FUNCTIONS OF SKELETAL SYSTEM

FUNCTIONS OF SKELETAL SYSTEM

1. Allows for muscle attachment therefore the bones are used as levers.

2. Hard framework that anchors the soft organs of the body.

3. Surrounds organs such as the brain and spinal cord

4. The bone marrow is responsible for blood cell production.

5. Minerals and lipids are stored within bone material.

1. Movement

2. Support

3. Protection

4. Blood Cell production

5. Storage

1. True or False: Bone surface is smooth

2. Reveal where ligaments, tendons, and muscles are attached as well as the passage of vessels

1. False

2. Bone Markings

Identify these bone markings

1. Air-filled spaces in the skull

2. A rounded projection that articulates with another bone

3. A small, nearly flat articular surface, e.g. joints between vertebrae in the spine

4. A hole or opening in the bone for blood vessels and nerves

5. A bony projection or outgrowth from a larger bone structure, essentially a bump or extension

6. A shallow depression in the bone’s surface

7. A ridge or raised border of a bone

8. A large, rounded, and roughened projection on a bone

9. A short tube-like channel extending into the bone

10. A prominent protrusion or elevation on a bone is commonly seen in the sacral and cochlear regions.

11. Any of the two bony protuberances found only in the femur

12. An indentation or depression in the edge of the bone, often serving as a passageway

Choices

• Crest

• Condyle

• Facet

• Foramen

• Fossa

• Meatus

• Notch

• Process

• Promontory

• Sinus

• Trochanter

• Tuberosity

1. Sinus

2. Condyle

3. Facet

4. Foramen

5. Process

6. Fossa

7. Crest

8. Tuberosity

9. Meatus

10. Promontory

11. Trochanter

12. Notch

1. Bone structure located in the outer layer of bone, very hard and dense ___________

2. Compact bones are organized in structural units called _________

3. Living bone cells that live in a matrix.

1. Compact bone

2. Haversian Systems

3. Osteocytes

Bone structure located in the ends of long bones. Many spaces that are filled with red bone marrow which produces bone cells.

Porous or spongy bone

needle-like threads of spongy bone that surround the spaces. Add strength to this portion of the bone

Trabeculae

Matrix is a firm gel with chondrocytes suspended in the matrix.

Cartilage

Classification of bone

1. Typically longer than wide. Have a shaft with heads at both ends and contain mostly compact bone.

2. Usually curved. Thin layers of compact bone around a layer of spongy bone

3. Generally cube-shape. Contain mostly spongy bone

4. Do not fit into other bone classification categories

1. Long bone

2. Flat bone

3. Short bone

4. Irregular

Parts of long bone

Diaphysis
Epiphysis
Metaphysis
Articular cartilage
Periosteum
Endosteum
Medullary cavity

Identify the parts of the long bone

1. Shaft. Composed of compact bone

2. the growing part of a long bone, located between the epiphysis and the diaphysis

3. contains the epiphyseal plate in children.

4. Ends of the bone. Composed mostly of spongy bone

5. Outside covering of the diaphysis. Fibrous connective tissue membrane

6. Covers the external surface of the epiphyses

7. Cavity of the shaft. Contains yellow marrow (mostly fat) in adults. Contains red marrow (for blood cell formation)

8. is a membrane that lines the center of your bones that contains bone marrow.

1. Diaphysis

2. Metaphysis

3. Metaphysis

4. Epiphysis

5. Periosteum

6. Articular Cartilage

7. Medullary Cavity

8. Endosteum

1. Secure periosteum and underlying bone

2. Supply bone cells with nutrients

1. Sharpey’s Fibers

2. Arteries

1. the intercellular substance of the bone that forms most of the mass of the bone

2. The matrix is composed of?

1. Matrix

2. Water 25%, collagen fibers 25%, crystalized mineral salt 50%

1. Seen in the periosteum and is the progenitor of bone cells. Turns into osteoblast

2. Secrete collagen fibers. Build a matrix and become trapped in lacunae

3. Once it is trapped in the lacunae, the cell from number 2 turns into __________

4. formed from monocytes Digest bone matrix for Normal bone turnover. releases calcium in the process

1. Osteogenic cells

2. Osteoblast

3. Osteocytes

4. Osteoclast

Osteogenic cell, osteoblast, osteocyte, osteoclast

concentric rings of interconnecting osteocytes surrounding a Haversian canal

Haversian system or osteon

Opening in the center of an osteon

Haversian Canal

Canal perpendicular to the central canal

Perforating Canal (Volkmann’s Canal)

1. Cavities containing bone cells (osteocytes)

2. Rings around the central canal

3. Tiny canals. Radiate from the central canal to lacunae. Form a transport system

Lacunae

Lamellae

Canaliculi

Changes in the Human Skeleton

1. When we are embryo, most of our skeleton are _________

2. Cartilage remains in isolated areas when we are adults. These are?

1. hyaline cartilage

2. Bridge of nose, ribs, and joints

1. allow for growth of long bone during childhood

2. True or False: Bones grow in width through periosteum

3. True or False: Bones do not change shape by gravity & muscle pull

1. Epiphyseal plates

2. True

3. False

involves the conversion of other types of connective tissue into bone.

Ossification

Ossification from a primitive connective tissue template, termed _______

Mesenchyme

1. Bone forms directly in mesenchyme layers (membrane like)

2. forms within hyaline cartilage developed from mesenchyme

Intramembranous ossification

Endochondral Ossification

What are the steps for intramembranous ossification

A. Calcification, Development of periosteum, development of ossification center, Formation of trabeculae

B. Development of ossification center, Calcification, Development of periosteum, formation of trabeculae

C. Development of ossification center, calcification, Formation of trabeculae, development of periosteum

D. Formation of trabeculae, Development of ossification center, calcification, development of periosteum

C.

• Calcification

• Development of periosteum

• Development of ossification center

• Formation of trabeculae

1. Development of ossification center

2. Calcification

3. Formation of Trabeculae

4. Development of periosteum

What are the steps for endochondral ossification
A. Medullary Cavity development

B. Secondary ossification center

C. Cartilage model development

D. Growth of cartilage model

E. Primary ossification center

F. Articular cartilage and epiphyseal line formation

C, D, E, A, B, F

A. Medullary Cavity development

B. Secondary ossification center

C. Cartilage model development

D. Growth of cartilage model

E. Primary ossification center

F. Articular cartilage and epiphyseal line formation

Periosteum is to _____ while epiphyseal plate is to _________

Width and height

True or false: chondrocytes in the epiphyseal plate divide and increase cartilage layer

True or False: This division only stops during adolescence

True both

Types of Fracture

1. incomplete break (crack)

2. bone in two or more pieces

3. Not through skin

4. broken ends break skin

1. Partial fracture

2. Complete fracture

3. Closed

4. Open

Bone remodeling and repair

1. Which cells are responsible for bone resorption during the remodeling process?
   A) Osteoblasts
   B) Chondroblasts
   C) Osteoclasts
   D) Fibroblasts

2. What is the initial step in bone repair after a fracture?
   A) Formation of a fibrocartilage callus
   B) Removal of dead tissue (hematoma formation)
   C) Spongy bone formation
   D) Bone remodeling

3. During bone repair, which type of tissue forms the temporary bridge across the fracture site?
   A) Compact bone
   B) Spongy bone
   C) Periosteum
   D) Fibrocartilage

4. What is the role of osteoblasts in bone remodeling and repair?
   A) Breaking down bone matrix
   B) Removing dead bone tissue
   C) Forming new bone tissue
   D) Producing fibrocartilage

5. What happens to the spongy bone after the fracture site stabilizes?
   A) It remains unchanged.
   B) It is remodeled into compact bone.
   C) It turns into fibrocartilage.
   D) It gets absorbed by osteoclasts.

6. Which cells are responsible for bone deposition during the remodeling process?

   A) Osteoblasts
   B) Chondroblasts
   C) Osteoclasts
   D) Fibroblasts

1. C

2. B.

3. D

4. C.

5. B.

6. A.

the process of deposition of minerals on the bone matrix for the development of bone.

This is typically done by the

Mineralization

Osteoblast

Factors Affecting Growth

Minerals (Ca, Mg, P)

Vitamins (A, C, D)

Hormones

Weight-bearing activity

Calcium Homeostasis is an example of what feedback?

Negative Feedback

1. A hormone that causes: increased osteoclast activity + decreased loss in urine

2. hormone made in the kidney (treats low calcium)

3. Hormone that decreases osteoclast activity

1. Parathyroid hormone

2. Calcitriol

3. Calcitonin

True or False: Bone strengthened in response to use and reabsorbed with disuse

True or False: If the bone is not used, it has less osteoclast than osteoblast and vice versa.

True

False

1. In ______________, connective tissue membranes are replaced by bone. This process occurs in the flat bones of the skull.

2. In ___________, bone tissue replaces hyaline cartilage models. Most bones are formed in this manner.

3. Bones grow in length at the ________ between the diaphysis and the epiphysis. It also grows in width in the ________

4. Bones may be classified as _________, _______, _________, or __________.

5. The __________ of a long bone is the central shaft. There is an _________ at each end of the diaphysis.

1. Intramembranous ossification.

2. Endochondral Ossification

3. Epiphyseal plate and periosteum

4. Long, short, flat, irregular

5. Diaphysis; epiphysis

In endochondral ossification, when does primary and secondary ossification occur?

1. Fetal Stage (first trimester) and after birth

1. refers to the complete process of bone formation

2. is a specific step within ossification where calcium salts are deposited into the bone matrix, essentially the hardening of the bone tissue

1. ossification

2. Calcification

Under the influence of hormones (especially sex hormones like estrogen and testosterone), the growth plates harden and close, a process called _______ which stops bone growth.

Epiphyseal plate fusion

What gland responds to low calcium? It releases what hormone?

Parathyroid gland, parathyroid hormone

What do you call a type of embryonic connective tissue that differentiates in to bone cells?

Mesenchyme