Integument came from the Latin word which means
Integumentum
To cover
Total surface area of the human skin is approximately
18 sq ft
The largest organ of the body is how many percent of the body weight?
12-15%
The skin’s most important function is
Protection
Main functions of the integ sys?
Barrier against infection and injury Regulate body weight Remove waste prods from the body Protect against uv radiation from the sun Produce vit D
2 layers of the integ sys
Epidermis and dermis
Composed of sheets of flattened, scaly epithelial cells
Epidermis
Most of its cells undergo rapid cell division or mitosis
Epidermis
Tough fibrous protein and forms the basic structure of hair, nails and calluses
Keratin
Melanin produced in skin depends on 2 factors
Heredity
Length of time the skin is exposed o uv radiation
Absorb uv radiation from sun and excess exposure lead to skin CA such as melanoma
Melanin
True or False
There are NO BLOOD VESSELS in epidermis
True
Epidermis layers
Stratum basale Stratum spinosum Stratum granulosum Stratum lucidum Stratum corneum
Pigment containing layer of the epidermis
Stratum granulosum
This layer is where its amount determines skin color
Stratum basale
Melanocytes
Innermost thick layer which lies beneath the epidermis
Dermis
The dermis contains
Blood vessels, nerve endings, glands, sense organs, smooth muscles and hair follicle
Collagen fibers hat tend to be horizontal forming the creasing of the skin
Langer’s lines
Classical caesarian cut
“Bikini cut”
Pfanensteil
Attached o underside of hairs, contraction pull hairs erect causing goose flesh “bumps”
Erector pili muscle
Pain is detected by
Free nerve endings
Coldness is detected by
Krause end bulbs
Pressure and vibration are detected by
Pacinian corpuscles
On a cold day when the body needs to conserve heat the blood vessels in the dermis
Narrow
Produce watery secretions which contains salt, water and other products
Sweat glands
Produce oily secretion called sebum
Sebaceous glands
This type of sweat gland is linked to the sympathetic nervous system
Eccrine glands
This type of sweat gland is found in the axillary and groin areas
Apocrine glands
If skin is subjected to repeated fiction the rate of mitosis will increase and create a thicker epidermis thus called
Callus
Layer of fat and loose connective tissue and insulates the body
Hypodermis or subcutaneous layer
Tubelike pockets of epidermal cells that extend into the dermis
Hair follicle
Hair gets its color from
Melanin
Children lacking sufficient vit D develop bone abnormalities known as
Rickets
