Inegumentary System Flashcards
Integumentary system
Includes the skin, hairs, nails and exocrine glands
3 layers of skin
Epidermis
Dermis
Hypodermis
Keratin
A protein which helps to waterproof the epidermis
Functions of the integumentary system
Protection against infection
Temperature regulation
Vitamin D synthesis
Sensation
Excretion
Protection
Acts as a physical barrier, first line of defence
Temperature regulation
Body temperature is controlled and coordinated by the hypothalamus.
Sweat glands
Release sweat when the body temperature rises. Thermal energy from the skin and blood in capillaries close to the surface of the skin is transferred to the water in sweat causing it to evaporate.
Arterioles
Supplying the capillaries near the surface of the skin can construct or dilate
Vasolidation
As the body temp rises, nerve impulses are sent to relax the muscles in the walls of the arterioles.
Diameter of arterioles increases.
More blood can flow through the capillaries close to the surface of the skin
Vasoconstriction
When body temp falls, nerve impulses are sent to cause contraction of the muscles in the walls of the arterioles.
The diameter of the arterioles decreases.
Less blood can flow through the capillaries close to the surface of the skin
Vitamin D synthesis
Lack of vitamin D from the sun results in it being consumed in the diet. Vitamin D works together with PTH and calcitonin to regulate the calcium balance of the body
Sensation
Allow us to touch
Excretion
Sweat contains inorganic ions and urea and so plays a part in excretion
melain
pigment for skin tone
collagen
provides support
