Cartilage and Bone

VIBS 443/602

OBJECTIVES

GENERAL ORGANIZATION

MECHANISM OF GROWTH

CHARACTERISTICS OF CELLS

CELLS OF CTFIBROBLASTSMESENCHYMAL

CELLS and RBCADIPOSE CELLS MACROPHAGEPLASMA CELLSMAST CELLS and WBC

CHONDROBLASTSCHONDROCYTES OSTEOBLASTSOSTEOCYTES OSTEOCLASTS

TYPES OF CARTILAGE

FIBROCARTILAGE

HYALINE CARTILAGE ELASTIC CARTILAGE

primary spongiosa of the Fetal finger220

Fetal elbow194

Fetal elbow194

Tibia, fetal

Trachea, monkey133

EM 11: cartilage

1. Chondrocyte

2. Fibroblast

3. Appositional growth region

4. Type I collagen

5. Type II collagen

Appositional growth of cartilage

EM 13: cartilage interstitial growth of chondrocytes

1. 2 daughter chondrocytes resulting from interstitial growth

2. Rough endoplasmic reticulum

interstitial growth of cartilage

HYALINE CARTILAGE

EPIPHYSEAL PLATE, RESPONSIBLE FOR LONGITUDINAL GROWTH OF LONG BONES

cartilage growth in endochondral bone formation of the Fetal finger

220

OSTEOCLAST

OSTEOBLAST

OSTEOCLAST

OSTEOBLAST

Elastic cartilage in pina of ear #19762

Elastic cartilage

Connective tissue

epitheliumConnective tissue

epithelium

Elastic cartilage

FIBROCARTILAGE

INTERMEDIATE BETWEEN DENSE REGULAR CONNECTIVE TISSUE AND HYALINE CARTILAGE

NO PERICHONDRIUM

Fibrocartilage of Fetal elbow194

Fibrocartilage

Fibrocartilage

Fibrocartilage of Fetal elbow194

Fibrocartilage

Fibrocartilage of Fetal elbow194

Fibrocartilage

Fetal finger – fibroblasts in tendon220

FibrocartilageTendon

endochondral bone formation

CELLS OF BONE OSTEOBLASTS - SECRETE OSTEOID - BONE

– EXPAND BONE BY APPOSITIONAL GROWTH

OSTEOCYTE =

OSTEOBLAST

TRAPPED IN

MATRIX OF

BONE

EM 12: osteoblast adjacent to osteoid; bone; RER and Golgi

1. Rough endoplasmic reticulum

2. Golgi

3. Osteoid

4. Nucleus of osteoblast

APPOSITIONAL GROWTH

CELLS OF BONE

FUNCTIONS OF BONE CALCIUM REGULATION

Parathroid hormone (BONE RESORPTION)

Calcitonin (PREVENTS RESORPTION)

These HORMONES areINVOLVED IN TIGHT REGULATION as

1/4 OF FREE CA++ IN BLOOD IS EXCHANGED EACH MINUTE.

HEMOPOIESIS

COMPACT BONE

HAVERSIAN SYSTEMS - LAMELLAE OF BONE AROUND HAVERSIAN CANAL LINKED BY VOLKMANN’S CANAL

COMPACT BONEREMODELING

Over time

COMPACT BONEREMODELING

Slide 121: compact bone (unstained ground bone)

1. Blood vessel

2. Haversian canal

3. Interstitial system

4. Lacuna

Bone (unstained) 425

Bone (unstained) 425

Bone, rabbit femur121

Bone, rabbit femur121

Bone, rabbit femur121

Tibia, fetal

Osteoblasts in the Fetal jaw195

Osteoclasts, osteoblasts, and osteocytes in Fetal jaw

195

osteocytes

osteoclasts

osteoblasts

Rib

How many Osteoclasts of Fetal finger can you spot?

Osteoclasts

ENDOCHONDRAL (SPONGY/ CANCELLOUS) BONE FORMATION

CARTILAGE MODEL

CENTERS OF OSSIFICATION

PRIMARY CENTER OF OSSIFICATION• DIAPHYSIS

SECOND CENTER OF OSSIFICATION• CENTER OF EACH EPIPHYSIS

cartilage growth in endochondral bone formation of the Fetal finger

Articular surfaces of hyaline cartilage of the

Fetal elbow

194

HISTOGENESIS OF BONEINTRAMEMBRANOUS

OSSIFICATION

FLAT BONES

OF SKULL

SKELETAL CONNECTIVE TISSUE

32583

Polychromatic normoblast