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01. Year 1: Science for Medicine > Skin > Flashcards

Flashcards in Skin Deck (60)
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1
Q

What is the largest organ in the body?

A

The skin

2
Q

What are the 4 tissue types that make up the skin?

A

Epithelium

Connective tissue

Muscle

Nervous

3
Q

Does the skin have its own blood and nerve supply?

A

Yes

4
Q

What does the skin provide evidence of diagnostically?

A

Underlying conditions

5
Q

What are some functons of the skin?

A

Prevents water loss (epidermis)

Permits body cooling (dermis)

Immune surveillance

UV protection

Energy storage

Sensory information

6
Q

What are the 2 layers of the skin?

A

Epidermis

Dermis

7
Q

What tissue type makes up the epidermis?

A

Epithelium

8
Q

What tissue type makes up the dermis?

A

Connective

9
Q

What is underneath the epidermis and the dermis?

A

Hypodermis

10
Q

What is the hypodermis?

A

A fatty layer that anchors the skin to underlying structures

11
Q

What does the hypodermis do?

A

Anchors the skin to underlying structures

12
Q

What is the class of the epithelium tissue of the epidermis?

A

Stratified, getting flatter as you go up

13
Q

What are the 4 basic cells in the epidermis?

A

Karatinocytes (contain keratine, waterproof)

Melanocytes (pigment formation, in basil layer)

Langerhans cells (immune surveillance)

Merkel cells (touch receptors)

14
Q

What are the layers of the epidermis like and what are they formed by?

A

Fine layers formed by maturing karatinocytes

15
Q

What are the 5 layers of the epidermis?

A

Stratum basule (basil layer)

Stratum spinosum

Stratum granulasum (keratine starts being synthesised)

Stratum lucidum

Stratum corneum

16
Q

What happens to keratine granules as you go up layers of the epidermis?

A

They breakdown and go up layers until they die and flatten out in the stratum corneum

17
Q

What is the class of cells in the stratum basal?

A

Tall columnar cells

18
Q

What cells are found in the stratum basal?

A

Melanocytes and merkel cells

19
Q

What are cells of the stratum basale bound to the BM by?

A

Hemidesmosomes

20
Q

What is the interface like between the stratum basale and the dermis?

A

Irregular

21
Q

What do the cells in the stratum basale do?

A

Stem cells that perform continuous proliferation

22
Q

What happens as cells go to the stratum spinosum?

A

They shrink and desmosome junctions create ‘spines’

23
Q

How does the stratum spinosum relate to keratinisation?

A

Preparative layer for keratinisation

24
Q

What defines the stratum glanulosum?

A

Pressure of granules

25
Q

What granules make up the stratum granulosum?

A

Granules of keratohyalin, precurser of keratine

26
Q

Are the properties of the stratum lucidum/corneum different?

A

Only that the stratum corneum has no cell organelles

27
Q

What happens in the stratum lucidum?

A

Converstion of keratohyalin to keratine

28
Q

What gives the strength of the stratum lucidum?

A

Disulphide bridges

29
Q

What is keratinisation?

A

Organic process where keratine is deposited in cells, becoming hard

30
Q

What does keratinisation allow dead cells to do?

A

Rub of (exfoliate)

31
Q

What properties does keratinisation give the skin?

A

Its resilience and strength

32
Q

How does the epidermis thickness vary around the body?

A

It varies around the body depending on function, hand and feet are thick, abdomen is thin

33
Q

What are the 2 layers of the dermis?

A

Papillary layer

Reticular layer

34
Q

What is the papillary layer made of?

A

Loose connective tissue

35
Q

Where are macrophages found?

A

In the papillary layer of the dermis

36
Q

What is a function of the papillary layer of the dermis?

A

Protects against pathogens

37
Q

What is found in the papillary layer of the dermis and what does this allow?

A

Blood vessels (thermoregulation, nutrition)

Nerve endings (sense organ)

38
Q

What kind of tissue if the reticular layer of the dermis?

A

Dense irregular connective tissue

39
Q

What is the reticular layer of the dermis composed of?

A

Collagen fibres in three planes

Elastic fibres

40
Q

What happens to the elasticity of the dermis with age?

A

Loss of elasticity

41
Q

What is waterproofing a function of?

A

The dermis, because the keratine is waterproof

42
Q

What is skin colour due to?

A

The melanin that is produced by melanocytes (protects against UV light)

43
Q

What is the function of melanin?

A

Protects against UV light

44
Q

What layer is hair derived from?

A

The epithelial layer, has a continuity with layers of the epidermis

45
Q

What is a hair follicle composed of?

A

Arrector pili muscles

Sebaceous glands

46
Q

What do arrector pili muscles do?

A

Straightens the hair when the muscle contracts

47
Q

Where are erector pili muscles found?

A

Attatched to follicle root and base of the epidermis

48
Q

Where are sebacceous glands found?

A

Between the hair follicle and arrector pili muscle

49
Q

What do sebaceous glands do?

A

Secretes sebum

50
Q

What are nails?

A

A specialised version of epithelium that becomes very hard due to keratine

51
Q

What is responsible for nails becoming very hard?

A

Keratine

52
Q

What are some skin glands?

A

Sebaceous glands

Appocrine sweat glands

Eccrine sweat glands

53
Q

Where does each gland secrete?

A

Sebaceous glands secrete directly into the hair follicle whereas the other glands do not

54
Q

What is the class of eccrine sweat glands?

A

Simple tubular gland

55
Q

Where are eccrine sweat glands located?

A

In the dermis

56
Q

What is the role of eccrine sweat glands?

A

Thermoregulatory role

57
Q

How is thermoregulation achieved?

A

Sweat glands

Blood vessel dilation

Hair (not in humans)

58
Q

What are some examples of nerve endings in the skin?

A

Meissner’s corpuscles (light touch)

Paccinian corpuscles (vibration and pressure)

Pain receptors

Thermoreceptors

59
Q

What is not formed in scar tissue?

A

Hair follicles or sweat glands

60
Q

What is skin very good at doing?

A

Repairing itself