Zusammenfassung der Ressource
3.Integumentary system
- Functions of the skin
- Temperature regulation
- Produce vitamin D
- Protect from the harmful radiation by melanin
- Protection
- Structure
- Three layers(simple)
- Epidermis
Anmerkungen:
- 1. composed of keratinized stratified squamous epithelium
- Sweet glands
- Melanocytes
Anmerkungen:
- 1. produce melanin(primarily responsible for skin color)
- Round cell + clear cytoplasm
- Locate in stratum basale
- Sebaceous glands
- Hair follicles and hair
- Dermis
Anmerkungen:
- 1. composed of a dense connective tissue:
- impact mechanical support
-strength
-thickness(e.g. papillae layer(PL), collagen fibers of the reticular layer(RL)
- Hypodermis
Anmerkungen:
- -contains large amount of adipose tissue
- Types of skin
- Thick
Anmerkungen:
- 1. epidermis is supported by dermis(a layer of dense fibro-elastic tissue)
2.Merges with the loose supporting tissue of hypodermis
- Stratified squamous keratinizing epithilium
Anmerkungen:
- 1.extremely thick
2.keratinized surface layer
- Structure
- Epidermis(five layers)
- Stratum corneum(SC)
Anmerkungen:
- 1. stratified squamous epithelium
2. consist of flattened, closely packed, dead cells and absent nuclei
- Stratum granulosum(SG)
Anmerkungen:
- 1. 2-5 layers of nucleated cells
2. basophilic granules(keratohyalin)
- Stratum basale(SB)
Anmerkungen:
- 1. single layer of cubondal cells on basement menbrane
- Stratum lucidum(SL)
Anmerkungen:
- - homogenous line of flattened cells
- Stratum spinosum(SS)
Anmerkungen:
- 1. 3-4 cells thick
2. polyhydral
3. basophilic
- Dermis(three layers)
- Subcutaneous layer
Anmerkungen:
- 1. loose connective tissue
2. adipose tissue
- Reticular layer
Anmerkungen:
- 1. mainly of bundle of coarse collagenous fibres(in various direction)
- Papillary layer
Anmerkungen:
- Consist of:
1. fine collagenous fibres
2. reticular fibre
3. elastic fibres
-all interweaving with Blood vessels
- Hypodermis
- Thin
- abdominal skin
Anmerkungen:
- 1. thin stratified squamous
2.only stratum corneum and stratum germinativum
- Scalp
- Papillary layer
Anmerkungen:
- 1. marrow zone of fibred dense irrugular connective tissue
- Reticular layer
Anmerkungen:
- 1. Hair follicle associated with sebaceous gland
2.also find cross section of sweet gland
- Hair follicle
Anmerkungen:
- 1. features: extended hair bulb and the dermal papilla
2. the main mass of hair bulb= matrix(for hair growth)
- Sebaceous gland
Anmerkungen:
- 1. simple branched acinar glands
2. appear encapsulated spherical masses form
3. Vacuolate cytoplasm( for lipid and waxy secretion)
- Sweet gland
Anmerkungen:
- 1. simple coil tubular gland
- appear in section as groups of small circular ovoid structure