Integument

Front 1

What is the epidermis?

Back 1

--Stratified squamous epithelium

--Epithelial cells accumulate more keratin as they migrate from basal layer

--# of layers of keratin-filled cells near the surface dictates the two types of epithelium: thick and thin

Front 2

What is the function of the skin?

Back 2

1)protection
2)excretion
3)thermal regulation
4)synthesis of vitamin D
5)perception of the environment

Front 3

What are the layers of the epidermis from superficial to deep?

Back 3

Corneum
Leucidum
Granulosum
Spinosum
Basale

Front 4

Describe stratum Basale?

Back 4

--Stratum basale (Stratum germinativum) (DEEP)
--Most mitotically active layer
--Single cell of columnar to cuboidal cells
--Numerous mitotic figures
--Cells contain numerous intermediate filaments
--Desmosomes on lateral and upper surface
--Hemidesmosomes bind cells to basement membrane

Front 5

Describe stratum spinosum?

Back 5

--Cells are cubodial to polygonal

--Cell processes filled with intermediate filaments that terminate with desmosomes

--Some mitotic figures may be present

Front 6

Describe stratum granulosum?

Back 6

--3-5 layers of flattened polygonal cells

--Cytoplasm has basophilic keratohyaline granules
--Glycolipid(Acylglucoceramide) serves a penetration barrier to foreign materials and MAINTAINS HYDRATION OF THE BODY

Front 7

Describe stratum lucidum

Back 7

--Most apparent in thick skin

--Thin layers of flattened eosinophilic cells

--ONLY EXISTS HISTOLOGICALLY IS NOT A REAL LAYERS

--organelles or nuclei present

--contains eleidin a transformation product of keratin

Front 8

Describe stratum corneum

Back 8

--Most superficial layer of flattened NonNucleated cells filled with keratin

--Ketatin pillows

--Cells are continuously being sloughed off

--Keratinized means generally 4+ layers (thick skin)

Front 9

Describe basal cell carcinoma

Back 9

--A cancer that grows in an avascular tissue.

--Begins in basal skin cell layer

--This layer is already mitotically active so this is bad \

--Very aggressive and can pierce down into the dermis.

--Histologically it is characterized by clusters of darkly staining basal cells with palisade arrangement of nuclei at the periphery of the clusters

Front 10

Describe squamous cell carcinoma

Back 10

--More aggressive than basal cancer

--Involves cancerous changes of the middle layer.

--May be slow growing but very likely to spread including to internal organs

--Shows complete disruption of skin a

--Can show changes that leave epidermis and move into the dermis.

If squamous is in the dermis then it is prob squamous

Front 11

Describe melanocytes

Back 11

--pigmant producing cells of S. Basale derived from neural crest

--Cells rest on BM and send dendritic processes into the S. spinosum. Distribute melanin to other cells in the S. spinosum and hair via their processes

--Pull them selfs away from stratum basale and form pseudo lacunae.

--In coloreds you will sell the pigmentation granules

Front 12

Langerhan Cells

Back 12

--Star shaped cells found in pale halo. Mainly in Stratum spinosum can migrate out of epidermis to lymph nides

--Bone marrow derived MONOCYTES

--Function as antigen-presenting cells

Front 13

What are Merkel cells

Back 13

--Tactile epithelium cell- Primarily in thick skin of palms and soles

--Base of cell in contact with the peripheral neuron terminal

--Present in Small numbers in the stratum basale located near areas of well vasuclarized richly innervated connective tissue

--Very tiny cell receptors

--THE ONLY RECEPTOR IN THE EPITHELIUM.

Front 14

Describe the papillary layer

Back 14

o Most superificial layer (Papillary layer) of th dermis is usually loose connective tissue
 Papillary layer keeps the epidermis on the dermis
 Papilla project into epidermis forming “ridges”
 Contains blood vessels and nerves (meissers)
 This is the important layer for diffusion of blood into the epidermis
o Fibroblasts, mast cells, & macrophages may be present

Front 15

Describe the reticular layer

Back 15

o Deeper layer (reticular layer) isdensse irregular connective tissue
 Dense irregular connective tissue
 Bundles of collagen and elastin fibers
 Extensive blood and nerve supply

Front 16

Describe the hypodermis

Back 16

• Elastic fibers become coarsers, densers, and less resilient
• Collage fibers decrease in number, organization, and density
• Changes in connective tissue composition( wear your spf and use products with vitamin C)
• Subcutaneous
o Loose (areolar) and adipopse connective tissue
o Contains largest artes, veins, nerves, and glands.

Front 17

Describe the nails

Back 17

• Elastic fibers become coarsers, densers, and less resilient
• Collage fibers decrease in number, organization, and density
• Changes in connective tissue composition( wear your spf and use products with vitamin C)
• Subcutaneous
o Loose (areolar) and adipopse connective tissue
o Contains largest artes, veins, nerves, and glands.

Front 18

What is the a first degree burn

Back 18

• Superifical burn that damages epidermis
o The appearance is red and blanches white when pressed n.
o There are no blisters( since epi is avascular) =1st degree burn.
o Burns only the epidermis

Front 19

What is a second degree burn

Back 19

dermis plus epidermis. Cause blisters due to vascular structures.
o Color is usally red and moist

Front 20

Describe a third degree burn

Back 20

• Third degree is epi, dermis, and impacts subcut tissue and underlying muscle it is usually dark brown or a leather appearance. Skin grafting is common for a 3rd degree burn

Front 21

tell me about hair

Back 21

• Hair
o Hair follicle is an invagination of epidermis
o The cell layers that project into the dermis are continuous with the epidermis.
o Stratum basale allows for growth.
o Know hair papilla. Part of the skin. Has melanocytes
o Hair is a derivatitive of EPITHERLIUM
• Erector pili are smooth muscles bundles extending from dermis papillary layer to hair follicle connective tissue sheath.
• Holocrine

Front 22

Holocrine glands

Back 22

• Holocrine: breakdown an ddischarge of the entire secretory cell. Only sebaceous glands. Mother fucking suicide bomber.
o Gland that secretes oil onto our hair shafts.
o Multicellular
o Gland would be sebaceous and mechanism would be holocrine
o Number 100 glands/cm2
o 400-600 glands on face and forehead
o NOT FOUND ON PALMS AND SOLES.
o Holocrine gland. Cells containg fat droplets & nuclei become pyknotic cells burst and release contents

Front 23

How about merocrine glands

Back 23

Glands can contain myoepithelial cells (contractile epithelial cells) that appear as along the basale aspect of the secretory segment
Cytoplasm contains actin myofilaments that are eosinophilic

Contraction of these cells expels sweat
)

Front 24

What about apocrine glands

Back 24

• Apocrine glands in skin associated with hair ONLY in certain places
o Located in axilla, anal, and areolar regions of nipple
o Associated with hair
o Viscous secretions
 Oily and thick and stinky HORMONALLY influenced
 Large slumens compared to eccrine sweat glands\

Front 25

Epocrine glands

Back 25

Eccrine sweat glands - simple coiled tubular gland
Secretory portion of gland deep in dermis or hypodermis.
Non-viscous secretion - little protein, contains water, NaCl, urea, ammonia, and uric acid

Front 26

Sebaceous glands

Back 26

About 100 glands/cm2 of skin. 400-600 glands/cm2 on face forehead and scalp.
Not found on palms & soles.
Secrete onto hair follicles*
Holocrine gland. cells containing fat droplets & nuclei become pyknotic. Cells burst and release contents.
Dead cells + cell contents = sebum

Front 27

Nail plate?

Back 27

The nail plate is derived from the stratum corneum (which is also responsible for forming the cuticle)

Front 28

The nail bed.

Back 28

The nail rests on a bed of epidermis called the nail bed which contains stratum basale and stratum spinosum - these layers are also important the mitotic activity of the nail matrix

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