Anat integumentary system

Epidermis

Epidermis

Made of stratified squamous epithelium

Avascular

4-5 sub- layers

Stratum basale

Stratum spinosum

Stratum granulosum

Stratum lucidum

Stratum corneum

Stratum basale

Single row of cells

2 cell types:

Keratinocytes (90%)- make keratin, migrate to surface as new cells

Melanocyte(10%) - produce pigment for UV light protection, skin colour

Stratum spinosum

Limited cell division

Stratum granulosum

Dark staining granules

Stratum lucidum

Flat, dead cells

Visible ONLY in thick skin

Stratum corneum

20-30 layers dead cell filled with keratin

Surrounded by waterproofing glycolipids

She’d and replaced from below

Dermis

Contains blood vessels, nerves, glands, hair follicles

2 layers

Papillary

Reticular

Papillary layer

Areolar CT

W

Vascular

Has protections into epidermis = dermal papillary= fingerprints

Reticular layer

Most of dermis

Dense irregular CT

Hypodermis

Subcutaneous/ superficial layer

Fascia= CT layer that surround and support organs

AdiposeCT

• stores ½ bodies adipose tissue( insulation)

Thick vs thin

Thin= lucidum not visible, had hair follicles, seb. gland, arrector pili muscle

Thick= found on palm and sole, lucidum visible, no hair follicle, seb. glands, arrector pili muscle

Hair

All dead cells

Root= dead cell below surface of skin

Shaft= above skin surface

Hair follicle= surrounds root

Hair follicle

Epithelial root sheath= several epidermal layers into the dermis

Bulb= expanded region at base of root

Matrix= single layer of cell, hair growth and melanin for hair colour

Associated with each hair follicle

Outer CT sheath= hold follicle in place

Hair papilla= extend upward beneath matrix( blood supply for hair growth, from dermis)

Root hair plexus = free nerve ending ( touch)

Sebaceous gland= opens into follicle

Arrector pili muscle= smooth muscle, goosebumps

Nails

Heavily keratinized epidermal cells

Nail root

Body

Free endge

Exocrine glands

Sebaceous gland

Sudoriferous gland

Ceruminous gland

Mammary gland

Sebaceous gland

Connect to hair follicle

Secret sebum

Lubricates hair and skin , antibiotic

Suderiferous gland

Sweat gland

Duct open onto skin surface

Cool body down,antibiotic,remove waste

Ceruminous gland

Modified sweat gland

In ear canal

Produce earwax

Mammary gland

Modified sweat gland

Produce milk

Sense receptors

Touch receptor- free nerve ending, root hair plexuses, meissner’s corpuscles

Pressure receptors- free nerve endings, pacinian corpuscles

thermoreceptors- free nerve ending for temperature

Nociceptors- free nerve ending for pain

3rd degree burn= destroyed niciceptors