Cartilage । Definition and elements of Cartilage

Cartilage is made up of semi-hard and elastic material called chondrin. Its matrix is ​​composed of proteins called chondromucoid and chondralbunoid. Chondromucoid and chondralbuinoid together are called chondrin. It contains collagen, elastin, proteoglycan, chondrocytes etc. Cartilage cells are called chondrocytes. Clusters of chondrocytes are called lacunae. It is covered by perichondrium.

Joint । Definition and types of joints

The junction of two or more bones or cartilages is called a joint. There are three types of joints.

  1. Fibrous or Synarthrosis Joints: The joints where the bones are connected by fibrous ligaments are called fibrous ligaments. It is of three types.

(i) Suchar (Treaty of Ten)

(ii) Syndesmosis (tibia-fibula joint)

(iii) Gomphosis (joint of teeth and jaws)

  1. Cartilaginous/Amphiarthrosis/Cartilaginous Joints: Bone joints containing cartilage are called amphiarthrosis joints. It is of two types.

(i) Symphysis (pubis symphysis)

(ii) Synchondrosis (joint of cartilage)

  1. Synovial joint: The joint containing oily and slippery fluid called synovial is called synovial joint. It is 7 types. namely-

(i) Pivot (atlas joint)

(ii) Hinge joint (elbow joint)

(iii) Ball and Cotoral Joints (Skandha/Femur Joints)

(iv) Flat joint (Carpal joint)

(v) Saddle (metacarpal joint)

(vi) Ellipsoid joint (carpal joint)

Osteon । Function, importance of bone or osteons

  1. Structure of the body : Bones form the structure of the body and give specific shape to the body.
  2. Preservation : The soft parts of the bony body protect the heart, lungs, brain, spinal cord, etc.
  3. Movement : Skeletal muscles control body movement through contraction and extension.
  4. Red blood cell production : Red blood cells are produced from the bone marrow.
  5. Immunity : A stable reticuloendothelial system increases the body’s immune system.
  6. Breathing and hearing : Some of the unstable parts are modified to help in breathing and hearing.
  7. Mineral salt storage : Bone stores calcium, phosphorus, potassium etc. About 97% of the body’s calcium is stored in bones.
  8. Accumulation of toxic elements : If there are toxic elements in the body like lead, arsenic, etc., the bones store them.
  9. As a junction : Acts as a junction of muscles, ligaments and tendons.
  10. Pressure and Ionic Balance : Maintains the internal pressure and ionic balance of the body.
  11. Hormonal action : Osteocalcin hormone is produced by bone marrow. This hormone regulates blood sugar and fat levels.
  12. Chemical energy storage : As we age, some red bone marrow turns into yellow bone marrow. Bile bone marrow contains adipose cells. Adipose cells store chemical energy.

Osteon : Anatomy of Osteon or Haversian

  1. Haversian Duct: The duct located in the unstable center is called Haversian duct. It contains veins, arteries and lymphatics. The Haversian ducts are connected to each other by the ducts of Vochmans.
  2. Lamellae: 5-15 layers surround the Haversian canal. Each layer is called lamellae. It contains calcium, phosphorus and collagen.
  3. Lacuna: Each lamella contains tiny cavities. Each cavity is called a lacuna. Each lacuna contains bone cells called osteocytes or osteoblasts or osteoclasts.
  4. Canaliculi: Each lacuna is surrounded by several fine tubules. These ducts are called canaliculi. Lacunae are connected to each other by canaliculi. It transports nutrients and waste materials.
  5. Medullary cavity: The cavity in the unstable center is called the medullary cavity. It is filled with red or yellow pulp