09/25/07 BSCC2093 Notes Membranes Skin Hair Nails

Underneath the skin, NOT part of the skin

The kind of follicles that produce hair.

The kind of glands that are associated with a hair shaft or follicle.

The kind of sebaceous gland NOT associated with a hair. NO HAIR in the one called a follicle. Weird.

A sebaceous follicle with a white blood cell attack on bacteria (infection), causes acne (pimple)

The way the skin grows on the body. Stretch marks can be found along them. Surgeons cut along them.

These last a few hours or days, it's a reddening of the blood vessls after being hit by lightning or being shocked by electricity.

Dust is dead skin, and these dermatophagoides "skin eaters" actually eat the edible flakes of keratin, mold, and other organisms. They are microscopic.

intubated, echoes the structure of skin.

"Little Lump" Lowest layer, holds the hair in place. Blood vessels feed the living portin of the hair here.

The second layer, the core of the dividing cells right above the papilla.

"Middle" or third layer of the hair, surrounding the matrix and starting to harden.

Means "Outside" , it's the fourth layer of the hair, on top of the medula.

The fifth layer, it forms outside the cortex. It is analagous to the stratum lucidum of the skin. Glassy.

The portion of hair above the skin surface. Except near the bulb all the tissue is dead.

There's really only one hair color, which is melanin. Different degrees of melanin create shades of hair. Melanin is a multiply expressive allele. Different amounts in different body parts create different shades of hair color on same body.

Carrot Top Hair, orangey red. People with this hair are prone to allergies. It is the one exception to the melanin rule of hair color.

Melanocytes develop air bubbles to produce white hair.

Straight hair is circular (round), Wavy hair or curly hair is more or less oval shaped. Determined by DNA from the lower part of the hair.

5 million hairs total, 2% on head, 98% on body, though fine and spread out.

Approximately 3 mm thick.

Hair grows about five inches a year.

50-100 hairs per day.

Stress/anxiety, high fever, excess of Vitamin A, Hormones (pregnancy), drugs, radiation, Dietary Factors.

"Peach Fuzz" on surface, moreso in women.

Heavier and deper pigment, can be curly. Found in men, and on eyebrows.

Fine, downy, unpigmented hair, lasts about 3 months in newborns.

"Guard Hairs" thick, robust ear and nose hairs, seen often in older people.

This type of hair starts to form in puberty.

This type of hair can be found on the head.

Body hair, eyebrows, eyelashes.

Aids in nonverbal communication.

Protective from sun and cooling (traps water). May spread out on water for babies to hold onto. Mammals without lots of hair need a water cycle.

Theory that humans evolved in water as a sort of aquatic ape, walked upright for buoyancy, and taht the epiglottis is a diving reflex.

Protective, especially of thin, pointy bone underneath.

"Below Nail". Skin under the free edge of the nail.

The skin on which the nail plate rests.

The clear, keratinized portion of the nail.

The proximal end of a nail, underlying the nail fold.

The major portion of the nail plate, overlying the nail bed.

The portion of the nail plate that extends beyond the end of the digit.

The epithelium of the nail bed.

The fold of skin around the margins of the nail plate.

The groove where the nail fold meets the nail plate.

Dead epidermis that covers the proximal end of the nail; commonly called the cuticle.

The growth zone (mitotic tissue) at the proximal end of the nail; corresponding to the stratum basale of the epidermis.

The region at the base of the nail that appears as a small white crescent because it overlies a thick stratum basale that obscures dermal blood vessels from view.

The bone underneath the nail, the tiny bone of the fingertip.

Bloodflow to the nail an be measured by sensing device worn on finger. Anemia can be indicated if you press the free edge and color doesn't come back.

Respiratory disease, AIDS, liver disease, thyroid gland disorders

psoraisis, fungal infections

some blood disorders, iron deficiency anemia

Cyanosis, from poor circulation.

anemia or circulatory problems

Mechanical stresses to the skin cause Stratum germanitivum (basale) stem cells to divide, thickness of skin increases.