Anatomy

ANATOMICAL POSITION

All anatomical descriptions are expressed in relation to one consistent position, ensuring that descriptions are not ambiguous. One must visualize this position in the mind when describing patients (or cadavers) whether they are lying on their sides, supi

ANATOMICAL PLANES

Based on four imaginary planes (median, sagittal, frontal, and transverse) that intersect the body in the anatomical position; used mainly to describe sections (longitudinal sections, transverse or cross-sections, oblique sections)

Median plane

vertical plane passing longitudinally through the body
divides the body into right and left halves
defines the midline of the head, neck, and trunk where it intersects the surface of the body

Sagittal plane

vertical plane passing through the body parallel to the median plane
parasagittal - commonly used; unnecessary; any plane parallel to and on either side of the median plane is sagittal by definition a plane parallel and near the median plane - may be refe

Frontal (coronal) plane

vertical plane passing through the body at right angles to the median plane
divides the body into anterior (front) and posterior (back) parts

Transverse plane

horizontal planes passing through the body at right angles to the median and frontal planes
divides the body into superior (upper) and inferior (lower) parts

TERMS OF RELATIONSHIP AND COMPARISON

adjectives, arranged as pairs of opposites, used to describe relationships of parts of the body or compare the position of two structures relative to each other

Anterior (ventral)

nearer to the front, e.g., the sternum is the anterior to the heart

Posterior (dorsal)

nearer to the back, e.g., the kidneys are posterior to the intestine *in the hands, the terms palmar and dorsal surfaces are used in place of anterior and posterior

Superior (cranial, cephalic)

nearer to the head, e.g., the heart is superior to the stomach

Inferior (caudal)

nearer to the feet, e.g., the stomach is inferior to the heart

Medial

nearer to the median plane, e.g., the 5th digit ( little finger) is on the medial side of the hand

Lateral

farther away from the median plane, e.g., the 1st digit (thumb) is on the lateral side of the hand

Proximal

nearer to the trunk or point of origin, e.g., the elbow is proximal to the wrist; the proximal part of an artery is its beginning

Distal

farther from the trunk or point of origin, e.g., the wrist is distal to the elbow; the distal part of the limb is the foot

Superficial

nearer to or on the surface, e.g., the arm muscle are superficial to the humerus

Deep

farther from the surface, e.g., the humerus is deep to the arm muscles

Unilateral

occurring on one side only, e.g., spleen

Bilateral

paired structures having right and left members, e.g. lungs

Ipsilateral

occurring on the same side of the body as another, e.g., the right thumb and the right big toe are ipsilateral

Contralateral

occurring on the opposite side of the body relative to another structure, e.g., the right hand and the left hand are contralateral

TERMS OF MOVEMENT

Movements take place in joints where two or more bones meet or articulate with one another

Flexion

bending or decreasing the angle between bones or parts of the body

Extension

straightening or increasing the angle between bones or part of the body, e.g., extending the knee joint

Abduction

moving away from the median plane in the coronal plane, e.g., abducting the upper limb

Adduction

moving toward the median plane in the coronal plane, e.g., adducting the lower limb

Circumduction

circular movement combining flexion, extension, abduction and adduction occurring in such a way that the distal end of the part moves in a circle, e.g., circumduction of the shoulder joint

Rotation

involves turning or revolving a part of the body around its longitudinal axis, e.g., turning one's head to the side

Medial (internal) roation

brings the anterior surface of a limb closer to the median plane, e.g., medial rotation of the shoulder joint

Lateral (external) rotation

takes the anterior surface away from the median plane, e.g., lateral rotation of the hip joint

Elevation

raising or moving a part superiorly, e.g., as occurs when shrugging the shoulders

Depression

lowering or moving a body part inferiorly, e.g., as occurs in depressing the shoulders when standing at ease

Protraction

anterior movement of the shoulders

Retraction

posterior movements of the shoulders

Protrusion

moving anteriorly, e.g., sticking the chin out

Retrusion

moving posteriorly, e.g., tucking the chin in

Pronation

movement of the forearm and hand that rotates the radius medially around its longitudinal axis so that the palm of the hand faces posteriorly and its dorsum faces anteriorly
when elbow joint flexed --> moves hand so that palm faces inferiorly

Supination

movement of the forearm and hand that rotates the radius laterally around its longitudinal axis so that the dorsum of the hand faces posteriorly and the palm faces anteriorly
� when elbow joint flexed --> moves hand so that palm faces superiorly

Abduction of digits

movement of the fingers away from the middle (3rd) digit or the toes away from the 2nd digit

Adduction of digits

movement of the fingers toward the 3rd digit or the toes toward the 2nd digit

Opposition

movement by which the 1st digit (thumb) pad is brought to another digit (finger) pad, e.g., when holding a pen, pinching something, or lifting a teacup by the handle

Reposition

movement of the 1st digit from position of opposition back to anatomical position

Dorsiflexion

flexion of the ankle joint, as occurs when when walking uphill or lifting the front of the foot and toes off the ground

Plantarflexion

bends the foot and toes toward the groundf, as occurs when standing on your toes

Eversion

moving the sole of the foot away from the median plane or turning the sole of the foot laterally

Inversion

moving the sole of the foot toward the median plane or sole of foot faces medially