Structure and Function 3 and 4

Question 1

What forms the interface between the dermis and epidermis?

Answer 1

Dermo-epidermal junction

Question 2

What are the key roles of the dermo-epidermal junction?

Answer 2

Support, anchorage, growth and differentiation of basal cells Semi-permeable membrane (barrier and filter) Wound healing

Question 3

What are the 3 layers of the dermo-epidermal junction, from superficial to deep?

Answer 3

• Lamina lucida - Lamina densa - Sub lamina densa zone

Question 4

What are two conditions which affect the DE junction?

Answer 4

Bullous pemphigoid Epidermolysis bullosa

Question 5

What is bullous pemphigoid?

Answer 5

Autoimmune condition where the immune system attacks the proteins in the DE junction

Question 6

Who does bullous pemphigoid occur in?

Answer 6

Older people, especially those with a history of stroke/Parkinson’s

Question 7

How do you test and treat for bullous pemphigoid?

Answer 7

Test: immunofluorescence for antibodies to the basal membrane Treat: oral steroids

Question 8

What is epidermolysis bullosa?

Answer 8

Inherited genetic problem at the DE junction

Question 9

What does the dermis mainly contain? What is the function of these?

Answer 9

Fibroblasts- producing collagen

Question 10

As well as fibroblasts, what other cells can be found in the dermis?

Answer 10

Macrophages, mast cells, lymphocytes and Langerhan’s cells

Question 11

What structures are found in the dermis?

Answer 11

Muscles, blood vessels, lymphatics and nerves

Question 12

Why does photoaging occur?

Answer 12

Collagen is broken down and lost

Question 13

What is angioma?

Answer 13

Overgrowth of blood vessels

Question 14

What is neurofibromatosis?

Answer 14

A rare genetic condition causing overgrowth of nerve endings or neural tissue

Question 15

Lymphatics of the skin allows continuous drainage of what?

Answer 15

Plasma proteins, cells and excess fluids

Question 16

What are the important functions of the lymphatics of the skin?

Answer 16

Immune surveillance by lymphocytes and Langerhan’s cells Channelling microorganisms and toxins

Question 17

Are problems with skin lymphatics easy to fix?

Answer 17

No, this is almost impossible

Question 18

What two types of nerves can be found in the skin?

Answer 18

Somatic sensory (dermatomes) Autonomic

Question 19

What types of somatic sensory receptors are found in the skin?

Answer 19

Free nerve endings (fine touch) Pacinian for pressure Meissner’s for vibration

Question 20

Autonomic nerves in the skin supply what?

Answer 20

Blood vessels, nerves and glands

Question 21

What are hair follicles known as?

Answer 21

A pilosebaceous unit

Question 22

What is acne?

Answer 22

An abnormality of the pilosebaceous unit where the sebaceous gland gets blocked

Question 23

What is the function of sebaceous glands?

Answer 23

Control moisture loss and protect from fungal infections

Question 24

As well as the sebaceous glands, what other gland develops as part of the pilosebaceous unit?

Answer 24

Apocrine glands

Question 25

Deficiency of what can cause problems with hair growth?

Answer 25

Iron

Question 26

Where are sebaceous glands most common?

Answer 26

Across the face and chest

Question 27

What do the sebaceous glands secrete? Into where?

Answer 27

Secrete sebum into the pilar canal

Question 28

What activates the sebaceous glands? When?

Answer 28

Hormones- once puberty has started

Question 29

Where are apocrine glands found?

Answer 29

Genital regions, especially axillae and perineum

Question 30

What hormone are apocrine glands dependent on?

Answer 30

Androgens

Question 31

What do apocrine glands produce?

Answer 31

An oily fluid which causes an odour

Question 32

What is the function of apocrine glands?

Answer 32

Unknown

Question 33

What are eccrine glands and where are they found?

Answer 33

Sweat glands, found all over the skin surface but especially the palms, soles and axillae

Question 34

What is the nerve supply to eccrine glands? What stimulates them?

Answer 34

Sympathetic, cholinergic nerve supply Mental, thermal and taste stimulation

Question 35

Eccrine glands allow reabsorption of what?

Answer 35

NaCl and HCO3

Question 36

What is the function of eccrine glands?

Answer 36

Cool by evaporation, moisten the palms/soles to aid grip

Question 37

What condition does this show?

Answer 37

Bullous pemphigoid

Question 38

What condition does this show?

Answer 38

Epidermolysis bullosa

Question 39

What does this photo show?

Answer 39

Photoaging

Question 40

What does this picture show?

Answer 40

Angioma

Question 41

What does this picture show?

Answer 41

Lymphoedema

Question 42

What does this picture show?

Answer 42

Pacinian corpsucles

Question 43

What condition does this picture show?

Answer 43

Neurofibromatosis

Question 44

What condition does this picture show?

Answer 44

Alopecia areata

Question 45

What condition does this picture show?

Answer 45

Acne

Question 47

What are the 6 main functions of the skin?

Answer 47

- Barrier function - Metabolism - Imune defence - Thermoregulation - Communication - Sensory function

Question 48

What can happen if the barrier function of the skin fails?

Answer 48

- Water loss and dehydration - Protein loss and hypoalbuminaemia - Infection

Question 49

The skin is involved in whcih two metabolic processes?

Answer 49

Vitamin D and thyroid hormone metabolism

Question 50

What do the warm and cold thermoreceptors on the skin allow?

Answer 50

They allow us to make behavioural changes such as sweating, shivering and vasodilation/constriction

Question 51

Is the skin involved in specific or non-specific immune defence or both?

Answer 51

Mainly non-specific, but involved in specific to antigens which have already been encountered

Question 52

What is toxic epidermal necrosis?

Answer 52

Acute skin failure, most commonly caused by drugs. There is a lot of fluid loss, causing the epidermis to come off the dermis

Question 53

What is steroid sulphatase deficiency?

Answer 53

X-linked disease which can occur as a side effect of HMG-CoA reductase inhibitors (cholesterol medication)

Question 54

What is eczema herpeticum?

Answer 54

Disseminated herpes virus infection

Question 55

What are crusted scabies and what makes them different to scabies?

Answer 55

They occur in people who are immunocompromised- there are many more mites than normal, making them more infectious

Question 56

What does this picture show?

Answer 56

Toxic epidermal necrosis

Question 57

What does this picture show?

Answer 57

Erythroderma

Question 59

What does this picture show?

Answer 59

Steroid sulphatase deficiency

Question 60

What does this picture show?

Answer 60

Crusted scabies

Question 61

What does this picture show?

Answer 61

Eczema herpeticum