Chapter 1: The Human Body: An Orientation

This flashcard set covers the introductory concepts of human anatomy and physiology, including levels of organization, life requirements, homeostasis, anatomical terminology, and body planes/cavities.

Anatomy

The study of the structure of body parts and their relationships to one another.

Physiology

The study of the function of body parts; how all the body parts work and carry out their life-sustaining activities.

Histology

A subdivision of microscopic anatomy that specifically studies body tissues.

Renal physiology

A subdivision of physiology that considers the operation of the urinary system and kidney function.

Principle of complementarity of structure and function

A key concept stating that what a structure can do depends on its specific form; form determines function.

Levels of structural organization

The hierarchy of body organization, sequenced from smallest to largest as: chemical, cellular, tissue, organ, organ system, and organismal.

Organ

A discrete structure composed of at least two tissue types (four is more common) that performs a specific function for the body.

Maintaining boundaries

The functional characteristic of life that ensures the internal environment remains distinct from the external environment.

Metabolism

A broad term that includes all chemical reactions that occur within body cells.

Digestion

The breaking down of ingested foodstuffs to simple molecules that can be absorbed into the blood.

Excretion

The process of removing wastes from the body.

Homeostasis

The ability of the body to maintain relatively stable internal conditions even though the outside world changes continuously.

Negative feedback mechanism

The most common homeostatic control system where the output shuts off the original stimulus or reduces its intensity, reversing the effect of the original stimulus.

Positive feedback mechanism

A control system where the response enhances or exaggerates the original stimulus so that the activity is accelerated.

Homeostatic imbalance

A disturbance in homeostasis, often associated with disease or the declining efficiency of control systems as the body ages.

Anatomical position

A standard body position where the person stands erect with feet slightly apart, palms facing forward, and thumbs pointing away from the body.

Superior (cranial)

Toward the head end or upper part of a structure or the body; above.

Inferior (caudal)

Away from the head end or toward the lower part of a structure or the body; below.

Anterior (ventral)

Toward or at the front of the body; in front of.

Posterior (dorsal)

Toward or at the back of the body; behind.

Medial

Toward or at the midline of the body; on the inner side of.

Lateral

Away from the midline of the body; on the outer side of.

Proximal

Closer to the origin of the body part or the point of attachment of a limb to the body trunk.

Distal

Farther from the origin of a body part or the point of attachment of a limb to the body trunk.

Superficial (external)

Toward or at the body surface.

Deep (internal)

Away from the body surface; more internal.

Transverse plane

A horizontal plane that divides the body into superior and inferior portions.

Frontal (coronal) plane

A vertical plane that divides the body into anterior and posterior portions.

Sagittal plane

A vertical plane that divides the body into right and left parts.

Serous membrane

A thin, double-layered membrane that covers the walls of the ventral body cavity and the outer surfaces of the organs it contains, providing lubrication to reduce friction.