Brainscape's Knowledge GenomeTM

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


See full index

week 9 > Skin Histology > Flashcards

Skin Histology Flashcards

1
Q

what are the 5 layers of the epidermis

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

where in the epidermis will langerhan cells and desmosomes reside

A

stratum spinosum

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

where in the epidermis does mitosis occur and melanocytes and merkel cells reside

A

stratum basale

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

where do kerato-hyaline granules reside

A

stratum granulosm

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

what layer of the epidermis is full of 2-3 layers of anucleated dead skin cells and is seen only in thick skin ( glaborous skin)

A

stratum lucidum

the thick skin that lacks this also lacks hair follicles and sebaceous glands

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

what layer of the epidermis keritin filled keratinocytes and protects against friction and water loss

A

stratum corneum

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

what are epidermal appendages

A

hair, glands, nails, teeth

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

what is the embryonic lineage of the

epidermis

melanocytes and merkle cells

hypodermis

A

majority of epidermis and appendages- ectoderm

merkle and melanocytes-neural crest

dermis and hypodermis- mesoderm

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

ID this skin type and the layers

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

what are the two layers of dermis

A

papillary and reticular

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q
  1. what layer of the dermis contains the areolar connective tissue
  2. what layer of the dermis contains dense irregular connective tissue
  3. what layer of the dermis contains hair follicles, sebaceous and sweat glands and nerves
  4. what layer of the dermis contains type 1 and what layer contains type 3 collagen and elastin
A
  1. papillary (also in subcutaneous layer)
  2. reticular
  3. reticular
  4. reticular- type 1 and elastin, abundant proteoglycans rich in dermatan sulfate

papillary- type 1, 3 and 7 (reticular fibers, contratry to the naming)

*papillary- From this layer, anchoring fibrils of type VII collagen insert into the basal lamina, helping to bind the dermis to the epidermis.

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

what layers of the dermis are these

A

Top is the reticular

Bottom (toward surface) is the papillary

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

ID

A

type 1 collagen bundles in reticular layer of dermis

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

ID

A

fine type 3 collagen in the papillary layer of dermis

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

ID

A

circle- artery

square- vein

pointer- capsule

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

where do the large arteries supplying blood to the skin reside and what do they give rise to

A

deep to the hypodermis –> give rise to deep plexus –> superficial plexus –> papillary loops

epithelium of the epidermis is avascular and receives all its nutrients from capillaries perfusing the papillary dermis

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

what are glomus bodies and what role do they play in thermoregulation

A

encapsulated AV shunts in glaborous skin, the AV shunts in fingers and toes divert blood away from epidermis when exposed to cold putting at risk for frost bite

oGlabrous skin covers the palms, soles, lips, glans penis, clitoris, and labia minora

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

what structures reside at the dermis- hypodermis junction

A

merocine sweat glands-

contain a secretory portion and an excretory duct segment

The secretory portion is formed by a simple cuboidal to columnar epithelium composed of cells with voluminous eosinophilic cytoplasm.

The secretory cells are surrounded by a discontinuous layer of myoepithelial cells (SMC)

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

ID

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

ID

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

distinguish between Meissner and pacinian corpuscles

A

detect- light tough

structure- myelinated, schwann cells

location- papillary dermis

detect- high freq fibration and pressure

structure- unmeyelinated but surrounded by mod. fibroblasts

location- hypodermis

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

ID the secretory portion and the excretory duct

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

differentiate between thin and thick skin

A

1- Thin skin has a thinner epidermis, which is most notable in the thickness of the stratum corneum.

2- Thin skin has hair folliclesand their associated sebaceous glands.

3- Thin skin has fewer dermal papillae reflecting the fact that thin skin is generally found in areas exposed to less abrasion

4- thin skin lacks a stratum luc

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

what is the function of papillae

A

Papillae serve to increase the surface area of the dermal-epidermal junction, which allows for more attachment sites between the dermis and epidermis and also increases the efficiency of diffusion of nutrients from the dermis to the epidermis

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

ID

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

ID

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

ID

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

ID

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

ID

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q
A
31
Q

where are hemidesmosomes

A

Stratum basale/germinosum

32
Q
A
33
Q

In what layer of the epithelium do the stem cells and hemidesmosomes reside

A

Stratum Basale

34
Q

what is responsible for forming the spines in the stratum spinosum layer

A

The “spines” are artifactual, during processing the cells shrink, and the cell membrane is retracted except where they are connected with desmosomes

specifically –> desmoglein(Dsg) and desmocollin(Dsc) are cadherins in that junction

35
Q

in what layer of the epithelium do the TJs reside

A

stratum granulosum

These serve to prevent microbe invasio. The normal bacteria of skin live on granulosum layer but above the TJ

36
Q

Identify 2 mechanisms by which water loss is prevented in the stratum granulosum layer

A

keratin granules and lamellar bodies

  1. Basophilic keratohyaline granules made of keratin filaments and filaggrin
  2. Lamellar bodies (lamellar granules, membrane-coating granules) containing lipids that are extruded to form a water-proof “cement” between cells (seen with EM only)
37
Q

what protein helps keratin filaments aggregate and cause atopic dermatitis when mutated

A

filaggrin

38
Q

which cells make up the majority of the cells in the dermis, express insulin-like growth factor receptor and are implicated in acanthosisnigricans

A

keratinocytes, also called prickle cells

39
Q

what determines skin pigmentation

A

The number of melanosomes and activity of the enzymes in the pathway, not the number of cells (melanocytes)

40
Q

describe the interaction of melanocytes and keratinocytes

A

melanocytes have long cellular extensions that run between the keratinocytes. The melanosomes that the melanocytes produce are transported to the tip of the processes in distal regions. Keratinocytes then phagocytose and put it at top to protect nuclei and dna

41
Q

what are merkle cells

A

mechanoreceptors sensitive to touch, attached to free nerve endings

42
Q

what is the key enzyme in albinism

A

albinism is due to a mutation in the tyrosinase gene

tyrosine catalyzes the rxn of

tyrosine –> dihydroxyphenylalanine(DOPA)

43
Q

what should you expect if a patient has patches of unpigmented skin

A

neural crest migration errors

44
Q

differentiate basale carcinoma and squamous cell carcinoma

A

basale carcinoma originates in the basale layer while squamous cell originates in the spinous layer

45
Q

ID EP and DP

A

epidermal ridge and dermal papillae

46
Q

what are these cells

A

melanocytes

47
Q

ID each layer

A

DP- vascularized dermal papilla

CTS- connective tissue sheath

IRS- internal root sheath

ERS- external root sheath

CO- cortex

G- glassy membrane that is continous with the membrane of the epidermis

The epithelial cells (keratinocytes) around the papilla proliferate and differentiate as the root of the hair itself

48
Q

where do stem cells

melanocytes

hair matrix

and the deep plexus reside in hair

A

stem cells- bulge region

melanocytes- hair matrix

hair matrix- in the bulb of the follicle and gives rise to 3 layers of hair

deep plexus- base (insufficient vascular supply leads to hair loss and may be an indication of chronic vascular disease)

49
Q

what are the three layers of hair

A
  1. Central core (medulla)
  2. Keratinized cortex
  3. Outer highly keratinized thin layer called the cuticle
50
Q

what kind of glands are sebaceous glands

A

Simple, branched, acinar glands

51
Q

what is the function of sebocytes

A

Sebocytes release an oily substance called sebum that coats the hair and epidermal surface and functions though holocrine secrection

52
Q

compare and contrast the two types of sweat glands

1- where are they located

2- what innervates then

3- changes with age

4- type of gland

5- where do they open to

A

Both merocrine secrection

eccrine-

  1. secrete sweat onto the surface of the epithelium via pores
  2. innervated by cholinergic nerve endings
  3. Can hypertrophy with training and atrophy with age
  4. Simple coiled tubular gland
  5. epithelium surface

apocrine-

  1. limited to the axilla, breast, pubic, and perineal regions
  2. Innervated by adrenergic nerve terminals and secrete cloudy fluid containing water, proteins, lipids, and odor precursors into the upper region of hair follicles
  3. develop wide lumens in puberty
  4. branched acinar
  5. hair follicle
53
Q

why are the elderly more susceptible to heat stroke

A

the eccrine glands atrophy with age

54
Q

How is odor produced

A

secretions of the apocrine glands are odorless but they produce odor when they are metabolized

axillary osmidrosis

Variant in ATP-binding cassette transporter sub-family C member 11 (ABCC11) develop excessive underarm odor, which can be treated by excising the glands

55
Q

ID

A

sebacous gland

D- duct

S- sebocyte

H- hair shaft

56
Q

ID

A

sebaceous gland

C- capsule

S- sebaceous gland

57
Q

ID

A

eccrine sweat gland

S- secretory componet

D- duct

58
Q

ID

A

eccrine sweat gland

M- myoepithelial cells

C- clear cells

D- dark cells

BL- basal lamina

L- lumen

IC- intracellular canaliculi (Na+ ions are recovered from this fluid through the action of cells in the ducts)

59
Q

ID

A

apocrine sweat gland

s- secretory

d- duct

h- hair follicle

60
Q

describe the mechanism of eccfrine secretion

A

Step 1: secretion

  1. Stimulation of muscarinic ACh receptors –>Ca+ release from intracellular stores and increased cytosolic Ca+
  2. •Ca2+-sensitive Cl−/ K+channels open –> Cl−and K+exit; water follows
  3. •Cell shrinkage stimulates Na+/K+/2Cl-cotransporters (NKCC1), bringing Na+, K+, and 2Cl−into the cell
  4. •Na+is recycled to the interstitium via the Na+/K+-ATPase located in the basolateral membrane
  5. •Net movement of Cl− ion across the apical membrane into the lumen creates negative charge that ‘pulls’ Na+ion into the lumen along a paracellular pathway
  6. •The final glandular secretion is the net movement of Na+, Cl−, and H2O into the glandular lumen to form the isotonic NaCl precursor of sweat

Step 2: Ductal Reabsorption

  1. •Luminal Na+reenters duct cells through the apical membrane via epithelial Na+channels (ENaC) and is transported across the basolateral membrane by Na+/K+ATPase
    * •Cl−movement is both transcellular and paracellular; cystic fibrosis transmembrane regulator (CFTR) Cl− channels play an important role in transcellular reuptake*

•final sweat product that is hypotonic (and acidic)

61
Q

where do muscarinic ACh receptors in eccrine glands lie

A

on clear cells

62
Q

where are the two places vascularture can directly be assessed

A

eyes and nails

63
Q

ID the parts of the nail

A

E- cuticle, DNM- dorsal nail matrix, VNM- ventral nail matrix, PNF- proximal nail fold

  • The nail plate - stratum corneum
  • The nail root lies in an epidermal fold; the stratum corneum of the epidermal fold forms the eponychium(cuticle)
  • The nail bed - stratum spinosum and

stratum basale

  • The nail matrix lies - stratum basale
  • The hyponychiumsecures the nail at the distal end of the nail bed
64
Q

differentiate the deep and superficial plexus

A

superficial plexus supplies the epidermis, repsonsible for pink colored skin

deep- hair follicles, sweat and sebaceous glands as well as adipose in hypodermis

65
Q
A
66
Q

differentiate blanching versus non blanching erythema

A

In non blanching erythemais redness that does not disappear within 20 minutes of removing pressure; signals erythrostasis in the capillaries and venules and hemorrhage, indicates tissue damage (usually ischemic injury) to tissues under the intact skin; considered an early stage of pressure ulcers

67
Q

ID

A

meissner corpusle- evident by the dermal and epidermal ridges

68
Q

what fo ruffini corpuscles detect

what do krause end bulbs detect

what do free nerve endings detect

A

ruffini- tissue distortion

krause- low freq vib and movement

free- •Sense light touch or movement, pain and temperature at extremes.. sometimes associated with merkle cells

69
Q

describe the formation of a scab

describe the formation of granulation tissue

A

scab- epidermal cells undergo EMT loose their junctions and migrate beneath the clot

granulation tissue-

myofibral cells in ther dermis secrete VEGF and new angiogensis as well as EMC full of type 3 collagen forms

70
Q

Outline the process of wound healing of the skin

A

1. Hemostasis Phase

  • bleeding and coagulation

2. Inflammatory Phase

3. Proliferative Phase

  • scab and granulation tissue formation

4. Maturation Phase

  • type 3 collagen replaced with type 1 –> scar tissue

Epidermis reestablishes continuity but does not form new hair or glands. Most myofibroblasts apoptose

•The granulation tissue undergoes remodeling, a more normal vasculature is reestablished

71
Q

Which components of the epidermis provides seal- ant between adjacent cells

A

Glycolipids and lipids

72
Q

ells responsible for producing the pigment for dark hair are located where

A

The hair matrix (zone of dividing and differentiating cells) of the hair bulb

73
Q

what separates the hair follicle from the connective tissue of the dermis?

A

glossy membrane

week 9 (6 decks)

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