Tecido Cartilagíneo
Tecido Ósseo
Cartilagem Hialina
Hyaline cartilage provides structural support in the
respiratory system (larynx, trachea and bronchi).
The airway of the trachea is held open
by cartilaginous rings of hyaline cartilage:
•Perichondrium - a layer of dense irregular connective
tissue that surrounds cartilage. It is divided into two
layers:
• Outer Fibrous Layer - contains fibroblasts
that produce the type I collagen on the
outer surface of the perichondrium.
• Inner Chondrogenic Layer - contains
fibroblast-like cells that can differentiate
into chondroblasts, initiate matrix
production (type II collagen) and become
immature chondrocytes.
•Chondrocytes - cells within lacunae inside the
cartilage that occur singularly or in clusters called
isogenous groups.
•Matrix - composed mostly of type II collagen and a
ground substance of proteoglycans.
• Territorial Matrix - basophilic area
immediately around chondrocytes.
• Interterritorial Matrix - less intensly stained
area between isogenous groups of
chondrocytes.
Hyaline cartilage contains no blood vessels or nerves.
Cartilagem
Elástica
Elastic and hyaline cartilage have similar
appearances when stained by H&E
because elastic fibers are unstained.
Compare with the next specimen stained
with Verhoeff's.
Elastic cartilage forms the core of the
epiglottis:
•Perichondrium - a layer of dense
irregular connective tissue that surrounds
cartilage. It is divided into two layers:
• Outer Fibrous Layer - fibroblasts
that produce the type I collagen
on the outer surface of the
perichondrium.
• Inner Chondrogenic Layer contains mesenchymal cells that
differentiate into chondroblasts,
initiate matrix production (elastin
and type II collagen) and become
immature chondrocytes.
Cartilagem
Fibrosa
Intervertebral discs that are found between adjacent
vertebrae of the spine contain fibrocartilage. They have
a fibrous appearance of mostly collagen fibers with
interspersed areas of cartilage.
(Note that the cytoplasm has been extracted from most
of the cells during sample preparation.)
•Collagen Fibers - the majority of the fibrocartilage is a
mixture of type I and type II collagen. They type I
collagen is stained pink/red.
•Fibroblasts - scattered cells within fibrous regions with
elongated or flattened nuclei. Few are seen in this
specimen.
•Chondrocytes - are dispersed between collagen
fibers singularly, in columns, or in isogenous groups and
are surrounded by a basophilic matrix.
•Matrix - much less material surrounds each
chondrocyte than in hyaline cartilage. It is composed of
type II collagen and a ground substance of
proteoglycans. The basophilia is due to a high content of
sulfated glycosaminoglycans (GAGs).
•There is no perichondrium.
Fibrocartilage contains no blood vessels or nerves.
Ossificação Endocondral
PE
CH
Endochondral bone formation occurs at
the epiphyseal plate of long bones. It can
be identified by the layer of
basophilic hyaline cartilage.
•Resting Zone - thin layer of non-dividing
chondrocytes.
•Proliferative Zone - rapidly dividing
chondrocytes (basophilic) that organize
into distinct columns ("stacks of coins").
•Zone of Hypertrophy - chondrocytes
(basophilic) cease dividing and grow in
size. The cartilage matrix forms (lightly
basophilic) linear bands between the
columns of hypertrophied cells.
•Zone of Calcification - the cartilage
matrix becomes calcified inhibiting the
diffusion of nutrients. The dying
chondrocytes are removed leaving
longitudinal spicules of calcified cartilage
(intensely basophilic).
•Zone of Ossification - osteoprogenitor
cells migrate into the cavities with the
new blood vessels. New bone
(eosinophilic) forms on the scaffold of
calcified cartilage (basophilic).
Ossificação
Intramembranosa
Different stages of intramembranous bone
formation are seen in the skull cap (calvarium)
when moving from the center to the right.
•Condensation - mesenchymal cells migrate
and aggregate into areas where bone will form
(a bone blastema).
•Osteoprogenitor Cells - the condensation of
mesenchymal cells initiates the differentiation
of osteoprogenitor cells.
•Osteoblasts - the synthesis of components of
the bone matrix indicates the further
differentiation of osteoprogenitor cells into
osteoblasts. Their basophilic cytoplasm is from
the synthesis of proteins in osteoid (mostly
type I collagen).
•Osteoid - unmineralized, organic portion (type I collagen and ground substance) of bone
matrix. Narrow, light-pink region between osteoblasts and the bone spicule.
•Osteocytes - osteoblasts trapped inside lacunae of the bone.
•Bone spicules - composed of women immature (or primary) bone with mineralized osteoid
that is more basophilic than unmineralized osteoid.
•Trabeculae - form from bone spicules that fuse with each other to provide the general
shape of a developing bone.
Tecido ÓSSEO COMPACTO Osteon
Ground section of bone stained with Schmorl's
stain to reveal small, open spaces in the bone.
The higher contrast allows the fine structure of
bone to be seen in excellent detail.
Osso Esponjoso
•Spongy (or cancellous) Bone - trabeculae
of woven immature (or primary) bone. The
osteocytes and collagen fibers are
randomly arranged in the mineralized
osteoid.
• Osteoblasts - found on the surface
of some bone spicules.
• Mesenchymal and
Osteoprogenitor Cells - found in
tissue between bone spicules.
• Osteoclasts - large, multinucleated
cells that remove bone tissue.
They form a resorption bay when
attached to bone.
• Haversian System - little evidence
of osteons characteristic of
mature (or secondary) bone. A
few developing osteons can be
found. Osteons are arranged
parallel with the lines of stress in
mature bone.
•Marrow Cavity - filled with developing
blood cells.
Observar Cartilagem, Osso
• Cartilagem Hialina
• traqueia
• Cartilagem Elástica
• orelha
• Fibrocartilagem
• Tecido Ósseo
• Compacto
• Esponjoso
• Desenvolvimento
endocondral
(cartilagineo)
• Desenvolvimento
intramembranoso