integumentary system (skin)

What is the largest organ in the body?

skin

Homeostasis

Critical for maintaining body temperature and fluid balance

protection of the integumentary system acts as _____

a barrier against physical damage and pathogens

skin is the site of ______

vitamin D synthesis

integumentary system enables ____

the sense of touch

epidermis

top layer of skin, 1st layer

dermis

middle layer of skin, 2nd layer

hypodermis

loose connective tissue layer of skin below the dermis, 3rd layer of

sweat glands

eccrine and apocrine

Aprocrine glands

specialized sweat glands, mainly located in the armpits, groin, and around the nipples

eccrine glands

glands that produce sweat; found over most of the body

Seabaceous gland

oil glands

What does the integumentary system consist of?

skin, hair, nails, sweat glands, & sebaceous glands

what is the primary organ of the integumentary system?

skin

Keratinocytes

produce keratin

Cornified Cells

dead cells

Stratum Corneum

dead cornified cells, continuously shed

Stratum Lucidum

only in thick skin

Stratum Granulosum

Keratinocytes flatten, develop granules, eventually lose organelles

Stratum Spinosum

Many layers of keratinocytes, contains cells that act like macrophages (spiny)

Stratum Basale

Deepest layer, single layer of basal cells, constant mitosis to produce keratinocytes.

Melanocytes

cells that produce melanin

Merkel Cells

touch receptors

Calluses

Formed by increased cell production in the stratum basale in response to frequent abrasion

Connective Tissue

Supports, binds, and protects other tissues.

Collagen

Fibrous protein that gives the skin form and strength

Elastin

elastic like fibers found in connective tissue

Fibroblasts

produce fibers and ground substance

Papillary Layer

loose connective tissue

Reticular Layer

Tightly packed connective tissue

Basal Cell Carcinoma

most common type of skin cancer, arises from basal cells

Melanoma

Arises from melanocytes

Merkel Cell Carcinoma

Aggressive, rare, arises from Merkel cells.

First-degree burn

only epidermis is damaged

second-degree burn

Epidermis and part of dermis damaged

third-degree burn

Epidermis and all of dermis damaged

fourth-degree burn

Extends beyond skin to bone and muscle damaged