Superior/Inferior:
Placement of a body structure along the long axis of the body. Divides the body into upper and lower
Anterior/Posterior
The most anterior structures or surfaces are those that are most forward (face, chest, abdomen). Posterior structures or surfaces are those toward the backside of the body.
Medial/Lateral:
Toward the midline/away from the midline
Cephalad/Caudal:
Toward the head/toward the tail. Used interchangeably with superior and inferior.
Dorsal/Ventral
Backside/belly side. Used interchangeably with anterior and posterior.
Proximal/Distal
Nearer the truck or attachment end/farther from the trunk or point of attachment. Used primarily to locate various areas of the body limbs.
Superficial/Deep
Toward or at the body surface/away from the body surface or more internal. Used to locate body organs in terms of their relative closeness to the body surface.
Anatomical position and Directional terms
essential to have an initial reference point and indications of direction.
anatomical position
body is erect with feet together and palms facing forward with the thumbs pointing away from the body.
direction
right and left" refer to those sides of the person or cadaver being viewed.
Regional Terms:
the most fundamental divisions of the body are its axial and appendicular parts.
axial
makes up the main axis of the body. Consists of the head, neck, and trunk
appendicular
- consists of the appendages or limbs
Body Planes and Sections
involves dissection in which the body or its organs are cut along an imaginary line, called a plane.
sagittal
runs longitudinally. Divides the body or organ into right and left portions.
midsagittal
(median plane) - exactly midline and the parts are symmetrical or equal.
parasagittal
all other sagittal planes
frontal
runs longitudinally, but the body or organs are divided into anterior and posterior.
transverse
runs horizontally across and at a right angle to the long axis of the body or organ and divides it into superior and inferior parts
Body Cavities and Membranes
there are two major closed body cavities within the axial portion of the body: Dorsal Body Cavity and Ventral Body Cavity
Dorsal Body Cavity
Located nearer to the dorsal or posterior surface of the body. Subdivided into cranial and vertebral or spinal. They are continuous with one another. They house vital and very fragile organs - brain and spinal cord.
Ventral Body Cavity
More anterior and larger. Two major subdivisions: thoracic and abdominopelvic.
Thoracic cavity
The thoracic is surrounded by the ribs and muscles of the chest and is subdivided: lateral pleural cavities each containing a lung. and medial mediastinum which contains the heart and remaining thoracic organs (esophagus, trachea etc.)
Abdominopelvic cavity:
Divided into the abdominal cavity which contains the stomach, intestines, spleen, liver, and other organs and the pelvic cavity which contains the bladder, some reproductive organs, and the rectum.
Serous Membranes
the walls of the ventral body cavity and the outer surfaces of the organs are covered with a thin, double layered membrane - serosa or serous membranes.
Parietal serosa
Part of the membrane lining the cavity walls - parietal serosa -folds on itself to form the visceral serosa which covers the organs in the cavity.
Parietal - "parie"- means wall
Visceral - "viscus"- means an organ in a body cavity
Serous fluid
The serous layers are separated by a thin lubricating fluid -serous fluid. It allows the organs to slide easily across the cavity walls and one another without friction.
1. parietal pericardium -
lines pericardial (heart) cavity
2. visceral pericardium
covers the heart
3. parietal pleura
lines thoracic wall in the pleural cavity
4. visceral pleura
covers the lungs
Pleurisy
Inflammation of serous membranes, accompanied by a deficit of lubricating fluid results in excruciating pain as organs stick together.
Abdominopelvic Regions
right to left by rows, top to bottom:
right hypochondriac region, eigastric region, left hypochondriac region, right lumbar region, umbilical region, left lumbar region, right iliac region, hypogastric region, left iliac region