❣️Integumentary System

Vocabulary flashcards reviewing the anatomical components, epidermal strata, dermal divisions, hypodermic structures, and cutaneous glands from the lecture notes.

Integumentary System

The largest system of the body, composed superficially to deeply of the epidermis, dermis, and hypodermis.

what is the overall structure of the skin?

Superficial to deep.

Epidermis dermis hypodermis

What types of cell found in the epidermis ?

keratinocytes, melanocytes

difference between thin and thick skin? Where would you find each ?

thick skin- all 5 layers, found in palms, feet sole,

thin skin- 4 layers (not lucidum), almost the rest of the body

Epidermis

An avascular, keratinized stratified squamous epithelium where nutrients and oxygen diffuse from capillaries in the dermis.

Stratum corneum

• outermost epidermal layer

• consists of 15-30 layers of dead keratinized cells that are water resistant, form a chemical and bacterial barrier, and exfoliate roughly every 2 weeks as dander.

Stratum lucidum

• present only in thick skin (palms and soles) composed of dying keratinocytes devoid of organelles and filled with keratin and keratohyalin.

Stratum granulosum

• consists of 3 - 5 layers of non-dividing keratinocytes that actively produce keratin and keratohyalin.

Stratum spinosum

• consists of 8 - 10 layers of dividing keratinocytes containing dendritic (Langerhans) cells active in immune response and cells that phagocytize melanin.

Stratum basale

AKA stratum germinativum

• deepest single layer of epidermal cells resting on the basement membrane containing stem cells, melanocytes, Merkel cells, and keratinocytes.

• mitosis occurs

Dermis

A vascular tissue layer located between the epidermis and hypodermis that anchors epidermal accessory structures and comprises a papillary layer and a reticular layer.

Papillary layer

The outermost dermal layer

-consists of areolar connective tissue containing capillaries, lymphatics, sensory neurons, and dermal papillae that form epidermal ridges (fingerprints).

-increase friction to grasp objects

Dermal papillae

Projections of the dermal papillary layer into the epidermis that form fingerprints, increase friction for grasping, and strengthen connection to the upper epidermal layer.

Reticular layer

• deeper to the papillary layer

• composed of dense irregular connective tissue containing collagen and elastic fibers, larger blood vessels, lymphatic vessels, and nerve fibers.

may cause stretch marks if overstretched

Hypodermis

AKA subcutaneous layer or superficial fascia

• ; a layer of loose connective tissue (areolar and adipose) deep to the dermis

• functions as an energy reservoir and thermal insulator.

• given many injections

Pacinian corpuscles

Sensory structures located in the hypodermis alongside the cutaneous plexus of arteries and veins.

Hair Follicle

An epidermal structure extending into the dermis that forms a jacket around the hair root and produces nonliving hair via dividing stratum basale cells at the dermal papilla.

Hair Shaft

The portion of a hair structure that projects past the epidermal skin surface and is not attached to the follicle.

Hair Root

The portion of hair embedded within the skin and attached to the hair follicle.

Hair Bulb

The expanded base of a hair containing actively dividing basal cells in the hair matrix and the vascularized hair papilla.

Arrector pili muscle

Involuntary smooth muscle attached to hair follicles that contracts to elevate hair and produce goose bumps.

• produces sebaceous glands to lubricate hair and control bacterial growth

Sebaceous glands

Exocrine oil glands associated with hair follicles that use holocrine secretion to produce sebum; absent on palms and soles.

Sebum

An oily secretion produced by sebaceous glands that lubricates hair and skin, protects the epidermis, and controls bacterial growth.

Sebaceous follicles

Oil-secreting glands not associated with hair follicles that discharge sebum directly onto the skin surface.

Merocrine sweat glands

Also known as eccrine glands; coiled tubular glands widely distributed on skin surfaces (especially palms and soles) that secrete water, salts, and wastes directly to surface pores for thermoregulation, excretion, and protection.

Apocrine sweat glands

Sweat glands limited to hairy areas (armpits and groin) that secrete sticky cloudy fluids into hair follicles during puberty and stress via merocrine secretion.