BIO 224

Physiology

The scientific study of how various parts (cells to organs) of an organism function.

Anatomy

The scientific study of body structure.

Multicellular Eukaryote

An organism made up of cells with a nucleus and complex structure, lacking a cell wall.

Heterotroph

An organism that cannot produce its own food and instead derives its nutritional requirements from complex organic substances.

Protostomes

Animals that undergo a developmental process where the mouth forms before the anus.

Deuterostomes

Animals that undergo a developmental process where the anus forms before the mouth.

Diploblasts

Animals with two germ layers (ectoderm and endoderm).

Triploblasts

Animals with three germ layers (ectoderm, mesoderm, and endoderm).

Homeostasis

The regulation of the body’s internal environment at or near a stable level.

Thermoregulation

The process by which animals maintain their body temperature within certain boundaries.

Negative feedback

A regulatory mechanism in which a change in a physiological variable triggers a response that counteracts the initial change.

Positive feedback

A regulatory mechanism in which a change in a physiological variable triggers a response that amplifies the change.

Ectotherms

Organisms that obtain heat from the external environment.

Endotherms

Organisms that generate their own body heat through internal physiological processes.

Skeletal Muscle

Voluntary muscle that is attached to bones and helps in movement.

Cardiac Muscle

Involuntary muscle that forms the heart; responsible for pumping blood.

Smooth Muscle

Involuntary muscle found in walls of hollow organs; helps in movement through these organs.

Action Potential

A rapid change in membrane potential that occurs along the axon of a neuron.

Synapse

The junction where a neuron communicates with another neuron or effector.

Neurotransmitter

Chemical messenger that transmits signals across the synapse between neurons.

Chemoreceptors

Sensory receptors that respond to chemical stimuli, responsible for taste and smell.

Olfaction

The sense of smell.

Gustation

The sense of taste.

Glial Cells

Non-neuronal cells in the nervous system that support and protect neurons.

Lipid Bilayer

A thin polar membrane made of two layers of lipid molecules.

Axon

The part of a neuron that carries impulses away from the cell body.

Dendrites

Branch-like structures of neurons that receive signals from other neurons.

Muscle Contraction

The activation of tension-generating sites within muscle fibers.

Antagonistic Muscles

Muscles that work in opposition to each other; one muscle contracts while the other relaxes.

Muscle Fiber

The basic unit of a muscle, a single muscle cell that can contract.

Visceral Muscle

Muscle found in the walls of organs and blood vessels, involuntary in nature.

Gastrulation

The phase early in the embryonic development during which the blastula reorganizes into the three germ layers.

Coelom

A fluid-filled body cavity that forms within the mesoderm.

Segmentation

The division of the body into repeated segments, which allows for greater flexibility and specialization.

Radial Symmetry

Symmetry around a central axis; can be divided into identical halves by any longitudinal plane.

Bilateral Symmetry

Symmetry where an organism can be divided into two equal halves along a single plane.

Proteoglycans

Complex molecules of protein and sugars that provide structural support in the extracellular matrix.

Hydration

Involves maintaining water balance within an organism.