CH: 1 Human Body Orientation

Anatomy

Studies the structure of body parts and their relationships to one another

Physiology

Focuses on the function of the body and how body parts work

Complementarity of structure and function

The concept that what a structure can do depends on its specific form

Hierarchy of structural organization

The levels of organization in the body from chemical to organ systems

Homeostasis

The ability to maintain relatively stable internal conditions

Form (anatomy) determines function (physiology)

The idea that the structure of a body part determines its function

Gross or macroscopic anatomy

The study of large body structures

Microscopic anatomy

The study of structures too small to be seen with the naked eye

Developmental anatomy

Studies structural changes that occur throughout the lifespan

Cytology

The study of the cells of the body

Histology

The study of the tissues of the body

Embryology

The study of developmental changes before birth

Plasma membrane

Separates the intracellular fluid inside cells from the extracellular fluid outside

Catabolism

The breaking down of substances into simpler building blocks

Anabolism

The synthesizing of complex substances from simpler building blocks

Homeostatic control

The communication within the body essential for maintaining homeostasis

Variable

A factor or event being regulated in the body

Receptor

Sensor that monitors the environment and responds to a stimuli

Control center

Determines the set point at which a variable is to be maintained and analyzes input to determine the appropriate response

Effector

Carries out the control center's response to the stimulus and feeds back the results to influence the effect of the stimulus

Negative feedback mechanisms

Output shuts off the original effect of the stimulus or reduces its intensity, causing variable changes in the opposite direction to return to its ideal value

Positive feedback mechanisms

Initial response enhances the original stimulus, causing further responses to be even greater and the variable to deviate further from its original value

Homeostatic imbalance

Condition in which there is a disturbance in homeostasis, often seen in aging when control systems become less efficient

Anatomical position

Standard body position with the body erect, feet slightly apart, palms facing forward, and thumbs pointing away from the body

Superior

Towards the head end or upper part of a structure

Inferior

Away from the head end or toward the lower part of a structure

Anterior (ventral)

Toward or at the front of the body

Posterior (dorsal)

Toward or at the back of the body

Medial

Toward or at the midline of the body

Lateral

Away from the midline of the body

Proximal

Closer to the origin of a 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

Axial part

Main axis of the body including the head, neck, and trunk

Appendicular part

Consists of the appendages or limbs attached to the body's axis

Sagittal plane

Vertical plane dividing the body into right and left parts

Transverse (horizontal) plane

Horizontal plane dividing the body into superior and inferior parts

Dorsal body cavity

Protects the nervous system and includes the cranial and spinal cavities

Ventral body cavity

Anterior and larger cavity that includes the thoracic and abdominopelvic cavities

Serosa (serous membrane)

Thin, double-layered membrane covering the walls of the ventral body cavity and outer surfaces of the organs

Abdominopelvic regions and quadrants

Regions and quadrants created by transverse and median planes passing through the umbilicus

Metabolism

all chemical reactions that occur within body cells

Serous fluid

thin layer of lubricating fluid that separated the serous membranes

Afferent pathway

information approaches the control center

Efferent pathway

information exits the control center