Skin Structure (physiology) Flashcards
(28 cards)
What makes up the epidermis ?
Stratified squamous (epithelium)
What body part have stratified squamous ?
Vaginal canal
Anus
Esophagus
What are the primary functions of the skin ?
Helps regulate temperature
Prevents loss of moisture
Provides a protective barrier against mechanical, thermal and physical injury.
Reduces harmful effects of UV radiation.
The skin is split into 3 main sections what are they ?
Epidermis
Dermis
Hypodermis
What’s the epidermis ?
It is the outermost layer of skin in the body.
Primary barrier between you and the outside world.
What does the epidermis consist of ?
Several layers of keritonised at various stages of keritinisation.
What is keratinization?
Process in which the cytoplasm of the outermost epidermal cells is replaced by keratin.
There are the 2 types of epidermis ?
Thick skin - usually free from hair.
Thin skin - hair is associated with it.
How many thick and thin layers are there?
4 thin
5 thick
What are the layers ?
Stratum basale
Forming the stratum spinosum, stratum granulosum, stratum lucidum ( only thick skin).
And stratum corneum (outer moist).
How long does it take for a keratinocyte to mature from the stratum basale tot he stratum corneum?
30 days
How is skin pigmentation caused ?
Caused by cells in the stratum basale called melanocytes.
These extend processes and fill keratinocytes with melanin.
The more cells they contract the more pigmented the skin becomes.
What is the main sensory cell in the stratum basale?
It’s the tactile epithelial (merkel) cell.
These are pale staining round cells that find free nerve ending and are accosted with the section of pain and itching.
What are the consequences of loss of melocytes?
Vitiligo occurs when pigment producing cells (melanocytes) die or stop producing melanin.
Involves patches of skin becoming lighter/ white.
What is the dermis?
The inner layer of the the two layer of the skin
What’s is the dermis composed of ?
Composed entirely of connective tissue and is attached to the epidermis by the baseman membrane.
This itself is composed of modified fibers.
Where are immune cells found ?
Found in various layers of the skin .
In the epidermis , epidermal dendritic cells can be ground up to the stratum granulosum.
Where are dermal dendritic cells found ?
Can be found throughout the dermis often seen entering or leaving the lymph capillaries.
What is the papillary Dermis?
Is the dermal region directly in contact with the epidermis.
Defined by its undulating dermal papillae.
What is the reticular dermis?
The thick bottom layer of the dermis.
Has blood vessels and connective tissue that supports the skin.
Hair follicles, oil and seta glands are found.
What does the dermis have?
Has a pattern of collagen fibers forming a distinctive net like design.
Where the first blood and lymph vessel are found.
Glandular tissues is found here.
What is the hypodermis?
Bottom layer of skin in the body.
Composed of fat cells, contained in fibrous compartments.
What’ is the function of hypodermis ?
Provides insulation
Protection
Temperature regulation
Connection between the bones and muscles.
Where are hair follicles found?
Located deep in the dermis and rose to exit the skin to the outside world. Hair is mostly composed of keratin.
The entire hair follicle is composed of the peri dermis.
