Directional Terms, Homeostatsis, & Body Planes

Superior

• above

• Toward the head end or upper part of a structure or the body

Inferior

• below

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

Cephalic

• flows toward head

Caudal

• flows toward tail

Anterior/ Ventral

• front

Posterior/ Dorsal

• back

Proximal

• closer to the point of reference
  (head is the point of reference in the picture)

Distal

• farther from the point of reference
  (head is the point of reference)

Lateral

• away from the midline

Medial

• towards the midline

Superficial

• Toward or at the body surface

• external

Deep

• Away from the body surface;

• internal

Contralateral

• opposite side of the body

Ipsilateral

• same side of the body

Intermediate

• between 2 structures

Ventral & Dorsal

This term is strictly used in humans

Homeostasis

• ability to maintain relatively stable internal conditions even though the outside world is continuously changing.

• internal balance

Stimulus

• produces change in variable.

• disrupts homeostasis

• triggers

Receptor

• detects change

Afferent pathway

• leads information TOWARDS the control center.

Control Center

• analyzes the information it receives and then determines the appropriate response

• receives and generates

Efferent Pathway

• leads information AWAY the control center.

Effectors

• provides the means for the control center’s response (output) to the stimulus.

• brings about change

Response

• Reduce or enhance effect of stimulus.

Negative Feedback System

• reverses a change in a controlled condition

• the net effect of the response to the stim ulus is to either shut off the original stimulus or reduce its intensity.

Positive Feedback System

• strengthen or reinforce a change in a controlled condition.

Clinical Connection

• Autopsy

• Diagnosis of Disease

Autopsy

• examination of the body and dissecting of internal organs to determine the disease or cause of death

• a.k.a necropsy

• necro- death

Diagnosis of disease

• the science and skill of distinguishing one disorder or disease from another

• basically whatever the doctors said

Body Planes

• imaginary flat surface that passes through the body.

Sagittal plane

• separates the body to left and right

Median plane

• a sagittal plane that passes through the midline of the body.

Transverse (horizontal) plane

• divides the body into superior and inferior

Frontal (Coronal) plane

• divides body into front and back