Appendicular skeleton

Appendicular skeleton is the portion of the skeletal system that consists of the pectoral and pelvic girdles, and the limbs that attach to them. It was designed to collaborate with the axial skeleton to give flexibility, strength, support, and movement to the body.

There are a great many bones in the appendicular skeleton. The pectoral girdle consists of the clavicle, scapula. The lower limbs include the humerus, radius, ulna, carpals, metacarpals, and phalanges. The pelvic girdle consists of the coxa and sacrum, and the lower limbs have the tarsals, metatarsals, and phalanges. The wrist and hand has twenty seven bones, an ankle and foot includes twenty six bones. In fact, wrists, hands, ankles, and feet contain more than half of the bones in the human body, summing up to 106 bones total.

Creation of man and God's command
 * Genesis 1:26-28. "Then God said, 'Let us make mankind in our image, in our likeness, so that they may rule over the fish in the sea and the birds in the sky, over the livestock and all the wild animals, and over all the creatures that move along the ground.' So God created mankind in his own image, in the image of God he created them; male and female he created them. God blessed them and said to them, 'Be fruitful and increase in number; fill the earth and subdue it. Rule over the fish in the sea and the birds in the sky and over every living creature that moves on the ground."

Pectoral girdle


Appendicular skeleton is the portion of the skeleton that consists of the girdles and the limbs. The primary function of the pectoral girdle, which is composed of the clavicle and the scapula, is to attach the upper limbs to the axial skeleton. The arm is made up of the humerus, and the forearm is made up of the radius and the ulna. The appendicular skeleton also consists of the pelvic girdle at which the lower limbs are attached to the axial skeleton.

The pectoral girdle - includes the clavicle and scapula.


 * Clavicle - It is a part of the appendicular skeleton that attaches it to the axial skeleton. The rounded end of the clavicle attaches to the sternum and the flat end attaches to the scapula. It is considered a long bone and the only bone in the body that lies horizontally. It supports the scapula and prevents the scapula from going forward, allowing the arms to hang at the sides. It collaborates with the scapula to allow the body certain movements.


 * Scapula - The scapula, also known as the shoulder blade, is found on the back shoulder. The scapula, shaped as flat triangular, lies from the shoulder to the vertebral column. The acromion, formed by the body ridge on the back, serves as a projection on top of the shoulder joint. The coracoid process also serves as a projection for the shoulder blade. The coracoid process, located beneath the clavicle, attaches the muscles. The glenoid cavity combined with the shoulder blade on the upper outer corner forms a ball and socket joint, allowing the body large movement.

Upper limbs

 * Humerus - It is the upper arm which lies on top of the forearm, the ulna and radius. The ball and socket joint lies at the lower humerus and connects the humerus to the forearm. The lower humerus and the upper ulna form hinge joint while the lower humerus and the upper radius form the ball and socket joint. Each joint allows the elbow flexibility and movement.


 * Radius and Ulna - The radius and the ulna make up the forearm, located on the outside and the inner side of the arm, respectively. Upper radius with the lower humerus form a ball and socket joint and the upper ulna with the lower humerus form a hinge joint. The lower parts of the radius and the ulna are attached to the carpals, the wrist bones. The radius is bigger in size and thus the majority of attachment of the forearm to the wrist comes from the radius. The radius rotates as the wrist rotates; the radius comes on top of the ulna.


 * Carpals - Carpals are the wrist bones that connect the lower radius and the lower ulna to metacarpals. Carpals consist of eight short bones.


 * Metacarpals - Metacarpals are the bones that make up the palm of the hand. There are 5 metacarpal bones. Metacarpals connect the carpals to the phalanges.


 * Phalanges - Phalanges consist of fourteen bones. They are also known as the finger bones. Each finger, except the thumb, has three phalanges bones. The phalanges are made up of the proximal, middle, and distal phalanx.

Pelvic girdle


The pelvic girdle (or simply pelvis), is the point of attachment for the lower limbs to the axial skeleton. It is composed of two coxae, one sacrum bones. The pelvis is attached to the lower limbs and provides a strong support for the pectoral girdle and the axial skeleton.


 * Coxa - coxa is also known as the hip bone. Human body contains two coxae bones, which consist of the ilium, pubis, and ischium bones. In a child, these three bones are spaced out; however, as the child matures, the bones combine into a single coxa. Two coxa bones and a sacrum provide strength and support for the upper body. The ilium, located in the middle of the coxa, has the largest size of the three bones. The pubis is found under the ilium and next to femur. Symphysis pubis bone is located next to the pubis.


 * Sacrum - The sacrum lies between the two coxae. It has a triangular shape and is inserted like a wedge.

Lower limbs

 * Lower limbs - The lower limbs are composed of thigh, made of one femur bone, and the leg, consisting of tibia and fibula. The leg is attached to the thigh at the knee. The patella, a sesamoid bone, is the tendon of the knee joint. The patella reduces the friction between the muscles.


 * Tarsals - Six tarsal bones form the ankle and are attached to metatarsals.


 * Metatarsals - There are five metatarsal bones in the foot. They are inserted between the tarsals and the phalanges.


 * Phalanges - Three phalanges, formed by fourteen short bones, make up the digits in the foot and also in the hands. The three phalanges are: a proximal phalanx, a middle phalanx, and a distal phalanx. However, the toes in the hands and in the feet only have two bones: proximal and distal.

Videos
Overview of the appendicular skeleton

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