Histological differences between types of cartilage
Reading File
Finding Sources
Searching PubMed
cartilage histology
Searching the Web
cartilage histology hyaline elastic fibrocartilage differences
Searching Images
histology comparison hyaline cartilage elastic cartilage fibrocartilage microscopy
Reading File
Reading File
Finding Sources
The three cartilage types are distinguished mainly by their extracellular matrix and the arrangement of chondrocytes.
| Feature | Hyaline cartilage | Elastic cartilage | Fibrocartilage |
|---|---|---|---|
| Matrix appearance on H&E | Smooth, glassy, homogeneous, bluish matrix | Similar to hyaline, but with visible branching elastic fibers using special stains | Dense, fibrous, eosinophilic matrix with prominent collagen bundles |
| Main fibers | Fine type II collagen fibrils, usually not visible by light microscopy | Type II collagen plus abundant elastic fibers | Mainly type I collagen, with some type II collagen |
| Chondrocytes | Rounded cells in lacunae, often in isogenous groups | Rounded chondrocytes in lacunae, often in small groups | Chondrocytes are fewer, typically arranged in rows between thick collagen bundles |
| Perichondrium | Usually present | Present | Absent |
| Special histological clue | Territorial matrix around lacunae stains darker because it is rich in GAGs | Elastic fiber network surrounds lacunae and makes the tissue flexible | Combination of cartilage cells and dense regular connective tissue appearance |
| Function reflected by structure | Resists compression and provides smooth, low-friction support | Flexible support that returns to shape | Resists both compression and tensile stress |
| Typical sites | Articular surfaces, costal cartilages, nose, larynx, trachea, bronchi, epiphyseal plates | Auricle of ear, epiglottis, auditory tube | Intervertebral discs, pubic symphysis, menisci, tendon-bone insertions |
Recognition under the microscope
- Hyaline cartilage: Look for a “glassy” matrix with lacunae and chondrocytes, but no obvious fibers. In articular cartilage, there is no perichondrium at the free joint surface.
- Elastic cartilage: Looks like hyaline cartilage, but elastic fibers can be demonstrated with stains such as orcein or Verhoeff-Van Gieson. Perichondrium is present.
- Fibrocartilage: Look for thick, parallel or interwoven collagen bundles with chondrocytes in rows. It merges gradually with dense connective tissue and lacks a perichondrium.
A practical memory aid:
- Hyaline = hidden fibers
- Elastic = elastic fibers
- Fibrocartilage = fibrous type I collagen bundles
The matrix of hyaline cartilage is rich in type II collagen and proteoglycans, which makes its collagen fibrils difficult to see on routine staining. Junqueira's Basic Histology - Text and Atlas, 17e, pp. 335-336. Fibrocartilage has less matrix around chondrocytes and no perichondrium, whereas elastic cartilage has elastic fibers in addition to the matrix components of hyaline cartilage. Histology: A Text and Atlas With Correlated Cell and Molecular Biology, pp. 557-558.
Histology of Cerebellum
Reading File
Finding Sources
Searching Images
cerebellum histology molecular layer Purkinje cell layer granular layer micrograph
Searching PubMed
cerebellar cortex histology
Searching the Web
cerebellum cortex histology molecular Purkinje granular layers
Histology of the Cerebellum
The cerebellum has a highly folded outer cerebellar cortex of gray matter surrounding central white matter. Each folium has a branching white-matter core, producing the tree-like arbor vitae appearance.
Layers of cerebellar cortex
From superficial to deep, the cortex has three layers:
| Layer | Histological appearance | Main cells and features |
|---|---|---|
| 1. Molecular layer | Pale, relatively cell-poor outer layer | Contains the extensive dendritic arbor of Purkinje cells, unmyelinated parallel fibers of granule cells, and inhibitory interneurons: stellate cells superficially and basket cells more deeply. |
| 2. Purkinje cell layer | A thin middle layer formed by a single row of very large neurons | Purkinje cells are flask-shaped, conspicuous in H&E sections, and have large vesicular nuclei. Their dendrites ramify upward through the molecular layer. Their axons pass inward and form the only output from the cerebellar cortex to the deep cerebellar nuclei. |
| 3. Granular layer | Thick, dark-staining, highly cellular inner layer | Packed with small granule cells, which have dark round nuclei and scant cytoplasm. Also contains larger Golgi cells and cerebellar glomeruli, where mossy fibers synapse with granule-cell dendrites. |
Beneath the granular layer lies the white matter, composed mainly of myelinated nerve fibers and supporting neuroglia.
Key cells to identify
- Purkinje cells: Large pear- or flask-shaped cells in one row. Their dendrites branch in a flat fan-like pattern in the molecular layer.
- Granule cells: Very small, numerous cells in the granular layer. Their axons ascend into the molecular layer and bifurcate as parallel fibers.
- Basket cells: Located in the deeper molecular layer. Their axons form basket-like terminals around Purkinje-cell bodies.
- Stellate cells: Located in the superficial molecular layer.
- Golgi cells: Larger inhibitory interneurons in the granular layer.
Microscopic identification points
- Look for folia with a pale central white-matter core.
- The cortex has a typical pale-dark-pale arrangement:
- pale molecular layer
- single row of large Purkinje neurons
- dark granular layer
- The single line of Purkinje cells is the most reliable diagnostic feature.
Functional correlation
- Mossy fibers synapse in cerebellar glomeruli with granule cells.
- Granule-cell parallel fibers excite Purkinje-cell dendrites in the molecular layer.
- Climbing fibers synapse directly on Purkinje dendrites.
- Purkinje-cell axons are inhibitory and project to the deep cerebellar nuclei.
The cerebellar cortex consists of molecular, Purkinje-cell, and granular layers; Purkinje cells are the sole cortical output neurons, while granule cells and local interneurons form the major intrinsic circuitry. Junqueira's Basic Histology - Text and Atlas, 17e, Central Nervous System chapter.
This is a shared conversation. Sign in to Orris to start your own chat.