Skeletal Physiology

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Skeletal physiology

1. Bone Types

2. Typical Long Bone

3. Bone Breakdown

4. Break Down the Haversian

5. The Three Bone Cells

6. Homeostatic Functions

7. Bone Development

8. Mending a Broken Bone

9. Comparing Bone and Cartilage

10. Types of Cartilage

11. Mechanism of Growth

12. Joints Classified

13. Synovial

Bone Types

1. Long Bones: Bones that have extended longitudinal axes and expanded and often uniquely shapes articular ends. 2. Short Bones: Have cubed-or box-shaped structures. they are as broad as they are long. 3. Flat Bones: Broad and thin with a flattened and often curved surface. 4. Irregular Bones: Clustered in groups and come in various sizes and shapes.

Examples:

1. Long Bones: Femur of the thigh and humorous of the arm.

2. Short Bones: Wrist (carpals) and ankle (tarsal) bones.

3. Flat Bones: Certain skull bones, the shoulder blades (scapulae), ribs, and breastbone (sternum).

4. Irregular Bones: Vertebral bones that form the spine and the facial bones.

This song has eight alternating versus: (1)

Typical Long Bone

• Written and preformed by Buildabone, Typical Long Bone consists of six versus that alternate throughout the song

1. Diaphysis: Shaft of a long bone. It’s hollow, cylindrical shape and is thick. 2. Epiphyes: Both ends of a long bone. Have a bulbous shape that provides space near joints for muscle attachments and also gives stability to joints.

3. Articular Cartilage: Layer of hyaline cartilage covering the joint surfaces of epiphyes. It cushions joints and blows.

4. Periosteum: Tough, connective tissue covering the bone. Depending on its location, its contains bone forming and destroying cells, and blood vessels.

5. Medullary (or marrow) Cavity: Hollow area inside the diaphysis of the bone that contains yellow bone marrow. Adults cavity is filled with connective tissue rich in a fat substance called yellow m arrow.

6. Endosteum: Fibrous membrane that lines the medullary cavity of long bones.

(1)

Bone Breakdown

• In Bone Breakdown Buildabone illustrates the constituents of bone tissue through facts stated in three verses, each describing one of the major types of cells in bone.

• Osteoblast• Small cells that synthesize and secrete a specialized organic matrix, osteoid• Framework for deposition of calcium• Found in endosteum and lining of the haversian canals

• Osteoclasts• Giant multinucleate cells• Responsible for active erosion of bone minerals• Formed by fusion of several precursor cells and contain large numbers of

mitochondria and lysosomes• Undergoes continuous change and remodeling

• Osteocytes• Mature non-dividing osteoblasts that have become surrounded by matrix and

now lie within lacunae

(1)

Break Down the Haversian

• Break Down the Haversian describes the major components of a Haversian system, which are explained below:

• Lamellae- concentric, cylinder shaped layers of calcified matrix• Lacunae- “little lakes” small spaces containing tissue fluid in which

bone cells lie imprisoned between hard layers of lamellae• Canaliculi- ultra small canals radiating to form lacunae and

connecting them to each other and into a larger canal, the haversian canal

• Haversian canal- extends lengthwise through center of each haversian system, contains blood vessels, lymphatic vessels, lymphatic vessels and nerves from the haversian canal; nutrients and oxygen move through canaliculi to lacunae and their bone cells. The canal is a short distance of about 0.1mm or less.

(1)

The Three Bone Cells

• Written and preformed by Buildabone, The Three Bone Cells consists of three alternating versus

1. Osteoblasts-small cells that synthesize and secrete a specialized organic matrix called osteioid-collagen fibrils line up in regular arrays in the osteoid and

serve as framework for the disposition of calcium and phosphate2. Osteoclasts

-Giant multinucleate cells-Responsible for the active erosion of bone miners-Contain large numbers of mitochondria and lysosomes

3. Osteocytes-mature, nonliving osteoblast surrounding by matrix lying

within lacunae.

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Homeostatic Functions

• Homeostatic Functions is written and preformed by Buildabone, and consists of 5 versus that alternate throughout the song.

1. Support- bones serve as supporting framework of the body and contribute to shape, alignment and positioning of the body parts

2. Protection- hard, bony boxes serve to protect the delicate organs underneath

3. Movement-bones with their joints constitute levers. Muscles are anchored firmly to bones, and muscles contract and shorten, they pull on the bones and produce movement.

4. Mineral storage- bones serve as the major reservoir for calcium, phosphorous and other minerals

5. Hematopoiesis- also known as blood cell formation- a vital process carried on by red blood marrow or myeloid tissue.

(1)

Bone Development

• Buildabone teaches us about how bones are formed in their song Bone Development

Intramembranous bone:

a) occurs within a connective tissue membrane

b) Trabeculae appear and join in a network to form spongy bone

c) flat bones begin when groups of cells differentiate into osteoblasts

d) Apposition growth occurs by adding osseous tissueEndochondral bone:

a)Primary ossification center forms

b) blood vessels enters the cartilage model at the mid point of the diaphysis

c) Bone grows in length as endochondral ossification progresses from the diaphysis toward each epiphysis

d) Most bones begin as a cartilage model with bone formation spreading essentially from the center to the ends

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Mending a Broken Bone

• Written and preformed by Buildabone

The song Mending a Broken Bone is based off of the following facts concerning bone fractures: Fracture- a break in the continuity of a bone

When healing a fracture:• Fracture tears and destroys blood vessels that carry nutrients to osteocytes • Vascular damage initiates repair sequence • Callus-specialized repair tissue that binds the broken ends of the fracture together • Fracture hematoma-blood clot occurring immediately after the fracture, is then resorbed

and replaced by callus

Steps involved in Bone Fracture a) Fracture of femur

b) Formation of fracture hematoma c) Formation if internal and external callus d) Bone remodeling complete

(1)

Comparing Bone and Cartilage

• Comparing Bone and Cartilage was written to teach the audience about types of bone an cartilage, below is a summary of the information in the song.

Bones and cartilages are types of connective tissue in the body. The difference between bone and cartilage is that while bones are hard tissue that form the skeletal structure of the human body, cartilages are not as hard and rigid as bones, and present in areas of the body like the ear, nose and joints.• Bones- Bones are classified into long, short, flat, irregular,

sesamoid and sutural bones.• Cartilage- Types of cartilage include hyaline cartilage,

fibrocartilage and elastic cartilage.

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Types of Cartilage

• Written and preformed by Buildabone, the lyrics of Types of cartilage are explained below.

• Hyaline Cartilage- Hyaline cartilage consists of living cells, chondrocytes, which are situated far apart in fluid-filled spaces, the lacunae. There is an extensive amount of rubbery matrix between the cells and the matrix contains a number of collagenous fibers. Hyaline cartilage is the most abundant type of cartilage and can be found lining bones in joints and inside the bones.

• Fibrocartilage- fibrocartilage is an extremely tough tissue. The orientation of the bundles depends upon the stresses acting on the cartilage. The collagenous bundles take up a direction parallel to the cartilage. Fibrocartilage is found in areas requiring tough support or great tensile strength, like intervertebral discs and sites where ligaments and tendons connect to bones

• Elastic Cartilage- Basically elastic cartilage is similar to hyaline cartilage, but in addition to the collagenous fibers, the matrix of the elastic also contains an abundant network of branched yellow elastic fibers. They run through the matrix in all directions. Elastic cartilage is found in the pinna of the ear and several tubes, like the auditory canals and the larynx.

• EX - in the ear for example, elastic cartilage helps to maintain the shape and flexibility of the organ.

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Mechanism of Growth

• Written and preformed by Buildabone• Here are some of the facts included in the song Mechanism

of Growth

(6)

• cartilage growth-Interstitial-cells in lacunae grow and are proliferated within

the lacuna and get trapped together Appositional- cells from inner edge of perichondrium will

produce cartilage• Bone Growth-

Osteoblast- secrete new bone based off disuse of bone.

Joints Classified

• Fibrous- immobile• Sutures• Syndesmosis• Gomphoses

• Cartilagionous-immobile• Synchodroses(hyaline

fibrous)• Symphyses(Fibrocartilage)

• Synovial- movement

• Uniaxial• Ginlymus• Trochioid

• Biaxial• Gingylymus• Trochoid

• Triaxial• Ball & Socket• Planar

(6)• Written and preformed by Buildabone• The song Joints Classified is about the different

classifications of joints:

Synovial

• Written and preformed by Buildabone, Synovial is a song about the various joints describes below.

(6)

• Ball in socket- freedom of rotation, and back in forth, has the most freedom• Hip and Shoulder

• Condyloid-bones move about, but cannot rotate.• Between radius and carpals

• Gliding – not great distance but lots of flexibility• Vertebra

• Hinge- ease in movement only provide movement on plane- no rotation• Elbow

• Pivot-rotation, one spins on another• Between first and second cervical vertebra

• Saddle- one bone concave and one convex• Thumb joint between first metacarpal and carpal bone

Discussion

• Cancer treatment may generate a need for a bone marrow transplant. Osteoporosis is a condition characterized by an excessive loss of calcium in bone. These 2 conditions are disruptions or failures of 2 bone functions. Identify these 2 functions and explain what their normal function should be.• 1. Creation of blood cells• 2. Calcium helps the bones to grow normally and develop better.

 • Explain why a bone fracture along the epiphyseal plate may have serious implications

among children and young adults.• 1. It can have serious implications because the bone is still growing. It needs space

to grow and if it is fractured it will stop the process.

• During the aging process, adults face the issue of a changing skeletal framework. Describe these changes and explain how these skeletal framework changes affect the health of older adults.• 1. Osteoporosis is one change, as you increase in age the bone density decreases

which will result in osteoporosis and bone breakage.