REVIEW SHEET THE APPENDICULAR SKELETON - domainedemanville

Appendicular Skeleton: Your Review Sheet to Understanding Movement

The appendicular skeleton, comprising the bones of your limbs and their attachments (girdles), is crucial for movement and interaction with the environment. It includes roughly 126 bones and allows for diverse actions like walking, running, grasping, and manipulating objects. This review sheet will help you understand its components and functions.

The Pectoral Girdle: Connecting Upper Limbs

The pectoral girdle attaches the upper limbs to the axial skeleton. It's comprised of two bones on each side of the body:

• Clavicle (Collarbone): A slender, S-shaped bone that connects the sternum to the scapula. It acts as a strut, keeping the shoulder joint away from the rib cage.
• Scapula (Shoulder Blade): A flat, triangular bone located on the posterior aspect of the thorax. It articulates with the clavicle and the humerus (upper arm bone). The glenoid cavity, a shallow depression on the scapula, forms the socket for the shoulder joint.

The pectoral girdle's design prioritizes flexibility and range of motion over stability, which is why the shoulder is prone to dislocations. review sheet 6 anatomy and physiology

Upper Limb: Bones of the Arm, Forearm, and Hand

The upper limb consists of the humerus (arm), radius and ulna (forearm), and the carpals, metacarpals, and phalanges (hand):

• Humerus: The long bone of the upper arm, articulating with the scapula at the shoulder and the radius and ulna at the elbow.
• Radius: One of the two forearm bones, located on the thumb side. It articulates with the humerus, ulna, and carpals.
• Ulna: The other forearm bone, located on the pinky finger side. It articulates with the humerus, radius, and carpals. The olecranon process forms the bony point of the elbow.
• Carpals: Eight small bones that form the wrist. They are arranged in two rows.
• Metacarpals: Five bones that form the palm of the hand, each articulating with a carpal bone and a proximal phalanx.
• Phalanges: The bones of the fingers. Each finger has three phalanges (proximal, middle, and distal), except the thumb, which has only two (proximal and distal). review sheet exercise 10 the appendicular skeleton

Learn more about the skeletal system and its parts at Wikipedia - Skeletal System.

The Pelvic Girdle: Connecting Lower Limbs

The pelvic girdle attaches the lower limbs to the axial skeleton and supports the weight of the body. It's formed by two hip bones (coxal bones), which articulate with the sacrum posteriorly.

• Hip Bone (Coxal Bone): Each hip bone is formed by the fusion of three bones: the ilium, ischium, and pubis. reviews of flvs The acetabulum, a deep socket on the lateral surface of the hip bone, receives the head of the femur (thigh bone).

The pelvic girdle is much more robust and less flexible than the pectoral girdle, providing stability for weight-bearing and locomotion.

Lower Limb: Bones of the Thigh, Leg, and Foot

The lower limb includes the femur (thigh), tibia and fibula (leg), and the tarsals, metatarsals, and phalanges (foot):

• Femur: The long bone of the thigh, articulating with the hip bone at the hip joint and the tibia and patella at the knee joint. It is the longest and strongest bone in the body.
• Patella (Kneecap): A sesamoid bone embedded in the tendon of the quadriceps femoris muscle. It protects the knee joint and improves the leverage of the quadriceps muscle.
• Tibia: The larger of the two leg bones, located on the medial side. It articulates with the femur, fibula, and talus (ankle bone).
• Fibula: The smaller of the two leg bones, located on the lateral side. It articulates with the tibia and talus.
• Tarsals: Seven bones that form the ankle and posterior part of the foot. reviews on hum flatter me
• Metatarsals: Five bones that form the arch of the foot, each articulating with a tarsal bone and a proximal phalanx.
• Phalanges: The bones of the toes. Each toe has three phalanges (proximal, middle, and distal), except the big toe, which has only two (proximal and distal).

Frequently Asked Questions

What is the main function of the appendicular skeleton?

The main function of the appendicular skeleton is to enable movement and manipulation of the environment.

How many bones are in the appendicular skeleton?

There are approximately 126 bones in the appendicular skeleton.

What is the difference between the pectoral and pelvic girdles?

The pectoral girdle connects the upper limbs to the axial skeleton and prioritizes flexibility, while the pelvic girdle connects the lower limbs and prioritizes stability and weight-bearing.

What bones make up the forearm?

The forearm is made up of two bones: the radius and the ulna.

What bones make up the hand?

The hand is made up of the carpals, metacarpals, and phalanges.

Summary

The appendicular skeleton is essential for mobility and interaction. Knowing its components—the pectoral and pelvic girdles, and the bones of the upper and lower limbs—is crucial for understanding human anatomy and biomechanics. Reviewing these elements will give you a solid foundation for further study.