Tissues 10-11

Question 1

Functions of the skin?

Answer 1

• Protection
• Waterproofing and fluid conservation
• Thermoregulation
• Absorption of UV and vitamin D production
• Sensory organ
• Cosmetic

Question 2

What is toxic epidermonecrolysis?

Answer 2

Rare condition whereby keratinocytes undergo mass apoptosis.

Question 3

What is psoriasis?

Answer 3

Common skin condition (15%) due to excess keratinocytes.

Question 4

Where does the herpes-zoster virus live?

Answer 4

Dorsal root ganglions

Question 5

How many layers are there to the epidermis?

Answer 5

4

Question 6

What are the four layers of the epidermis?

Answer 6

1) Stratum corneum
2) Stratum granulosum
3) Stratum spinosum
4) Stratum basale/parabasale

Question 7

What is a markel cell?

Answer 7

Involved in touch and sensation. Located in basement membrane.

Question 8

What are melanocytes?

Answer 8

Cells that produce melanin (a pigment giving us our skin colour) to protect the keratinocytes from UV damage. 1:5 ratio.

Question 9

What does the basement membrane do?

Answer 9

Join the epidermis and dermis

Question 10

What is eccrine?

Answer 10

Watery sweat that is distributed all over the body.

Question 11

What is apocrine?

Answer 11

Thick, viscous sweat that is secreted in certain areas such as the groin and axillary regions. Prone to bacterial metabolism and therefore odour.

Question 12

What is the embryology of the epidermis?

Answer 12

Ectoderm

Question 13

What is the embryology of the dermis?

Answer 13

Mesoderm

Question 14

What is the embryology of melanocytes?

Answer 14

Neural crest

Question 15

What are the functions of hair?

Answer 15

• Protection against UV damage
• Sensation
• Thermoregulation
• Communication

Question 16

Where are the only places with no hair?

Answer 16

Palms and soles of the feet

Question 17

When does hair start growing in pregnancy?

Answer 17

Third trimester

Question 18

What is lanugo hair?

Answer 18

Long, wispy hair that is common in young children and anorexics.

Question 19

What is vellus hair?

Answer 19

Body hair (unpigmented and wispy)

Question 20

What is terminal hair?

Answer 20

Pigmented, coarse hair found on the scalp and in facial hair

Question 21

What are the four stages of the hair cycle?

Answer 21

Anagen - growing phase
Catagen - regression phase
Telogen - resting phase
Exogen - shedding phase

Question 22

When does hair growth become asynchronous?

Answer 22

After the first exogenous phase.

Question 23

What is the cause of male-pattern baldness?

Answer 23

Decrease in androgens.

Question 24

What is hirsutism?

Answer 24

Excessive hair growth due to high levels of androgens.

Question 25

What are the function of nails?

Answer 25

• Cosmetic
• Grip
• Weapons
• Touch

Question 26

What do clubbed fingers indicate?

Answer 26

Cardiovascular or respiratory disease.

Question 27

What is koilonychia?

Answer 27

Spoon-shaped nails that indicate iron deficiency anaemia.