The Skin(Complete) Flashcards
(39 cards)
What are the two layers of the skin called?
The epidermis.
The dermis.
Describe the structure and role of the Malpighian layer.
Cells are formed by mitosis.
They are hardened by waterproof protein keratin to replace dead cells in the outer cornified layer.
Cells produce the pigment melanin
Where is the protein keratin found?
The skin.
The hair.
The nails.
What is the role of melanin?
To protect against UV radiation.
Where is melanin found?
In the iris of the eye.
In the skin.
In hair.
What is melanoma?
When the cells that produce melanin become cancerous.
Describe the granular layer.
Cells are larger and keratinized as they migrate to the outer cornified layer.
Why are cells dead in the cornified layer?
As no blood supply and cells are coated with too much keratin.
Describe the cornified layer.
The outer layer of the skin with dead cells which is constantly shedding- the epidermis is replaced every 30 days.
What are the main roles of the outer cornified layer?
Cells have keratin with a natural waterproof layer which prevents natural moisture from leaving the skin keeping it hydrated.
It acts as a barrier against all pathogens and protects against pressure changes.
Describe the structure of the dermis.
Consists of live connective tissue with elastic and collagen fibres.
What is inside of the dermis?
Receptors, sweat glands, hair follicles, arterioles and sebaceous glands are all embedded into the dermis.
What is the role of the receptors?
The touch and temperature receptors detect a stimulus and generate impulses as a result.
What is the role of sweat glands?
Sweat glands produce the excretory fluid sweat which is carried to the surface of the skin by sweat ducts. Sweat is evaporated to cool down the body.
Has a big role in thermoregulation.
What is the role of sebaceous glands?
Sebaceous glands are connected to the side of the hair follicle.
They secrete sebum which is an oil which creates a moisturising layer, preventing the skin from cracking.
Where are hair follicles formed?
In the infoldings of the Malpighian layer.
What is hair?
A solid cylinder made of dead cells and keratin.
The root of the hair is under the skin surface.
The shaft of the hair is above the skin surface.
Hair erector muscles control the movement of hair and therefore contract to allow hair to stand upright-thermoregulation.
Where is adipose tissue located?
Under the dermis.
How is adipose tissue formed?
Subcutaneous tissue and fat cells.
What are the roles of adipose tissue?
To insulate the body.
To act as a food store.
What are the main functions of the skin?
Formation of vitamin D in the presence of UV radiation.
Acts as a sense organ.
Insulates and acts as a food store by means of subcutaneous fat.
Protection.
Excretory role.
Thermoregulation.
Describe the role of the skin in the formation of vitamin D.
The skin produces vitamin D which is essential for the absorption of calcium.
Lack of this vitamin would result in rickets causing the bones to become soft and legs would become bowed.
Describe the role of the skin in acting as a sense organ
The skin contains receptors on its surface which detect stimuli such as heat, cold and touch and generate impulses as a result.
Describe the role of the skin in insulating the body and acting as a food store.
Adipose tissue contains fat cells which insulate the body and act as a food store.
