Structure and Function of Skin Flashcards
What are the two parts to the Integumentary System?
The Cutaneous Membrane (skin) and the Accessory Structures
What is the Cutaneous Membrane comprised of?
The Outer Epidermis and the Inner Dermis
Where is the Subcutaneous Layer located?
Below the Inner Dermis
What are the functions of the Skin?
- Protects underlying tissues and organs
- Excretes salts, water and organic wastes (glands)
- Maintains body temperature (insulation and evaporation)
- Synthesizes Vitamin D3
- Stores lipids
- Detects touch, pressure, pain and temperature
- Produces melanin
- Produces keratin
What are the three cells of the Epidermis?
- Keratinocytes
- Basal cells
- Melanocytes
What is Skin Colour influenced by?
- Carotene (Pigment)
- Melanin (Pigment)
- Blood Circulation (Red Blood Cells)
What type of Tissue is the Epidermis?
Avascular Stratified Squamous Eptihelium
How do Nutrients and Oxygen get to the Epidermis?
Nutrients and Oxygen diffuse from Capillaries in the Dermis
What is the the most abundant cell in the Epidermis and what is their purpose?
Keratinocytes have the purpose of containing large amounts of Keratin
What’s the purpose of Melanocytes
To produce Melanin
What is Keratinisation and how long does it take to happen?
- The formation of a layer of dead, protective cells filled with Keratin
- It takes roughly 7-10 days for a cell to move from the deepest layer to the surface
In which area of the body would you expect to find an especially thick stratum?
In the sole of your hands and foot
The Epidermis provides a Physical Barrier due to the presence of?
Keratin
What are the colours of the two pigments and where do they occur?
- Carotene has a Orange-Yellow pigment accumulating in the epidermal cells and fatty tissues of the dermis
- Melanin is a Yellow-Brown or Black Pigment produced by Melanocytes
What’s the Function of Melanocytes?
They produce Melanin which serves to protect the skin from sun damage from UV Radiation
The melanin production is what decides Skin Colour, not the number of Melanocytes.
How do Capillaries influence Skin Colour?
The oxygenated Red Blood contributes to skin colour
Blood vessels dilate from heat moving the heat to the surface of the skin hence creating a reddish appearance. When blood flow decreases skin becomes pale.
Cyanosis is where there is a severe reduction in blood flow or oxygenation and gives a Bluish Skin Tint as a result.
Which cells Produce Vitamin D3?
The Epidermal Cells
What are the two organs that convert Vitamin D into a substance that helps with the absorption of Calcium and Phosphorus?
The Liver and Kidneys convert Vitamin D into Calcitrol
What purpose does the Dermis serve?
To Anchor Epidermal Accessory Structures such as hair follicles and sweat glands
What are the two components of the Dermis?
- Outer Papillary Layer
- Deep Reticular Layer
The Dermis supplies the skin with nerves, what does this help with?
- Blood Flow
- Gland Secretion
- Monitor Sensory Receptors
What does the Papillary Layer consist of?
- Areolar Tissue
- Contains smaller Capillaries, Lymphatics and Sensory Neurons
What does the Reticular Layer consist of?
- Has Dense Irregular Connective Tissue
- Contains larger blood vessels, lymph vessels, and nerve fibres
- Contains Collagen and Elastic Fibres
What is the purpose of the Hypodermis/ Subcutaneous Layer?
- Stabilises the skin
- Made up of Loose Connective Tissue
- It is the site of Subcutaneous Injections
