Brainscape's Knowledge GenomeTM

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


See full index

Pharmacy > Structure (& Function) of the Skin > Flashcards

Structure (& Function) of the Skin Flashcards

1
Q

Function

A

protection, regulation and sensation

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

The integumentary system

A

Skin, cutaneous glands, fingernail, hair

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

what is the Skin

A

largest and fastest growing organ in body

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

Cutaneous glands

A

sebaceous (sebum) and sweat glands

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

Fingernails

A

densely packed cells covered in keratin

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

Hair

A

pigmented filament (mostly keratinised cells)

Part of the integumentary system

Hair grows in the dermis from the hair follicle (from downward extension of epidermis)

Growth of hair is like skin: keratinocytes get pushed up, become flattened, dead, keratinised cells

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

Small muscles (arrector pili) contract when

A

you experience physical/ emotional changes to give you goosebumps

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

Two types of skin on the body

A

hairy and glabrous (non-hairy)

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

Hairy skin

A

covering more than 90% of the body. Hair contribute to tactile sensations, forms part of our social interaction and can detect foreign objects

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

Glabrous skin

A

mainly on palms and soles of feet. Specialised nerves to detect tactile details. Thicker than hairy skin.

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

Skin-function

A

Protection (against external environment including invasion from bacteria)

Thermoregulation
Humidity control
Produces vitamin D

Viruses, bacteria and fungi live on your skin (ecosystem)! Demodex

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

Stratified epithelium

A

(usually thinner than dermis)

Outer layer of skin with no
blood vessel supply (squamous epithelium receives blood by diffusion)

Layers (strata) of keratinocytes. Continuous cycle of cell division and death

Also contains melanocytes, Merkel cells and Langerhans cells
30-45 days for basal cells to mature and migrate to top of epidermis

Production of keratin

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

Basement membrane separates

A

the epidermis and dermis-
connection between the two allows cells and bioactive molecules to move between the two regions

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

Stratum corneum

A

flat dead keratinocytes and cross-linked keratin fibres (squamous cells) protect body from water loss. Often described as ‘bricks’ (corneocytes) and ‘mortar’ (intercellular lipids). Loss of cells from this layer (desquamation) causes barrier to become weak (entry point for irritants)

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

Stratum lucidum

A

rows of dead keratinocytes only in glabrous skin. Lipid-rich eleidin keeps out water

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

Stratum granulosum

A

mostly mature keratinocytes migrating from spinosum, keratohyalin granules and lamellar bodies (also to waterproof skin)

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

Stratum spinosum

A

mature keratinocytes linked by desmosomes producing keratin. Also contains Langerhans cells (protection form microbes)

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

Stratum basale

A

deepest layer. Basal cells push older cells up. New keratinocytes made.
Also contains melanocytes (skin pigment)

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

corgis lick grandpas saggy bums - make up the epidermis

A

stratified corneum, Stratum lucidum, Stratum lucidum, Stratum granulosum, Stratum spinosum, Stratum basale

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

Dermis Two parts

A

papillary (20% of dermal thickness) and reticular (80% of dermal thickness)

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

Dermis- Papillary

A

mostly loose connective tissue some elastic fibres, capillary loops and nerves

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

dermis-Reticular

A

dense irregular connective tissue containing collagen fibres, elastin, proteoglycans and glycosaminoglycans

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

Fibroblasts and keratinocytes

A

principal cell of dermis. Production of collagen, elastic and reticular fibres and extracellular matrix

Cells of the dermis

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

Adipocytes

A

Cells of the dermis

fat cells (insulation, energy storage and wound healing)

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

Mast cells

A

Cells of the dermis

inflammatory cells that help with collagen remodelling and wound healing

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

Myofibroblasts

A

Cells of the dermis

rich in smooth muscle actin and myosin (contractile cells)

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

Myoepithelial cells

A

Cells of the dermis

cells in sweat glands

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

Keratinocytes

A

Make up more than 90% of the cells in the epidermis

Essential for stratification and forming protective barrier

Changes in structure and function as you move towards outer layer

29
Q

Keratins

A

80% of internal cell structure of differentiated
keratinocytes

bundles are major component of the cytoskeleton of the keratinocytes

Network of fibre bundles extending from periphery to nucleus

Bundles composed of keratin subunits wrapped around each other (coil).

Different types of keratin expressed

Contribute to structural integrity of epidermis (dissipate force)

Few drugs can disrupt keratin intermediate filaments (though mutations in the keratin genes can lead to weak filaments)

30
Q

Desmosomes

A

anchors (cells to each other and to basement membrane

Multiprotein complexes important in adhesion and signalling

connect cells to each other (junctions) via cadherin proteins.

Also provide strength as they link intracellularly (through the filaments in the cytoskeleton)

Loss of connection can cause significant issues e.g., skin blistering (pemphigus- an autoimmune disease)

31
Q

Lamellar granules-Also known as: lamellar bodies, membrane-coating granules, keratinosomes, Odland bodies

A

help form lipid protective barrier
Produced by keratinocytes (also found in lungs)

Round/ oblong in shape (though some say they’re branched) approx. 300-400nm width and 100-150 nm length

Secretory organelles: contain glucosylceramides, lipids, enzymes and other proteins.

These are required for desquamation (skin shedding)

Skin function: help form the impermeable lipid-containing barrier
Abnormalities can cause eczema and other skin conditions

32
Q

Hemi-desmosomes

A

anchors (cells to each other and to basement membrane

Multiprotein complexes important in adhesion and signalling
connect keratinocytes to the basement membrane via integrin receptors and also contribute to strength

Loss can again lead to skin blistering (tissue separation)

33
Q

Why does our skin not constantly rupture from the mechanical forces of the outside world?

A

Keratinocytes >70 times stiffer than other cell types (even after they die!)

Due to their cytoskeleton and keratin filaments

34
Q

Melanocytes

A

Produce melanin (skin colour) and protects against UV radiation while supporting the immune system.

Found in bottom layer of epidermis.
transfer melanosomes to keratinocytes (through dendrites)

35
Q

Langerhans cells

A

also known as dendritic cells and contain Birbeck granules (rod shaped with function not clear).
Found throughout epidermis and support immune system.

36
Q

Merkel cells

A

oval shaped and responsible
for light touch and sensation through their connection to nerve fibres

37
Q

Melanosomes

A

formed in melanocytes and contain melanin

38
Q

Epidermal melanin unit

A

anatomical relationship between melanocytes and keratinocytes (each melanocyte is in contact with approx. 40 keratinocytes)

39
Q

Hyperpigmentation- causes

A

increased melanin production or increased number of melanocytes (less common as melanocyte number is approx. similar in all individuals)

40
Q

Hyperpigmentation-epidermal

A

too much melanin or too many melanosomes transferred

41
Q

Hyperpigmentation- dermal

A

melanin crosses damaged
basement membrane. Deeper and harder to treat

42
Q

Hyperpigmentation-Treatment

A

varied from photoprotection to prevent new spots to inhibitors of melanin production

43
Q

Merkel cells: allodynia

A

Hypersensitivity to touch which can manifest as pain

A type of neuropathic pain

Everyday tasks become difficult, e.g., combing hair, putting on a t-shirt, even temperature changes

Causes: many e.g., diabetes, fibromyalgia, migraines

44
Q

Langerhans cells and immunity

A

Dendritic cells: ‘sense’ by extending dendrites through intercellular tight junctions towards stratum corneum
Able to interpret the external environmental threats (inflammation or tolerance)
Non-dangerous: coordinate immune tolerance (no immune activation)
Dangerous: work with keratinocytes to instruct T lymphocytes to mount a response

As they interact with keratinocytes to ‘activate’, any damage to keratinocytes could 	affect immune response
45
Q

Langerhans cell histiocytosis

A

Buildup of excess immature Langerhans cells form granulomas (tumors) in skin and other organs. Stimulus for excess proliferation unknown
Cancer? Labelling controversial

Rare (1 in 5 million)

Can severely affect the immune system (can involve multiple organs and can be fatal)

Treatments: depends on severity from topical to chemotherapy and surgery

46
Q

Shaft

A

Hair exposed on skin surface

47
Q

Hair root

A

Rest of the follicle

48
Q

Hair bulb

A

Bulge at the base of the hair root (contains a layer of basal cell: ‘hair matrix’ which form the hair)

49
Q

4 different hair growing stages

A

anagen: growing phase
catagen: transition phase
telegen: resting phase
exogen: shedding phase

50
Q

hair- function

A

protect from sun, prevent heat loss, trap particulates (hair in nose and ears), prevent sweat from running into eyes (eyebrows)
Much more sensitive than skin to changes in environment (see arrector pili muscle)
Hair grows at approx. 0.3 mm a day
Approx. 50 hairs lost per day

Like skin melanin gives it colour (melanin production decreases with age: grey hair)

51
Q

Alopecia and baldness

A

genetic sensitivity to androgen hormone dihydrotestosterone (DHT): less blood flow at hair follicle

52
Q

Male pattern baldness

A

mutation on X chromosome (women can be carriers!)

53
Q

Nails - anatomical

A

Part of the integumentary system
Nail body formed on the nail bed (rich in blood vessels making the nail appear pink)

Lunula: Crescent shape at the base of the nail

Nail folds anchor the nail to the body

Keratin-rich and densely packed dead keratinocytes

54
Q

nail function

A

protective as they are the furthest extremities that experience the maximum mechanical stress
Infections and trauma to nail
easily seen

Changes in shape could be a
symptom of something else
(e.g., iron deficiency)

55
Q

Exocrine glands

A

excrete substances via a duct

56
Q

Glands of the integumentary system

A

sudoriferous glands, sebaceous glands, ceruminous glands, mammary glands (all exocrine

57
Q

Subcategories of exocrine glands; Structure:

A

Simple- a single duct
Compound- multiple, branched ducts

58
Q

Subcategories of exocrine glands; Secretion method

A

Merocrine- most common. Excretion via exocytosis
Apocrine- cell membrane buds off into the duct
Holocrine- cell membrane ruptures to release the product

59
Q

Sweat glands

A

eccrine (open directly onto surface of skin) and apocrine (opens into hair follicles)

60
Q

Eccrine glands

A

cover most of the body. Opens to epidermal surface
Starts at birth
Merocrine excretion
Thermoregulatory function and ion excretion
500-750mL water lost per day

61
Q

Apocrine glands

A

mostly where hair follicles are abundant (scalp, beard, armpits, groin)

Active from puberty (linked to emotions: pheromone excretion)

Viscous and protein rich

62
Q

Oil-producing glands

A

release sebum into follicular duct

63
Q

sebum

A

Sebum coats, moisturises and protects skin
Several types of lipids.
57.5% triglycerides and fatty acids
26% wax esters
12% squalene

64
Q

Ceruminous glands

A

Modified apocrine glands: found in the external auditory canal
Together with sebaceous glands, produce cerumen (ear wax). Important protective
role but also trap and take particulates away for tympanic membrane (eardrum)
1000-2000 ceruminous glands in a normal ear

65
Q

Mammary glands

A

Type of apocrine gland
Production of milk after birth2 (in both men and women) on either side of the front of the chest wall
Semicircular when young but begin to lose shape
Each weighs 500-1000g

66
Q

Mechanoreceptors; sensory receptors

A

Respond to physical changes
Hair: light touch
Meissner’s corpuscle:
indentation and slipping
Pacinian corpuscle:
vibrations
Merkel’s disk: texture
Ruffini corpuscle: stretch

67
Q

Thermoreceptors : sensory receptors

A

Body has both cold receptors (sensing 25-30°C) and warm receptors (sensing 30-46°C)

When changes in temperature occur, the opposite receptor stops discharging

Some proteins involved are known (TRPV1, TRPM3, ANO1 etc.) but largely 	mechanisms are unknown
68
Q

Nociceptors

A

Signal pain related to pressure, temperature and chemicals

The receptors only signal when tissue damage occurs- inflammatory markers caused by 	tissue damage binding to the receptors are the trigger

TRP (transient receptor potential) ion channels: 
one of the ion channel families present on 
nociceptor neurons

A-delta fibres: relay pain information related 
to painful temperatures, uncomfortable 
pressures, and chemicals 
C fibres: relay pain information related to 
thermal and mechanosensitive pain

Pharmacy (15 decks)

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