Human Skeletal System: Structure, Functions and Diseases
The skeletal system provides the rigid structure or framework to the human body that protects the body. The skeletal system is made up of connective tissues such as bones, cartilage, tendons and ligaments. In this article we will read about its structure, function, disorders of bones and different types of joints.
The skeletal system provides the rigid structure or framework to the human body that protects the body. It is made up of connective tissues such as bones, cartilages, tendons and ligaments. Do you know that if the skeleton is without any joints then there will be no movement and the human body will be nothing but a stone?
On the basis of the skeleton present in the body, skeletons are of two types:
- Exterior Skeleton: The skeleton found in the outer layer of the body is called the outer skeleton. It is basically formed from the immature outer skin (ectoderm) or mesoderm. It protects and protects the internal organs and the dead. Such as scales of fish, outer hard layer of turtle, feathers of birds etc.
- Endo Skeleton: This skeleton is found inside the human body and is made up of mesoderm. It is found in almost all vertebrates and forms the main structure of the body. Did you know that these skeletons are covered with muscles?
The internal skeleton is composed of two basic components, depending on the structure:
- Bone: It is a solid, tough and strong connective tissue composed of fibers and matrix. Its matrix is ​​made up of proteins and it is also rich in calcium and magnesium. Do you know that the strength of bones is due to the minerals present in it? The matrix of bone is in the form of concentric rings called lamellae. Bone cells are called osteoblasts or osteocytes. It resides between lamellae in fluid-filled spaces called lacunae.
The bone is surrounded by a double layered membrane made up of connective tissue called periosteum. Muscles, tendons and nerves are attached through this membrane.
Thick and long bones have hollow pit-like spaces, which are called marrow cavity. A fluid is found in this cavity. This substance is called bone marrow. The surprising thing is that the bone marrow is yellow in color in the middle and red in the sides of the bones. Hence known as yellow bone marrow and red bone marrow respectively. The function of red bone marrow is to make RBCs and the function of white bone marrow is to make WBCs.
Bone works:
- It gives shape to the body.
- Protects vital organs like brain, lungs etc.
- Provides structural support to the body and supporting muscles (anchor muscles).
- Stores calcium and phosphate.
- Cartilage: It is special connective tissue which is solid and less vascularised. Its matrix is ​​made up of proteins and due to calcium salts hardens slightly but it is solid, cheese-like and strong. Also it has some flexibility. For this reason cartilage is not as hard and rigid as bone.
Its matrix consists of a large network of collagen fibers and living cells called chondrocytes. These are present in fluid-filled spaces called lacunae. Remember blood vessels are not in the matrix. A membrane is found around the cartilage which is called perichondrium.
Cartilage is found in the following parts of the body – the outer part of the ear, the tip of the nose, the hyoid, the intervertebral discs, on the ends of the long bones, on the lower part of the ribs and in the rings of the trachea.
Let us now discuss the human skeletal system in detail.
The skeleton of the entire human body consists of 206 bones and is mainly composed of two parts:
Axial Skeleton system – 80 Bones
The skeleton that forms the main axis of the body is called the axial skeletal system. It consists of skull bone, spinal cord, ribs and sternum.
• Components of Axioskeleton Skull: Human skull consists of 29 bones, out of which 8 bones provide protection to the human brain and are attached to the bone sutures of the skull. The rest of the bones make up the human face, of which 14 are remarkably reactive.
• Vertebral Column: This is the main axis of the body and looks like a rod made of long and thick bones. It occurs in the rough surface of the human body from the middle of the head to the back of the waist. It is made up of 33 bones and is developed jointly and smoothly by the notochord. Each bone of the spine is hollow in the center.
Sternum: The bone connecting the ribs is called the sternum and it is located in the middle of the chest of the human body.
• Rib: There are 12 pairs of ribs found in the human body and it is a fibrous structure of bone.
Skull – consists of cranium, face and ears (auditory ossicles – auditory ossicles).
The hyoid – the English letter U-shaped bone or complex bone, is in the neck between the chin and the larynx.
Spinal cord – bone segment of the spinal cord.
Thoracic Cage – Contains ribs and sternum (thoracic bone).
Appendicular Skeleton System – 126 bones
This skeletal system is made up of the bones of the hands and feet and their support. Under this the bones of the waist, hands, feet etc.
• Girdles: Two circular-like structures on the axial skeleton that accommodate the front and rear limbs (forelimb and hindlimb) are called girdles. The girdle of the forelimb is called the pectoral girdle and the girdle of the posterior limb (the hindlimb) is called the pelvic girdle.
The bone of the front limb in the muscular circle and the bone of the posterior limb in the pelvic circle are attached to the humerus and femur respectively and accommodate in a cavity known as the acetabulum.
• Muscle girdles and arm bones: In the human body, both parts of the muscle girdles are separated and in each part only one flat and triangular bone is found together called the scapula and the bones of the hands. The muscle girdles themselves provide the joints for connecting.
Each front limb (forelimb) and hand consists of five parts: the upper hand, the front hand, the wrist, the palm, and the fingers.
The humerus, radius ulna, wrist bone, metacarpals and finger/thumb bone are the bones of the upper hand, front hand, wrist and fingers respectively.
• Pelvic chakra and leg bones: The pelvic chakra is mainly made up of three bones – the hip bone (Ilium), the ischium and the pubis. In adults, these three bones are interconnected. At the joint of these bones there is a narrow cavity called acetabulum. The end of the femur bone is attached to it. Even the pelvic chakra provides joints to connect the leg bones. There are many types of foot bones found in humans like femur, tibia, fibula, tarsals, meta tarsals, etc. Of these bones, the tibia fibula is free and a circular bone is found at the joint of the femur and tibia fibula, which is called the knee bone petal. The human foot turns only once at this place.
Therefore, we can say that in the provisional skeletal system :
- Pectoral Girdle – Contains the bones of the shoulder (clavicle and scapula).
- Upper Limbs – Contains the bones of the hands.
- Pelvic Girdle - Contains the bones of the hip.
- Lower limbs – Contains bones of feet and toes.
bone disorders in skeletal system
Arthritis:
This is a common disease of old age. It is caused by inflammation in the joints, due to which there is a lot of pain and stiffness in the joints. There is no cure for it, only painkillers can be used.
Osteoarthritis:
This is a degenerative disease of the joints in which the bones of the joints keep on weakening and new bones start growing rapidly.
Rheumatoid arthritis:
This is due to the presence of an arthritis-like factor called immunoglobulin (IgM) and the primary symptom is inflammation of the synovial membrane.
Gout arthritis: This occurs due to the body's inability to build up too much uric acid or eliminate it from the body. Basically this disease is diet related so the patient should avoid eating meat.
Osteoporosis:
It is a progressive age-dependent disorder characterized by a decrease in bone mass, a gradual decrease in bone formation, and the likelihood of fractures.
Joints in the skeletal system
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Joints in the skeletal system |
The places Joints that serve to connect two or more bones or a bone and cartilage.
The type of joint in the skeletal system
On the basis of mobility and movement, joints are classified into three categories: Perfect Joint, Imperfect Joint and Fixed Joint.
Perfect Joint
In this type of joint, the bones can move in different directions and there can be movement or movement in them simultaneously. Bones with this type of joint also have a thin layer of cartilage on their sides and ligaments at the joints of the bones.
Full addition is divided into five subcategories:
- Ball and Socket Joint: In this type of joint the ball-shaped bones can move in any direction like the muscle girdle and the humerus bone joint, the femur and pelvic ligament etc. In this, the femur and humerus bone can be bent or movable in any direction.
- Hinge Joint: The bones of this type of joint can move or move in only one direction. Example elbow and knee joints.
- Pivot Joint: This type of joint has a sharp pointed bulge and a narrow gap in the other bone in which the pointed bulge is adjusted. It moves like an axle. Example- Secondary vertebral bone and atulus.
- Gliding Joint: In this type of joint, the bones can push each other to a certain extent but can never bend or bend. Example, joints of elbow and carapace etc.
Saddle joint
In this type of joint the bulge of one bone is fully accommodated in the gap of the other bone but cannot move or move smoothly and smoothly. For example, the carapace of the thumb and the joint of the meta carpal.
Incomplete Joints:
Bones found within the synovial cavity and ligaments do not have this type of joint. In addition, some dynamic movements are also found in these bones. Like found in the pubis bone of the pelvic chakra and also between the joints of the vertebrae.
Fixed Joint:
These types of joints are fixed and do not show any kind of movement, hence they are called fixed joints. For example, bones of the skull and girdles.
Conclusion
The skeletal system is very very important for a human and any other. so please taker it.
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