inability to hear.
Two types:
1. Conductive Deafness-Persistant build-up of fluid within the middle ear, often due to ear infections, is the most common cause of hearing difficulties in children.

22. Problems of the Ear
2. Sensorineural Deafness- sounds reach the inner ear but are not sent to the brain. Result of damage to the cochlea, auditory nerve, or to part of the brain. Caused by prolonged exposure to loud noises, increased fluid pressure in the inner ear, viral infections, and tumors.