Anatomy Overview and Anatomical Position

Study Notes

The study of the human body structure that examines how body parts are organized.
Anatomical descriptions occur while the body is in the anatomical position.

Skin: the outermost layer of the body.
Superficial fascia: subcutaneous layer that lies beneath the skin.
Arteries, veins, and nerves: blood vessels and nerves that run through the body.
Deep fascia: dense, organized connective tissue found beneath superficial fascia.
Muscles: tissues responsible for movement.
Bones: the hard, rigid structures providing support and protection.
Joints: points where bones connect, allowing movement.

A collection of connective tissue.
Superficial fascia: loose connective tissue found beneath the skin.
Deep fascia: more dense connective tissue with collagenous bundles arranged more compactly and regularly, often forming membranes.

Investing fascia: Covers the surfaces of muscles.
- In the neck: forms layers that define fascial spaces, limiting the spread of infection and determining its path.
- In the limbs: forms sheaths surrounding muscles.
Retinacula: Localized thickenings of deep fascia around joints that hold tendons in place and prevent bowstringing (excessive movement).
There is no deep fascia in the face except the parotid and masseter, breast, penis, or anterior abdominal walls.

These planes are used for reference when describing the location or direction of body parts.
Median Sagittal Plane (Midsagittal): Divides the body into equal right and left halves.
Coronal Plane: Vertical plane that divides the body into anterior (front) and posterior (back) parts. Also known as a Frontal plane.
Transverse (Horizontal) Plane: Perpendicular to both the median and coronal planes. Divides the body horizontally into upper and lower parts.

Anterior (Ventral): Towards the front of the body. E.g., The nose is on the anterior of the head.
Posterior (Dorsal): Towards the back of the body. E.g., The heel is posterior to the toes.
Superior (Cephalic): Towards the top of the body. E.g., The shoulders are superior to the hips.
Inferior (Caudal): Towards the bottom of the body. E.g., The stomach is inferior to the heart.
Medial: Towards the midline of the body.
Lateral: Away from the midline of the body.
Distal: Away from the trunk.
Proximal: Nearer to the trunk
Axis: An imaginary line running through the center of the body or a body part.
Central: Towards the central axis of the body.
Peripheral: Away from the central axis of the body.
Prone: Face down.
Supine: Face up.
Deep: Towards the inside of a part, away from the surface. E.g., The thigh muscles are deep to the skin.
Superficial: Toward the surface of a part, away from the inside. E.g., The skin is a superficial organ.

Flexion: Decreases the angle between bones or body parts.
Extension: Increases the angle between bones or body parts.
Dorsiflexion: Flexion at the ankle joint, moving the foot upward so the dorsal surface approaches the shin.
Plantarflexion: Extension at the ankle joint, moving the foot downwards, increasing the angle between the dorsal surface and the shin.
Abduction: Moving away from the body midline.
Adduction: Moving towards the body midline.
Rotation: Turning or revolving a body part around its longitudinal axis.
- Medial Rotation: Rotation towards the midline of the body.
- Lateral Rotation: Rotation away from the midline of the body.
Pronation: Rotation of the forearm so that the palm of the hand faces posteriorly (backward), and the dorsum of the hand faces anteriorly (forward).
Supination: Rotation of the forearm so the palm of the hand faces anteriorly (forward), and the dorsum of the hand faces posteriorly (backward).
Opposition: Movement where the pad of the thumb is brought to another digit pad. Used in pinching and buttoning.
Protrusion: Anterior (forward) movement.
Retrusion: Posterior (backward) movement.
Protraction (Scapular Abduction): Movement of the shoulder girdle forward.
Retraction (Scapular Adduction): Movement of the shoulder girdle backward.
Eversion: Lateral (outward) rotation of the sole of the foot.
Inversion: Medial (inward) rotation of the sole of the foot.