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Flashcards in Structure and Function of Skin Deck (34):
1

Skin - Fxns
**

Barrier
Thermoregulation
Convey somatosensory information from environment to nervous system
Immunologic - antigen presentation
Endocrine
Excretion

2

Epidermis - Characteristics and components
**

Keratinized stratified squamous epithelium
from Ectoderm
Avascular
Composed of kerationocytes, melanocytes and Langerhen's cells

3

Dermis - Characteristics and components, origin
**

Dense irregular connective tissue
from Mesoderm
imparts mechanical support

4

Hypodermis - Characteristics and components, origin
**

Variable amounts of lobules of adipose tissue seperated by connective tissue
Insulates and provides energy

5

Thin skin v Thick skin

hair follicles NOT in thick skin
Thick - adapted for great amount of abrasion e.g. palmar

6

Stratum Basale - a.k.a, desc, fxn, components

SB - Germinativum
Stem cells on basal lamina
Give rise to to keratinocytes
includes Keratinocytes & Melanocytes

7

Keratinocytes - fxn

Form physical and chemical barrier of skin
through production of cytokeratin proteins which organize as intermediate filaments

8

Melanoctyes - location, fxn, origin

in SB
Synthesize melanin pigment from the amino acid tyrosine
Neural crest derivatives

9

Stratum Spinosum

cell layers w/ desmosome at ends forming attachment between adjacent cells.

10

Stratum Granulosum

thin layer, w/ intense basophilic (dark staining) as result of keratohyalin, a precursor to filaggrin - which bundles keratin filaments in SC.

11

Stratum Corneum

lucidum
most superficial layer
No Nucleus or cell organelles in cells. only keratin.

12

Water proofing in skin
**

At base of SC.
by complex arrangement of submembrane proteins and lipids secreted from lamellar bodies from stratum granulosum keratinoctyes

13

Life progression of Keratinocyte

1. Basal Cell
2. Spinous Cel
3. Granule Cell
4 Stratum corneum
5.

14

Stage 1- keratinocyte progression
**

Basal cell synthesize intermediate filaments( keratin), which bundles together as Tonofilaments. => Spinous layer

15

Stage 2 - keratinocyte progression
**

Spinous layer make keratohylain granules and lamellar bodies

16

Stage 3 - keratinocyte progression
**

Granule Cell layer makes Keratohyalin granules and lamellar bodies.
Secreted by exocytosis into extracellular space btwn SG and SC

17

Stage 4 - keratinocyte progression
**

Stratum Corneum cells are Keratinized

18

Stage 5 - keratinocyte progression
**

pH decrease controls desquamation of cells Protease molecules lead to digestion and detachment of most superficial layer of SC

19

Filagrin - fxn, origin

Bundles Keratin filaments in SC.
precursors are keratohylanin granules

20

Melanocyte - fxn, action, origin

formation of melanin pigment and secretion into keratinocytes
neural crest

21

Langerhans Cells - def, origin
**

Antigen presenting cell in epidermis
derived from Bone Marrow - part of mononuclear phagocytic system

22

Dermal Papillae
**

Fingler-like extension in dermis projecting into epidermis
accomadate mechanical stress/increased abrasion forming pattern on hands and feet

23

Dermis Layers

Papillary Layer
Reticular Layer

24

Dermis - cellular components

Fibroblasts
Lymphocytes, mast cells, macrophages and graanulocytes
Langerhan cells

25

Dermis - EC components + other components

Collage fibers (type 1)
Elastic Fibers

Blood vessels
Muscle - Arrector pili mm
Nerves and Sensory receptors

26

Meissner Corpuscles (MC) - def, location
**

touch receptor
low frequency stimuli
in dermal papillae

27

Pacinian Corpuscles - location, def
**

Dermis
Sensitive to vibration an deep pressure

28

Autonomic motor nerves in skin innervate ...

Blood vessels, arrector pili muscle, and glands

29

Eccrine Glands - def, nervous regulation, components
**

Simple coiled tubular glands
Autonomic Cholinergic innervation for temperature regulated sweat
Andergenic innervation for emotional related secretion
Contains Myoepithelial cells which cause rapid excretion from sweat gland when contracted

30

Apocrine Sweat Gland - def, locations, characteristics**

Simple coiled tubular and branched tubular gland w/ dust reaching skin through hair follicle
specific to axilla, inguinial and perianal areas
active at puberty, affected by pheromones
Majorhistocompatabilty complex (MHC) within define scent and composition of secretions

31

Sebaceous Gland - def, characteristics
**

Outgrowth from epithelium that gives rise to hair
Contains oily sebum
Cause acne when fat (skin irritant) in sebum broken down by bacteria

32

Temperature regulation

Eccrine sweat glands and blood vessels

if hot, more seat and vasodilation

33

Epidermal cancers
**

Basal Cell Carcinoma - does not metastasize
Squamous Cell Carcinoma - can metaztasize if basement membrane disrupted
Malignant Melanoma - SERIOUS

34

Skin Repair
**

Primary Union (least severe)
Secondary Union
--Dermal Repair
--Epidermal Repair
Skin graftin (for major damage)