Cartilage and bone histology
Cartilage is a type of elastic connective tissue that fulfills a supporting and protective function in the body. Cartilage tissue is avascular and therefore relies on obtaining its nutrients via diffusion, sometimes even over large distances.
There are 3 types of cartilage:
- Hyaline cartilage
- Elastic cartilage
Fibrocartilage is a type of cartilage that should be viewed as a blend between hyaline cartilage and dense fibrous connective tissue. It is a white, densely arranged, opaque, tufted tissue with a mixture of both chondrocytes and fibroblasts. The former typically lie between bundles of type I and type II collagen fibers. Due to its unique composition and anatomical location, it is resistant to mechanical stress and has a great tensile strength. Fibrocartilage is found in the intervertebral discs, in the socket of the temporomandibular joint or in the menisci in the knee joint.
Solidify your knowledge of fibrocartilage histology with this study unit:
Test your knowledge of the histology of fibrocartilage with the following quiz:
Hyaline cartilage is the most common type of cartilage in the human body. It is typically characterized by a firm consistency and a smooth surface. In contrast to fibrocartilage, there is no dense and fibrillar ECM in hyaline cartilage. Light microscopy usually reveals many densely grouped chondrocytes with strongly stained cartilage capsules in hyaline cartilage. Between them, there is an extracellular ground substance made up of proteoglycans and glycoproteins, which appears much brighter and more homogeneous. The proteins in the ground substance have a high water-binding capacity, which allows the hyaline cartilage to carry out its function.
Hyaline cartilage is usually surrounded by a perichondrium. It is found in joints as articular cartilage, in costal cartilage, in the cartilaginous framework of the nose, the larynx (most parts), the trachea, the bronchi and in growing bones.
Want to learn more about the histology of hyaline cartilage? Then work your way through the following study unit:
Test your knowledge of the histology of hyaline cartilage with this quiz:
Elastic cartilage has a similar composition as hyaline cartilage. However, the chondrocytes present are rather isolated and there is an abundance of elastic fibers embedded in the ground substance. These fiber networks typically appear yellowish in a fresh specimen, while in histological slides, they can be easily visualized using special stains.
Elastic cartilage is always surrounded by a perichondrium. It is found in the auricle, the external auditory canal, the ear trumpet, the epiglottis, the larynx and the small bronchi, where its flexibility and resistance to bending forces and deformation is functionally important.
Solidify your knowledge of elastic cartilage histology with this study unit:
Test your knowledge of the histology of elastic cartilage with the following quiz:
Bone tissue consists of various cell types such as osteoblasts, osteocytes and osteoclasts, as well as a mineralized extracellular matrix. Osteoblasts deposit bone material (protein fibers) into the bone matrix, the osteocytes are the bone cells that lie in the lacunae of the bone matrix and osteoclasts can dissolve and break down the mineralized bone matrix again.
Flat bones, like those of the cranium, consist of a layer of spongy bone, covered on either side by a layer of compact bone. Long bones are made mostly of compact bone, with lesser amounts of spongy bone and bone marrow.
Every time bone is formed, woven bones are formed first, in which collagen fibrils and bone cells are still irregularly arranged. Mature bones are called lamellar bones, where osteons form the functional units and collagen fibrils are arranged in an organized manner in the lamellar system.
Want to learn more about the histology of bone tissue? Then work your way through the following study unit:
Test your knowledge of the histology of bone tissue with this quiz:
Bone tissue formation
During intramembranous, direct ossification, mesenchymal tissue is directly converted into woven bone. This type of bone formation takes place in the calvarium (skull), in parts of the mandible and in the clavicle.
However, most bones are formed through endochondral, indirect ossification. Cartilage tissue (hyaline cartilage) is initially formed from aggregated mesenchymal cells, which is later broken down and ossified.
Both types of ossification play an essential role in the formation of long bones, while only endochondral ossification takes place in short bones.
Solidify your knowledge of the histology involved in bone tissue formation with this study unit:
Test your knowledge of the histological features of bone tissue during ossification with the following quiz:
Articles within this topic:
Cartilage and bone histology: want to learn more about it?
Our engaging videos, interactive quizzes, in-depth articles and HD atlas are here to get you top results faster.
What do you prefer to learn with?
“I would honestly say that Kenhub cut my study time in half.”