Anatomy Lecture 5

• Protection
• Prevents water loss
• Regulates temperature
• Metabolic regulation (vitamin d)
• Immune defense
• Sensory reception
• Excretion

The epithelium of the skin.

5th layer

Single layer of cells that are either cuboidal or columnar.

Attached to the basement membrane. 

Contains large numbers of keratinocyte stem cells, melanocyte cells, and tactile cells.

"Spiny layer"--4th layer

Contains keratinocytes that are rising up the epidermis.

3rd layer

Keratinization begins (keratinocytes fill with keratin)

Keratinocytes begin to die here

2nd layer (only found in thick skin)

Only two or three cells thick.

Keratinocytes here are flattened and filled with eleidin.

1st layer (superficial)

20-30 dead cells thick of heavily keratinized cells.  These cells interconnect and lack a nucleus.

Cells containing keratin.  Found in the epidermis.

They provide the skin's strength and waterproof it.

A tough and insoluble protein that twists and intertwines with each other.  Found in skin.

Process where keratinocytes fill with keratin.

Process pigments called melanosomes.

Melaonsomes then wrap around keratinocyte nucleii to protect the DNA from damage

Immune cells that attack pathogens and cancer cells in the epidermis.

Stretch marks.

Its when collagen fibers break in the dermis, resulting in missing sections of the dermis.

Deep to epidermis.  Composed of cells of connective tissue and has primarily collagen fibers.

Deepest part of dermis.  It is not considered to be part of the skin.  Contains areolar and adipose connective tissue. 

Drugs are injected in this layer because of the vast vascular networks.

1st degree only effects the epidermis

2nd degree effects the epidermis and part of the dermis

3rd degree effect the epidermis, dermis and subcutaneous layer.

Nail body: pinkish and a distal white edge.

Nail root: Proximal and embedded under the skin.

Hyponychium: A region of thickened stratum under the nail where it projects.

• Shaft: portion outside epidermis
• Root: hair within the follicle internal to skin surface.
• Arrector pili: muscle that contracts to raise hair
• Follicle: oblique tube that surrounds the hair.
• Hair bulb: epithelial cells that swell at the base where hair originates.

Discharge oily, waxy secretion balled sebum (usually into a hair follicle).

Acts as a lubricant and has antibacterial properties.

Aka Sweat gland

have coiled , tubular secretory portions.  A sweat duct gland carryies the sweat to the surface of epidermis.