Unit 2 - Chp. 5 Integumentary System

What two layers is the skin divided into

Epidermis & Dermis

Subcutaneous Layer

Hypodermis, adipose layer deep in the dermis (attaches skin to muscle and bones) 

What are the four main cells of the epidermis & their function

Keratinocytes - makes keratin

Melanocytes - makes melanin

Langerhans/Dendritic Cells - phagocytizes cells and debris

Merkel/Tactile Cells - senses LIGHT touch

Name in order the layers of the epidermis & their functions from superficial → deep

Stratum Corneum - superficial layer of dead cells that flake away (protection)

Stratum Lucidum - layer of dead cells **ONLY found in thick skin

Stratum Granulosum - Waterproof, keratin is created here (aka keratinocytes r here)

Stratum Spinosum - cells in this layer r more resistant to tension & pulling forces

Stratum Basale - has stem cells that will replace the cells in the other layers

Where is thick skin located?

Soles of feet & palms of hands (wear & tear areas) 

What are the two layers of the dermis? 

Papillary & Reticular

Function of the Reticular layer of the dermis

Deep layer of the dermis

Contains Pacinian corpusles, detects deep pressure

deepest layer that contains acessory structures (hair/nails)

Function of the papillary layer

superficial layer of the dermis

contains dermal papillae (finger-shaped blood vessels that supply the epidermis from the dermis)

contains meissner corpsucles, detects light touch

Name the three pigments that give skin it’s color

Melanin - brown/red, UV protection

Hemoglobin - pink/red, carries oxygen in blood

Carotene - yellow/red, Vitamin A & eye development/vision

What are the four main abnormal skin diagnoses & why they occur

Jaundice - yellow, liver dysfunction

Vitiligo - absence of pigment in patches, multicolored, unknown cause

Albinism - pale/white, absence of pigment (congenital disorder)

Erythema - red, vasodilation of blood vessels (usually due to increased temperature)

3 types of hair

Lanugo - on fetus, no pigment

Vellus - short, fine, no pigment hair on women and babies faces

Terminal - Coarse hair on axillary areas/head/beard

Stages of hair growth

Anagen - 2-7 YEARS, growth rapid 

Catagen - 2-3 WEEKS growth slows

Telogen - 2-4 MONTHS, hair rests

2 main types of glands

sebaceous - produces sebum

sweat gland - regulates body temperature

What are the four types of sweat glands

eccrine - most numerous gland, thermoregulation 

apocrine - body odor (b/c of protein-rich sweat), activates in puberty, axillary & pubic region 

Mammary - produces milk 

ceruminous - produces cerumen in the ear that helps make earwax 

Identify the nail parts

What are the three types of skin cancer?

• Basal cell carcinoma - begins in the stratum basale

• Squamous cell carinoma - begins in the stratum spinosum

• Maglinant melanoma - deadliest form, starts as melanocytes (moles)

5 signs of skin cancer (ABCDE)

• asymmetry

• border irregularity

• color mixing

• Diameter >6mm

• Evolving

What are the 4 signs of inflammation

• erythema - redness

• tumor - swelling

• dolor - pain

• calor - heat

Rule of nines (burns)

9% - head, upper limbs (individually)

36% - Trunk

18% - lower limb each

1% - genitalia 

Difference in 1st 2nd & 3rd degree burns

• 1st - epidermis affected

• 2nd - epidermis & dermis (partial)

• 3rd - not initially painful, epidermis, dermis, & underlying structure (affected muscle/bone)

Functions of the skin

• Sensation

• Vitamin D

• Protection

• Excretion of waste (sweat) & absorption (sunlight)