BIOL LAB INTEGUMENTARY SYSTEM

Epidermis

The thin superficial layer of the skin.

Dermis

The thick deeper layer of the skin.

Layers of the Epidermis

Stratum Corneum, Stratum Lucidum, Stratum Granulosum, Stratum Spinosum, Stratum Germinativum/Basale.

Function of Stratum Germinativum

Contains stem cells that replenish cells as superficial layers slough off.

Melanocytes

Special cells in the stratum germinativum that dictate skin color.

Melanin

The pigment produced by melanocytes.

Function of Melanin

Absorbs UV radiation.

Melanocyte Activity in Pale Skin

Low melanocyte activity.

Melanocyte Activity in Dark Skin

High melanocyte activity.

Factors Determining Skin Color with Low Melanocyte Activity

Carotene (orange pigment) and dermal blood supply (rosy appearance).

Epidermis-Dermis Connection

Secured through epidermal ridges and dermal papillae that act as a lock.

Prominence of Epidermal Ridges

More prominent in areas with high frictional stress, such as the soles of the feet.

Effect of Excess Friction

Causes separation of epidermal ridges and dermal papillae, leading to blister formation.

Components of the Dermis

Blood vessels, nerves, sensory receptors, extracellular fibers, hair follicles, and glands.

Blood Vessel Division

Divided by location (superficial to deep).

Composition of Hair and Nails

Both are composed of keratin.

Basic Function of Hair and Nails

Protect the integument.

Areas Without Hair

Soles of the feet, palms of the hands, lips, and portions of the external genitalia.

Terminal Hair

Typically long and thick, found on the head, eyebrows, eyelashes, and pubic regions.

Vellus Hair

Typically short and thin, comprising most (75%) of the hair on the body.

Function of Arrector Pili Muscle

Lifts the hair shaft upon nervous stimulation, increasing skin sensitivity.

Function of Papilla

Vascular structure that provides nutrients.

Function of Matrix

Location of new hair growth.

Shaft Layers of Hair

Cuticle, cortex, medulla.

Specific Function of Nails

To strengthen the distal portion of the digits.

Function of Nail Matrix

Mitotically active zone of nail growth.

Lunula

Half-moon shaped region at the proximal end of the nail bed, containing newly formed and undifferentiated white cells.

Eponychium

Epidermal cells dragged forward along the body as the nail grows; also known as the cuticle.

Hyponychium

Epidermal cells dragged beneath the body as the nail grows.

Location of Secretory Glands

Found in the dermis of the skin.

Types of Secretory Glands

Sudoriferous, sebaceous, ceruminous, mammary glands.

Function of Sudoriferous Glands

Excrete sweat to regulate body temperature and eliminate waste products.

Eccrine Glands

Found abundantly across the body, excreting mostly water.

Apocrine Glands

Secrete concentrated sweat, found in armpits, groin, and surrounding nipples.

Sebaceous Glands

Secrete an oily substance called sebum, typically associated with hair follicles.

Ceruminous Glands

Produce a waxy secretion called cerumen, found exclusively in the ear.

Mammary Glands

Produce milk, active in pregnant and nursing women.

General Function of Secretions

To cool, lubricate, and protect the skin.

Hypodermis

A connective tissue that lays adjacent to the dermis.

Effect of Hypodermal Adipose Distribution

Shapes give each person a unique superficial appearance.

Thickness of Hypodermis

Typically quite thick depending on bodily location.

Causes of Severe Burns

Fire, electricity, radiation, and certain chemicals.

Categories of Burns

1st, 2nd, and 3rd degree.

1st Degree Burn

Burns only the epidermis, e.g., sunburn.

2nd Degree Burn

Burns both epidermis and dermis, most painful due to pain receptors.

3rd Degree Burn

Burns epidermis, dermis, and hypodermis, painless due to destruction of pain receptors.

Estimating Burn Percentage

Each major body region is assessed for burn extent.

stratum lucidum

which stratum is only found in thick skin?

soles

where would you find skin without hair?

false

the skin on the sole of your foot is very different than the skin on the palm of your hand

fingernail

the lunula is associated with the…

cyanosis

when your skin turns blue due to lack of oxygen, this is called?

true

skin prints are found on your toes

false

the hypodermis is part of the skin

dermatologist

a medical doctor that studies skin is called a..

scrotum

where might you find thin skin?

cutaneous membrane

the integument is also known as the

improve grip

what is the function of finger prints?

pituitary gland

which gland is not associated with the integument?

melanocyte

which cell is primarily responsible for skin color?

false

the hypodermis is part of the integumentary system.

600,000

approximately how many hairs are located on the head?