Anatomy Module 2: Connective, Nervous, Muscle & Integumentary Tissues

Vocabulary practice flashcards covering human tissue types, histology, connective, muscle, nervous, and integumentary systems.

Intracellular Environment

The internal environment of cells, contained within the cell membrane.

Extracellular Matrix (ECM)

The environment outside cells formed by secreted substances and fluids that help regulate extracellular material.

Histology

The microscopic study of tissues and the extracellular matrix around them.

Four Major Tissue Types

Epithelial (covers and lines), Connective (supports, connects, protects), Muscle (produces movement), and Nervous (conducts electrical impulses). Memory cue: Every Cat Must Nap.

Epithelium

A thin layer of tissue that covers body surfaces, lines cavities and hollow internal organs, and forms glands.

Microvilli

Finger-like extensions on the apical surface of epithelial cells that add extra surface area.

Cilia

Longer cytoplasmic extensions with internal structures that allow movement, found in the trachea and bronchi.

Tight Junctions

Occluding junctions located in the apical region between cells that create an impermeable barrier preventing diffusion of solutes and fluids.

Hemidesmosomes

Cellular structures that attach cells to extracellular structures and anchor them to fibers of the basement membrane.

Gap Junctions

Communicating junctions that allow rapid cellular communication and transfer between adjacent cells.

Simple Epithelium

Epithelial tissue consisting of a single layer of cells.

Stratified Epithelium

Epithelial tissue consisting of several layers of cells.

Squamous Cells

Flat and scalelike epithelial cells.

Cuboidal Cells

Medium height, boxy epithelial cells.

Columnar Cells

Tall epithelial cells shaped like columns.

Pseudostratified Columnar Epithelium

A single layer of tall cells with staggered nuclei, giving the appearance of multiple layers.

Transitional Epithelium

A type of epithelium able to stretch and change shape when a cavity fills with liquid.

Ground Substance

The clear, viscous, liquid, rubbery, or solid part of the extracellular matrix that fills spaces between cells.

Connective Tissue Fibers

Fibers within the extracellular matrix that provide strength, elasticity, or support, consisting of collagen fibers (red), reticular fibers (dark brown), and elastic fibers (dark brown).

Collagen Fibers

Straight, strong, and abundant connective tissue fibers that possess high tensile strength.

Elastic Fibers

Long, thin elastin fibers that stretch and recoil.

Reticular Fibers

Short, fine, highly branched connective tissue fibers that form a supportive network.

Fibroblasts

Connective tissue cells that secrete ground substance and fiber proteins; essential for matrix formation and wound healing (Memory cue: Fabulous Fibroblasts).

Macrophages

Phagocytic connective tissue cells that ingest pathogens and damaged cells and activate immune responses.

Adipocytes

Fat cells that store energy, provide padding, and offer insulation.

Mast Cells

Connective tissue cells that release histamine and heparin following tissue injury.

Mesenchymal Cells

Embryonic connective-tissue stem cells that assist in tissue repair.

Connective Tissue Proper

A category of connective tissue subclassified into loose and dense connective tissue.

Areolar Tissue

A common loose connective tissue packing material that wraps and cushions, found beneath the dermis, between muscles, and around joints.

Dense Regular Connective Tissue

Dense connective tissue with parallel fibers that withstands tensile stress in one direction; found in tendons and ligaments.

Dense Irregular Connective Tissue

Dense connective tissue with fibers arranged in many directions to withstand stress from multiple directions.

Erythrocytes

Red blood cells responsible for transporting oxygen ($O_2$) and carbon dioxide ($CO_2$).

Leukocytes

White blood cells that function in fighting infection and disease.

Platelets

Cell fragments present in blood that assist in blood clotting.

Lymph

Fluid connective tissue derived from interstitial fluid that contains white blood cells and is screened by the immune system.

Chondrocytes

Mature cartilage cells residing inside small chambers called lacunae.

Perichondrium

A layer of connective tissue that surrounds cartilage.

Hyaline Cartilage

The most common cartilage type; stiff yet flexible, reducing friction between bone ends as articular cartilage.

Fibrocartilage

Durable cartilage that absorbs shock, located between vertebrae and pubic bones.

Osteocytes

Mature bone cells located in lacunae within osseous tissue.

Canaliculi

Microscopic passageways in bone tissue allowing osteocytes to communicate with each other and with blood vessels.

Periosteum

A protective membrane covering outer bone surfaces.

Neuron Structure

Composed of a cell body (contains nucleus and major organelles), dendrites (receive information), axon (carries information AWAY from cell body), and axon terminals (communicate with other neurons).

Neuroglia

Supporting cells in nervous tissue that protect and support neurons.

Skeletal Muscle

Voluntary, striated muscle tissue composed of large, multinucleate fibers attached to bone by tendons.

Cardiac Muscle

Involuntary, striated muscle tissue found only in the heart, composed of short, branched cardiocytes, intercalated discs, and pacemaker cells.

Smooth Muscle

Involuntary, nonstriated muscle tissue made of small, spindle-shaped cells with high regenerative capacity; controls diameters of blood vessels and passageways.

Intercalated Discs

Specialized cell connections in cardiac muscle that contain gap junctions to support rapid electrical communication.

Five Cardinal Signs of Inflammation

Redness, swelling, heat, pain, and loss of function.

Prostaglandins

Chemical compounds that act as SOS signals during inflammation to direct repair processes.

Autolysis

The breakdown of damaged cells by their own lysosomal enzymes during tissue damage.

Necrosis

Cell death occurring in living tissue; creates pus composed of dead cells, debris, and fluid.

Stratum Basale

The deepest layer of the epidermis containing stem cells that continually rebuild skin.

Stratum Corneum

The superficial layer of the epidermis consisting of dead, keratinized, water-resistant cells.

Langerhans Cells

Immune cells residing in the epidermis.

Merkel Cells

Sensory cells in the skin that function as tactile discs to detect mechanical information.

Nociceptors

Sensory receptors in skin specialized to detect pain.

Pacinian Corpuscles

Sensory receptors in skin that detect deep pressure.

Thermoreceptors

Sensory receptors in skin responsible for detecting hot and cold temperatures.

Sebaceous Glands

Exocrine glands that produce oily sebum to prevent skin drying and inhibit microorganisms.

Apocrine Sweat Glands

Glands in the armpits and around nipples that produce a thicker sweat secretion beginning at puberty.

Merocrine Glands

Also called eccrine glands; sweat glands located throughout the body that release watery sweat onto the skin surface.

Insensible Perspiration

Continuous, unnoticeable water loss diffusing through skin, measuring approximately $500\,\text{mL/day}$.

Calcitriol

The active hormone converted by kidneys (from a liver intermediate synthesized via UV exposure and vitamin D) required for bone growth and maintenance.

First-Degree Burn

Superficial burn affecting only the epidermis; an example is a sunburn.

Second-Degree Burn

Partial-thickness burn involving the epidermis and part of the dermis, causing redness and blisters.

Third-Degree Burn

Full-thickness burn damaging the epidermis, entire dermis, and subcutaneous tissue; characterized by white or charred appearance and loss of sensation.

Fourth-Degree Burn

Severe burn extending through the skin into underlying tissue, resulting in loss of sensation.

Malignant Melanoma

An extremely dangerous skin cancer originating from melanocytes that can metastasize through the lymphatic system.

ABCDEs of Skin Cancer

Diagnostic criteria for skin lesions: Asymmetry, Border (irregular/blurred), Color (uneven/multiple), Diameter ($>5\,\text{mm}$), and Evolution (changes in size or shape).