What and What are Flat Bones? Function and Types

The Flat bones Are one of five types in which the bones are classified, whose main functions are to provide protection to an area and to offer a wide surface to allow the fixation of the muscles.

These bones are characterized by sheets of spongy bone tissue, which are covered by compact bone tissue.

Composition of the flat bones

Among the flat bones are the following, which I will explain later:

  • The bones of the skull or cranial vault : Occipital, temporal, sphenoid, frontal, parietal, vomer and lacrimal.
  • The bones of the thorax : The shoulder blade, the ribs and the sternum.
  • The bones of the hip : The ilium, the ischium and the pubis.

Function of the flat bones

The function of flat bones is to protect the internal organs of the body, such as the brain, heart and pelvic organs. This is why they are flattened, since they do the role of shields.

Likewise, being flattened makes them provide ample areas in which the muscles of the body can be fixed.

Types of flat bones

The bones of the skull

The skull, also called the cranial vault, is composed of a series of bones, including the frontal, parietal, occipital, nasal, temporal, lacrimal and sphenoid bones.

The main role of the skull is to protect the brain from damage that could be generated by blows or falls. The bones of the skull are also responsible for forming the eye sockets and nostrils.

In infants and children, the bones of the cranial vault are separated by spaces called sutures, which allow the skull to expand as the brain it grows.

Once the brain reaches its maximum size, the sutures close and the bones of the skull merge.

What and What are Flat Bones?  Function and Types

1- The frontal bone

As the name implies, this bone occupies the entire front of the skull.

2- The parietal bone

The parietal bones are two and are one on each side of the head, between the occipital bone and the frontal bone.

The occipital bone

The occipital bone is located at the back of the skull. In this is the occipital foramen, which is an opening that connects the skull to the spine .

4- The temporal bone

This bone occupies the lower and lateral part of the skull.

5- The sphenoid bones

The sphenoids are located in the lower part of the skull, at the base, and present a cavity in which the pituitary is located.

The bones of the thorax

What and What are Flat Bones?  Function and Types 1

In the thorax are three bony structures that belong to the classification of long bones, namely: the ribs, the sternum and the shoulder blades.

1- The sternum

The sternum is shaped like a tie and is in the center of the chest. The first seven pairs of ribs are connected directly to the sternum; Pairs 8, 9 and 10 are attached to the sternum through cartilage.

The two lower pairs, unlike the rest, are not connected in any way to the sternum, so they are called"floating ribs". In the sternum, three parts are distinguished:

  • Top, which is called manubrio or mango.
  • Middle part, called sternum body.
  • Bottom, called xiphoid tip or appendix.

2- The ribs

The ribs are composed of twelve pairs of bones. All these pairs are connected to the spine, while only ten of these are connected to the sternum.

Ribs protect the heart , To the lungs and to the aorta (one of the main arteries of our body).

The ribs extend to the upper abdomen, offering protection to the liver and spleen.

In addition, during respiration, the ribs move forward allowing the lungs to fill with air.

3- The shoulder blades

The shoulder blades, also called scapulae, are two flat, triangular, slightly curved bones that connect the upper arms to the collarbone. These bones have the function of protecting the back of the chest.

In addition, the shoulder blades are involved in the movements of the back, as well as in the movement of the arms (up, forward and back).

They also provide attachment points for the rotator cuff muscles, which stabilize the shoulder joints.

The bones of the pelvis

What and What are Flat Bones?  Function and Types 2

The bones of the pelvis include the ilium bone, the ischium bone, and the pubis. These bones are organized into two cavities: the major pelvis and the smaller pelvis.

This set of bones provides structural support to the body and allows people to stand.

It is also the area of ​​attachment of various muscles, including the muscles of the abdomen and muscles of the back. In addition, these bones protect certain internal organs like the bladder.

1- The ilion

The ilium is located at the top of the pelvic structure. It is composed of the iliac crest and the iliac spines.

2- The isquion

The ischium is located on the lateral side of the pelvic structure. This presents an area in which the upper muscles that surround the femur are fixed.

3- The pubis

The pubis is located in front of the pelvic structure and closes this structure by the front.


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