Lecture 2; The Skin

Question 1

Describe the layers of the skin;

Answer 1

Superficial: Epidermis -basement membrane- Dermis Sub cutaneous fat

Question 2

Describe the epidermis layers;

Answer 2

Stratum corneum Stratum granulosum Stratum spinosum (hemidesmosomes give appearance) Stratum basilar Basement membrane (anchors stratum spinosum) Melanocytes

Question 3

Describe the anatomical features found in the skin

Answer 3

Epidermis Dermis Subcutaneous fat Nail Hair Eccrine sweat glands Pilosebacous unit

Question 4

What are the basic functions of the skin;

Answer 4

Protection Immune Vit D synthesis Temperature regulation Sensory organ Fluid balance Psychology

Question 5

What is the role of skin colour and disease?

Answer 5

Darker skin protects against folate degradation (the protein that absorbs UV) However, in lower latitude places darker persons can have more skin conditions due to decreased UV absorption.

Question 6

Vit D Deficiency leads to;

Answer 6

Rickets Osteoporosis

Question 7

Are there keratinocytes in the skin?

Answer 7

Yes, 10 to 1 melanocytes. They produce keratin which is highly present in the skin.

Question 8

Describe the basement membrane found between the epidermis and dermis.

Answer 8

Dual layer; Superficial #Hemidesmosomes anchoring cells such as keratinocytes - laminar lucida - laminar densa #Collagens I.e 7 and 3. Deep.

Question 9

What’s a condition impacting the hemidesmosomes anchoring keratinocytes to the basement membrane?

Answer 9

Bullocks pemphigoid Might be a protein targeting the hemidesmosomes anchoring keratinocytes to the basement membrane Blistering appearance.

Question 10

What can a gene mutation in collagen type seven cause in the basement membrane

Answer 10

Epidermolysis bullous

Question 11

What does milignant changes in melanocytes cause? Extra Q; in a melanoma, what is the white in the mole?

Answer 11

Melanoma Extra; white spots can be caused by the body creating antibodies to the cancerous melanocytes.

Question 12

Describe the embryological origin of melanocytes

Answer 12

Melanocytes are derived from neural crest cells in the formation of the neural tube.

Question 13

What is the disease where melanocytes are destroyed

Answer 13

Vitiligo Note the clinical symmetrical appearance

Question 14

Keratin forms;

Answer 14

Hair Nails Skin

Question 15

Describe the types of keratin and potential keratin related genetic conditions

Answer 15

54 variants of keratin type one (ch. 17) and type two (ch. 12). Diff tissues have dif keratin combinations Pachyonychia congetia

Question 16

Describe Pachyonychia congetia features

Answer 16

Keratin 6a mutation on ch 12 Clinical notes; Cysts can form Thick nail beds Plantar pain Mucosal involvement

Question 17

What’s the function of the dermis and what’s found in it?

Answer 17

Structural and nutritional support to the epidermis. Muccopolysaccharides. Elastin Collagen Vessels Cells; - fibroblasts - macrophages - mast cells - dermal dendritic cells

Question 18

What conditions occurs with excess collagen?

Answer 18

Scleroderma

Question 19

What is the function of subcutaneous fat?

Answer 19

Protection Insulation Energy sources Biologically active - hormone interaction I.e leptin and generation.

Question 20

What is the inflammation of subcutaneous fat called?

Answer 20

Panniculitis

Question 21

Review the diagram of the nail bed from each view.

Answer 21

Do it now.

Question 22

Review hair follicle diagram

Answer 22

Now.

Question 23

What is folliculitis?

Answer 23

Inflammation of the hair follicle

Question 24

Describe where deep inflammation of the hair follicle and what it can lead to?

Answer 24

Deep inflammation of the hair follicle can result in damage to the bulge area of the hair follicle containing stem cells. Damage to this area leads to intense scarring; Discoid lupus erythromotsus. More common in pasifika and Maori.

Question 25

How does the eccrine sweat gland function

Answer 25

Symp. Nerve. Ach stimulated.

Question 26

What does blockage of the pilosebacous unit lead to?

Answer 26

Acne vulgaris.

Question 27

How does the skin protect?

Answer 27

Tough mechanical layer Micro biome protection

Question 28

What are two conditions related to immunity when the skin barrier is broken?

Answer 28

Atopic Eczema Contact dermatitis.

Question 29

Describe fluid loss in the skin when it’s layers are broken and an example;

Answer 29

Drugs can cause toxic epidermal necrolysis. Shedding of epidermis. Fluid management becomes very important as does infection prophylaxis.

Question 30

Describe the physiological functions of skin again;

Answer 30

• Immune organ • Temperature regulation • Vitamin D synthesis • Fluid balance • Sensory organ • Protection (against external environment

Question 31

Describe the layers

Answer 31

Epidermis

Dermis

Capillary bed

Sub cutaneous fat

Question 32

Describe the layers

Answer 32

Stratum corneum

Stratum granulosum

Stratum spinosum

Stratum Basale

Basement membrane

Melanocytes

Question 33

Identify the structures

Answer 33

Question 34

Identify the structures

Answer 34

Question 35

Identify the structures

Answer 35

Question 36

Identify the structures

Answer 36