Histology Exam 1: Cartilage

Front 1

Matrix

Back 1

A solid but somewhat pliable material. Its composition is crucial to condrocyte survival (due to their lack of blood supply)

Front 2

Chondroblasts

Back 2

Active cells in cartilage that produce the ground matrix and become surrounded by it.

Front 3

Chondrocytes

Back 3

Inactive cells in cartilage that get their name once they become surrounded by extra-cellular matrix.

Front 4

The Three Types of Cartilage

Back 4

Hyaline, Elastic, Fibrocartilage

Front 5

Cartilage

Back 5

A specialized form of connective tissue derived from mesoderm and containing both cells and matrix. It is not mineralized and so it is solid but somewhat pliable and more flexible and resistant than bone. It has a low metabolic/cellular turnover, no blood vessels, no nerves, and no lymphatics.

Front 6

Effects of the Lack of Blood Vessels in Cartilage

Back 6

As size increases, cartilage becomes more isolated from perichondrium (and thus blood supply and nutrition). Mature cartilage is relatively inactive with minimal ability to respond to injury.

Front 7

What features are similar between elastic and hyaline cartilages?

Back 7

They have a similar structure and the same appearance of clustered cells in lucunae. Also, both have an outer perichondrium.

Front 8

How can you distinguish between hyaline and elastic cartilages?

Back 8

Hyalin has more matrix, less fibers, and more defined isogenous groups. Elastic has less matrix, elastic fibers, and crowded isogenous groups. Cells are larger in elastic than hyaline cartilage.

Front 9

Functions of Hyaline Cartilage

Back 9

Forms a model for developing skeleton (replaced by bone) (fetal skeleton & growth plates), Shock absorption (articular surfaces), and Flexible Support (nasal cavity, trachea, larynx, bronchi, ends of the ribs).

Front 10

Locations of Hyaline Cartilage

Back 10

Fetal skeleton, growth plates, articular surface of synovial joints, cartilage of nasal cavity, larynx, trachea, and bronchi, and costal cartilage at the ends of ribs.

Front 11

Chondromucoprotein

Back 11

An important component of ground substance responsible for the "jello" effect. Its level within the ECM falls throughout life (and thus so does water content).

Front 12

What are the effects of reduced chondromucoprotein with age?

Back 12

There is impaired diffusion of nutrients to and from the chondrocyte, resulting in starvation and death of the impaired chondrocyte. A cycle begins whereby the dead chondrocyte can no longer maintain its surrounding ECM which may calcify and hinder diffusion to nearby chondrocytes.

Front 13

Locations of Elastic Cartilage

Back 13

Ear (pinnna), External auditory tube, Eustachian tube, Larynx (epiglottis).

Front 14

Functions of Elastic Cartilage

Back 14

Confers flexibility and shape retention and is adapted to resist bending.

Front 15

General Features of Fibrocartilage

Back 15

"Less matrix; many collagen ribers- T1; few cells in rows"
It resembles dense connective tissue and never occurs alone (always merges with adjacent tissues). It is found in only a few locations and has no true perichondrium.

Front 16

Locations of Fibrocartilage

Back 16

It is present in locations that need resistance to compression and sheer forces. Sites include: Intervertebral discs, pubic symphysis, articular discs of the tempromandibular joint, and menisci of the knee joint.

Front 17

Functions of Fibrocartilage

Back 17

To absorb shock and resist compression, it occurs where tough support or high tensile strength is needed.

Front 18

ECM of Fibrocartilage

Back 18

It has more collagen than the other kinds of cartilage, minimal matrix with less chondromucoprotein, mostly Type 1 collagen (with some Type 2), and collagen fibers are oriented in the direction of stress.

Front 19

Cells of Fibrocartilage

Back 19

Chondrocytes in lacunae are squeezed into short rows between collagen fibers in the ECM, they look more like fibroblasts (spindle shaped), and their primary job is synthesis of collagen Type 1.

Front 20

General Features of Hyaline Cartilage

Back 20

"More matrix; less fibers, collagen Type 2; defined isogenous groups"
It is the most abundant type of cartilage, with a smooth and glassy appearance, and is found at both articular and non-articular sites.

Front 21

ECM of Hyaline Cartilage

Back 21

Is produced by chrondroblasts and maintained by chondrocytes, it has a homogenous, amporphous, pink appearance. It is located around and between chondrocytes and can be territorial (immediately surrounding lacunae and staining dark blue) or between clusters of cells (staining lighter blue). It consists motly of collagen fibers in ground substance.

Front 22

Ground Substance

Back 22

Is what the matrix consists of. It binds to collagen, has a high affinity for water, and consists of varying amounds of chondromucoprotein.

Front 23

How Are Cells of Hyaline Cartilage Different from Cells of Elastic Cartilage?

Back 23

Chondrocytes live in lacunae either as single cells or isogenous groups in both types. Cells are larger in elastic cartilage and packed more densely into isogenous groups.

Front 24

Perichondrium of Hyaline Cartilage

Back 24

A dense layer of CT that surrounds the cartilage but is not seen at articular locations. It is the source of progenitor cells that produce chondroblasts and consists of two layers. The outer fibrous layer contains fibroblasts that make collagen Type 1. The inner cellular layer differentiates into condroblasts.

Front 25

Histologic Appearance of Elastic Cartilage

Back 25

It is similar in structure to hyaline cartilage, having clustered cells in lacunae and an outer perichondrium. Its matrix is criss-crossed by elastic fibers (some Type 2 collagen). Cells of elastic cartilage are larger than those of hyaline and isogenous groups are more densely packed.