Anatomy and Physiology - The Human Body: Orientation

Vocabulary flashcards covering human anatomy and physiology concepts, organ systems, directional terms, body planes, cavities, and homeostatic mechanisms based on Chapter 1 lecture notes.

Anatomy

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

Physiology

The study of the function of body parts and how they work to carry out life-sustaining activities.

Principle of Complementarity of Structure and Function

The principle stating that function always reflects structure, and what a structure can do depends on its specific form.

Chemical Level

The structural level of body organization that includes atoms, molecules, and organelles.

Cellular Level

The structural level of body organization consisting of single cells.

Tissue Level

The structural level of body organization consisting of groups of similar cells that perform a common function.

Organ Level

The structural level of body organization containing two or more types of tissues.

Organ System Level

The structural level of body organization consisting of organs that work closely together.

Organismal Level

The highest level of structural organization, representing all organ systems combined to make the whole human organism.

Integumentary System

Organ system that forms the external body covering, protects deeper tissues from injury, synthesizes vitamin D, houses cutaneous receptors and sweat/oil glands, regulates temperature, and excretes salts and urea.

Skeletal System

Organ system that protects and supports body organs, provides a framework for muscle movement, forms blood cells within bones, and stores minerals.

Muscular System

Organ system that allows manipulation of the environment, locomotion, and facial expression, maintains posture, and produces heat.

Nervous System

Fast-acting control system of the body that responds to internal and external changes by activating appropriate muscles and glands, and helps maintain homeostasis through electrical signals.

Endocrine System

Organ system containing glands that secrete hormones regulating processes such as growth, reproduction, and nutrient use (metabolism) by body cells.

Cardiovascular System

Organ system consisting of blood vessels and the heart; blood vessels transport blood carrying oxygen, carbon dioxide, nutrients, and wastes, while the heart pumps blood.

Lymphatic System/Immunity

System that picks up fluid leaked from blood vessels and returns it to blood, disposes of debris in the lymphatic stream, and houses white blood cells (lymphocytes) involved in immunity.

Respiratory System

Organ system that keeps blood constantly supplied with oxygen and removes carbon dioxide, conducts gaseous exchanges through air sac walls, and helps maintain acid-base balance via carbonic acid/bicarbonate buffer system.

Digestive System

Organ system that breaks down food into absorbable units that enter the blood for distribution to body cells, and eliminates indigestible foodstuffs as feces.

Urinary System

Organ system that eliminates nitrogenous wastes from the body and regulates water, electrolyte, and acid-base balance of the blood.

Male Reproductive System

Organ system with overall function of offspring production; testes produce sperm and male sex hormone, while ducts and glands aid in delivery of sperm to female reproductive tract.

Female Reproductive System

Organ system with overall function of offspring production; ovaries produce eggs and female sex hormones, remaining structures serve as sites for fertilization and fetus development, and mammary glands produce milk.

Survival Needs

Factors required for life maintenance in appropriate amounts, including nutrients, oxygen, water, normal body temperature ($37^\text{o}\text{C}$), and appropriate atmospheric pressure.

Homeostasis

The maintenance of relatively stable internal conditions despite continuous changes in the external environment; a dynamic state of equilibrium maintained by all organ systems.

Receptor (Sensor)

Homeostatic control component that monitors the environment and responds to stimuli by sending input along afferent pathways.

Control Center

Homeostatic control component that determines the set point at which a variable is maintained, receives input from receptors, and determines appropriate output.

Effector

Homeostatic control component that receives output from the control center along efferent pathways and provides the means to respond to the stimulus.

Negative Feedback

The primary homeostatic feedback mechanism where the response reduces or shuts off the original stimulus, driving the variable in the opposite direction of initial change.

Positive Feedback

Homeostatic feedback mechanism where the response enhances or exaggerates the original stimulus, causing an amplifying cascade (e.g., blood clotting or labor contractions).

Anatomical Position

Standard reference position where the body is erect, feet are slightly apart, and palms face forward with thumbs pointing away from the body.

Superior (cranial)

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

Inferior (caudal)

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.

Intermediate

Directional term meaning between a more medial and a more lateral structure.

Proximal

Directional term meaning closer to the origin of the body part or point of attachment of a limb to the body trunk.

Distal

Directional term meaning farther from the origin of a body part or point of attachment of a limb to the body trunk.

Superficial (external)

Directional term meaning toward or at the body surface.

Deep (internal)

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

Axial Division

Major division of the body consisting of the head, neck, and trunk.

Appendicular Division

Major division of the body consisting of the limbs (legs and arms).

Sagittal Plane

Vertical plane that divides the body into right and left parts.

Midsagittal (median) Plane

Specific sagittal plane that lies perfectly on the midline of the body.

Parasagittal Plane

Sagittal plane that is off-center and does not lie on the midline.

Frontal (coronal) Plane

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

Transverse (horizontal) Plane

Horizontal plane that divides the body into superior and inferior parts (top and bottom), producing a cross section.

Oblique Section

A body section resulting from cuts made diagonally at an angle other than $90^\text{o}$ to vertical planes.

Dorsal Body Cavity

Internal cavity that protects the nervous system; subdivided into the cranial cavity (encasing brain) and vertebral cavity (encasing spinal cord).

Ventral Body Cavity

Internal cavity that houses internal organs (viscera); subdivided by the diaphragm into the thoracic cavity and abdominopelvic cavity.

Serosa (Serous Membrane)

Thin, double-layered membrane covering surfaces in the ventral body cavity, separated by serous fluid.

Parietal Serosa

Layer of serous membrane lining internal body cavity walls.

Visceral Serosa

Layer of serous membrane directly covering internal organs (viscera).

Pericardium

Serous membrane associated with the heart.

Pleurae

Serous membranes associated with the lungs in the thoracic cavity.

Peritoneum

Serous membrane associated with the abdominopelvic cavity.

Synovial Cavities

Joint cavities enclosed within fibrous capsules that are not exposed to the external environment.