Hyaline cartilage
Encyclopedia
Hyaline cartilage consists of a slimy mass, pearly bluish in colour with firm consistency and considerable collagen. It contains no nerve
s or blood vessels, and its structure is relatively simple.
Hyaline cartilage is covered externally by a fibrous membrane, called the perichondrium
, except at the articular ends of bones and also where it is found directly under the skin, i.e. ears and nose. This membrane contains vessels that provide the cartilage with nutrition.
If a thin slice is examined under the microscope
, it will be found to consist of cells of a rounded or bluntly angular form, lying in groups of two or more in a granular or almost homogeneous matrix
.
The cells, when arranged in groups of two or more, have generally straight outlines where they are in contact with each other, and in the rest of their circumference are rounded.
They consist of clear translucent protoplasm
in which fine interlacing filaments and minute granules are sometimes present; embedded in this are one or two round nuclei
, having the usual intranuclear network.
The cells are contained in cavities in the matrix, called cartilage lacunae; these are actually artificial gaps formed by the shrinking of the cells during the staining and setting of the tissue for observation. The interterritorial space between the isogenous cell groups contains relatively more collagen fibers, causing it to maintain its shape while the actual cells shrink, creating the lacunae.
This constitutes the so-called capsule of the space.
Each lacuna is generally occupied by a single cell, but during the division of the cells it may contain two, four, or eight cells. (see isogenous group
)
Hyaline cartilage also contains chondrocytes which are cartilage cells that produce the matrix. Hyaline cartilage matrix is mostly made up of type II collagen and Chondroitin sulfate
, both of which are also found in elastic cartilage
.
Hyaline cartilage exists on the ventral ends of ribs; in the larynx, trachea, and bronchi; and on the articular surface of bones.
s.
Though it is often found in close contact with menisci
and articular disk
s, articular cartilage is not considered a part of either of these structures, which are made entirely of fibrocartilage
.
Nerve
A peripheral nerve, or simply nerve, is an enclosed, cable-like bundle of peripheral axons . A nerve provides a common pathway for the electrochemical nerve impulses that are transmitted along each of the axons. Nerves are found only in the peripheral nervous system...
s or blood vessels, and its structure is relatively simple.
Hyaline cartilage is covered externally by a fibrous membrane, called the perichondrium
Perichondrium
The perichondrium is a layer of dense irregular connective tissue which surrounds the cartilage of developing bone. It consists of two separate layers: an outer fibrous layer and inner chondrogenic layer. The fibrous layer contains fibroblasts, which produce collagenous fibers. The chondrogenic...
, except at the articular ends of bones and also where it is found directly under the skin, i.e. ears and nose. This membrane contains vessels that provide the cartilage with nutrition.
If a thin slice is examined under the microscope
Microscope
A microscope is an instrument used to see objects that are too small for the naked eye. The science of investigating small objects using such an instrument is called microscopy...
, it will be found to consist of cells of a rounded or bluntly angular form, lying in groups of two or more in a granular or almost homogeneous matrix
Matrix (biology)
In biology, matrix is the material between animal or plant cells, in which more specialized structures are embedded, and a specific part of the mitochondrion that is the site of oxidation of organic molecules. The internal structure of connective tissues is an extracellular matrix...
.
The cells, when arranged in groups of two or more, have generally straight outlines where they are in contact with each other, and in the rest of their circumference are rounded.
They consist of clear translucent protoplasm
Protoplasm
Protoplasm is the living contents of a cell that is surrounded by a plasma membrane. It is a general term of the Cytoplasm . Protoplasm is composed of a mixture of small molecules such as ions, amino acids, monosaccharides and water, and macromolecules such as nucleic acids, proteins, lipids and...
in which fine interlacing filaments and minute granules are sometimes present; embedded in this are one or two round nuclei
Cell nucleus
In cell biology, the nucleus is a membrane-enclosed organelle found in eukaryotic cells. It contains most of the cell's genetic material, organized as multiple long linear DNA molecules in complex with a large variety of proteins, such as histones, to form chromosomes. The genes within these...
, having the usual intranuclear network.
The cells are contained in cavities in the matrix, called cartilage lacunae; these are actually artificial gaps formed by the shrinking of the cells during the staining and setting of the tissue for observation. The interterritorial space between the isogenous cell groups contains relatively more collagen fibers, causing it to maintain its shape while the actual cells shrink, creating the lacunae.
This constitutes the so-called capsule of the space.
Each lacuna is generally occupied by a single cell, but during the division of the cells it may contain two, four, or eight cells. (see isogenous group
Isogenous group
An isogenous group is a cluster of chondrocytes, all formed through division of a single progenitor cell, found in hyaline cartilage growing by interstitial growth....
)
Hyaline cartilage also contains chondrocytes which are cartilage cells that produce the matrix. Hyaline cartilage matrix is mostly made up of type II collagen and Chondroitin sulfate
Chondroitin sulfate
Chondroitin sulfate is a sulfated glycosaminoglycan composed of a chain of alternating sugars . It is usually found attached to proteins as part of a proteoglycan. A chondroitin chain can have over 100 individual sugars, each of which can be sulfated in variable positions and quantities...
, both of which are also found in elastic cartilage
Elastic cartilage
Elastic cartilage or yellow cartilage is a type of cartilage present in the outer ear, larynx, and epiglottis. It contains elastic fiber networks and collagen fibers. The principal protein is elastin....
.
Hyaline cartilage exists on the ventral ends of ribs; in the larynx, trachea, and bronchi; and on the articular surface of bones.
Articular Cartilage
The term "articular cartilage" refers to the hyaline cartilage on the articular surfaces of boneBone
Bones are rigid organs that constitute part of the endoskeleton of vertebrates. They support, and protect the various organs of the body, produce red and white blood cells and store minerals. Bone tissue is a type of dense connective tissue...
s.
Though it is often found in close contact with menisci
Meniscus (anatomy)
In anatomy, a meniscus is a crescent-shaped fibrocartilaginous structure that, in contrast to articular disks, only partly divides a joint cavity. In humans it is present in the knee, acromioclavicular, sternoclavicular, and temporomandibular joints; in other organisms they may be present in other...
and articular disk
Articular disk
The articular disk is a thin, oval plate of fibrocartilage present in several joints which separates synovial cavities. This separation of the cavity space allows for separate movements to occur in each space....
s, articular cartilage is not considered a part of either of these structures, which are made entirely of fibrocartilage
Fibrocartilage
White fibrocartilage consists of a mixture of white fibrous tissue and cartilaginous tissue in various proportions. It owes its flexibility and toughness to the former of these constituents, and its elasticity to the latter...
.
See also
- CartilageCartilageCartilage is a flexible connective tissue found in many areas in the bodies of humans and other animals, including the joints between bones, the rib cage, the ear, the nose, the elbow, the knee, the ankle, the bronchial tubes and the intervertebral discs...
- HyalineHyalineThe term hyaline denotes a substance with a glass-like appearance.-Histopathology:In histopathological medical usage, a hyaline substance appears glassy and pink after being stained with haematoxylin and eosin — usually it is an acellular, proteinaceous material...
- Articular cartilage injuriesArticular cartilage injuriesCartilage structures and functions can relatively easily be harmed, often resulting in damage. Such damage can result from a variety of causes, resulting from a bad fall or sport-accident , previous knee injuries or wear and tear over time...
- Articular cartilage repairArticular cartilage repairThe aim of an articular cartilage repair treatment is to restore the surface of an articular joint's hyaline cartilage. Over the last decades, surgeons and researchers have been working hard to elaborate surgical cartilage repair interventions...