هياكل الحيوانات .. دراستها تكشف عن الوحدة الجارية بينها -٢- كتاب في سبيل موسوعة علمية

Animal structures...studying them reveals the ongoing unity between them - 2 -

- Chest and arm belt

The pectoral girdle is what holds
The arms.

The thoracic girdle consists of the scapula, which is a thin, wide bone, and two bones, right and left, behind the back. They are anchored in the muscle and do not connect to the vertebral column. They connect at the shoulder to the clavicle (right and left bones), and in the chest. They are two bones whose other ends connect to the breastbone or sternum, and you see them crossing the chest like a bridge in every human body. This completes the banding of the four bones around the chest.
This belt holds the arms.
The upper half of the arm is made up of the humerus. The head of this bone has a gap in the shoulder bone suitable for its rotation. It resides in it, and in it the joint, which consists of (a ball and acetabulum), rotates in it, and this allows the arm to freely move widely.

After the humerus comes the forearm, and the forearm is two bones, the radius, which is the bone closest to the thumb, and the ulna. The two bones, especially the ulna, are connected at the top to the humerus with a single, stable joint, like the hinge of a room door or a regular girder joint, which rotates the two things that always bring them together at one level. You can see this joint prominently in the elbow.

As for the ends of these two lower bones, I mean the forearm bones, the radius and the ulna, they are connected to the palm through the carpal bones, which are eight short bones, the largest of which form a hinge joint with the palm that moves the palm and the forearm at one level. As you hold the key, you open a door and turn it with your hand. But what rotates in your hand and wrist is the forearm bone, the radius.

Then, next to the wrist is the metacarpal, which consists of 5 metacarpal bones, which are intermediate between the wrist and the fingers. The comb is followed by the fingers, which are five. Including the thumb, which is in its position facing the palm of the hand, making the hand a wonderful grasping tool. The human hand is one of the body parts that has had countless accomplishments in human history. The head thinks, and the hand works in every aspect of life.

- Pelvic girdle and legs

We note that the chest girdle is not supported by the vertebral column, but rather by its muscle pillars. But he carries the arms, and does not carry anything else.

If we come to talk about the P-Ivie Girdle, we find it connected to the vertebral column, from above, and the legs are connected to it. It is part of the skeleton, along with the legs, the part that carries the weight of bodies, especially the viscera contained in the abdomen.

The pelvic girdle is a shallow bowl. Each side of it consists of three fused bones: the ilium, the pubic bone, and the hip bone: the Ischium. Where they meet, there is a gap occupied by the head of the upper leg bone, the femur. This head and the gap it occupies is a joint, a “ball in the right.” It is The hip joint is the deepest joint in the body and the most ligamentous, due to the danger of what it does.

The lower end of the femur ends at the lower half of the leg and, as in the forearm, has two parallel bones, but they are much stronger than the forearm bones. They are the tibia, or tibia, and the fibula, and the femur articulates with these two bones at the knee. This dangerous joint is protected from accidents: a disc known as the kneecap.

These two bones articulate at the bottom with bones
Tarsals or Ankle Bones, which are the bones that include the heel bone. These bones are closely connected to each other, making them less mobile.
Next come the metatarsal bones. and she too
It is tied with tight ligaments that keep the sole of the foot arched. The foot splays out if the metatarsal and heel joints become loose, and the foot then loses much of its flexibility when walking and jumping.

From the ball of the foot to the fingers, it is inactive in humans, and its inactivity is due to the fact that the thumb does not face the sole of the foot as in the hand. This ambiguity in humans is less effective than in other animals.

(A drawing showing the similarity between the arms and the pectoral girdle that carried them, in a single human or animal, and between the legs and the pelvic girdle that carried them)

- Skeletal functions

Perhaps it has three apparent functions.
Firstly, it determines the shape of the body, whether it is short or long.
Is it wide or chunky?
The structure is a solid, cohesive structure that holds everything
Contact her and the body parts that have accumulated on her.

The structure is how the limbs of the muscles are connected, and the movement of bodies is nothing but contraction and extension of the muscles, accompanied by tension and relaxation of the bones of the body. The body relies on these to walk, and the hands and feet depend on them for every movement. Life is nothing but movement.

- The human skeleton
Model" for building animal skeletons

By animals, we mean those species that are included in the so-called vertebrates, that is, those that have a vertebra, just as humans have a vertebra. These include humans, and animals such as camels, cows, sheep, goats, and many more, and we have already enumerated a few of them.

As for the rest of the animals, they are those that do not have vertebrae and are called invertebrates. Many of them have structures to support them, but they are not like the structures of vertebrates, and we will return to them.

What we want to say here, in order to reinforce unity, even in vertebrate animals alone, is that the structures of these animals are similar, and they all trace back to the human structure.

(A general picture of the skeleton of a quadruped)