Term
Function of Skin
Protection |
|
Definition
From desiccation (is the state of extreme dryness) because impermeable to water)
From injury due to UV light, bacteria, and mechnical insults
|
|
|
Term
Skin Functions to Excrete |
|
Definition
| Through the glands of the skin |
|
|
Term
| Skin functions to regulate |
|
Definition
| temperature, waterbalance, all for homeostasis |
|
|
Term
| Skin functions for sensation |
|
Definition
| Touch, Pressure, Pain, temperature |
|
|
Term
| Skin functions for metabolism |
|
Definition
| For fat storage, vitamine D synthesis |
|
|
Term
| The skin functions in immunity |
|
Definition
| It provides immune information to lymphatic tissue |
|
|
Term
| The skin functions in the endocrine system |
|
Definition
| By secreting hormones, cytokines, and growth factors |
|
|
Term
Structure of the Epidermis |
|
Definition
Outer Layer
Avascular
Keratinized(acts as water-proofing where tissue is subject to drying)
Stratified Squamous Epithelium (Keratinocytes) |
|
|
Term
|
Definition
Deeper Layer
Vascularized
Dense Irregular Connective Tissue
Intended for protection
Here the abundant collagen fibers run every-which-way |
|
|
Term
Thick Skin
Location and Structure |
|
Definition
On palms of hands and soles of feet
Thick epidermis with an thick outer layer of keratin
Epidermal Ridges and grooves: the ridges of the epidermis found in the palms and soles, where the sweat pores open;
Dermal Papillae: finger like projections in the papillary region of the dermis where the epidermis conforms for fingerprints
Has numerous sweat glands |
|
|
Term
Thin Skin
Location and Structure |
|
Definition
- covers the remainder of the body
- thin epidermis and keratin layer
- contains hair follicles
- fewer sweat glands and no ridges and grooves |
|
|
Term
Layers of Epidermis and their main features |
|
Definition
Thick skin has 5 layers
1. Stratum Basale
2. Stratum Spinosum
3. Stratum Granulosum
4. Stratum Lucidum
5. Stratum Corneum
Thin skin of the epidermis is thinner and simpler; there is NO stratum lucidum |
|
|
Term
|
Definition
- single layer of basophilic columnar cells - abundant ribosomes
- anchored by desmosomes and hemi-desmosomes
- intermediate filaments (cytokeratins) called tonofilaments produced
- contains stem cells from which keratinocytes arise i.e. germinal layer |
|
|
Term
Epidermal
stratum spinosum |
|
Definition
- polyhedral cells bearing processes (spines)
- spines from adjacent cells are attached by desmosomes
- intermediate filaments form bundles (tonofibrils)
- project into spines & desmosomes
- maintain cohesion between cells, resist effects of abrasion
- mitotic figures common in basale and spinosum (i.e. Malpighian layer)
|
|
|
