Skin Anatomy and Physiology Lecture

Vocabulary flashcards covering layers of the skin, dermal structures, glands, and hair anatomy from the lecture notes.

Epidermis

Outermost skin layer; multi-layered barrier that protects against pathogens.

Stratum Basale

Deepest epidermal layer; single row of dividing keratinocytes, melanocytes, and Merkel cells attached to basement membrane.

Stratum Spinosum

‘Spiny’ epidermal layer where desmosomes join keratinocytes producing keratin filaments.

Stratum Granulosum

Epidermal layer with keratohyalin granules; cells begin to die as they migrate upward.

Stratum Lucidum

Clear layer of dead keratinocytes present only in thick skin (palms, soles).

Stratum Corneum

Surface layer of fully keratinized, lipid-coated cells that are continuously shed.

Dermis

Thick fibrous skin layer beneath epidermis; contains connective tissue, vessels, nerves, hair follicles, and glands.

Papillary Layer

Superficial dermal region of loose areolar CT with dermal papillae, capillaries, and Meissner corpuscles.

Reticular Layer

Deep dermal region of dense irregular CT rich in thick collagen, elastic fibers, hair follicles, glands, and Pacinian corpuscles.

Hypodermis

Deepest skin layer of fat and loose CT; stores energy, insulates, cushions, and anchors skin to underlying structures.

Sebaceous Gland

Oil-producing gland connected to hair follicles; secretes sebum to lubricate skin and hair and prevent water loss.

Merocrine (Eccrine) Gland

Most common sweat gland; secretes watery sweat for thermoregulation over most of the body.

Apocrine Gland

Large sweat gland in axilla and genital regions; releases thick, milky secretion that becomes odorous after bacterial action and aids pheromone signaling.

Dermal Papillae

Fingerlike projections of papillary dermis that interlock with epidermal ridges and supply nutrients.

Meissner Corpuscle

Light-touch mechanoreceptor located within dermal papillae.

Pacinian Corpuscle

Pressure (deep touch/vibration) receptor found in the reticular dermis and hypodermis.

Hair Shaft

Visible part of hair consisting of medulla, cortex with melanin, and protective cuticle.

Medulla (Hair)

Innermost core of the hair shaft.

Cortex (Hair)

Middle layer of the hair shaft containing pigment granules (melanin).

Cuticle (Hair)

Outermost, scale-like protective layer of the hair shaft.

Hair Root

Portion of hair below the skin surface, ending in the bulb.

Hair Bulb

Base of hair follicle containing actively dividing cells for hair growth.

Hair Papilla

Connective tissue at the base of the hair bulb containing blood vessels to nourish growing hair.

Arrector Pili Muscle

Small smooth muscle attached to follicles; contraction causes ‘goosebumps’.

Root Hair Plexus

Network of sensory nerve endings around hair follicle that detect hair movement.