Introduction to the Body
Directional Terms
Directional terms describe the positions of structures relative to other structures or locations in the body, it is necessary to learn some useful terms for describing body structure.
- Superior: Above the point of referral.
- Inferior: Below the point of referral.
- Anterior: Front or frontal
- Posterior: Back or behind
- Medial: Toward the midline of the body.
- Lateral: Away from the midline of the body.
- Proximal: Nearest to point of origin of a part.
- Distal: Away from or farthest from the point of origin of a part.
- Deep: Further away from body surface
- Superficial: Closer to the body surface
Body cavities and their Contents
There are 4 main body cavities, these are:
- Head (cephalic)
- Chest (thoracic)
- Abdomen
- Pelvis
Head
The head consists of:
- Cranium
- Brain
- Origins of cranial nerves
- Inner and middle ears
- Major blood vessels
- Eyes
- Nasal cavities
- Oral cavity
Thorax
The chest or thoracic cavity contains:
- Lungs - Lie lateral to the mediastinum
- Heart
- Trachea
- Oesophagus
- Major blood vessels
- Nerves
These organs are protected by the thoracic cage, and this is formed by the thoracic vertebrae, the ribs, the costal cartilages, and the sternum
Abdomen
The abdomen contains:
- Stomach
- Liver
- Kidneys
- Adrenal Glands
- Pancreas
- Duodenum
- Small Intestine
- Large Intestine
- Gall Bladder
- Ureters
- Spleen
- Major blood vessels
- Nerves
Pelvis
The pelvis contains:
- Rectum
- Bladder
- Urethra
- Reproductive organs
Planes of the Body
Although the planes of the body are not generally used in the pre-hospital environment I thought I'd add them as they come under the same heading of anatomical directional terms.
- Frontal (or coronal) - Divides the body into front and rear sections
- Horizontal (transverse) - Divides the body into a superior and an inferior section.
- Median sagittal - Divides the body or any of its parts into right and left sides.