Cartilage and Bone - CTB Histo

firm connective tissue

cartilage and bone

hyaline cartilage

connective tissues of cartilage

chondrocytes
ECM

cartilage vascularity

avascular (receives nutrients by diffusion)

types of cartilage

hyaline, elastic, fibrocartilage

all forms of cartilage contain isogenous groups of chodrocytes when they grow

which forms of cartilage contain isogenous groups of chodrocytes when they grow?

interstitial expansion

all forms of cartilage can grow by ______

Hyaline cartilage

found in
Fetal, Articular Respiratory, Costal rib

Hyaline cartilage

Resist compression Cushioning

Hyaline cartilage

Collagen II Aggrecan

Hyaline cartilage

has perichondrium except for the articular cartilage

elastic cartilage

Hyaline cartilage

elastic cartilage

Ear, Larynx (epiglottis)

elastic cartilage

flexible support

elastic cartilage

Collagen II Aggrecan
Elastic fibers

elastic cartilage

has perichondrium

Fibrocartilage

Fibrocartilage

IVD, meniscus,TMJ

Fibrocartilage

Resist compression Resist shearing forces

Fibrocartilage

Collagen II Collagen I
Versican, aggrecan

Fibrocartilage

does not have perichondrium

Appositional growth

from perichondrium, form at surface

Increases in girth

Interstitial growth

cell divisions within the matrix

increases in length and girth

fibrocartilage

elastic cartilage

proteoglycan

cartilage matrix structure that is basophilic

collagen

cartilage matrix structure that is eosinophilic

herniated disk

protrusion of a degenerated or fragmented intervertebral disk so that the nucleus pulposus protrudes, causing compression on the nerve root

herniated disk

rupture of annulus fibrosis

intervertebral disc

synovial joint

created where two bones articulate to permit a variety of motions

has articular cartilage between

synovial joint

arthritis

caused by degradation of articular cartilage

Osteoarthritis risk factors

age (menopause)
joint injury
obesity
genetic (joint alignment, cartilage thickness)

cartilage ECM

not mineralized

cartilage growth

interstitial and appositional

bone growth

appositional

bone blood supply

vascular

bone function

support

calcium and phosphate storage

bone ECM

mineralized

bone organic fibers

collagen I

ground substance proteoglycan

bone inorganic matrix

hydroxyapetite

epiphysis

End of a long bone

metaphysis

where diaphysis and epiphysis meet

diaphysis

shaft of a long bone

periosteium

a dense layer of vascular connective tissue enveloping the bones except at the surfaces of the joints.

transverse canals

osteon / Haversion system

found in compact bones

spongey bone

Cannaliculi

contain processes of osteocytes
to communicate with each other

concentric lamella

rings within osteon

intersticial lamella

rings between osteons

Volkmann's canal

transverse canal, perforating canal

Volkmann's canal

bone making

Osteoprogenitor cells
osteoblasts
osteocytes

Osteoprogenitor cells

periosteal cells and endosteal cells

osteoblasts

secrete bone matrix

not yet surrounded by matrix

osteocyte

Matrix deposition: maintains bone matrix

Surrounded by matrix

bone reabsorption

osteoclasts

osteoclasts

Large multinucleated cells

Derived from mononuclear hemopoietic cells

Phagocytotic

Howship's lacuna

space created by osteoclast resorption

Osteoclasts-mediated bone resorption

1. Decalcify through acidification

2. Degradation of bone matrix

3. Clean up: recycle

Decalcify through acidification

Pumping out proton (H+) (note cytoplasmic infolding)

Degradation of bone matrix

digestion by enzymes released from lysosomes

Clean up: recycle

endocytosis

Osteoporosis

characterized by low bone density

can be prevented by weight bearing exercises

caused by increase in osteoclasts and decreased osteoblasts

osteoporosis

Low bone mass, structure deterioration of bone tissue Bone fragility, and more susceptible to fracture

Osteopetrosis

Increased bone mass, due to defect osteoclast function
Bone fragility, and more susceptible to fracture; Unerrupted teeth

Paget disease

Increased bone remodeling, overactive osteoclast

Softer bone, more susceptible to fracture

Rheumatoid arthritis

Osteoarthritis

elastic cartilage

elastic cartilage

fibrocartilage

ground section

-no organic tissue
-air spaces (formerly organic)
are dark
-fine detail visible

decalcified section

-no mineralized tissue
-stains well with H&E
-fine detail less visible

interstitial lamellae

overlapping aversion canals

spongey bone

contains bone lamellae but no Haversian system

red

many mitochondria, myoglobin & oxidative enzymes (aerobic)

red

these can contract for long periods without fatigue

white

these are quick to fatigue

white

fewer mitochondria & oxidative enzymes (anaerobic)

red

slow twitch

white

fast twitch

Golgi tendon

Dense bodies (Z disc equivalent in smooth muscle cells)

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