Lecture 1 Flashcards
What percent of body weight does skin make up?
16%
How does human skin differ from other mammals?
We traded most of our hair for sweat glands to osmoregulate
What tissue types is skin made up of?
All four
List some functions of the skin (8):
- protect underlying tissues and organs
- excretes waste
- maintain body temp
- produce melanin to protect tissue from UV radiation
- produce keratin ( water repellant + protection)
- synthesise vitamin D3 ( calcium metabolism)
- store lipids in adipocytes in dermis and adipose tissue in subcutaneous tissue
- ## detect touch, pressure, pain, and temp stimuli
What are the 3 main layers of the skin?
- epidermis
- dermis
- hypodermis
What two skin layers make up the cutaneous?
- epidermis
- dermis
What is the epidermis?
Stratified barrier mostly made up of keratinocytes that is avascular.
Are cells in the epidermis dead or alive?
Dead
What is the role of the dermis in respect to the epidermis
Dermis in vascular so provides nutrients to the epidermis
What is contains in the hypodermis that is not found in the epidermis or dermis
Adipose tissue
Name the 6 types of epithelia?
- simple squamous
- simple cuboidal
- simple columnar
- stratified squamous
- stratified cuboidal
- stratified columnar
What type of epithelium is the epidermis made of?
Stratified squamous
Name the 4 layers of the epidermis?
- stratum corneum (horny layer)
- Stratum granulosum ( granular layer)
- stratum spinosum ( spiny layer)
- Stratum basale ( basal layer)
Describe the cells in the stratum corneum layer:
- dried out hard cells without nuclei
Describe the stratum granulosum layer:
- contains granules that promote dehydration of the cell and cross linking of keratin fibre ( killing cell)
- waxy material is secreted into the intercellular spaces