Chapter 6: Skeletal System Study Guide Study Ver.

#### 1. Differentiating Structures and Cell Types

- Cartilage vs. Bone:

- Cartilage: ____________________________, avascular connective tissue. Types include ____________________________, ____________________________, and ____________________________. It lacks blood vessels and nerves, and its primary cells are ____________________________.

- Bone: ____________________________, mineralized connective tissue. It is vascular, innervated, and contains a matrix rich in calcium and phosphate. It has two types: ____________________________and ____________________________bone.

- Spongy (Cancellous) Bone vs. Compact Bone:

- Spongy Bone: ____________________________, lightweight, found at the ____________________________of long bones, in the ____________________________of vertebrae, and in the core of bones like the pelvis. It contains ____________________________(honeycomb structure) and ________________________________________________________.

- Compact Bone: ____________________________, forms the ____________________________layer of bones, and provides ____________________________. It contains ____________________________(Haversion systems), which are cylindrical structures for nutrient and waste transport.

- Three Types of Cartilage:

- ____________________________Cartilage: Most common type; found in the nose, trachea, and at the ends of long bones. Provides support with some flexibility.

- ____________________________Cartilage: Contains more elastin fibers; found in the external ear and epiglottis. It is highly flexible.

- ____________________________: Contains thick collagen fibers; found in intervertebral discs and pubic symphysis. It is highly durable and absorbs compressive forces.

- Interstitial vs. Appositional Growth:

- Interstitial Growth: Growth from ____________________________the cartilage, where chondrocytes divide and secrete new matrix.

- Appositional Growth: Growth at the ____________________________of the cartilage, where new chondroblasts differentiate and secrete matrix on the outer edge.

- Cell Types:

- ____________________________: Immature cartilage cell that produces cartilage matrix.

- ____________________________: Mature cartilage cell, located in lacunae, maintains the cartilage matrix.

- ____________________________Cells: Stem cells that differentiate into osteoblasts.

- ____________________________: Bone-forming cell, secretes bone matrix.

- ____________________________: Mature bone cell, maintains the bone matrix, located in lacunae.

- ____________________________: Bone-resorbing cell, breaks down bone tissue during growth, healing, and remodeling.

#### 2. Functions of the Skeletal System and Its Components

- Skeletal System: Provides ________________________________________________________, protects vital organs, allows ____________________________, stores ____________________________(calcium, phosphate), and houses ________________________________________________________ for blood cell production.

- Cartilage: Provides ____________________________and ____________________________, reduces ____________________________between bones, and absorbs ____________________________.

- Bone: Provides ____________________________support, ____________________________, mineral ____________________________, blood cell production, and facilitates ____________________________.

- Bone Cells:

- ____________________________: Build bone tissue.

- ____________________________: Maintain bone tissue.

- ____________________________: Break down bone tissue.

#### 3. Histology of Cartilage and Bone (Compact and Spongy)

- Cartilage Histology:

- Chondrocytes in ____________________________, surrounded by ________________________________________________________.

- Hyaline Cartilage: ____________________________matrix, few fibers.

- Elastic Cartilage: Matrix with elastic ____________________________.

- Fibrocartilage: Matrix with thick ____________________________fibers.

- Bone Histology:

- Compact Bone:

- ____________________________(Haversion Systems): Cylindrical structures with a central canal (Haversion canal) containing blood vessels and nerves.

- ____________________________: Concentric rings of bone matrix.

- ____________________________: Small spaces containing osteocytes.

- ____________________________: Tiny channels connecting lacunae for nutrient and waste exchange.

- Spongy Bone:

- ____________________________: Network of bone tissue supporting red marrow.

#### 4. Gross Anatomy of a Long Bone

- ____________________________: Outer fibrous layer covering the bone, provides nutrients and contains osteogenic cells.

- ____________________________Cartilage: Hyaline cartilage covering joint surfaces, reduces friction and absorbs shock.

- ____________________________: Thin membrane lining the medullary cavity, involved in bone growth, repair, and remodeling.

- ____________________________: The expanded ends of a long bone, contains spongy bone and red marrow.

- ____________________________(Shaft): The long, cylindrical part of the bone, composed mainly of compact bone.

- ________________________________________________________: Growth plate in children, ossifies to become the epiphyseal line in adults.

- ____________________________: Central cavity in the diaphysis, contains yellow marrow (fat storage).

- ____________________________Marrow: Located in the spongy bone, site of hematopoiesis (blood cell formation).

- ____________________________Marrow: Found in the medullary cavity, stores fat.

- ____________________________ (Cancellous Bone): Found in the epiphyses, contains red marrow.

- ____________________________: Dense outer layer providing strength.

#### 5. Composition of Bone (Extracellular) Matrix

- Organic Components:

- Collagen Fibers: Provide ____________________________strength and ____________________________.

- ____________________________: Aid in resisting compressive forces.

- Inorganic Components:

- ____________________________________________________________________________________ (Calcium Phosphate): Provide hardness and resistance to compression.

#### 6. Layers and Growth Activity at the Epiphyseal Plate

- ____________________________ (Quiescent) Zone: Small, inactive cartilage cells.

- ____________________________(Growth) Zone: Chondrocytes undergo rapid mitosis, increasing bone length.

- ____________________________Zone: Chondrocytes enlarge and lacunae begin to erode.

- ____________________________Zone: Cartilage matrix calcifies, chondrocytes die.

- ____________________________(Osteogenic) Zone: New bone forms as osteoblasts deposit bone matrix on calcified cartilage spicules.

#### 7. Bone Markings: Projections vs. Depressions

- Projections:

- ____________________________: Prominent projection (e.g., mastoid process).

- ____________________________: Large, rounded projection (e.g., tibial tuberosity).

- ____________________________: Sharp, slender projection (e.g., ischial spine).

- Depressions:____________________________________________________________________________________________________________________________________________________________________________________________

- ____________________________: Shallow depression (e.g., iliac fossa).

- ____________________________: Round or oval opening (e.g., foramen magnum).

- ____________________________: Furrow (e.g., intertubercular groove).

#### 8. Ossification Processes: Endochondral vs. Intramembranous Ossification

- Endochondral Ossification:

1. Development of a ____________________________ model.

2. ____________________________ of cartilage model.

3. Development of ____________________________ ________________________________________________________ center.

4. Development of ____________________________ ________________________________________________________centers.

5. ____________________________of ____________________________cartilage and ____________________________plate.

- Intramembranous Ossification:

1. ____________________________of ossification centers ____________________________a fibrous membrane.

2. ____________________________of the matrix.

3. Formation of ____________________________and ____________________________of spongy bone.

4. Development of ____________________________and compact bone.

- ____________________________ Bone Structures: Periosteum, articular cartilage, endosteum, epiphysis, diaphysis, epiphyseal plate/line, medullary cavity, red marrow, yellow marrow, spongy bone, compact bone.

- Histology of Compact Bone: ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________