Lecture 3- Integumentary System

epidermis

avascular, keratinized, stratified squamous, protection

dermis

flexible connective tissue, fibroblasts, mast, macrophage

hypodermis

(subcutaneous tissue), and note that it is not truly part of the skin. under dermis. adipose (fat)

stratum basale

Simple keratinocytes, regenerative, Melanocytes

& Merkels present

stratum
stratum spinosum

Desmosomes create web, Melanin granules, Langerhans cells

stratum granulosum

3-5 layers, keratinocyte appearance changes

granules accumulate

stratum lucidum

(in thick skin only) thin & clear, keratinocytes

stratum corneum

keratinized cells, ¾ of epidermis, waterproofs, protects (physical, biological, chemical)

melanocyte

make melanin. In the basale layer and hair

keratinocyte

make keratin. in stratum basale, granulosum, and lucidem

papillary layer

• Areolar CT,

• Dermal Papillae

  Loops

  Meissner’s Corpuscles

  nerve ending

skin

functions include protection, regulation of body temperature, sensation, metabolism, serving as a blood reservoir, and excretion

vitamin D

protection from UV radiation

Prevents skin damage, risk of skin cancer, protects eyes, percents dna damage, protects overall health

sudoriferous glands

Sweat Glands.

-Eccrine ~ palms/soles, forehead

•Apocrine ~ Axillary, Anogenital

sebaceous glands

everywhere. Sebum softens skin

hairs

warmth, protection, sensation.

Hard Keratin ~ Shaft + Root

Medulla / Cortex / Cuticle

Melanocytes

hair follicles

epithelial tissue, Dermis

tissue repair

inflammation, organization, regeneration

fibrosis

a condition characterized by the excessive production and accumulation of fibrous connective tissue, typically in response to injury, inflammation, or disease

Inflammation

injured Macrophage & Mast →chemicals

Organization

stages, multiple cells, new tissue forms

Regeneration

fibrosis, surface epithelia replaced, fibrous layer contracts