Brainscape's Knowledge GenomeTM

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


See full index

Dermatology > Structure and function > Flashcards

Structure and function Flashcards

You may prefer our related Brainscape-certified flashcards:
Dermatology Board Prep flashcards
1
Q

What ratio of GP appointments are concerned with skin?

A

1:5

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

Name the outer layer of the skin

A

Epidermis

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

What is the second layer of the skin called?

A

Dermis

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

What type of cell is the epidermis made of?

A

stratified squamous epithelium

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

What is the dermis made up of?

A

Connective tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Embryologically, where does the epidermis come from?

A

The ectoderm forms a single layer of periderm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Embryologically, where are melanocytes produced from?

A

The neural crest, adjacent to the neural tube.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Between 4 and 16 weeks gestation what does the periderm separate into?

A

The keratin layer
The granular layer
The prickle cell layer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are Blaschko’s lines?

A

Developmental growth pattern of skin

Looks like dermatomes but do not confuse the two!

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Name the layers of the skin

A

Epidermis- made up of the keratin layer, granular layer, prickle cell layer and basal layer.
Appendages - nail, hair, glands
Dermis
Sub-cutis

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

What cell primarily makes up the epidermis?

A

keratinocytes

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

Where are keratinocytes produced?

A

The basal layer of the epidermis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is normal epidermal turnover time?

A

50 days

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Name a part of the body where the epidermal layer is thicker

A

Sole of the foot or palm of the hand

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Epidermal cell turnover is not controlled in psoriasis. Is the turnover time less or more?

A

Less
Around 4-5 days.
Normal migration from basement membrane to the keratin layer is around 28 days.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is keratinisation?

A

Process of differentiation to produce a surface layer or stratum corneum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Describe the basal layer

A 
1-3 cells thick
Small cuboidal
lots of keratin filaments
Highly metabolically active
Melanocytes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the prickle cell layer made of?

A

Larger polyhedral cells
Lots of desmosomes
Intermediate filaments which connect to desmosomes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is in the granular layer?

A

2-3 layers of flatter cells
Odland bodies.
No cell nuclei at this layer - cells start to die.
Cornified cell envelope- barrier functions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is an Odland body?

A

Contain lipids and enzymes which are discharged and act as glue between intercellular spaces between the granular layer and the keratin layer.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is in the keratin layer (or horny layer)?

A

Corneocytes - overlapping non-nucleated cell remnants ( also called stratum corneum)
Forms a tight waterproof barrier

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

How does HPV affect the skin?

A

Causes warts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Where do melanocytes come from?

A

Migrate to the epidermis from the neural crest in first 3 months of gestation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What do melanocytes do?

A

They live in the basal layer and above ( only epidermis) and are pigment producing dendritic cells.
Transfer melanin to adjacent cells.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What organelles do melanocytes contain?

A

Melanosomes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What do melanosomes do?

A

Convert tyrosine to melanin pigment.

Either eumelanin in black or brown hair or phaeomelanin in red or blonde hair.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What does melanin do?

A

Stimulated by UV light- the more UV light the more melanin. Positive feedback.
Acts as a barrier to protect cell nuclei from UV light. (therefore no cells with nuclei above where melanocytes are present)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Why are people with darker skin less likely to develop skin neoplasms?

A

Melanosomes are larger so cover a bigger area, remain separate as opposed to forming complexes, like in white skin.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What is vitiligo?

A

an autoimmune disease, involved with the loss of melanocytes - skin appears whiter than usual.
more noticable in people of darker skin.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What is albinism?

A

Affects 1:20,000
partial loss of pigment production.
Because of this neoplasms are more likely since nuclei are not protected.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What is Nelson’s syndrome?

A

The hormone which stimulates eumelanin production is in excess due to a fault in the pituitary gland so the patient complains of unusually dark skin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What is a malignant melanoma?

A

A tumour of the melanocyte cell line

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What is a Langerhans cell?

A

Recognises antigen-presenting cells. Sticks to and circulates to lymph nodes.
Found in prickle cell level in epidermis.
Also found in dermis.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What is a merkel cell?

A

Mechanoreceptors.

Found between keratinocytes and nerve fibres.

35
Q

What is merkel cell cancer?

A 
Very uncommon. 
Abnormal division of merkel cells.
Red/purple lumps on skin
Not usually painful but can develop into ulcers
Prognosis is dull
36
Q

What is a hair follicle made up of?

A

Dermal papilla with an epidermal component.
Adjacent sebaceous gland.
Hair is pigmented via melanocytes above dermal papilla.

37
Q

Name the phases of growth hair follicles go through

A

Anagen - active growth
Catagen - transitional phase
Telogen - rest phase

38
Q

What are the three types of hair?

A

Lanugo - in utero only - sheds before 8 months gestation
Vellus - fine hair which covers most of the body
Terminal - developing after puberty, aided by androgens.

39
Q

What shape is caucasian hair?

A

Elliptical shape - except pubic, beard and eyelash hairs which are always oval.

40
Q

Explain the importance of hair follicles having independent cycles ( being asynchronous)

A

If all hairs grew and subsequently shed at the same time we would go bald!

41
Q

Describe male pattern hair loss

A

Change of hair from terminal to villus

42
Q

Why does hair go grey (canities) ?

A

Reduction in amounts of tyrosinase activity which means less melanin can be produced.

43
Q

What is virilisation?

A

Hirsituism in females due to excess androgen from a tumour

44
Q

What is alopecia areata?

A

Autoimmune disease which causes hair loss.

Hair will first go back looking grey.

45
Q

What protein is missing in eczema?

A

Filaggrin

46
Q

HPV is common in who?

A

Children under 6

47
Q

How does a wart change the skin structure?

A

?

48
Q

What is scar tissue?

A

Defined as loss of skin appendages

49
Q

Which organelle creates melanosomes?

A

Golgi apparatus

50
Q

Birbeck granules are found in which cells?

A

Langerhans cells.

51
Q

What happens when merkel cells are found in abundance?

A

Higher sensitivity to touch since merkel cells are mechanoreceptors

52
Q

Which common disease affects the myelin sheath of nerve fibres?

A

Diabetes therefore parathesia or dysthesia.

Excess glucose disrupts proteins.

53
Q

What does increased sebum. blocked sebaceous ducts and increased bacterial activity result in?

A

Acne

54
Q

How long is the anagen phase?

A

between 1-8 years

55
Q

Male pattern balding starts at what part of the scalp?

A

Vertex

56
Q

What is a hair transplant?

A

Removal of hair from hair line posteriorly, to the vertex by punch biopsy.

57
Q

Which nails grow faster: fingers or toes?

A

Fingers

58
Q

Where do stem cells live in the nail?

A

In the nail matrix, just under the cuticle

59
Q

Why is the nail red and the lunula white?

A

Lunula is thicker.

Blood vessels seen more easily in nail

60
Q

Where is the dermo-epidermal junction?

A

Between the epidermis and the dermis

61
Q

What is the dermo-epidermal junction’s role?

A

Support, anchorage, adhesion, growth.

62
Q

What is epidermolysis bullosa?

A

It is an inherited disease which results in a fragile dermo-epidermal junction.

63
Q

What are the two forms of epidermolysis bullosa?

A

simplex (collagen or protein issue) and dystrophica (“mitten deformity” in hands and feet”)

64
Q

What is pemphigoid

A

An acquired auto-immune disease to the proteins in the DEJ.
Skin biopsy then it can be diagnosed as a positive immunofluorescence on histology.
Controlled with steroids.

65
Q

in the dermis, what do fibroblasts do?

A

Secrete collagen (tensile strength) and elastin

66
Q

In the dermis, what do Langerhans cells do?

A

antigen presentation

67
Q

What is an angioma?

A

Tumour of vascular tissue.

Dilated vascular spaces make the mark look red.

68
Q

What is a haemangioma?

A

A strawberry birthmark.
Normally found in infants.
Treated with beta blockers.

69
Q

Where are the lymphatics in the skin?

A

Sub-epidermal

70
Q

What are pacinian corpuscles?

A

receptors which detect pressure (P for Pressure)

On staining, they look like an onion cut in half

71
Q

What are meissners corpuscles?

A

Receptors which detect vibration

72
Q

What kind of nerve supply does the skin have?

A

Autonomic

73
Q

What is neurofibromatosis?

A

When tumours grow along the nerve which is abnormally thickened.
Benign.

74
Q

What is an eccrine gland?

A

Covers the whole skin surface
Sympathetic cholingeric supply.
Purpose: heat control. “Hot day” sweating.

75
Q

What is an apocrine gland?

A

Mostly found in the axilla and perineum.

Androgen dependent and emit pheromones.

76
Q

What is a sebaceous gland?

A

Part of the pilosebaceous unit- includes the hair.
Largest glands on face and chest.
Hormone sensitive so “dormant” pre-puberty.
Produces sebum

77
Q

What is erythroderma?

A

widespread (80/90%) redness of skin

78
Q

In what way is the skin metabolically active?

A

Metabolises vitamin D with help of UV light

Metabolises thyroid hormone (T4)

79
Q

Where is vitamin D stored?

A

In the liver as 2hydroxycholecaliferol

80
Q

What is vitamin D converted to in the kidney?

A

1,25 dihydroxycholecaliferol.

81
Q

What is thyroxine (T4) converted to in the skin?

A

Tri-iodothyronine (T3)

82
Q

Which is the most metabolically active layer of the skin?

A

Basal layer

83
Q

At what stage in foetal development is the skin complete?

A

6 months

84
Q

What is the hyponychium?

A

Area of skin underlying the edge of the nail

Dermatology (19 decks)

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