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
What causes a callus?
It is caused by the friction on the skin surface stimulates additional mitotic activity of the stratum basale, resulting in thicker skin in that localized area.
Children deprived of UV light and vitamin D may develop this disease. increase with videogames and less mild in diet
rickets
How is a tattoo permanent?
It requires an injection of ink/dyes to be inserted deep to the stratum basale.
Carotene
It is the weakest of the skin pigments. It is yellow-orange in color and is acquired by eating carrots, corn, squash, and brussel sprouts. It accumulates inside the keratinocytes in the stratum corneum and within the subcutaneous fat. Carotene is converted to Vitamin A in the body which helps improve vision.
the enzyme which is needed to synthesize melanin is nonfunctional so the melanocytes can’t produce melanin. It is caused by a recessive gene.
Albinism
Is a condition that causes depigmentation of parts of the skin. It occurs when melanocytes die or are unable to function. The cause is unknown.
Vitiligo
Cyanosis and acrocyanosis
It is caused by reduced oxygenation of hemoglobin in blood vessels.
Paleness. It is caused by a deficiency of erythrocytes, a deficiency of hemoglobin, or both.
Pallor
Jaundice
Is caused by the hemoglobin breakdown product, bilirubin.
Is caused by increased blood flow in the dermis because of dilated blood vessels. It can be caused by sunburn, excess heat, emotions, or infection.
Erythema
1-2 hours after death, the skin will blanch when squeezed. 8 hours after death, the red blood cells escape in the surrounding tissue and the area will not blanch when squeezed.
Postmortem lividity
This occurs 3-5 days after death (depending on temp.) and is caused by the bacterial degradation of the hemoglobin in the subdermal blood vessels.
Venous Marbling
found in the dermis, it makes the skin elastic.
Collagen
2 layers of the Dermis
Papillary Layer (stratum papillarosum) and the Reticular Layer (stratum reticularosum)
It is in contact with the epidermis. The epidermal ridges and dermal papillae increase the area of contact between the epidermis and the dermis to connect these layers.
the papillary layer (stratum papillarosum):
forms the deeper and major portion of the dermis. It is a network of collagen and elastic fibers that contribute to the skin’s strength and elasticity.
The reticular layer (stratum reticularosum):
It is caused by yeasts that belong to the genera Pityrosporum or Malassezia
Dandruff
Rapid stretching of the reticular layer can cause tears in the collagen fibers resulting in:
“stria” or “linea albicantes” (stretch marks)
decubitus ulcers
bed sores. continuous local pressure can restrict vital blood flow.
when a blunt hollow tube is roughly inserted into the hypodermis so that adipose cells can be removed
liposuction
hypodermis
subcutaneous layer
hardened, transparent stratum corneum. the cells are densely packed together and filled with parallel fibers of hard keratin
nails
pili
hair
regardless of its location, pili is produced by this layer
epidermal
3 zones of hair
Hair bulb, Root, and Shaft
contraction of arrector pili muscles pull on and elevate the pili. What is the common term for this?
goose bumps
skin glands secrete substances through ducts
exocrine glands
2 types of exocrine glands in the skin
sudoriferous glands (sweat) and sebaceous glands (oil)
mammary and ceruminous glands are modified from which type of exocrine gland?
sudoriferous
enzyme within cerumen capable of destroying bacterial cells
lysozyme
