Introduction to Anatomy

• Anatomy is a descriptive science, giving names to the body's structures and processes.

Human Anatomy

• It is the study of the structure, shape, size, weight, and location of all organs.
• It includes detailed knowledge of the structures of the various systems within the body.

Methods of Studying Anatomy

• Regional anatomy dissects the body region by region to gain detailed knowledge.
• Systemic anatomy studies the human body system by system.

Anatomical Position

• A person stands in an erect position.
• The head, eyes, and toes are directed anteriorly.
• Arms are adjacent to the sides.
• Palms are facing anteriorly.
• The lower limbs are close together.

Anatomical Planes

• Sagittal plane
• Coronal plane
• Transverse plane

Sagittal Planes

• Are vertical planes dividing the body into right and left halves
• The mid-sagittal (median) plane divides the body into equal right and left halves.
• The para-sagittal plane is parallel to the median plane on either side of the body

Coronal Plane

• Divides the body into anterior and posterior parts.

Transverse Plane

• Divides the body into upper and lower segments.

Terms of Direction

• Anterior means towards the front of the body.
• Posterior (dorsal) means towards the back of the body.
• Superior (cephalic, cranial) means near the upper end.
• Inferior (caudal) means near the lower end.
• Medial means near the median plane.
• Lateral means away from the median plane.
• Superficial means near the surface.
• Deep means away from the surface.
• Proximal means near to the trunk.
• Distal means away from the trunk.
• Radial refers to the lateral side of the forearm.
• Ulnar refers to the medial side of the forearm.
• Tibial refers to the medial side of the leg.
• Fibular refers to the lateral side of the leg.
• Palmer refers to the anterior surface of the hand.
• Planter refers to the sole of the foot.
• Dorsum refers to the other surface of the hand and foot.

Terms of Movement

• Flexion involves bending toward the ventral surface; the anterior surface of the distal segment moves toward the proximal segment.
• Extension is the opposite of flexion, straightening the joint and typically occurring in a posterior direction.

Exceptions to Flexion

• At the shoulder, flexion involves the arm moving forward in front of the chest.
• At the knee flexion involves the posterior surface of the leg moving towards the posterior surface of the thigh.
• At the ankle, dorsiflexion occurs during walking by lifting the front of the foot and toes toward the ground.
• Plantar flexion involves bending the foot and toes towards the ground while standing.
• Abduction is moving away from the median plane.
• Adduction is moving towards the median plane.

Exceptions to Abduction and Adduction

• Abduction and adduction of fingers happens away or towards the middle finger.

• Abduction and adduction of toes happens away or towards the second toe

• Circumduction is a circular movement involving sequential flexion, abduction, extension, and adduction, so the distal and moves in a circle.

• Rotation is movement of a part of the body around its long axis.

• Medial (internal) rotation brings the anterior surface of a limb close to the median plane.

• Lateral (external) rotation takes the anterior surface away from the median plane.

• Pronation and supination are rotational movements of the forearm and hand.

Pronation and Supination

• Movement of the distal end of the radius medially and laterally around the anterior aspect of the ulna, and the proximal end of the radius rotates.
• In pronation, the palm of the hand faces posteriorly, and the dorsum faces anteriorly.
• When the elbow is flexed, pronation moves the hand, so the palm faces inferiorly. Placing the palm flat on a table exemplifies this.
• Supination is the opposite rotational movement, returning the pronated forearm to the anatomical position.
• When the elbow is flexed, supination moves the hand, so the palm faces superiorly.
• Eversion moves the sole of the foot away from the median plane, turning the sole laterally (outward).
• Inversion moves the sole of the foot towards the median plane, turning the sole medially (inward).
• Elevation moves apart superiorly, as in elevation of the shoulder.
• Depression moves apart inferiorly, such as in depression of the shoulder.
• Protraction is to move forward.
• Retraction is to move backward. Movement of the lower jaw is an example.