Integumentary System. Fun Fact! the average square inch of skin holds: – 650 sweat glands, – 20 blood vessels, – 60,000 melanocytes – more than a thousand.

Integumentary System

Fun Fact!

• the average square inch of skin holds: – 650 sweat glands, – 20 blood vessels, – 60,000 melanocytes – more than a thousand nerve endings!

Mole vs. Melanoma

• The common mole is a benign tumor called a nevus.

Nails• Provide a protective covering at the end of

fingers and toes• Has a Nail plate that overlies the nail bed • What makes nails hard?

Anatomy of the HAIR

• Hair • Hair root• hair follicle

• Hair bulb– Papilla – base of hair

follicle – matrix

Goose bumps!

• Arrector Pili– smooth muscle cells

Sebaceous glands (oil!)

• holocrine glands • sebum

Acne

Sudoriferous gland (sweat!)

• Exocrine glands• Two types:

– Eccrine – apocrine glands

Eccrine glands• most numerous variety • Purpose:

– Temp. regulation– Excretory function

• are smaller • are active from birth

• Found in forehead, neck, back – and release sweat on hot days or with physical activity

Apocrine glands• less numerous variety• Secrete when someone is

emotionally upset, frightened or in pain

• Most numerous in the axillary region and groin, and usually connected to hair follicles

OTHER glands:

• Ceruminous glands: external ear

• Mammary glands – in females

Negative feedback mechanism

• Stimulus

• Compares with • Set Point

• Response

Effector• Muscles

• Blood vessels

Receptors

Homeostasis

Extremes

• Hypothermia

Fact: 80% of the body’s head escapes through the head! SO, wear a HAT!

Extremes

• Hyperthermia

Wound Healing

• A process of tissue regeneration:1. Inflammation2. formation of blood clot3. development of scab and migratory phase4. proliferation phase – growth of epithelium and

blood vessels5. maturation phase – scab disappears,

homeostasis is regained

Shock:shock include fainting, general weakness, rapid

pulse and breathing, nausea and vomiting, a blue tinge to the lips and finger nails, and pale, cold, moist skin.

BSA (body surface area) – Rule of 9

• In patients older than nine years, they apply what’s called the “rule of nines” to determine the percentage of BSA. For example, the genital area is considered 1% of BSA. The head and neck are 9%. Burns on each arm, including the hand, is also 9% of BSA. Each leg, including the foot, is 18%. The front of the torso is 18%, as is the back of the torso, including the buttocks.

Let’s think about it…

• Mrs. Park volunteered to help at a hospital for children with cancer. When she first entered the cancer ward, she was upset by the fact that most the children had no hair. What is the explanation for their baldness?

• After studying the skin in anatomy class, Toby grabbed the large “love handles” at his waist and said, “I have too thick a hypodermis, but that’s okay because this layer performs some valuable functions!” What are the functions of the hypodermis?

• Mrs. Wilkins received second degree burns on her abdomen when she dropped a kettle of boiling water. She asked the clinic physician (worriedly) if she would have to have a skin graft. What do you think he told her?

These symptoms of your nails could be signs of what diseases or problems?

• Yellow discoloration• Separation of your nail from the nail bed

(onycholysis)• Indentations that run across your nails (Beau's lines)• Nail pitting• Opaque or white nails• Curled nails