Lab 6 –Cartilage and Bone A560 – Fall 2015 I. Introduction Cartilage and Bone II. Learning Objectives III. Slides and Micrographs A. Cartilage 1. Hyaline 2. Fibrocartilage 3. Elastic B. Bone 1. Woven 2. Lamellar a. Compact b. Cancellous (seen later) IV. Summary

Light micrograph of human bone in cross section under polarized light – Kent Wood Photography Lab 6 –Cartilage and Bone A560 – Fall 2015

I. Introduction Cartilage and Bone II. Learning Objectives III. Slides and Micrographs 1. Cartilage is a specialized type of solid A. Cartilage connective tissue which, along with bone, is 1. Hyaline distinguished by its relative rigidity of the 2. Fibrocartilage extracellular matrix (ECM); it is distinguishable 3. Elastic from bone by its avascularity B. Bone 1. Woven 2. Types of cartilage (hyaline, fibrocartilage, elastic) are distinguished by the characteristics 2. Lamellar of their matrix (e.g., the dominant type of a. Compact protein fiber) b. Cancellous (seen later) IV. Summary 3. Bone is a specialized type of solid connective tissue characterized by a mineralized ECM that stores calcium and phosphate

4. Woven (immature) bone differs from lamellar (mature) bone in its collagen fiber arrangement; woven bone is replaced by lamellar bone in adults, with few exceptions Lab 6 –Cartilage and Bone A560 – Fall 2015 I. Introduction Learning Objectives II. Learning Objectives III. Slides and Micrographs 1. Understand the variations in structure and function of the three major A. Cartilage 1. Hyaline types of cartilage, with regard to both the cellular and extracellular 2. Fibrocartilage elements. 3. Elastic B. Bone 2. Understand the key ultrastructural features of the chondroblast and how 1. Woven they relate to function. 2. Lamellar a. Compact b. Cancellous (seen later) 3. Understand the structural features and functions of osteogenic cells: IV. Summary osteoblasts, osteocytes, and osteoclasts.

4. Know the major differences in structure and function between woven and lamellar bone, and between compact and cancellous bone.

5. Understand the structure and composition of an osteon and how it is formed. Lab 6 –Cartilage and Bone A560 – Fall 2015 Slide 2: Trachea, Trichrome I. Introduction II. Learning Objectives III. Slides and Micrographs A. Cartilage 1. Hyaline Look here for 2. Fibrocartilage hyaline cartilage 3. Elastic B. Bone 1. Woven 2. Lamellar a. Compact b. Cancellous (seen later) IV. Summary

What kind of epithelium is present here? Lab 6 –Cartilage and Bone A560 – Fall 2015 Slide 2: Trachea, Trichrome I. Introduction II. Learning Objectives III. Slides and Micrographs A. Cartilage 1. Hyaline 2. Fibrocartilage hyaline 3. Elastic cartilage B. Bone Greek = “glassy” 1. Woven 2. Lamellar a. Compact b. Cancellous (seen later) IV. Summary

perichondrium

Hyaline cartilage, the most common type, contains the smallest proportion of fibers in the ECM – giving it a homogenous, glassy appearance; it is rich in Type II collagen and aggrecan complexes (chondroitin sulfate and keratan sulfate) with bound water Lab 6 –Cartilage and Bone A560 – Fall 2015 Slide 2: Trachea, Trichrome I. Introduction II. Learning Objectives III. Slides and Micrographs A. Cartilage 1. Hyaline 2. Fibrocartilage

3. Elastic perichondrium B. Bone 1. Woven 2. Lamellar a. Compact b. Cancellous (seen later) cartilage hyaline IV. Summary

Perichondrium is dense CT essential for the growth and maintenance of cartilage; it consists largely of Type I collagen and fibroblasts, which act as progenitor cells for chondroblasts that divide and differentiate into chondrocytes; hyaline is generally surrounded by perichondrium expect as articular cartilage and at epiphyseal plates; elastic cartilage also has perichondrium, but fibrocartilage does not Lab 6 –Cartilage and Bone A560 – Fall 2015 I. Introduction Slide 2: Trachea, Trichrome II. Learning Objectives III. Slides and Micrographs

A. Cartilage cartilage hyaline 1. Hyaline 2. Fibrocartilage

3. Elastic B. Bone perichondrium 1. Woven chondrocytes (cells) 2. Lamellar located in a. Compact lacunae (spaces) b. Cancellous (seen later) IV. Summary

chondroblasts

Dividing cells are called chondroblasts and chondrocytes once proliferation has ceased; both have basophilic cytoplasm rich in rER for collagen synthesis; production of the ECM encloses the cells in their lacunae (Lt. “little lake”); chondrocytes synthesize and maintain ECM components Lab 6 –Cartilage and Bone A560 – Fall 2015

I. Introduction Slide 7: Larynx, Trichrome II. Learning Objectives III. Slides and Micrographs A. Cartilage 1. Hyaline look here for 2. Fibrocartilage hyaline cartilage 3. Elastic B. Bone 1. Woven 2. Lamellar a. Compact b. Cancellous (seen later) IV. Summary Lab 6 –Cartilage and Bone A560 – Fall 2015

I. Introduction Slide 131: Fibrocartilage, H&E II. Learning Objectives III. Slides and Micrographs A. Cartilage 1. Hyaline 2. Fibrocartilage 3. Elastic B. Bone 1. Woven 2. Lamellar a. Compact b. Cancellous (seen later) IV. Summary Lab 6 –Cartilage and Bone A560 – Fall 2015

I. Introduction Slide 131: Fibrocartilage, H&E II. Learning Objectives III. Slides and Micrographs A. Cartilage 1. Hyaline 2. Fibrocartilage 3. Elastic B. Bone 1. Woven 2. Lamellar a. Compact b. Cancellous (seen later) IV. Summary

Fibrocartilage is characterized by a matrix containing a combination of dense CT (Type I/II collagen fibers) and hyaline cartilage; relative scarcity of proteoglycans makes the matrix of fibrocartilage more acidophilic than that of hyaline or elastic cartilage;thereisno distinct surrounding perichondrium in fibrocartilage; it is found in intervertebral discs, in attachments of certain ligaments, and in the pubic symphysis Lab 6 –Cartilage and Bone A560 – Fall 2015

I. Introduction Slide 56: Elastic Cartilage, H&E, AF II. Learning Objectives III. Slides and Micrographs A. Cartilage 1. Hyaline 2. Fibrocartilage 3. Elastic B. Bone Look here 1. Woven for elastic 2. Lamellar cartilage a. Compact b. Cancellous (seen later) IV. Summary

Elastic cartilage is essentially similar to hyaline cartilage except that it contains an abundant network of elastic fibers in addition to Type II collagen; visualization oftheelasticfibersusually requires special stains; it is found in the auricle of the ear, the walls of the external auditory canals, the auditory (Eustachian) tubes, the epiglottis, and the cuneiform cartilage in the larynx Lab 6 –Cartilage and Bone A560 – Fall 2015 I. Introduction Slide 56: Elastic Cartilage, H&E, AF II. Learning Objectives III. Slides and Micrographs A. Cartilage 1. Hyaline 2. Fibrocartilage 3. Elastic B. Bone 1. Woven 2. Lamellar a. Compact b. Cancellous (seen later) Perichondrium IV. Summary

Chondrocyte Lab 6 –Cartilage and Bone A560 – Fall 2015

I. Introduction Slide 56: Elastic Cartilage, H&E, AF II. Learning Objectives III. Slides and Micrographs A. Cartilage 1. Hyaline 2. Fibrocartilage 3. Elastic B. Bone 1. Woven 2. Lamellar Dark area a. Compact b. Cancellous (seen later) around cells = IV. Summary elastic fibers Lab 6 –Cartilage and Bone A560 – Fall 2015 I. Introduction Slide 87: Epiglottis, Masson AF II. Learning Objectives III. Slides and Micrographs A. Cartilage 1. Hyaline 2. Fibrocartilage 3. Elastic B. Bone 1. Woven 2. Lamellar a. Compact b. Cancellous (seen later) IV. Summary Lab 6 –Cartilage and Bone A560 – Fall 2015

I. Introduction Slide 87: Epiglottis, Masson AF II. Learning Objectives III. Slides and Micrographs A. Cartilage 1. Hyaline elastic cartilage 2. Fibrocartilage 3. Elastic perichondrium B. Bone 1. Woven 2. Lamellar lamina propria a. Compact (loose CT) b. Cancellous (seen later) IV. Summary nonkeratinzed stratified squamous epithelium Lab 6 –Cartilage and Bone A560 – Fall 2015

I. Introduction II. Learning Objectives III. Slides and Micrographs A. Cartilage 1. Hyaline 2. Fibrocartilage 3. Elastic B. Bone 1. Woven 2. Lamellar a. Compact b. Cancellous (seen later) IV. Summary Lab 6 –Cartilage and Bone A560 – Fall 2015

I. Introduction II. Learning Objectives Slide 32: Ground Bone III. Slides and Micrographs A. Cartilage 1. Hyaline 2. Fibrocartilage 3. Elastic B. Bone 1. Woven 2. Lamellar a. Compact b. Cancellous (seen later) IV. Summary

Transverse Longitudinal section section Lab 6 –Cartilage and Bone A560 – Fall 2015 Slide 32: Ground Bone I. Introduction Transverse section II. Learning Objectives III. Slides and Micrographs A. Cartilage 1. Hyaline central 2. Fibrocartilage (Haversian) 3. Elastic canal B. Bone 1. Woven 2. Lamellar a. Compact b. Cancellous (seen later) IV. Summary outline of 2 osteons

Most lamellar bone (remodeled from woven bone; matrix deposited in distinct layers with parallel collagen bundles) consists of lamellae organized concentrically around small central canals containing blood vessels and nerves; this organization is called an osteon or Haversian system Lab 6 –Cartilage and Bone A560 – Fall 2015 Slide 32: Ground Bone

I. Introduction II. Learning Objectives Transverse section III. Slides and Micrographs interstitial A. Cartilage lamellae 1. Hyaline 2. Fibrocartilage 3. Elastic lamellae B. Bone (rings) 1. Woven central 2. Lamellar canal a. Compact b. Cancellous (seen later) IV. Summary

small, dark lines = canaliculi

osteocytes (cell) in lacunae (space)

Within each osteon,osteocyticlacunae occur between the lamellae,withcanaliculi (Lt. “small channels”) radiating through the lamellae, which allow all cells to communicate with the central canal; interstitial lamellae are remnants of osteons partially resorbed during bone remodeling Lab 6 –Cartilage and Bone A560 – Fall 2015 Slide 32: Ground Bone I. Introduction II. Learning Objectives Transverse section III. Slides and Micrographs A. Cartilage 1. Hyaline perforating 2. Fibrocartilage (Volkmann’s) 3. Elastic canals B. Bone 1. Woven 2. Lamellar a. Compact b. Cancellous (seen later) IV. Summary

Perforating canals carry neurovascular bundles from the periosteum into the bone and provide links between central (haversian) canals Lab 6 –Cartilage and Bone A560 – Fall 2015 Slide 32: Ground Bone I. Introduction II. Learning Objectives III. Slides and Micrographs A. Cartilage Longitudinal section 1. Hyaline 2. Fibrocartilage 3. Elastic B. Bone 1. Woven 2. Lamellar a. Compact central b. Cancellous (seen later) canal IV. Summary Lab 6 –Cartilage and Bone Common Confusion: A560 – Fall 2015 Dense regular CT vs. Fibrocartilage I. Introduction II. Learning Objectives Dense regular connective tissue: prominent in III. Slides and Micrographs tendons and ligaments; collagen bundles and fibroblasts A. Cartilage aligned in parallel for resistance to prolonged or 1. Hyaline repeated stresses 2. Fibrocartilage Look for: (1) parallel, closely packed bundles of collagen 3. Elastic separatedbyverylittlegroundsubstance;(2) B. Bone fibroblasts are relatively sparse and have elongated 1. Woven nuclei lying parallel to the fibers; (3) cytoplasm of fibroblasts is rarely revealed in H&E stains 2. Lamellar a. Compact b. Cancellous (seen later) Dense regular CT IV. Summary Fibrocartilage: found in intervertebral discs, in attachments of certain ligaments, and in the pubic symphysis; essentially a combination of hyaline cartilage and dense connective tissue

Look for: (1) chondrocytes usually appear in linear clusters surrounded by cartilage matrix; (2) nuclei are more oval/round and euchromatic; (3) perinuclear cytoplasm is evident; (4) lacunae are usually visible

Fibrocartilage Lab 6 –Cartilage and Bone Common Confusion: A560 – Fall 2015 Hyaline vs. Fibrocartilage I. Introduction II. Learning Objectives Hyaline cartilage: most common form of cartilage; III. Slides and Micrographs located in the articular surfaces of movable joints, in the A. Cartilage walls of larger respiratory passages, in the ventral ends 1. Hyaline of ribs, and in the epiphyseal plates of long bones 2. Fibrocartilage Look for: (1) homogenous, slightly basophilic matrix; 3. Elastic (2) lacunae often contain two or more chondrocytes B. Bone (isogenous group); (3) lacunae immediately rimmed 1. Woven with basophilic matrix (less collagen, more GAGs); (4) generally surrounded by perichondrium (not seen here) 2. Lamellar a. Compact b. Cancellous (seen later) Hyaline cartilage IV. Summary Fibrocartilage: found in intervertebral discs, in attachments of certain ligaments, and in the pubic symphysis; essentially a combination of hyaline cartilage and dense connective tissue

Look for: (1) collagen fibers in eosinophilic matrix; (2) usually only individual chondrocytes in lacunae; (3) lacunae arranged in rows or clusters; (4) lack of perichondrium

Fibrocartilage Lab 6 –Cartilage and Bone Common Confusion: A560 – Fall 2015 Central vs. Perforating canals I. Introduction II. Learning Objectives Transverse section: sectioned perpendicular to osteons, III. Slides and Micrographs so long canals (black arrow) are perforating canals A. Cartilage connecting central canals of osteons 1. Hyaline 2. Fibrocartilage Look for: (1) lamellae surrounding central canals of osteons (green arrow); (2) osteocytes (lacunae) are 3. Elastic oriented in multiple directions representing multiple B. Bone different lamellae and osteons 1. Woven 2. Lamellar a. Compact b. Cancellous (seen later) Slide 32, Ground bone, Transverse IV. Summary Longitudinal section: sectioned parallel to osteons, so long canals (black arrow) are central canals of osteons

Look for: (1) lack of lamellae; (2) osteocytes (lacunae) may appear in straight lines all of which are generally parallel to the canal

Slide 32, Ground bone, Longitudinal Lab 6 –Cartilage and Bone Summary A560 – Fall 2015 1. Cartilage is a specialized type of solid connective tissue that, along with I. Introduction bone, is distinguished by its relative rigidity of the extracellular matrix II. Learning Objectives (ECM); it is distinguishable from bone by its avascularity, also lacking III. Slides and Micrographs A. Cartilage lymphatics and nerves 1. Hyaline 2. Fibrocartilage 2. Mesenchymal cells differentiate into chondroblasts which begin secreting 3. Elastic cartilage matrix; once surrounded, they are called chondrocytes,each B. Bone occupying a lacuna (space in the matrix) 1. Woven 2. Lamellar 3. Types of cartilage (hyaline, fibrocartilage, elastic) are distinguished by a. Compact the characteristics of their matrix (e.g., the dominant type of protein fiber); b. Cancellous (seen later) except for fibrocartilage, most cartilage is surrounded by dense CT called IV. Summary perichondrium

4. Bone is a specialized type of solid connective tissue characterized by a mineralized ECM that stores calcium and phosphate

5. Woven (immature) bone differs from lamellar (mature) bone in its collagen fiber arrangement; woven bone is replaced by lamellar bone in adults, with few exceptions

6. The functional unit of compact bone is the osteon, consisting of a central canal (containing a neurovascular bundle) and concentric rings of bony matrix called lamellae (osteocytes occupy lacunae between lamellae) Lab 6 – Cartilage Memory Matrix

Hyaline Cartilage Elastic Cartilage Fibrocartilage

Locations

Function

Perichondrium?

Cell Types Present

ECM Characteristics