Epithelial Tissue Flashcards
What are the functions of the skin?
- Protect body from foreign material and pathogens
- Prevents loss of body fluid
- Thermorégulation through heat retention and dissipation
- Protects body from predators (frog’s poisonous skin)
- Sensory abilities like touch
- Communication through visual and pheromonal signals
- Appendages: hair, nails, sebaceous glands, sweat glands
How would you classify skin?
Stratified squamous keratinized epithelium
What are the three main layers of the skin?
Epidermis, dermis, hypodermis
What are the layers of the epidermis?
Basement membrane
Stratum germinativum
Stratum spinosum
Stratum granulosum
Stratum corneum
Is the basement membrane stained?
No
Describe the cells in the stratum germinativum
Singular layer of columnar cells
What do the cells in the stratum germinativum do?
Either divides and creates copy of itself in the same layer or differentiates
Describe the cells in the stratum spinosum
Polygonal shape, has spines between cells
What is special about the cells in the stratum granulosum?
They have keratohyalin granules
What is the function of keratohyalin granules?
Makes skin waterproof
Describe the cells in the stratum corneum?
Flat cells (dead because they burst and released granules)
What are the different types of simple epithelia?
Simple squamous (flat)
Simple cuboidal (cube)
Simple columnar (column)
What are the types of stratified epithelia?
Stratified squamous (keratinized and non-keratinized)
Transitional
What is transitional epithelium?
Tissue changes when expanding
What type of epithelia looks stratified but is only one layer?
Pseudostratified columnar