Histology

Question 1

Where are eccrine and apocrine glands found on the body?

Answer 1

Eccrine sweat glands are found all over the body except lips and genitals; apocrine are only found in axillae, nipples and genitals.

Question 2

What is the function of Meissner’s corpuscles and Pacinian corpuscles??

Answer 2

Meissners’s corpuscles are for tactile sensation

Pacinian corpuscles are for sensing deep pressures

Question 3

Give some features of palm skin

Answer 3

Thick keratin layer

Undulations follow those of underlying dermis giving ridges and grooves of fingerprints

Question 4

Give some features of sole of foot skin

Answer 4

Very thick keratin layer

Helical structures in keratin layer are terminal parts of sweat ducts

Question 5

Eccrine sweat glands

• Where are they found
• Structure and function?

Answer 5

Found over the whole body except the lips & genitals. Coiled tubular structures which regulate heat and salt loss

Question 6

Sebaceous glands

• Derived from where?
• Structure and function?
• Where aren’t they found?

Answer 6

Derived from the epidermis
Lobulated masses in dermis which usually secrete sebum into hair follicle to coat hair and skin.
Not present in palm and sole skin

Question 7

Apocrine sweat gland

• Where are they found?
• When do they develop?
• Which structure are they related to?

Answer 7

Limited to axillae / nipple / genitals. Develop at puberty and open into hair follicles above sebaceous gland

Question 8

Which three types of nerve ending are found in the skin?

Answer 8

1. Meissner’s corpuscles for tactile sensation
2. Pacinian corpuscles (deep pressure) are found in the dermis
   Free nerve endings (for pain) are located in the basal layer of the epidermis

Question 9

What is a hair follicle?

What are the four main parts?

Answer 9

An invagination of the epidermis

1. Central medulla containing ‘soft’ keratin 2. Outer cortex of ‘hard’ keratin
2. Papilla (bulge at base) contains multiple vascular channels
3. Matrix region - contains the keratin producing cells

Question 10

What are the four main structures of the nail?

Answer 10

1. Nail plate – sits on the nail bed
2. Matrix – cells divide and then produce hard keratin
3. Cuticle – extension of the skin fold covering the nail root
4. Hyponychium – secures the free nail edge

Question 11

Toxic epidermal necrolysis

• What causes it?
• Which cells die and what does this result in?

Answer 11

• Drug induced
• Keratinocyte death
• Results in epidermal detatchment at the dermoepidermal junction –> skin detaches in large necrotic sheets
• High mortality rate, 25-40%

Question 12

What are the three main problems in skin failure?

Answer 12

1. Loss of thermoregulation
2. Increased risk of infection -> sepsis
3. Failure of homeostatic function - enormous fluid + electrolyte loss, may result in cardiac and renal failure

Question 13

What are the three stages of wound healing?

Answer 13

1. Inflammation
2. Proliferation and tissue remodelling - involves granulation tissue, fibroblasts and angiogenesis
3. Tissue remodelling