Ch.1 Human Body Orientation

Flashcards covering key vocabulary from the Anatomy and Physiology lecture, including definitions of terms related to body structure, function, organizational levels, life requirements, homeostasis, and anatomical terminology.

Anatomy

The study of body structure and the relationships between body parts.

Physiology

The study of how the body and its parts function.

Gross (macroscopic) anatomy

The study of large, visible body structures (e.g., organs, muscles).

Microscopic anatomy

The study of structures too small to be seen without a microscope (e.g., cells, tissues).

Principle of Complementarity

Structure determines function; the way something is built (anatomy) enables what it can do (physiology).

Chemical Level

The most basic level of structural organization, including atoms and molecules (e.g., water, proteins, DNA).

Cell

The basic unit of life.

Tissue

A group of similar cells with a common function.

Organ

A structure composed of at least two tissue types performing a specific function.

Organ system

A group of organs working together to perform major functions.

Organism

The complete living being.

Maintaining boundaries

A necessary life function involving separation between the internal and external environments (e.g., skin for the organism, plasma membrane for a cell).

Movement

A necessary life function including locomotion and movement of substances within the body.

Responsiveness (excitability)

A necessary life function defined as the ability to sense and respond to stimuli.

Digestion

A necessary life function involving the breakdown of ingested foodstuffs to simple molecules for absorption.

Metabolism

A necessary life function encompassing all chemical reactions that occur in body cells.

Excretion

A necessary life function involving the removal of wastes from the body.

Reproduction

A necessary life function referring to the production of offspring (at cellular or organismal levels).

Growth

A necessary life function involving an increase in size of a body part or the entire organism.

Anabolism

A metabolic process of building larger molecules from smaller ones, which requires energy.

Catabolism

A metabolic process of breaking down molecules into smaller units, which releases energy.

Homeostasis

The body’s ability to maintain stable internal conditions despite external changes.

Variables

Factors within the body that can change (e.g., temperature, pH, blood sugar), which are regulated by homeostatic control.

Receptor

A component of homeostatic control that detects changes or stimuli in the internal or external environment.

Control center

A component of homeostatic control that determines the set point, analyzes input from the receptor, and sends output.

Effector

A component of homeostatic control that carries out the response dictated by the control center to return conditions to balance.

Afferent pathways

The pathway along which receptors send input (information) to the control center.

Efferent pathways

The pathway along which the control center sends output (commands) to the effector.

Set point

The ideal value that the body tries to maintain for a particular variable.

Negative Feedback

A homeostatic control mechanism that reduces or shuts off the original stimulus, opposing the change to maintain stability.

Positive Feedback

A homeostatic control mechanism that enhances or exaggerates the original stimulus, accelerating the change in the same direction.

Anatomical Position

A standard body position where the body is upright, feet slightly apart, palms face forward, and thumbs point away from the body.

Superior

Directional term meaning toward the head end or upper part of a structure or the body; above.

Inferior

Directional term meaning away from the head end or toward the lower part of a structure or the body; below.

Anterior (ventral)

Directional term meaning toward or at the front of the body; in front of.

Posterior (dorsal)

Directional term meaning toward or at the back of the body; behind.

Medial

Directional term meaning toward or at the midline of the body; on the inner side of.

Lateral

Directional term meaning away from the midline of the body; on the outer side of.

Proximal

Directional term meaning closer to the origin of the body part or point of attachment of a limb to the body trunk (used for limbs).

Distal

Directional term meaning farther from the origin of a body part or the point of attachment of a limb to the body trunk (used for limbs).

Superficial

Directional term meaning toward or at the body surface.

Deep

Directional term meaning away from the body surface; more internal.

Plane

An imaginary line through the body along which sections are made.

Section

An actual cut or slice made along a body plane.

Sagittal Plane

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

Frontal (coronal) Plane

A vertical plane that divides the body into anterior (front) and posterior (back) parts.

Transverse Plane

A horizontal plane that divides the body into superior (top) and inferior (bottom) parts.

Median (midsagittal) plane

A sagittal plane that lies exactly in the midline, dividing the body into equal left and right halves.

Cross-section

A section made along a transverse plane.

Dorsal Cavity

A body cavity located posteriorly, subdivided into the cranial and vertebral cavities.

Ventral Cavity

A body cavity located anteriorly, subdivided into the thoracic and abdominopelvic cavities.

Diaphragm

A large, dome-shaped muscle that separates the thoracic cavity from the abdominopelvic cavity.

Cranial cavity

A subdivision of the dorsal cavity that houses the brain.

Vertebral (spinal) cavity

A subdivision of the dorsal cavity that houses the spinal cord.

Thoracic cavity

A subdivision of the ventral cavity superior to the diaphragm, containing the heart and lungs.

Abdominopelvic cavity

A subdivision of the ventral cavity inferior to the diaphragm, composed of the abdominal and pelvic cavities.

Pleural cavities

Subdivisions within the thoracic cavity, each enclosing a lung.

Mediastinum

The central compartment of the thoracic cavity, containing organs like the heart, esophagus, and trachea.

Pericardial cavity

A subdivision within the mediastinum that encloses the heart.

Abdominal cavity

The superior portion of the abdominopelvic cavity, housing organs like the stomach, liver, and intestines.

Pelvic cavity

The inferior portion of the abdominopelvic cavity, housing organs like the bladder, reproductive organs, and rectum.