Lecture 1 Flashcards
what are the 3 layers of the skin?
- epidermis
- dermis
- hypodermis
what basic tissue type is dominant in the epidermis layer?
epithelial tissue
what type of epithelia is predominant in the epidermis ?
stratified squamous epithelium
what is the difference between stratified and simple epethelia
simple = single layer of cells
stratified = stacked layer of cells
is the epidermis vascular or avascular?
avascular = meaning there is no blood circulation
primary functions of the skin and accessory structures ? 6
- protecting underlying tissues and organisms against abrasion, impact, fluid loss and chemical attack
- excretion of salts, water and organic wastes
- maintain normal body temp
- produce melanin = protects underlying tissue from UV radiation
- produce keratin = protects against abrasion + water repellent
- detect touch, pressure, pain and temperature
the difference between thick and thin skin and where they are found
thick skin = 5 layers and found on plams of hands and soles of feet
thin skin = mostly everywhere apart from where thick skin is
what are the layers of thin skin?
- Stratum Corneum
- Stratum Granulosum
- Stratum Spinosum
- Stratum Basale
what are the layers of thick skin ?
- Startum Corneum
- Stratum Lucidum
- Startum Granulosum
- Stratum Spinosum
- Stratum Basale
cell type of stratum corneum
dead, dried out hard cells without nuclei
cell type of stratum granulosum
- contains granules that promote dehydration of the cell, crosslinking of keratin fibre
- waxy material is secreted into intercellular spaces
cell type of stratum spinosum
- intercellular bridgescalled desmosomes link the cells together
- the cells become increasingly flatted as they move upwards
cell type of stratum basale
- columnar (tall) regenerative cells
- as the basal cell divides, a daughter cell migrates upwards to replenish the layer above
what are desmosomes?
anchors adjacent/neighbouring cells WITHIN the epidermis
what are the hemidesmosomes?
anchors stratum basale to the dermis
- BETWEEN the epidermis and dermis
what helps to provide strength in the dermis?
protein fibres
is the dermis vascular or avascular
highly vascular = lots of blood vessels, nourishes the epidermis
does the dermis shed?
NO it does not shed
the dermis is divided into two layers, what are they?
papillary layer and reticular layer
what does the papillary layer consist of ?
highly vascularised tissues (for nourishment)
what does the reticular layer consist of?
mesh like structure of collagen and elastin fibres (for strength)
what does plexus stand for ?
a network of blood vessels or nerves
what are the two types of plexus?
cutaneous plexus and sub papillary plexus
what is in the cutaneous layer?
the epidermis and the dermis
