The Skin- outer body covering

Question 1

List 5 function of The Skin

Answer 1

1. Maintenance of body integrity
2. Waterproofing
3. Protection from infection
4. Sensory functions
5. Control of body temperature
6. Absorption(vitamin D)/Excretion (sweat)

Question 2

List the 3 main structures of the Skin

Answer 2

1. Epidermis (the epithelium ectodermal origin)
2. Dermis (the connective mesodermal origin)
3. Subcutaneous adipose tissue

Question 3

List 2 variability in the skin and what it is dependent on

Answer 3

1. Thick hairless skin
2. Thin hairy skin
   Variability is dependent on location.
   The epidermis is thicker(much more keratin) in thick skin than in thin skin

Question 4

What type of cells are in the epidermis of the skin

Answer 4

Keratinised Stratified Squamous epithelium

Question 5

List 4/5 layers of the Epidermis

Depending on whether it is a thick skin or a thin skin

Answer 5

5. Cornified cell layer (stratum corneum)
6. Stratum lucidium - only found in thick skin. Its the pink layer that separates SC and SG
7. Granular cell layer (stratum granulosom)
8. Spinous/Prickle cell layer (stratum spinosum)
9. Basal cell layer (stratum basale)

Question 6

What is a desmosome

Answer 6

Desmosome are structures that holds cells together

Question 7

What is squamous cell carcinoma

Answer 7

When neoplastic cells in epidermis invades the BM, get through to the dermis and now have access to blood vessels (malignant- can form a secondary tumour). If the neoplastic cell does not invade the BM, it is known as Squamous cell dysplasia

Question 8

List 4 main cell types in the Epidermis

Answer 8

1. Keratinocytes
2. Melanocytes
3. Merkel cells
4. Langerhans cells

Question 9

Why is melanoma not a carcinoma

Answer 9

Carcinoma involves epithelial cell. Melanoma isn’t an epithelial cell. it is a pigment cell

Question 10

one Melanocytes supplies to 36 Keratinocytes through phagocytosis of melanocyte dendrite. True or False

Answer 10

True

Question 11

Melanocytes has a hallow with brow pigment on stains. True or False

Answer 11

True

Question 12

Where does melanocytes origin from

Answer 12

The neural crest (the part which will develop into brain and nerves)

Question 13

Where does Langerhans cells origin from

Answer 13

The bone marrow

Question 14

Function of Langerhans cells

Answer 14

1. They are dendritic immune cells

2. They are antigen presenting cells

Question 15

What is the functions Merkel cells

Answer 15

Responsible for sensory- Associated with sensory nerve endings

Question 16

What 2 epidermis cell type originates from the neural crest

Answer 16

1. Melanocytes

2. Merkel cells

Question 17

List 2 forms of diseases of BM

Answer 17

1. Autoimmune disease

2. Genetic disease

Question 18

List 5 tissues in the Dermis

Answer 18

1. Blood vessels
2. Subcutaneous fat
3. Nerves
4. Lymphocytes/Myeloid cells
5. Pilosebaceous units (Hair+ sebaceous gland- secretes sebum to reduce friction)
6. Sweat glands

Question 19

How is skin patterning determined

Answer 19

It is determined by the pattern in the dermis

Question 20

List 2 types of sweat glands

Answer 20

1. Eccrine Sweat gland - almost everywhere
   Responsible for control of body temp.
   2.Apocrine sweat gland- Axilla, nipples, groin
   Responsible for body odour

Question 21

Name a disease of Eccrine sweat gland

Answer 21

Eccrine spiradenoma. BM is intact. So it is not invasive.

Question 22

Numerous hair follicles in scalp and face (men) is accompanied by sebaceous glands which causes dandruff(hair) and acne spots (face). True or False

Answer 22

True

Question 23

Skin from the back has a thin epidermis, but thick dermis. True or False

Answer 23

True

Question 24

What layer of the epidermis are desmosomes prominent ?

Answer 24

In the Stratum spinosum - (Spinous/prickle cell layer)

Question 25

What is Acanthosis

Answer 25

Irritation of the skin that results in the development of a thick stratum corneum (cornified layer) and stratum spinosum (spinous cell)

Question 26

List 2 fibres that are present in the Dermis

Answer 26

1. Collagen Fibre | 2. Elastin Fibre

Question 27

Collagen and Elastin fibres in the dermis are produced by the ..

Answer 27

Fibroblast

Question 28

Excessive sun exposure can lead to

Answer 28

Solar elastosis (loss of elasticity). like wrinkles

Question 29

The Eccrine sweat gland is made up of 2 layers. List them

Answer 29

1. The outer myo-epithelial cells - shape of cuboidal cells | 2. The inner secretory epithelial cells

Question 30

In Apocrine sweat glands, snouts burst into the lumen to create sweat. Presence of bacteria, also causes it to smell. True or false

Answer 30

True

Question 31

Excessive sun exposure can lead to

Answer 31

1. Sun elastosis (loss of elasticity) | 2. Excess production of melanin by melanocytes

Question 32

What enzyme controls melanin production by melanocyte

Answer 32

Tyrosinase

Question 33

Lack of Tyrosinase causes

Answer 33

Albinism - which increases risk of cancer

Question 34

Abnormal migration and concentration of melanocyte in a single site can lead to

Answer 34

Congenital naevus or birth mark (which can lead to high risk of developing melanoma)

Question 35

List 2 causes of skin cancer

Answer 35

1. Genetic abnormalities | 2. Sun exposure

Question 36

Assessment of cancer uses

Answer 36

The TNM stage T= Tumour size/depth of invasion N= Node (whether there is a lymph node metastasis or not) M= Metastasis to liver, lungs or brain etc

Question 37

List 3 cancers of the Skin

Answer 37

1. Melanoma 2. Squamous cell carcinoma (SCC) 3. Basal cell carcinoma

Question 38

Describe squamous cell carcinoma and its 3 classifications

Answer 38

Squamous cell carcinoma involves keratin cells. Well differentiated - lots of keratin Moderately differentiated - moderate amount of keratin Poorly differentiated - low amounts of keratin

Question 39

What is the different between cancer staging and cancer grading

Answer 39

Cancer staging uses TNM | Cancer grading is based on how closely the cancer tumour resembles the normal cells

Question 40

On staining, basal cell carcinoma has numerous blue cells cause they resemble the basal cell that's above the BM. True or false

Answer 40

True