Organs, Organ Systems, and Homeostasis Vocabulary

Vocabulary flashcards defining key histological, anatomical, physiological, and homeostatic terminology from

Physiology

The study of the functions of living organisms, including cell physiology, special physiology, systemic physiology, and pathophysiology.

Anatomy

The study of internal and external structure and the physical relationships between body parts.

Tissue

A collection of specialized cells and cell products that perform a limited number of functions by working in concert.

Histology

The study of microscopic cells and tissues.

Epithelial Tissue

A primary tissue type that covers exposed surfaces, lines internal passageways and chambers, and produces glandular secretions.

Connective Tissue

A primary tissue type that connects all parts of the body; it binds, supports, protects, insulates, stores energy, and transports substances.

Muscle Tissue

A primary tissue type composed of actin and myosin that contracts to produce active movement.

Nervous Tissue

A primary tissue type specialized to respond to stimuli, propagate electrical impulses, and carry information over long distances.

Simple Epithelium

Epithelial tissue consisting of a single layer of cells covering a basement membrane.

Stratified Epithelium

Epithelial tissue consisting of multiple layers of cells.

Simple Squamous Epithelium

A single layer of flattened cells lining capillaries that allows for rapid diffusion of solutes and gases and reduces friction.

Stratified Squamous Epithelium

Multiple layers of flattened cells lining the mouth and esophagus that protect underlying tissues from friction and abrasions.

Simple Cuboidal Epithelium

A single layer of cube-shaped cells found in glands like the kidney that secretes and reabsorbs solutes.

Simple Columnar Epithelium

A single layer of tall cells found in the small and large intestines that secretes mucus and reabsorbs solutes.

Matrix

The extracellular material of connective tissue generated by specialized cells, composed of protein fibers (collagen and elastin) and ground substance.

Ground Substance

The liquid, jelly-like, or solid component of the connective tissue matrix made of proteoglycans that holds protein fibers.

Areolar Connective Tissue

A type of connective tissue proper that acts as glue to hold everything together.

Skeletal Muscle

Muscle tissue with elongated, unbranched, longitudinally stacked cells (fibers) that is under voluntary control.

Cardiac Muscle

Muscle tissue with short, branched cells connected by intercalated disks for synchronized contraction, under involuntary control.

Smooth Muscle

Muscle tissue with spindle-shaped, non-striated cells under involuntary control.

Neurons

Specialized nervous system cells that conduct and propagate electrical signals.

Neuroglia

Nervous system cells that maintain a neuron's environment by filtering blood components, insulating processes, and providing immune protection.

Homeostasis

The process by which an organism maintains a constant internal environment despite changes in the external environment.

Set Points

The ideal target ranges for physiological variables (such as body temperature of $36.5\text{--}37.5^{\text{o}}\text{C}$) maintained by homeostasis.

Negative Feedback Loop

A homeostatic regulatory mechanism where the body's response moves the physiological variable away from the stimulus, reversing the direction of change.

Positive Feedback Loop

A homeostatic regulatory mechanism where the body's response moves into the stimulus, reinforcing or amplifying the change.

Sensory Receptor

A homeostatic element that detects a specific physical or chemical change (stimulus) in the internal or external environment.

Afferent Structure

A pathway, such as a sensory nerve or hormone traveling in blood, that conducts signals from a receptor to a control center.

Control Center

An integration center (typically the central nervous system or an endocrine gland) that analyzes sensory information and determines the response.

Efferent Structure

A pathway, such as a motor nerve or hormone, that conducts response signals from the control center to an effector.

Effector

A muscle or gland that executes the physical response commanded by the control center to help restore or alter physiological state.

Dynamic Equilibrium

A continuous state of balance maintained by the body through active, ongoing physiological adjustments.