Key Terms

abdominopelvic cavity

division of the anterior (ventral) cavity that houses the abdominal and pelvic viscera

anabolism

assembly of more complex molecules from simpler molecules

anatomical position

standard reference position used for describing locations and directions on the human body

anatomy

science that studies the form and composition of the body’s structures

anterior

describes the front or direction toward the front of the body; also referred to as ventral

anterior cavity

larger body cavity located anterior to the posterior (dorsal) body cavity; includes the serous membrane-lined pleural cavities for the lungs, pericardial cavity for the heart, and peritoneal cavity for the abdominal and pelvic organs; also referred to as ventral cavity

catabolism

breaking down of more complex molecules into simpler molecules

caudal

describes a position below or lower than another part of the body proper; near or toward the tail (in humans, the coccyx, or lowest part of the spinal column); also referred to as inferior

cell

smallest independently functioning unit of all organisms; in animals, a cell contains cytoplasm, composed of fluid and organelles

computed tomography (CT)

medical imaging technique in which a computer-enhanced cross-sectional X-ray image is obtained

control center

compares values to their normal range; deviations cause the activation of an effector

cranial

describes a position above or higher than another part of the body proper; also referred to as superior

cranial cavity

division of the posterior (dorsal) cavity that houses the brain

deep

describes a position farther from the surface of the body

development

changes an organism goes through during its life

differentiation

process by which unspecialized cells become specialized in structure and function

distal

describes a position farther from the point of attachment or the trunk of the body

dorsal

describes the back or direction toward the back of the body; also referred to as posterior

dorsal cavity

posterior body cavity that houses the brain and spinal cord; also referred to the posterior body cavity

effector

organ that can cause a change in a value

frontal plane

two-dimensional, vertical plane that divides the body or organ into anterior and posterior portions

gross anatomy

study of the larger structures of the body, typically with the unaided eye; also referred to macroscopic anatomy

growth

process of increasing in size

homeostasis

steady state of body systems that living organisms maintain

inferior

describes a position below or lower than another part of the body proper; near or toward the tail (in humans, the coccyx, or lowest part of the spinal column); also referred to as caudal

lateral

describes the side or direction toward the side of the body

magnetic resonance imaging (MRI)

medical imaging technique in which a device generates a magnetic field to obtain detailed sectional images of the internal structures of the body

medial

describes the middle or direction toward the middle of the body

metabolism

sum of all of the body’s chemical reactions

microscopic anatomy

study of very small structures of the body using magnification

negative feedback

homeostatic mechanism that tends to stabilize an upset in the body’s physiological condition by preventing an excessive response to a stimulus, typically as the stimulus is removed

normal range

range of values around the set point that do not cause a reaction by the control center

nutrient

chemical obtained from foods and beverages that is critical to human survival

organ

functionally distinct structure composed of two or more types of tissues

organ system

group of organs that work together to carry out a particular function

organism

living being that has a cellular structure and that can independently perform all physiologic functions necessary for life

pericardium

sac that encloses the heart

peritoneum

serous membrane that lines the abdominopelvic cavity and covers the organs found there

physiology

science that studies the chemistry, biochemistry, and physics of the body’s functions

plane

imaginary two-dimensional surface that passes through the body

pleura

serous membrane that lines the pleural cavity and covers the lungs

positive feedback

mechanism that intensifies a change in the body’s physiological condition in response to a stimulus

positron emission tomography (PET)

medical imaging technique in which radiopharmaceuticals are traced to reveal metabolic and physiological functions in tissues

posterior

describes the back or direction toward the back of the body; also referred to as dorsal

posterior cavity

posterior body cavity that houses the brain and spinal cord; also referred to as dorsal cavity

pressure

force exerted by a substance in contact with another substance

prone

face down

proximal

describes a position nearer to the point of attachment or the trunk of the body

regional anatomy

study of the structures that contribute to specific body regions

renewal

process by which worn-out cells are replaced

reproduction

process by which new organisms are generated

responsiveness

ability of an organisms or a system to adjust to changes in conditions

sagittal plane

two-dimensional, vertical plane that divides the body or organ into right and left sides

section

in anatomy, a single flat surface of a three-dimensional structure that has been cut through

sensor

(also, receptor) reports a monitored physiological value to the control center

serosa

membrane that covers organs and reduces friction; also referred to as serous membrane

serous membrane

membrane that covers organs and reduces friction; also referred to as serosa

set point

ideal value for a physiological parameter; the level or small range within which a physiological parameter such as blood pressure is stable and optimally healthful, that is, within its parameters of homeostasis

spinal cavity

division of the dorsal cavity that houses the spinal cord; also referred to as vertebral cavity

superficial

describes a position nearer to the surface of the body

superior

describes a position above or higher than another part of the body proper; also referred to as cranial

supine

face up

systemic anatomy

study of the structures that contribute to specific body systems

thoracic cavity

division of the anterior (ventral) cavity that houses the heart, lungs, esophagus, and trachea

tissue

group of similar or closely related cells that act together to perform a specific function

transverse plane

two-dimensional, horizontal plane that divides the body or organ into superior and inferior portions

ultrasonography

application of ultrasonic waves to visualize subcutaneous body structures such as tendons and organs

ventral

describes the front or direction toward the front of the body; also referred to as anterior

ventral cavity

larger body cavity located anterior to the posterior (dorsal) body cavity; includes the serous membrane-lined pleural cavities for the lungs, pericardial cavity for the heart, and peritoneal cavity for the abdominal and pelvic organs; also referred to as anterior body cavity

X-ray

form of high energy electromagnetic radiation with a short wavelength capable of penetrating solids and ionizing gases; used in medicine as a diagnostic aid to visualize body structures such as bones