Integumentary System and Body Temperature-Chapter 7. J oe Pistack MS/ED. Integumentary system includes: The skin Accessory structures:- sweat glands -oil glands - hair
Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.
Acts as a gland by synthesizing vitamin D. Vitamin D is necessary for absorption of calcium from the digestive tract.
Performs a sensory role by housing the sensory receptors for touch, pressure, pain, and temperature.
Plays an important role in the regulation of body temperature.Functions of the skin
The epidermis can be divided into 5 layers the two of interest here are the deeper stratum germinativum and the more superficial stratum corneum
-lies on top of the dermis.
-has access to a rich supply of blood.
-cells of this layer constantly divide, push old cells to the surface.Layers of skin
Changes take place as cells move away from surface: 1. cells begin to die
2. keratinization takes place
Keratinization-process whereby tough protein
called keratin is deposited within the cell, keratin hardens and flattens the cells as they move toward surface. This makes the skin water-resistant.Layers of skin
Insensible perspiration-500ml/day of perspiration that is lost through the skin.
Sensible perspiration-due to activity of the sweat glands.
If the epidermis is damaged, the rate of insensible perspiration increases. E.g. burnsLevels of skin
22 to20 ga. 5/8 to 3/4 long
- melanocytes fail to secrete melanin.
- skin, hair, and iris (colored part of eye) are white.
-loss of pigment in certain areas of skin.
-creates patches of white skin.
Freckles and Moles:
-Areas in the skin where melanin is concentrated
-A mole that has changed in character and has become cancerousMalfunctioning melanocyte
Epidermal cells –receive blood supply from the dermal blood vessels.
Keratinization of cells- cells die as they move away from their source of nourishment.
Hair that we brush, blow dry, and curl is dead.Hair Follicle
Bundle of smooth muscle fibers, when these muscles contract, hair stands on end.
Contract when cold or frightened.
Also called goose bumps.Hair follicle
Nail growth-determined by half-moon shaped lunula located at the base of the nail.
As nail grows, it slides over the nailbed.
Underlying dermal layer contains blood vessels which give pink color to nail.
Cuticle-fold of stratum corneum-grows onto proximal portion of the nail body.Nail structure
clubbing-condition that indicates fingertips have received an insufficient supply of oxygenated blood over a period of time.
Fingertips become large, nails become think, hard, shiny and curved at the free end.
Causes-chronic heart and lung disease.Nail conditions
Cyanosis-poor oxygenation makes the blood appear bluish, this in turn makes the nails appear bluish.
Nail abuse-trauma to the nail that causes the nail to thicken and hypertrophy.
Brittle- generally due to poor oxygenation or poor nutrition, or anemias.cyanosis
Body odor- occurs when the substances in sweat are degraded by bacteria into chemicals with a strong unpleasant odor.
2) Eccrine glands-more numerous and widely distirubuted throughout the body. Especially numerous on the forehead, neck, back, upper lip, palms, and soles.Sweat glands
Thermoregulation-the mechanism whereby the body balances heat production and heat loss.
Failure to regulate body temperature causes the body temperature to fluctuate.
Hypothermia-excessive decrease in body temperature.
Hyperthermia-excessive increase in body temperature.
Extreme changes in body temperature may be fatal.Body temperature
Radiation-heat is lost from a warm object (the body) to the cooler air surrounding the warm object. Eg. Person loosing heat in a cold room.
Conduction-loss of heat from a warm body to a cooler object in contact with the warm body.
Eg. Warm person becomes cold when sitting on a block of ice.
Eg. Cooling blanket for hyperthermia-warm object (feverish patient) looses heat to the cooler object, the cooling blanket.Heat loss
Convection-loss of heat by air currents moving over the surface of the skin. E.g. Fan moving across the surface of the skin.
Evaporation-heat may be lost through changing a liquid (sweat) to a gas.
E.g. during strenuous exercise, sweat on the surface of the skin evaporates and cools the body.Heat loss
- Hypothalamus-thermostat of the body, located in the brain.
-senses changes in body temperature and sends information to the skin. (blood vessels, sweat glands and skeletal muscle).Body temperature
Skeletal muscles contract vigorously and involuntarily causing shivering and an increase
in the production of heat.
Contraction of the arrector pili muscles causes goose bumps indicating a decline in body temp.Response to decreasing temp.
First degree burns:
Second degree burns:
Third degree burns:
(full thickness burns)