Integument System Study Flashcards

This set of flashcards covers essential terms and concepts from the lecture on the integument system, including its structure, function, and cellular components.

Integumentary system

Composed of the skin and its derivatives or accessories such as glands, hair, and nails.

Largest organ

The skin, which makes up about 15-20% of the total mass and volume of the body.

Epidermis

The outer layer of skin composed of keratinized stratified squamous epithelium.

Dermis

The inner layer of skin composed of dense connective tissue providing support and strength.

Hypodermis

Layer beneath the dermis containing adipose tissue and not considered part of the skin.

Barrier functions of skin

Includes mechanical, permeability, and ultraviolet barriers.

Sensory function of skin

The ability to convey external environmental information to the nervous system.

Homeostasis function of skin

Regulates body temperature and water loss.

Immunology function of skin

Defense against pathogens and antigen processing.

Endocrine functions of skin

Involving hormone production, growth factors, cytokines, and vitamin D activation.

Excretion function of skin

Involves secretion of substances through sweat, sebaceous, and apocrine glands.

Cell types in epidermis

Includes keratinocytes, melanocytes, Langerhans’ cells, and Merkel’s cells.

Keratinocytes

The predominant cell type in the epidermis responsible for forming a barrier.

Melanocytes

Pigment-producing cells that insert melanin into keratinocytes.

Langerhans’ cells

Antigen-presenting cells involved in the immune response.

Merkel’s cells

Cells associated with sensory nerve endings for touch.

Stratum corneum

The outermost layer of the epidermis composed of flattened keratinized cells.

Stratum lucidum

A clear layer found only in thick skin, below the stratum corneum.

Stratum granulosum

Contains granules and is the layer where keratinization begins.

Stratum spinosum

Known for its spiny appearance due to desmosomal connections.

Stratum basale

The deepest layer of the epidermis consisting of mitotically active cells.

Pacinian corpuscles

Receptors for deep pressure and vibration found in deeper dermis.

Meissner’s corpuscles

Receptors responsible for sensitivity to light touch located in the papillary layer.

Eccrine sweat glands

Glands producing watery sweat, crucial for temperature regulation.

Apocrine sweat glands

Glands associated with scent, found in specific regions, and activated at puberty.

Sebaceous glands

Glands producing sebum to keep skin soft and moist.

Arrector pili muscles

Muscles that cause hair to stand on end in response to cold or fear.

Hair follicle

An invagination of the epidermis responsible for hair growth.

Hair bulb

The lowest part of the hair follicle containing the dermal papilla and matrix cells.

Nail matrix

Area where nail growth occurs; contains stem cells that produce keratin.

Translucent keratinized cells

Structure of the nail plate composed of hardened keratin.

Dermis layers

Divided into papillary and reticular layers.

Papillary dermis

The thin superficial layer of the dermis rich in blood vessels and sensory receptors.

Reticular dermis

The thicker layer of the dermis composed of dense irregular connective tissue.

Fingerprints

Formation on skin surface due to dermal papillae reflecting underlying structures.

Cell junctions

Structures connecting basal cells to each other and to the basal lamina.

Keratohyalin granules

Contain proteins that aggregate keratin filaments in the stratum granulosum.

Intercellular epidermal water barrier

Barrier formed by lamellar bodies to prevent water loss.

Desmosomes

Cell junctions that provide mechanical stability between keratinocytes.

Hemidesmosomes

Cell junctions anchoring basal cells to the basement membrane.

Apoptosis

Process of programmed cell death important during keratinocyte differentiation.

Basal lamina

Thin extracellular matrix separating epithelium from underlying connective tissue.

Keratin filaments

Intermediate filaments contributing to the strength of the epidermis.

Granular cell

Cell type found in the stratum granulosum containing keratohyalin granules.

Spinous cell

Cuboidal cells located in the stratum spinosum with spiny processes.

Basal cell

Stem cells in the stratum basale responsible for epidermal renewal.

Tissue Types

Includes epithelium, connective, muscle, blood vessel, and nervous tissues.

Sebum

Oily substance produced by sebaceous glands.

Myoepithelial cells

Specialized cells that help eject sweat from eccrine glands.

Eponychium

The cuticle; protective layer at the junction of skin and nail.

Hyponychium

Thickened epidermal layer beneath the nail plate.

Perionychium

Skin surrounding the edge of the nail.

Lamina

Layer of cells that surrounds hair follicles and nails.

Apocrine secretion mechanism

Method of secretion involving the release of portions of the cell.

Melanin

Pigment produced by melanocytes that gives color to the skin.

Heat regulation

A primary function of eccrine glands through sweat production.

Fibrils

Thread-like structures that add tensile strength to the dermis.

Connective tissue sheath

Layer surrounding hair follicles made of connective tissue.

Dermal papilla

Structures that form the basis of fingerprints and supply nutrients to hair follicles.

Merocrine secretion mechanism

Secretion method where glands expel substances without losing cellular material.

Tonofilaments

Bundles of keratin filaments found in the stratum spinosum.

Filaggrin

Protein that aggregates keratin filaments in the stratum corneum.

Stratum Malpighi

Term referring to both the stratum basale and spinosum together.

Binding properties

Characteristics of the dermis that allow it to support the epidermis.

Cutaneous membrane

Another term for the skin, comprising dermis and epidermis.

Intrinsic factor

A factor required for proper skin function and regeneration.

Lipid-rich coating

Substance on the outer layer of the stratum corneum forming the water barrier.

Melanosome

Organelle responsible for storing and transporting melanin.

Keratinization

Process where keratinocytes fill with keratin as they move toward the skin surface.

Protein synthesis

Description of metabolic processes occurring in the basal layer of the epidermis.

Regenerative capacity

The ability of the epidermis to renew itself approximately every 15-30 days.

Basophilic cells

Cells that stain readily with basic dyes, often found in deep epidermal layers.

Epidermal growth factor

A molecule that stimulates cells to grow and reproduce in the skin.

Pavement epithelial cells

Flat epithelial cells found in the basal layer of the epidermis.

Hydration balance

The regulation of moisture levels within the skin layers.

Microvilli

Small projections that increase the surface area of cells, enhancing absorption.

Cell differentiation

Process by which cells develop specialized functions and characteristics.

Nutrient supply

Refers to the delivery of essential substances to skin cells via blood vessels.

Maturation of skin cells

The process by which skin cells progress through various stages of development.

Ultraviolet barrier

Protective function of the skin against harmful UV radiation.

Protein composition

Refers to the types and arrangements of proteins in skin cells.

Apocrine vs. Eccrine

Apocrine glands are associated with scent, while eccrine glands regulate temperature.

Skin appendages

Structures derived from the epidermis including hair follicles, nails, and glands.

Sebaceous gland secretion

Release of sebum via holocrine secretion, keeping skin moist.

Normal skin pH

Typically ranges from 4.5 to 5.3, contributing to barrier functions.

Keratinocyte renewal

Process where new keratinocytes replace older ones in the epidermis.

Impermeability barrier

Part of the skin's function to prevent excessive water loss.

Friction ridges

Convolutions of the stratum germinativum leading to unique fingerprint patterns.

Elastic fibers

Fibers that provide elasticity and resilience to the dermis.

Skin surface characteristics

Qualities such as texture, moisture, and resilience determined by epidermal structure.

Hormonal control

Influences hair growth cycles through various hormonal signals.

Growth factors in skin

Molecules that promote cellular proliferation and healing in the skin.

Dense connective tissue

Type of connective tissue found in the dermis, providing strength.

Meissner's corpuscle

Touch receptor located in the papillary layer of the dermis.

Cell cycle phases

Stages in which the keratinocytes progress through during their life span.

Dermal blood vessels

Structures that supply nutrients and oxygen to the skin.

Skin's protective layer

Barrier formed by keratinized cells that protects against pathogens.

Cuticle

The protective outer layer of the nail, also known as the eponychium.

Locational differences in skin

Variations in thickness and properties of skin depending on its anatomical location

Hair follicle segments

Infundibulum, isthmus, and bulb represent the three parts of hair follicles.