Week 2: Epithelia, supporting tissue and skin

Question 1

Name the 4 types of simple epithelia

Answer 1

Simple squamous, simple columnar, simple cuboidal, pseudostratified columnar cells

Question 2

Name the 3 layers of the skin and what characterises the parts

Answer 2

Epidermis - keratinised stratified epithelium
Papillary dermis - connective tissue + Meissners corpuscle
Reticular dermis - thicker layer + collagen and elastin + fibroblasts
Hypodermis (subcutis) - adipose and sweat glands

Question 2

Name the 3 layers of the skin and what characterises the parts

Answer 2

Epidermis - keratinised stratified epithelium
Papillary dermis - connective tissue + Meissners corpuscle
Reticular dermis - thicker layer + collagen and elastin + fibroblasts
Hypodermis (subcutis) - adipose and sweat glands

Question 3

Name the stratified epithelial tissues

Answer 3

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

Question 4

Name the exocrine gland cells and where they are found

Answer 4

Simple tubular cells (large intestines), Simple coiled tubular glands (sweat glands), simple branched (stomach mucus)

Question 5

What is collagen secreted as?

Answer 5

Tropocollagen - it is polymerised in the extracellular matrix

Question 6

Where is type 1 collagen found?

Answer 6

The dermis, tendons, ligaments (most common)

Question 7

Where is type 2 collagen found?

Answer 7

Hyaline cartilage, fine fibrils

Question 8

Where is type 3 collagen found?

Answer 8

Mesh-like work in the liver, bone marrow and lymphoid organs

Question 9

Where is type 4 collagen found?

Answer 9

Mesh-like work in the basement membrane

Question 10

Where is type 7 collagen found?

Answer 10

It anchors fibrils in the BM

Question 11

What types of cells do mesenchymal cells differentiate into?

Answer 11

Adipocytes, fibroblasts (maintain slow overturn of EM), chondrocytes (cartilage), myofibroblasts (contractile)

Question 12

What are the main components of the basement membrane?

Answer 12

Type 4 collagen, glycoproteins (e.g. laminin and enractin)

Question 13

Name the layers of the basement membrane

Answer 13

Lamina lucida, lamina densa (makes the basal lamina - type 4 collagen), lamina fibroreticularis (type 3 collagen)

Question 14

Name the differences between white and brown adipose

Answer 14

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

Question 15

Name and draw the layers of the dermal-epidermal junction

Answer 15

Stratum corneum
Stratum granulosum (keratinisation- lose nuclei and cytoplasm)
Stratum spinosum - polyhedral keratinocytes
Stratum Basale - continuous proliferation (cuboidal/columnar)
Papillary dermis

Question 16

Name the different epidermal cell types

Answer 16

Melanocytes, Langerhan cells, Merkel cells

Question 17

What is the function of a melanocyte

Answer 17

To produce melanin which provides extra protection against UV light

Question 18

What are the functions of Langerhand cells in the skin?

Answer 18

Histiocytes, the migrate to the dermis via the lymph nodes
-Are mainly found in the stratum spinosum and granulosum

Question 19

What is the function of a Merkel cell?

Answer 19

They are touch receptors, usually half in the epidermis half in the dermis

Question 20

What is a syringoma

Answer 20

Tumour of the sweat glands

Question 21

Within the sebaceous glands what are the types of cells found

Answer 21

The clear cells (water and electrolytes) and dark cells (macromolecule)

Question 22

Where are eccrine glands found vs the apocrine glands

Answer 22

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

Question 23

What type of cells are secretory cells (shape)?

Answer 23

secretory cells are usually low cuboidal with eosinophilic cytoplasm.

Question 24

What are the main components of the dermis?

Answer 24

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.