skin

Question 1

what are the 3 main layers of the skin? (add fucntion as well)

Answer 1

• epidermis - OUTERMOST LAYER that provides a waterproof barrier
• dermis - contains connective tissue, blood vessels and sensory receptors
• hypodermis (subcutaneous adipose layer) - consists mainly of FAT and CONNECTIVE TISSUE, providing insulation and cushioning

Question 2

what is the epidermis made of?

Answer 2

• granular layer
• basal layer
• (specialised cells - coenocytes)
• squamous epithelial tissue

Question 3

what are coenocytes filled with?

Answer 3

keratin

Question 4

what does keratin do?

Answer 4

• stops water loss from inside
• stops penetration of water from outside

Question 5

what are 4 major cells found in epidermis?

Answer 5

• keratinocytes - produce keratin
• melanocytes - synthesise melanin
• langerhans cells - act as antigen presenting cells
• merkel cells - function as mechanoreceptors for touch sensation

Question 6

what are the 5 layers of epidermis (deepest to superficial)

Answer 6

• stratum basale - contains basal cells (that divide and differentiate)
• stratum spinous - provide structural support
• stratum granulosum - provides keratohyalin and lamellar bodies
• stratum lucidum
• stratum correum - composed of dead keratinised cells acting as a protective barrier

Question 7

what are the 2 layers of the dermis?

Answer 7

• papillary layer
• reticular layer

Question 8

what does the dermis contain?

Answer 8

• fibrous, filamentous and amorphous connective tissue

Question 9

what is the papillary dermis layer?

Answer 9

• upper most layer of the dermis, joined to basal membrane of epidermis

Question 10

what does the papillary dermis layer contain?

Answer 10

• loosely arranged collagen fibres
  and
• papillae (that extend towards the epidermis )

Question 11

what is the reticular dermis layer?

Answer 11

• lower layer of the dermis - under the papillary dermis

Question 12

what does the reticular dermis layer consist of?

Answer 12

• dense connective tissue - such as packed collagen and elastic fibres
• roots of hair
• sebaceous glands and sweat glands

Question 13

name a cell in the dermis layer

Answer 13

• dermal fibroblast

Question 14

what is the function of the dermal fibroblast?

Answer 14

• production of important matrix proteins such as
• fibrillin
• elastin
• collagen

Question 15

another function of dermal fibroblast

Answer 15

• heavily involved in
  would healing
  and
  generating connective tissue

Question 16

what is the function of subcutaneous adipose tissue?

Answer 16

• thermoregulation
• storage of energy when needed
• controls hormones