Brainscape's Knowledge GenomeTM

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


See full index

BRS > intro to derm 1 > Flashcards

intro to derm 1 Flashcards

1
Q

Describe how the skin acts as an immunological barrier

A

Langerhans cells:

‘sentinel’ cells

dendritic processes extend through intercellular tight junctions to reach the stratum corneum

without any danger it upregulates Treg

when it recognises PAMPs it upregulates innate and adaptive immune response

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

Describe what happens to melanin synthesis in the presence of UV light (

A

1) increased PAR2 in keratinocytes so increased uptake and distribution of melanosomes 2)increased production of MITF and downstream melanogenic proteins (eg pmel 17, MART 1…) to increase melanin content

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

Describe the blood supply to the skin

A
  • does NOT cross the epidermis
  • in vascular plexuses
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

name the 2 parts of the dermis and compare and contrast

A

papillary dermis - superfical, vascularised and less dense connective tissue (contains meissener and pacinin corpuscle)

reticular dermis - deep, and more dense connective tissue

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

What are the functions of the top middle layer and innermost of the stratum corneun

A

upper layer - absorbs solutes middle layer - absorbs water innermost - mechanical defence barrier (fatty acids and sterols )

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

Describe the structure and function of desmosomes

A

FUNCTION: to anchor keratin to the cell membrane AND to form bridges between adjacent cells

DESCRIPTION: keratin is attached to desmoplakin, which is attached on the RHS to plakophalin. To the LHS of desmoplakin is plakogoblin and on top of that is desmogoblin

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

think cytoskeleton

To what do adherens junctions engage with

A

actin cytoskeleton

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

What is a protein involved in regulating the flatenning of keratinocytes

A

filagrin

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

Why are the keratinocytes of the stratum corneum ‘brick like’

A

no organelles nor nuclei cytoskeleton of intermediate keratin filiaments

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

Describe Meisseners corpuscles

A
  • non myelinated
  • encapsulated
  • fine touch
  • mechanoreceptors
  • in superficial dermis

●Most concentrated in thick hairless skin, (finger pads and lips)

●Light Touch (+slow vibration)

●Senses low-frequency stimulation at level of dermal papilla

lamellated capsule

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

Whats the function of Merkel Cells and where are they

A
  • mechanoreceptors
  • in epidermis
  • non encapsulated
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the dermal papillae and why is it significant

A

where the epidermis produces into the dermis where the neurovascular supply is

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

What is the predominant cell in the dermis

A

fibroblast

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

Embryologically, from where does the dermis originate. Draw a diagram to show this

A

from mesoderm

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

what is the purpose of tight junctions

A

barrier integrity and cell polarity

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

Describe Merkel cells and their location in detail

A

●Non-encapsulated mechanoreceptors

●Light / sustained touch, pressure

●Oval-shaped

●Modified epidermal cells

➢Stratum basale, directly above basement membrane

➢Most populous in fingertips

➢Also in palms, soles, oral & genital mucosa

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

What is the dermis mostly composed of

A

connective tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What happens in weeks 9 to 13

A

hair follicles (pilosebacious units) develop and appearance of lanugo hair

19
Q

How long does it take for a cell to go from the basal layer to the stratum corneun and when is it accelerated

A

30 days and in some diseases (eg psoriasis)

20
Q

what parts of the skin are the most richly innervated

A

face, extremities and genitalia

21
Q

Name the 5 roles of keratin

A

1) structural properties

22
Q

Embryologically, from where does the epidermis originate. Draw a diagram to show this

A

from the ectoderm

23
Q

Are melanocytes dendritic cells? Explain

A

Yes to allow them to distribute melanosymes via their dendritic processes to keratinocytes

24
Q

What are the main components of the demis by percentage

A

proteins: collagen 1 and 3 (80-85% )

fibrilin and elastin

glycoproteins: fibronectin, fibulin, interins

ground substances: glycoaminoglycasides, proteoglycans (hylauronic acid can absorb a lot of water to keep the dermis hydrated)

25
Q

What is the dermal epidermal membrane called

A

basement membrane

26
Q

Describe the development of melanocytes

A

1)neural crest cells turn into bipotent melanoblast glia progenitor which turns into a melanoblast 2) a melanoblast can differentiate directly into a melanocyte OR 3) develops into a melanocyte stem cell which may later differentiate into a differentiated melanocyte

27
Q

By which week have most melanocytes been differentiated into

A

weeks 12 to 13

28
Q

By week 11 what happens to the basal layer of skin

A

proliferates to form 5 layers (from deepest to most superficial) stratum germinativum (basal layer of cuboidal cells) stratum spinosum stratum granulosum stratum lucidum (only in palms of hand and soles of feet) stratum corneum

29
Q

From what week does the epidermis begin developing and what does it begin developing as

A

from WEEK 4 as a SINGLE BASAL LAYER of CUBOIDAL cells

30
Q

What are gap junctions and what are they important for

A

Form connexions between cells (intercellular channels)

Directly forms connections between cytoplasms of adjacent keratinocytes

essential for cell synchronisation, cell differentiation, cell growth and metabolic co orination

31
Q

What cells develop in week 5 and what does this layer develop

A

squamous non keratinising cells called periderm WHITE waxy protective substance called

32
Q

Describe the pacinian corpuscle

A

●Encapsulated

●Rapidly adapting (phasic) mechanoreceptor

●Deep pressure and vibration (deep touch)

➢Vibrational role - detects surface texture

●Ovoid

●Dermal papillae of hands and feet

33
Q

describe the autonomic innervation to the skin

A

cholinergic - eccrine sweat glands

adrenergic - eccrine and apocrine

34
Q

What is the mesoderm essential for

A

inducing differentiation of epidermal structures (eg hair follicle)

35
Q

Describe Ruffini’s capsule

A

deeper in dermis than Meissners

encapsulated

spindle shaped

detects skin stretching

high density around fingernails

monitors slipping

36
Q

give 3 facts about melanocytes

A
  • dendritic
  • makes melanosomes that they deliver to keratinocytes
  • people of all skin colours have the same number of melanin, those of darker tones just have more eumelanin whereas lighter tones have pheomelanin
37
Q

In what layer of the epidermis do you find the flattened keratinocytes

A

stratum corneum

38
Q

describe the structure of the basement membrane and its role

A

collagens 4 and 7, laminins and integrins

roles: cell migration and cell adhesion

39
Q

Name the 3 things that make up the filiamentous cytoskeleton of keratinocytes and their lengths

A

Actin containing filiaments (7nm) Tubilin containing filiaments ( 20-25nm) intermediate keratin filiaments (7-10nm)

40
Q

What collagens are present in the dermis and by what percentage

A

collagens 1 and 3 and they are 80 to 85%

41
Q

Describe how how the quantity and quality of melanin is produced (in the absence of UV light)

A

1) Melanocortin 1 Receptor ( MC1R) is a G coupled protein receptor that regulates the quality and quantity of granules produced 2) Agonists are alpha melanocyte stimulating hormone ( alpha MSH) and adrenocorticotrophic hormone (ACTH) which increases synthesis of eumelanin 3) ACTHS also upregulates transcription of the gene coding for the MC1R 4) Antagonist is Agouti signalling protein (ASP) which reverses synthesis of eumelanin and increases synthesis of pheomelanin

42
Q

describe the sensory innervation of the skin

A

on expanded tips, hair follicles and free

43
Q

what is below the dermis

A

subcutaneous fat

44
Q

name the 6 functions of the skin

A

physical barrier

immunological barrier

metabolism

sensation

thermoregulation

aesthetic

BRS (13 decks)

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