Anatomy Terminologies

Anatomical Terminologies

• Ventral/Anterior: Refers to the front of the trunk.
• Dorsal/Posterior: Refers to the back of the trunk.
• Medial: A plane close to the median plane.
• Lateral: A plane away from the median plane.
• Proximal/Cranial/Superior: Refers to the area close to the head end of the trunk.
• Distal/Caudal/Inferior: Refers to the area close to the lower end of the trunk.
• Superficial: Refers to areas close to the skin or towards the surface of the body.
• Deep: Refers to areas away from the skin or away from the surface of the body.
• Ipsilateral: Located on the same side of the body as another structure.
• Contralateral: Located on the opposite side of the body from another structure.
• Invagination: A projection that goes inside.
• Evagination: A projection that goes outside.

Introduction to Skeleton Bones

• The skeleton is the framework that supports soft tissues and protects internal organs in humans and animals.
• It forms a structural framework for the body.

Anatomical Position

• Anatomical position refers to the positioning of the body when standing upright and facing forward.
• Arms hang by the sides, palms facing forward, legs are parallel, and feet are flat on the floor and facing forward.
• The purpose of standard anatomical position is to clearly discuss different parts of moving organisms without confusion.

Subdivisions of Human Skeleton

• The human skeleton is divided into three parts: upper limb, lower limb, and spine.

Upper Limb Bones

• The upper limb bones include:
  • Shoulder bones (scapula, clavicle, and humerus)
  • Arm bones (humerus)
  • Forearm bones (radius and ulna)
  • Hand bones (carpal bones, metacarpals, and phalanges)

Shoulder Bones

• Clavicle:
  • A long, slender bone that connects the upper limb to the trunk.
  • Ends: sternal end (enlarged and triangular) and acromial end (flat).
  • Body (shaft): elongated.
  • Surfaces: inferior, superior, anterior, and posterior.
  • Articulates: medially with the manubrium of the sternum and 1st costal cartilage at the sternoclavicular joint, and laterally with the acromion process of the scapula at the acromioclavicular joint.
  • Function: holds the arm away from the trunk, transmits forces from the upper limb to the axial skeleton, and provides attachment for muscles and ligaments.

Scapula

• A flat, triangular bone that lies on the posterior chest wall between the 2nd and 7th ribs.
• Borders: medial, lateral, and superior.
• Angles: superior, inferior, and lateral.
• Surfaces: anterior, posterior, and superiorolateral.
• Function: engages in 6 types of motion to allow for full-functional upper extremity movement.

Humerus

• A long bone that extends from the shoulder to the elbow.
• Proximal aspect articulates with the glenoid fossa of the scapula, forming the glenohumeral joint.
• Distal aspect articulates with the head of the radius and trochlear notch of the ulna.

Radius and Ulna

• Radius: a bone in the forearm that forms the radiocarpel joint at the wrist and the radio-ulnar joint at the elbow.
• Ulna: a bone in the forearm that forms the elbow joint with the humerus and articulates with the radius both proximally and distally.
• Function: assists in pronation and supination of the forearm and hand.

Hand Bones

• Carpal bones: a set of eight irregularly shaped bones in the wrist area.
• Metacarpals: five bones that articulate with the carpal bones and the phalanges.
• Phalanges: the bones of the fingers, each consisting of a proximal, middle, and distal phalanx (except for the thumb, which has only two).

Lower Limb Bones

• Pelvic bone: a complex of bones that connects the trunk and the legs, supports and balances the trunk, and contains and supports the intestines, urinary bladder, and internal organs.
• Thigh bone: the femur, which occupies the space between the hip and knee joints.
• Leg bones: the tibia and fibula.
• Foot bones: a complex of bones that form the ankle and foot.

Femur

• The longest and strongest bone in the body, which extends from the hip to the knee joint.
• Proximal aspect articulates with the pelvic bone.
• Distal aspect articulates with the patella and the proximal aspect of the tibia.

Patella

• A flat, inverted triangular bone situated on the front of the knee joint.
• Articulates with the femur to form the patellofemoral joint.
• Function: allows for smooth movement during knee flexion/extension and protects the anterior surface of the knee joint.

Sesamoid Bones

• Protect tendons from excessive wear and act as a spacer to change the angle of tendons before they reach their attachment point.
• Examples: patella, sesamoid bones in the metatarsophalangeal joint of the big toe, and sesamoid bones in the metacarpophalangeal joint of the thumb.

Tibia and Fibula

• The tibia is a medial and large long bone that connects the knee and ankle joints.
• The fibula is a thinner and posteriolaterally situated bone that provides stability to the ankle joint.
• The tibia and fibula are connected by the interosseous membrane.

Foot Bones

• A complex of bones that form the ankle and foot.

Spine

• The spine is composed of 33 individual bones stacked on top of each other.
• It provides the main support for the body, allowing for upright posture, bending, and twisting, while protecting the spinal cord from injury.
• The vertebrae are divided into regions: cervical, thoracic, lumbar, sacrum, and coccyx.
• Only the top 24 bones are moveable; the vertebrae of the sacrum and coccyx are fused.

Understanding basic anatomical terminologies is crucial for describing the human body. This quiz covers essential terms for directions and positions in the body.