Integumentary System Flashcards
What is the integumentary system composed of?
- Epidermis
- Dermis
- Subcutaneous tissue
What is the largest organ in the body?
- Skin
- compromising up to 15% of total body weight
- Surface area ranges between 1.2 to 2 square meters
Functions of the Integumentary System
- Protection
- Sensory reception
- Temperature regulation
- water and salt excretion
- water loss prevention
- metabolic regulation
- immurial defense mechanisms
Selectively permeable membrane
- Skin
- which prevents water loss, provides protection and regulates the body temperature
What does the integument provide protection from?
- Injury and trauma
- UV light
- Microbes
- Toxin radiation
- chemicals
Sensory reception
- Pain
- Heat
- cold
- pressure
specialized sensory nerve endings
capable of detecting slight variations in temperature, pressure, vibration and texture
nociceptors
nerve cells specialized to precieve damage to the skin which register a positive pain response when stimulated
Temperature regulation
- Erect Hairs
- Sweat
Evaporative Cooling
when the body is too warm, excessive perspiration evaporates on the skin surface
vasodilation
- when the body is too warm, blood vessels of the integument dilate
- this allows more blood to flow through the issues giving off heat along the way; thus lowering the bodys temperature
vasoconstriction
when the body is too cold, blood vessels of the integument thus preventing blood flow to the outer tissues and conserving body heat
Integument functions in salt excretion
integument is water resistant. water along with salts and urea, can be actively secreted through sweat glands
trasepidermal water loss
small amounts of interstitial fluids can escape through the skins surface
perspiration
- “sensible” or “insensible”
- an estimated 500 mL of water is secreted through the integument each day
what is done to prevent additional water loss?
the water that is secreted mixes with sebum to produce a oily, slightly acidic, barrier which prevents too much water from escaping
what causes the formation of Vitamin D?
- Integument
- vitamin D is essential for calcium absorption from foods we eat
Cholecalciferol
exposure to UV radiation triggers cells of the integument to be produced
calitriol (vitamin d)
cholecalciferol travels through the circulatory system to the kidneys where it is synthesized to make vitamin d
what is essential for proper bone development?
- calcium
- phosphorus
what is important to promote calcium and phosphorus absorption through the small intestines?
vitamin d
how much of exposure to the sun is sufficient to obtain enough vitamin d to sustain the bodys needs for calcium and phosphorus?
15 minutes
Langerhan’s Cells or Epidermal dendritic cells
possesses specialized cells of the immune system
phagocytosis
epidermal dendritic cells or langerhans cells specialized to destroy pathogens that have invaded the outer layers of the integument
layers of strata of the epidermis superficial to deep
- Stratum Corneum
- Stratum Lucidum
- Stratum Granulosum
- Stratum Spinosum
- Stratum Basle
two distinct layers of the skin
- Epidermis
- Dermis
- both lie on an underlying layer called the subcutaneous tissue or hypodermis
thickest integument
thinnest integument
- thickest integument: Back. ranges up to 1/2 cm in thickness
- thinnest integument: eye lid. as thin as 1/2 mm
what is the epidermis comprised of?
- Keratinized
- stratified squamos epithelium
Epidermis
- outermost layer of the integument.
- the visual portion of the skin
is the epidermis vascular
- No
- does not contain blood vessels
- contains nerves and nerve endings
what happens in the deepest layers of the epidermis?
some cells undergo mitosis and migrate to the outermost layers where they become desiccated, convert to keratin and eventually slough off
how long is the process of skin cells birth to slough?
- 30 days
- epidermis is constantly being replaced