Anatomy and Physiology: The Human Tissues – Part 2

Comprehensive vocabulary flashcards covering connective, nervous, and muscular tissues, body membranes, and associated cell types based on Kenneth S. Saladin's Anatomy & Physiology lecture notes.

Connective tissue

The most abundant, widely distributed, and variable primary tissue type in the body, characterized by cells that occupy less space than the extracellular matrix.

Ground substance

The fluid, usually gelatinous extracellular component of connective tissue that fills the space between cells and can slow the movement of infecting pathogens.

Extracellular matrix

The extracellular component of connective tissue made of solid protein fibers and fluid ground substance, constituting the majority of the tissue volume and determining its specialized function.

Mesenchyme

The first embryonic connective tissue that gives rise to all other connective tissues; not found in adults, though mesenchymal stem cells persist to repair surrounding tissue.

Mucous connective tissue (Wharton's jelly)

A temporary embryonic loose connective tissue found in many parts of the embryo, including the umbilical cord, that contains stem cells with potential therapeutic applications.

Connective tissue proper

A broad category of connective tissue that functions primarily to connect and protect structures; examples include tendons and adipose tissue.

Fluid connective tissue

A category of connective tissue characterized by a liquid ground substance that suspends cells and functions in transportation; examples include blood and lymph.

Supporting connective tissue

A category of connective tissue that provides structural support and strength to the body; examples include cartilage and bone.

Fibroblasts

Cells in fibrous connective tissue that produce the extracellular protein fibers and ground substance of the matrix.

Macrophages

Large immune cells derived from monocytes that phagocytize foreign material and activate the immune system when they sense antigens.

Leukocytes

White blood cells found in connective tissue and circulation that function in immune defense against infection and disease.

Neutrophils

A specific type of leukocyte that attacks and phagocytizes bacteria.

Lymphocytes

A class of leukocytes that reacts against bacteria, toxins, and other foreign agents.

Plasma cells

Connective tissue cells that arise from B lymphocytes and synthesize antibodies.

Mast cells

Connective tissue cells that secrete heparin to inhibit blood clotting and histamine to dilate blood vessels.

Adipocytes

Fat cells that store triglycerides; they are produced by the mitosis of surrounding mesenchymal cells rather than through their own division.

Fasciae

Connective tissue frameworks that wrap, support, or surround internal body organs.

Superficial fascia (hypodermis)

The layer of connective tissue situated directly beneath the integumentary system (skin) that provides insulation and padding.

Deep fascia

A tough connective tissue layer that resists multidirectional force, wraps organs in capsules, attaches muscles to bone as tendons, and connects bones to each other as ligaments.

Subserous fascia

A connective tissue layer that protects the linings of body cavities during movements of muscles or muscular organs.

Adipose tissue

A connective tissue in which adipocytes are the dominant cell type, serving as the body's primary energy reservoir.

White adipose tissue (WAT)

The most abundant adipose tissue type in adults, functioning in thermal insulation, cushioning organs, body contours, and hormone secretion; microscopically visible as empty-looking cells with peripheral nuclei.

Brown adipose tissue (BAT)

A heat-generating adipose tissue found predominantly in fetuses, infants, and children, deriving its dark color from abundant blood vessels, mitochondria, and mitochondrial enzymes.

Erythrocytes

Red blood cells; formed elements shaped as pale pink discs with lighter centers that transport $O_2$ and $CO_2$.

Platelets

Small, non-nucleated cell fragments in blood that participate in clotting.

Extracellular fluid (ECF)

Any bodily fluid situated outside of cells, including blood plasma, interstitial fluid, and lymph.

Blood plasma

The fluid matrix component of blood that suspends the formed elements.

Interstitial fluid

The extracellular fluid that directly bathes and surrounds tissue cells.

Lymph

Extracellular fluid collected from interstitial spaces that was not reabsorbed by capillaries; filtered by the lymphatic system and returned to the venous circulation.

Cartilage

A stiff, avascular connective tissue containing a flexible, rubbery matrix rich in glycosaminoglycans (GAGs) and collagen fibers.

Chondroblasts

Immature cartilage cells responsible for producing and secreting the extracellular cartilage matrix.

Chondrocytes

Mature cartilage cells that reside entrapped within small matrix cavities termed lacunae.

Anti-angiogenesis factor

A chemical substance produced by chondrocytes that prevents the development of blood vessels, maintaining cartilage in an avascular state.

Osseous tissue

Calcified connective tissue that forms the skeleton, consisting of calcium salt crystals and flexible collagen fibers to provide support and protection.

Osteoblasts

Bone cells that synthesize and deposit the calcified extracellular matrix.

Osteocytes

Mature bone cells that maintain the surrounding calcified matrix.

Cutaneous membrane

The skin; the largest membrane of the body, consisting of stratified squamous epithelium (epidermis) overlying a connective tissue dermis.

Mucous membrane (mucosa)

A membrane lining passages opening to the exterior environment, consisting of an epithelium, lamina propria, and muscularis mucosae.

Lamina propria

The layer of areolar connective tissue that supports the epithelial lining in a mucous membrane.

Muscularis mucosae

A thin layer of smooth muscle underlying the lamina propria in a mucous membrane.

Serous membrane (serosa)

A membrane lining internal closed body cavities, consisting of a simple squamous mesothelium resting on areolar tissue, which secretes serous fluid.

Serous fluid (transudate)

A watery lubricating fluid derived from blood that sits between the parietal and visceral layers of serous membranes.

Pleura

The serous membrane lining the pleural cavity (parietal layer) and the external surface of the lungs (visceral layer).

Peritoneum

The serous membrane lining the peritoneal cavity (parietal layer) and covering the visceral surfaces of abdominal organs.

Pericardium

The serous membrane lining the pericardial cavity (parietal layer) and covering the surface of the heart (visceral layer).

Synovial membrane

A connective tissue membrane lining moving, articulating joint cavities that lacks a basement membrane and a continuous epithelial layer.

Synoviocytes

Cells in the synovial membrane that produce lubricating synovial fluid for articulating joints.

Excitability

The physiological capacity of a cell to respond to stimuli by altering its electrical membrane potential.

Membrane potential

The electrical charge difference (voltage) across a cell membrane that drives signal conduction in nerves and contraction in muscle cells.

Nervous tissue

Excitable tissue specialized for rapid communication through electrical and chemical signals, composed of neurons and neuroglia.

Neurons

Excitable nerve cells that detect stimuli, respond rapidly, and transmit coded electrical information to other cells.

Neuroglia (glial cells)

Supportive non-conducting cells in nervous tissue that protect, assist, and maintain neurons.

Neuron cell body

The portion of a neuron housing the nucleus and major organelles, responsible for controlling protein synthesis.

Dendrites

Short, branched extensions of a neuron that receive input signals from other cells and convey them toward the cell body.

Axon

A single, long nerve fiber extending from a neuron cell body that transmits outgoing signals to other cells.

Muscular tissue

Excitable tissue specialized to shorten and contract when stimulated, exerting physical force on organs, tissues, or fluids and generating heat.

Skeletal muscle

Voluntary, striated muscle tissue composed of long, non-mitotic cylindrical fibers containing multiple peripheral nuclei, typically attached to bones.

Cardiac muscle

Involuntary, striated muscle tissue restricted to the heart wall, composed of branched cardiomyocytes joined by intercalated discs.

Cardiomyocytes

Short, branched cardiac muscle cells that typically contain one centrally placed nucleus.

Intercalated discs

End-to-end junctions between neighboring cardiomyocytes that feature gap junctions for direct intercellular communication.

Smooth muscle

Involuntary, non-striated muscle tissue made of short, fusiform-shaped cells containing a single central nucleus that can divide by mitosis.

Visceral muscle

Smooth muscle forming parts of the walls of hollow internal organs (such as the digestive, respiratory, and urinary tracts) and blood vessels.