Integumentary System Flashcards
Function of the Integumentary system
Provides protection, regulates body temperature, prevents water loss, and synthesizes vitamin D.
Integument
It is the skin that covers the body. The skin is also called the Cutaneous layer. The integument is the largest organ OF the body. (The liver is the largest IN the body)
The integumentary consists of
Skin, Nails, hair, and skin glands. It also consists of the Epithelial, Connective, Vascular, Nervous tissue, and others.
How much weight does the skin account for
It accounts for 7-8% of the body’s weight.
A small population of immune cells to combat infection and cancer. They are found in the Stratum Spinosum
Epidermal Dendritic Cells
Temperature Regulation in the Integumentary system
When the body is hot, dermal blood vessels dilate (vasodilatation), epidermal sweat glands release perspiration that evaporates, and heat is dissipated to the outside.
When the body is cold, the dermal blood vessels constrict (vasoconstriction), epidermal sweat glands become inactive and heat is conserved inside the body.
It is the outer portion of the integument and is stratified into 4 or 5 layers that vary in thickness.
Epidermis
All but the deepest layers of the epidermis are dead cells that contain a protein, which toughens and makes the skin water resistant
keratin
The epidermis has 5 layers because they are exposed to greater fiction.
palms, soles, and lips
Layers of the epidermis (From bottom to top layer)
1) Stratum Basale
2) Stratum Spinosum
3) Stratum Granulosum
4) Stratum Lucidum
5) Stratum Corneum
It is tightly attached to the underlying dermis. Cells in this layer are continually going through mitosis or dividing identical cells. As the cells move upward they lose nutrients and oxygen from the underlying dermal blood vessels and die. It takes 6-8 weeks for the cells produced here to reach the surface of the epidermis and die.
Stratum Basale
3 Types of Cells in the Stratum Basale
Keratinocytes, Melanocytes, and Tactile (Merkel) cells
Keratinocytes:
synthesizes keratin which toughens skin and makes in insoluble.
Melanocytes:
They produce and store the pigment melanin in response to UVlight exposure. produce brown/darker granules of pigment that given skin brown and darker tones. It is believed that melanin helps shield the DNA of skins cells from UV radiation.
Tactile (Merkel) cells:
they are few in number and are sensitive to touch.
It is located superior to the Stratum Basale. The deepest cells in this layer are still dividing (mitosis). Epidermal Dendritic cells are found in this layer and help stimulate the immune system.
Stratum Spinosum
There are 3 to 5 layers of keratinocytes containing dark staining granules. Within this layer, keratinocytes begin to die and the cells fill up with the protein keratin.
Stratum Granulosum
This layer is thin and is a clear region of two to three layers of flat dead cells. This layer is only found in the SOLES of the feet, PALMS of the hand, and the LIPS at the entrance of the mouth.
Stratum Lucidum
This layer consists of 20-30 layers of flattened, dead, scale-like cells which contain large amounts of keratin. This is the real PROTECTIVE layer of the skin.
Stratum Corneum
is brought on by keratinization, and the hardening, flattening process that takes place as the cells migrate to the surface.
Cornification