Week 2: Epithelia, supporting tissue and skin Flashcards
Name the 4 types of simple epithelia
Simple squamous, simple columnar, simple cuboidal, pseudostratified columnar cells
Name the 3 layers of the skin and what characterises the parts
Epidermis - keratinised stratified epithelium
Papillary dermis - connective tissue + Meissners corpuscle
Reticular dermis - thicker layer + collagen and elastin + fibroblasts
Hypodermis (subcutis) - adipose and sweat glands
Name the 3 layers of the skin and what characterises the parts
Epidermis - keratinised stratified epithelium
Papillary dermis - connective tissue + Meissners corpuscle
Reticular dermis - thicker layer + collagen and elastin + fibroblasts
Hypodermis (subcutis) - adipose and sweat glands
Name the stratified epithelial tissues
Stratified squamous epithelium - squamous at the apical surface and cuboidal at the basal surface
Stratified cuboidal (e.g. breast)
Transitional epithelium - only found in the urinary tract, stratified cuboidal and squamous epithelium
Name the exocrine gland cells and where they are found
Simple tubular cells (large intestines), Simple coiled tubular glands (sweat glands), simple branched (stomach mucus)
What is collagen secreted as?
Tropocollagen - it is polymerised in the extracellular matrix
Where is type 1 collagen found?
The dermis, tendons, ligaments (most common)
Where is type 2 collagen found?
Hyaline cartilage, fine fibrils
Where is type 3 collagen found?
Mesh-like work in the liver, bone marrow and lymphoid organs
Where is type 4 collagen found?
Mesh-like work in the basement membrane
Where is type 7 collagen found?
It anchors fibrils in the BM
What types of cells do mesenchymal cells differentiate into?
Adipocytes, fibroblasts (maintain slow overturn of EM), chondrocytes (cartilage), myofibroblasts (contractile)
What are the main components of the basement membrane?
Type 4 collagen, glycoproteins (e.g. laminin and enractin)
Name the layers of the basement membrane
Lamina lucida, lamina densa (makes the basal lamina - type 4 collagen), lamina fibroreticularis (type 3 collagen)
Name the differences between white and brown adipose
White adipose is found in the deep dermis, nucleus is squashed to one side. Main function is for energy storage.
Brown adipose- new born’s, for temperature regulation
Name and draw the layers of the dermal-epidermal junction
Stratum corneum
Stratum granulosum (keratinisation- lose nuclei and cytoplasm)
Stratum spinosum - polyhedral keratinocytes
Stratum Basale - continuous proliferation (cuboidal/columnar)
Papillary dermis
Name the different epidermal cell types
Melanocytes, Langerhan cells, Merkel cells
What is the function of a melanocyte
To produce melanin which provides extra protection against UV light
What are the functions of Langerhand cells in the skin?
Histiocytes, the migrate to the dermis via the lymph nodes
-Are mainly found in the stratum spinosum and granulosum
What is the function of a Merkel cell?
They are touch receptors, usually half in the epidermis half in the dermis
What is a syringoma
Tumour of the sweat glands
Within the sebaceous glands what are the types of cells found
The clear cells (water and electrolytes) and dark cells (macromolecule)
Where are eccrine glands found vs the apocrine glands
Eccrine glands are found everywhere in the body, around the junction between the dermis and the hypodermis. Whereas the apocrine glands are found in the head and armpits
What type of cells are secretory cells (shape)?
secretory cells are usually low cuboidal with eosinophilic cytoplasm.
What are the main components of the dermis?
The dermis is composed of:
- bundles of collagen fibres
- strands of elastic fibres
- there are a few fibroblasts which synthesise the collagen, elastic fibres and matrix.
