Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

LOCO2 > Introduction to Skin > Flashcards

Introduction to Skin Flashcards

1
Q

What are the 2 main functions of skin?

A
  • protection

- insulation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

How does skin offer protection?

A
  • physical trauma
  • infection
  • penetration of drugs and chemicals
  • UV radiation
  • water loss
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How does skin allow function?

A
  • sensory information
  • vitamin D synthesis
  • heat insulation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the 2 layers of the skin?

A
  • epidermis (protection)
  • dermis (strength and elasticity)
  • also contains glands, hair follicles, arterioles
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the epidermis?

A
  • stratified squamous epithelium
  • outermost, protective
  • keratinocyte is main cell
  • 4 main layers
  • includes and hair and sebaceous gland
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are keratinocytes?

A

produces keratins:

  • intermediate size (larger than microfilament but smaller than microtubule)
  • keratin = most abundant proteins in stratum, corneum, hair and nails
  • alpha = soft/loose, coiled
  • beta = hard, beta sheets, cross by disulphide and hydrogen bonding
  • generally acidic or basic in pH and pair up accordingly so whole structure is neutral
  • K5 and K14 always pair up so neutral
  • expression pattern specific to epidermal layer
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the 4 main layers of the epidermis?

A
  • Stratum corneum (outermost part of skin)
  • stratum lucidum
  • stratum granulosum (dark purple, flattened)
  • stratum spinosum (spiny processes)
  • stratum basale (bottom)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the features of the stratum corneum?

A
  • main protective skin barrier
  • thick cornified envelope
  • cross linked by enzymes
  • dead cells
  • intracellular lipids containing moisture
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the features of the stratum granulosum?

A
  • 2-3 cell layers
  • large granules of kertohyalin (filaggrin, involucrin, loricrin)
  • nucleus breaks down
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the features of the stratum spinosum?

A
  • 3-4 layers thick

- desmosomes giving spiny appearance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What occurs in the straum basale?

A
  • proliferation

- adult stem cells maintaining epidermis = self-renewal, terminal differentiation, long lived

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the basement membrane?

A
  • basal cells adhere to ECM
  • laminin 332, collagen IV, collagen VII
  • hemidesmosomes link keratin cytoskeleton(inside) to basement membrane (outside)
  • cell polarity, regulating basal function, anchor epidermis to dermis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the types of cell-cell adhesions?

A
  • adherens junctions = cadherin receptor linked to actin cytoskeleton
  • desmosomes = cadherin receptor linked to keratin cytoskeleton
  • tight junction = claudin and occludin seal IC space
  • gap junctions = intercellular pores made up of connexins
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the dermis?

A
  • provides strength and elasticity
  • macromolecule mix
  • vascularised and innervated
  • fibroblast main cell
  • 3 layers=
  • papillary
  • reticular
  • adipose
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the papillary layer of the dermis?

A
  • beneath epidermis and basement membrane
  • many blood capillaries
  • fine randomly organised collagen III
  • elastin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the reticular layer of the dermis?

A
  • large and densely packed collagen fibres

- mechanical strength of skin

17
Q

What is the adipose layer of the dermis?

A
  • strength and elasticity
  • macromolecule complex mix
  • vascularised and innervated
18
Q

What is a fibroblast?

A
  • in the dermis
  • most abundant cell in dermis
  • mesenchymal origin
  • synthesises collagen, elastin and proteoglycans
19
Q

What is a pilosebaceous unit?

A
  • hair follicle and associated sebaceous gland
20
Q

What is a hair follicle?

A
  • part of epidermis
  • 2 types -> vellus body hair (fine and non-pigmented) and terminal scalp/secondary sexual hair (pigmented)
  • produced by matrix keratinocyte
  • dermal papilla fibroblasts control hair growth
21
Q

What are hair follicle stem cells like?

A
  • localised to bulge region
  • express keratin 15
  • slow cycling
  • give rise to hair cells under normal conditions
22
Q

How do hair follicle stem cells differentiate?

A
  • migrate own from bulge to bulb of follicle
  • receive signal from dermal papilla to rapidly proliferate
  • differentiation depends on spatial location
23
Q

What are the 3 stages of the hair growth cycle?

A
  • anagen = active
  • catagen = regressive
  • telogen = resting
24
Q

What is a sebaceous gland?

A
  • exocrine gland
  • androgen sensitive
  • enlarges at puberty
  • mature sebocytes contain sebum
  • cell ruptures and sebum released into sebaceous duct onto skin
  • infection = acne
25
Q

What are the 2 types of sebaceous glands?

A
  • eccrine sweat gland

- apocrine gland

26
Q

What is an eccrine sweat gland?

A
  • allows thermoregulation

- 2 components = excretory duct and secretory coil

27
Q

What is an apocrine gland?

A
  • sweat glands associated with hair follicles
  • in axilla and pubic region
  • secretion is odourless
  • sweat broken down on skin by bacteria
  • release volatile fatty acids
28
Q

What are melanocytes?

A
  • dendritic cell
  • epidermis on basement membrane and hair matrix
  • produce melanin protecting against UV
29
Q

What are langerhan cells?

A
  • dendritic
  • in basal and spinous layer
  • APC
  • first line of defence
  • presents antigens to T lymphocytes
30
Q

What are merkel cells?

A
  • in stratum basale
  • sensory perception
  • primary communication between epidermis and sensory nerve endings below
31
Q

What are mast cells?

A
  • in dermis
  • immune response
  • secretes histamine
32
Q

What are the 3 wound types?

A
  • superficial = epidermis
  • partial thickness = epidermis and dermis
  • full thickness = epidermis and dermis hypodermis
33
Q

What are the 3 stages of normal wound healing?

A
  • inflammation (minutes up to 6 days)
  • proliferation (several days to weeks)
  • maturation/remodelling (weeks to months)
34
Q

What does inflammation in would healing involve?

A
  • haemostasis (endothelial cells and platelets, within minutes)
  • minutes to days T cells, macrophages, lymphocytes etc
  • interleukin mediated, TNFa
35
Q

What does proliferation in wound healing involve?

A
  • keratinocyte migrate into wound, proliferation and differentiated (mediated by GF) and new vascularisation angiogenesis, fibroblasts produce new collagen, granulation tissue
36
Q

What are the 4 main types of skin diseases?

A
  • Cancer = malignant melanoma
  • Inflammation = Psoriasis
  • Wounds = diabetic ulcer
  • Genetic diseases = epidermolysis bullosa
37
Q

What are the 2 types of melanin?

A
  • eumelanin (brown)

- pheomelanin (red)

38
Q

What does the maturation phase in wound healing involve?

A
  • collagen deposited broken down and remodelled to form normal tissue structure
39
Q

What are the main complications of wound healing?

A
  • infection
  • chronic wounds (not healed >6 weeks due to pressure sores, diabetic ulcers)
  • scarring extreme so wound process does not stop

LOCO2 (26 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions