Brainscape's Knowledge GenomeTM

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


See full index

Skin MS: Week 1 > Histology: Skin > Flashcards

Histology: Skin Flashcards

1
Q

Which epidermal layers are mitotically active?

A

Stratum germanativum, stratum spinosum

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

Layers of epidermis

A

stratum germinativum, stratum spinosum, stratum granulosum, (stratum lucida), stratum corneum

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

Stratum Germinativum

A
  • Basal layer
  • Mitotically active
  • Hemidesmosomes & desmosomes
  • Polyribosomes
  • Intermediate filaments (keratin type) in cytoplasm

Tall cuboidal/columnar

Single layer

Keratinocytes NOT differentiated

Melanocytes HERE to give melanin

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

Skin Functions

A
  • Protection
  • Reception of stimuli
  • Excretion
  • Secretion
  • Thermoregulation
  • Wound healing
  • Fat metabolism
  • Vitamin D production
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Stratum Spinosum

A
  • Mitotically active
  • Desmosomes –> ‘Prickle’ cell layer (spiny cells)
  • Polyribosomes
  • Intermediate filaments (keratin type) & tonofibrils
  • Membrane coating granules (keratinosomes)

Variable Thickness

Between SG - Sgran

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

Stratum Granulosum

A
  • No mitotic activity
  • Keratohyalin granules –> keratin
  • Nuclei become pyknotic (condense)

3-5 layers thick, flattened polygonal

Differentiated

Discharge lamellar bodies to surface

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

Stratum lucidum

A
  • Thick skin only
  • May be artifact
  • Appears ‘glassy’; eleidin???
  • Nuclei gone
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Stratum corneum

A
  • Outermost layer
  • Cells are dead and flat
  • Cells are completely ‘keratinized’

Thickness varies

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

–Fibrous and proteinaceous material produced by epidermal cells

A

Keratin

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

2 Major components of keratin

A
  • Intermediate filaments/tonofibrils
  • Interfilamentous matrix
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Phases of keratinization

A
  • Synthetic phase: Intermediate filaments, Membrane coating granules, Keratohyalin granules (Filaggrin and trichohyalin) made
  • Degradative phase: Membrane coating granule discharge, Lysosomal degradation of organelles, Consolidation of filaments and keratohyalin into a fibrous amorphous mass
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Hard vs. Soft Keratin

A

•Hard keratins

–No granular cell layer phase

–Hair & nails

•Soft keratins

–Granular cell layer phase

–Epidermis and internal root sheath of hair

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

Functions of keratin

A

–Water-proofing

–Protection of underlying cells

–Defense against bacterial invasion

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

Psoriasis

A

–Results from an increase in the number of proliferating cells in the stratum basale and stratum spinosum

–Also, there is an increase in the rate of cell turnover

–Result: greater epidermal thickness and continuous turnover of the epidermis

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

Pemphigus Vulgaris

A

–An autoimmune blistering disorder caused by disruption of desmosomes linking keratinocytes

–Antibodies made against desmogleins

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

Bullous Pemphigoid

A

–Autoimmune blistering disorder of the dermis-epidermis junction

–IgG is directed against an antigen (BPA) in the dense plaque of the hemidesmosome

–Blister occurs in the lamina lucida region of the basement membrane

17
Q

Layers of Dermis

A

•Papillary layer

–Vascular papillae

–Nervous papillae

•Reticular layer

18
Q

Papillary layer of dermis

A

superificial, immediately beneath basement membrane of epidermis

Loose CT - collagen, some ret/elastic

Vascular papillae - capillary loop projections, nourish epidermis, thermoregulatory

Nervous papillae - special nerve terminations (meissners corpuscules, Krause end bulbs)

19
Q

Reticular layer of dermis

A

Deep layer, dense irregular CT (mostly type 1, some reticular fibers, many elastic fibers), less cellular

20
Q

Langer lines

A

direction of fibers in reticular layer create lines of skin tension (surgical insicisions paraless to these gape less and heal better)

21
Q

Hypodermis

A

Not part of skin

Loose CT

Fat

22
Q

Epidermal Cellular Elements

  • Keratinocytes
  • Melanocytes
  • Langerhan’s cells (APCs)
  • Merkel cells
A
  • Keratinocytes - skin cells, create keratin
  • Melanocytes - produce melanin to SG and SS
  • Langerhan’s cells (APCs) - macrophages, Fc and C3 receptors, APCs
  • Merkel cells - unmyelinated sensory nerves (light touch)
23
Q

Pigmentation of skin

A

Melanin - melanocytes in SB - pre-melanosome from ER w/ tyrosinase, put melanin in pre=melanosome - matures - secrete for pigmentation

24
Q

Vascular Supply to skin

A
  • Supplying vessels are subcutaneous
  • Rete cutaneum

–Network that sends branches in two directions

  • Subcutaneous side
  • Dermal side –> Rete subpapillare = Between papillary and reticular layers of dermis
25
Q

General hair structure

A

Shaft

Follicle in dermis/epidermis

Associated w/ sebaceous glands, arector pili, apocrine sweat glands

26
Q

Arrector Pili Muscles

A

Smooth muscle associated w/ hair follice

one end anchored to CT sheath of follicle - one end in papillary layer of dermis

Pulled perpendicular - goose bumps, allow sebaceous glands to secrete onto skin

Sympathetic innervation

27
Q

Nails

A

Nail plate (hard keratin)

Nail bed - no stratum granulosum

Nail matrix - closest portion of nail bed where cells proliferate

28
Q

Sebaceous Glands

A

Usually w/ hair follicles

Simple, branched alveolar gland - empty duct into hair follicle

Holocrine secretion of oily sebum

29
Q

Eccrine sweat glands

A

Merocrine (exocytosis)

Simple coiled tubular glands

Secretory portion - in deep dermis or hypodermis, coiled, dark cells-protein rich, clear cells - watery, myoepithelial cells squeeze secretion out - simple columnar

Excretory duct - rises to epidermal surface, small lumen, stratified cuboidal

30
Q

Apocrine sweat gland

A

Certain areas of body

Secretory - large lumin, not as coiled, simple cuboidal/columnar, myoepithelial cells

Excretory - duct into hair follicles, stratfied cuboidal

Odorless but bacteria –> scent

31
Q

Free nerve endings in epidermis

A

May wrap around tactile cell of Merkel (touch) or just terminate (pain)

32
Q

Encapsulated Nerve Endings

A

Glomerular (like Corpuscles of Ruffini, Krause’s End Bulb’s) = mechanoreceptors

Tactile - fibrous capsule –Meissners and Pacinian

33
Q

Meissner’s Corpuscle

A

touch

hairless skin

34
Q

Pacinian corpuscle

A

Thick fibrous capusle, looks like onion, deep pressure and vibration, hypodermis

35
Q

Wound Healing

A

Fibrin clot at bottom of cut, epidermis extends down sides of incision until both meet, fibroblasts and capillaries repair CT

36
Q

Skin grafting options

A

Split-Skin grafts - piece of skin cut halfway down dermis, donor site re-epithelializes d/t hair follicles and sweat glands

Full thickness graft - remove all dermis/epidermis - donor site cannot re-epithelialize self

Skin MS: Week 1 (9 decks)

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