The Skeletal System: Bone Tissue Overview

Questions and Answers

What are the primary functions of bones in the skeletal system?

Providing support to soft tissues and facilitating mineral storage (correct)

Only serving as attachment sites for muscles

Exclusively assisting in blood formation

Acting solely as protective coverings for internal organs

Which part of a long bone is known as the shaft?

Periosteum

Metaphysis

Diaphysis (correct)

Epiphysis

What type of cartilage is present at the ends of long bones to reduce friction?

Hyaline cartilage (correct)

Elastic cartilage

Fibrocartilage

Spongy cartilage

What are osteoprogenitor cells responsible for?

Undergoing cell division to form osteoblasts Signup and view all the answers

Which of the following is NOT a part of the structure of a long bone?

Thyroid cartilage Signup and view all the answers

What does the periosteum do for the bone?

Covers the bone surface and aids in growth Signup and view all the answers

Which mineral is primarily stored and released by bones to maintain mineral homeostasis?

Calcium Signup and view all the answers

What is the main role of yellow marrow found in adult bones?

Triglyceride storage Signup and view all the answers

What is the primary function of osteoblasts in bone tissue?

To promote bone deposition Signup and view all the answers

How do osteocytes contribute to bone health?

They maintain bone tissue Signup and view all the answers

Which statement accurately describes the matrix of bone?

It is composed mainly of inorganic salts and collagen fibers Signup and view all the answers

What structures are formed by compact bone?

Haversian systems Signup and view all the answers

What is one of the main characteristics of spongy bone?

It consists of trabeculae surrounding red marrow spaces Signup and view all the answers

Which of the following describes the role of mineral salts in bone?

They confer hardness on the bone Signup and view all the answers

What does calcification require to occur?

Collagen fibers Signup and view all the answers

What is the primary function of osteoclasts?

To break down and resorb bone tissue Signup and view all the answers

What is the first step of endochondral ossification?

Development of the cartilage model Signup and view all the answers

During endochondral ossification, when does the primary ossification center develop?

In the diaphysis Signup and view all the answers

Which zone of the epiphyseal plate is responsible for new cell production?

Zone of proliferation cartilage Signup and view all the answers

What indicates that a bone has completed its growth in length?

Closure of the epiphyseal plate Signup and view all the answers

How does bone grow in thickness?

By appositional growth at the periosteum Signup and view all the answers

What is the role of osteoblasts during bone remodeling?

Constructing new bone tissue Signup and view all the answers

What happens when the balance between osteoclasts and osteoblasts is disrupted?

Bones become misshaped and brittle Signup and view all the answers

What process replaces old bone tissue with new bone tissue?

Bone remodeling Signup and view all the answers

What is the primary role of bone in calcium homeostasis?

Bone is the major reservoir for calcium ions in the body. Signup and view all the answers

Which hormone increases blood calcium ion levels?

Parathyroid hormone Signup and view all the answers

What is the effect of mechanical stress on bone tissue?

It increases deposition of mineral salts. Signup and view all the answers

What happens to bones when mechanical stress is removed?

Bones experience demineralization. Signup and view all the answers

Which disorder is characterized by a decrease in the amount and strength of bone tissue?

Osteoporosis Signup and view all the answers

What condition may result from the demineralization of bone matrix due to aging?

Osteoporosis Signup and view all the answers

Which of the following best describes osteoporosis?

A decrease in hormone output leading to weak bones. Signup and view all the answers

Calcitonin's role in calcium homeostasis is to:

Decrease blood calcium levels. Signup and view all the answers

What role do insulin-like growth factors (IGFs) play in bone growth?

They stimulate bone growth when stimulated by human growth hormone (hGH). Signup and view all the answers

Which vitamins are essential for proper bone growth and maintenance?

Vitamins A, C, K, and B12 Signup and view all the answers

At which stage of life do sex hormones start to significantly affect bone growth?

Puberty Signup and view all the answers

What is the initial step in the repair process of a bone fracture?

Creation of a fracture hematoma Signup and view all the answers

Which type of fracture involves a bone breaking into multiple pieces?

Comminuted fracture Signup and view all the answers

What characterizes a stress fracture?

Microscopic fissures in a bone without a significant injury Signup and view all the answers

What is the final step in the healing process of a bone fracture?

Remodeling of the callus to nearly original form Signup and view all the answers

What dietary components are crucial for bone health?

Vitamins A, C, K and minerals such as calcium and phosphorus Signup and view all the answers

Study Notes

Bones facilitate movement by assisting skeletal muscles.
Major minerals, especially calcium and phosphorus, are stored and released by bones to maintain mineral balance.
Hemopoiesis, or blood cell formation, occurs in the red marrow of bones.

The Skeletal System: The Bone Tissue

Bone comprises multiple tissues, including bone, cartilage, dense connective tissue, epithelium, blood-forming tissues, adipose tissue, and nervous tissue.
Each bone is categorized as an organ, collectively forming the skeletal system along with cartilages.

Functions of Bone and the Skeletal System

Bones support soft tissues and provide muscle attachment sites, serving as the body's structure.
Internal organs are protected by bony coverings.

Yellow marrow serves as a triglyceride storage site in adults.

Structure of Bone

Long bones consist of several parts: the diaphysis (shaft), epiphyses (ends), and metaphyses (areas between).
The epiphyseal plate is critical for bone elongation during growth.
Hyaline cartilage at the ends minimizes friction and absorbs shock.
The periosteum covers the bone, promoting growth and repair and anchoring ligaments and tendons.
The marrow cavity within the diaphysis contains yellow marrow or adipose tissue.

Histology of Bone Tissue

Osseous tissue consists of widely spaced cells and significant extracellular matrix.
Four principal bone cell types:
- Osteoprogenitor cells develop into osteoblasts.
- Osteoblasts are responsible for bone formation.
- Osteocytes maintain mature bone tissue.
- Osteoclasts break down bone tissue.
The bone matrix includes inorganic salts (like hydroxyapatite and calcium carbonate) and collagen fibers, which confer hardness and tensile strength.
Bone regions are classified as compact (dense) or spongy (lightweight with open spaces for marrow).

Blood and Nerve Supply of Bone

Bones receive a rich blood supply through various vessels.
Endochondral ossification involves transforming a cartilage model into bone, with six stages:
- Cartilage development and growth.
- Formation of primary and secondary ossification centers.
- Development of a medullary cavity and articular cartilage.
Bone growth in length occurs at the epiphyseal plate, which has zones for resting, proliferation, hypertrophy, and calcification.

Growth and Remodeling of Bone

Appositional growth allows bone thickness increase via osteoblast activity in the periosteum.
Bone remodeling is the continuous process of replacing old bone tissue with new tissue, influenced by factors like dietary intake and hormonal regulations.
Acute hormonal signals are required for bone growth during childhood and major growth spurts.

Fracture and Repair of Bone

A fracture represents any break in bone integrity.
Fracture repair involves several stages, from clot formation to restoration of the bone structure.
Common fracture types include open, comminuted, and stress fractures.
Treatment requires realignment and immobilization to facilitate healing.

Bone’s Role in Calcium Homeostasis

Bones act as the primary reservoir for calcium, regulating blood calcium levels through parathyroid hormone (PTH) and calcitonin.
PTH increases blood calcium levels, while calcitonin decreases them.

Exercise and Bone Tissue

Mechanical stress strengthens bone through increased mineral deposition and collagen production.
Lack of stress leads to demineralization and reduced collagen.
Weight-bearing exercises, like walking, promote bone mass retention.

Aging and Bone Tissue

Aging primarily results in the loss of minerals (demineralization) and decreased protein synthesis, heightening fracture risk.

Disorders: Homeostatic Imbalances

Bone scans serve as a diagnostic tool for identifying bone abnormalities.
Osteoporosis involves decreased bone density and strength due to hormonal changes.
Rickets and osteomalacia are conditions characterized by poor bone mineralization.

Medical Terminology

Familiarity with medical terms related to skeletal tissue is essential for effective communication in the field.

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Description

This quiz explores the skeletal system, specifically focusing on the structure and functions of bone tissue. Learn about the various tissues that comprise bone, the critical roles bones play in the body, and their classification as organs within the skeletal system. Test your knowledge of how bones support movement, protect organs, and participate in mineral storage.