SKIN Flashcards
Function of the Integumentary System
-Cover the body and protects
-Maintains Body temp. ( By sweating)
-Prevents excessive loss of Fluids
-Contains sensory organ
-Synthesizes Vit. D ( Sunlight Convert Cholesterol to Vit D)
Structures of the Skin :1. Epidermis
- Epidermis: Contains-
- Thins layer ( outerlayer)
- Contains Proteins : Keratin ( waterproof) and Melanin ( skin color)
- Made of 5 small layers of Stratified Squamous
Layers of the Epidermis
Bottom to top
- Stratum Basale (germinativum)
- Stratum Spinosum
- Stratum Granulosum
- Stratum Lucidum
- Stratum Corneum
Stratum Basale
Bottom layer
Cells are alive and growing- Receive nutrients from blood supply below
Stratum Spinosum
Keratin begin product
Cells begin to die as they move upward
Stratum Granulosum
Contains granules of filaggrin that cross links with keratin
Keratin Production continues
Stratum Lucidum
See through layer ( not present in all skin )
- Contains mostly keratinocytes
- Cells are dead
- Only present in thick skin ( palm & soles)
Stratum Corneum
Top layer, clear allow light to enter
-Also dead and contain keratin
- Cells rub off and are lost
Structures of the Skin : 2. Dermis
Underneath epidermis
- Thick layer
- Has 2 Layers - Papillary layer and Reticular layer
Papillary Layer
Origin of fingerprints
has some sensory receptors
Located on - palm, finger and sole of feet, Provide Grips
Reticular Layer
Contain most of the Structure
- Blood vessels and dense irregular connective tissue
- Sweat and oil gland
- Hair Follicles
- Sensory Receptors
Structures of the Skin : 3. Hypodermis
Contain adipose (fat) ( AKA Subcutaneous) / Insulation
Accessory Organ of the Skin
- Hair
- Gland
- Nails
- Skin color
Hair ( Pili)
-Found on in THIN SKIN
-Made of Protein. Grows in a hair root that is surrounded by hair follicle and muscle ( arrector pili)
Glands - 1.Sebaceous Glands
- Sebaceous Glands
- Connected to hair follicles
- Some open directly to skin surface
- Not present in thick Skin ( palms and soles)
- Large numbers on FACE and NECK
- Provide moisture for Hair
Glands - 2. Sudoriferous Gland ( Sweat)
- Regulate body temp.
- Excrete waste ( ammonia & urea ) - Sweat also waste
Two types:
Eccrine ( coiled) : - The most common
- In palm : 3,000 sq inch
Apocrine ( branched tubular) - Found in Axilla ( armpit)
Glands - 3. Ceruminous
Modified sweat glands
Secrete cerumin ( wax) - Sticky, job is to trap dust/dirt entering the ears
Found only in EAR ( auditory canal)
Nails
100% Keratin
- produced by Keratinized cells in the epidermis
- A clear solid covering is produced
- Found only in fingers and toes
Skin Color
Due to Melanin
- Melanin is a pigment produced in the epidermis
- Melanin is produced by cells called Melanocytes
- The number of melanocytes is the same in ALL people
- The amount of melanin being produced will differ
- Melanin Protects the Skin from the SUN
- Blood flow also plays a role in skin color.
