Module 3 Lab: Integumentary System - Vocabulary Flashcards

Vocabulary flashcards covering key terms related to the integumentary system from Module 3 Lab notes.

Integumentary system

The skin and its appendages (hair, nails, sweat glands) that form a protective barrier, enable sensation, aid in vitamin D production, and help regulate body temperature.

Epidermis

Outermost, avascular layer of the skin composed of keratinized stratified squamous epithelium.

Dermis

Thick, inner layer of the skin made of dense irregular connective tissue; contains blood vessels, nerves, hair follicles, and glands; has papillary and reticular sublayers.

Hypodermis

Subcutaneous layer beneath the dermis rich in adipose tissue and connective tissue; anchors skin and stores fat.

Keratinized stratified squamous epithelium

Epithelial tissue type that forms the epidermis and accumulates keratin for toughness.

Avascular

Lacking blood vessels; characteristic of the epidermis.

Stratum basale

Deepest epidermal layer; single row of basal cells where mitosis occurs; attached to the basement membrane.

Stratum spinosum

Layer above basale; keratinocytes with a spiny appearance and several cell types (e.g., Langerhans cells).

Stratum granulosum

Layer where keratinization begins; contains keratohyalin granules and cells begin to die as they move outward.

Stratum lucidum

Clear, thin layer present only in thick skin (palms, soles) between granulosum and corneum.

Stratum corneum

Outermost protective layer of thick, dead, keratinized cells.

Thin skin

Skin lacking the stratum lucidum; has four epidermal layers.

Thick skin

Skin with five epidermal layers including stratum lucidum; located on palms and soles.

Papillary layer

Superficial dermal layer of loose areolar connective tissue; contains capillaries and nerve endings and forms dermal papillae.

Reticular layer

Deeper dermal layer of dense irregular connective tissue with a dense mesh of collagen and elastic fibers.

Areolar connective tissue

Loose connective tissue in the papillary dermis; provides elasticity and nutrients.

Dense irregular connective tissue

Thick, interwoven collagen fibers in the reticular dermis; provides strength in multiple directions.

Dermal papillae

Finger-like projections of the dermis that indent the epidermis and form ridges.

Basement membrane

Thin extracellular layer separating epidermis from dermis; anchors epidermal cells.

Pacinian corpuscles

Lamellated mechanoreceptors in the deep dermis/hypodermis that detect deep pressure and vibration.

Meissner’s corpuscles

Tactile receptors in the dermal papillae of hairless skin that detect light touch.

Arrector pili muscle

Small smooth muscle attached to hair follicles; contracts to cause hair to stand (goosebumps).

Hair follicle

Infolding of the epidermis into the dermis that surrounds the hair root and shaft.

Hair shaft

Visible portion of hair that extends above the skin surface.

External root sheath

Outer portion of the hair follicle derived from the epidermis, surrounding the hair root.

Sebaceous gland

Oil-producing gland associated with hair; secretes sebum to lubricate skin and hair.

Sudoriferous glands

Sweat glands in the skin; include eccrine and apocrine types; regulate temperature and excrete wastes.

Adipose connective tissue

Fat-storing connective tissue in the hypodermis; provides insulation and energy storage.

Dermal blood vessels

Arteries and veins in the dermis that supply nutrients and assist in thermoregulation.

Nerves (in the skin)

Sensory and autonomic nerve fibers in the dermis that detect touch, pressure, temperature, and pain.

Vitamin D production

Skin participates in synthesizing vitamin D when exposed to UVB light, aiding calcium absorption.

Thermoregulation

Maintenance of body temperature via sweating, vasodilation/constriction, and adipose tissue.

Sensory receptors

Nerve endings in the skin that detect mechanical, thermal, and chemical stimuli.