19.1 Anatomy and Physiology of Bones

• Bone is a living tissue; therefore, it develops and undergoes repair.
• The fetal skeleton is cartilaginous, and then it is replaced by bone.
• The adult bones undergo remodeling – they are constantly being broken down and rebuilt.

1. What two types of connective tissue are associated with adult bones?
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2. What three types of bone cells are involved in the continual remodeling of bone?
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Essential Study Partner
    Introduction
    Bone Structure
    Bone Development & Growth
    Remodeling & Repair
    Calcium Homeostasis

General Biology Weblinks
    Anatomy & Physiology

Case Study
    Osteoporosis

19.2 Bones of the Skeleton

• The bones of the skeleton are divided into those of the axial skeleton and those of the appendicular skeleton.
• Joints are classified according to their anatomy, and only one type is freely movable.

1. List five functions of the skeleton.
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2. Give the three classifications of joints and tell which one is capable of free movement.
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Essential Study Partner
    Bone Function
    Skeleton
    Skull
    Vertebral Column
    Thoracic Cage
    Pectoral Girdle
    Upper Limb
    Pelvic Girdle
    Lower Limb
    Full Skeleton
    Classes of Joints
    Types of Movement
    Selected Joints

Art Quiz
    Joints – Freely Movable

Labeling Exercises
Bones of the Pectoral Girdle and Arm (24.0K)
Bones of the Pelvic Girdle and Leg (21.0K)

19.3 Skeletal Muscles

• Skeletal muscles work in antagonistic pairs to move bone in opposite directions.

1. Is the movement of a body part dependent on one muscle alone? Explain.
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Essential Study Partner
    Muscular System Introduction
    Muscles
    Body Musculature
    Head and Neck Muscles
    Trunk Muscles
    Pelvic Floor Muscles
    Upper Limb Muscles
    Lower Limb Muscles

Labeling Exercises
Skeletal Muscles (21.0K)
Attachment of Skeletal Muscles (36.0K)

19.4 Mechanism of Muscle Fiber Contraction

• Following nervous stimulation, a chain of events leads to muscle fiber contraction.
• Nervous stimulation requires a neuromuscular junction where the stimulus is passed from nerve fiber to muscle fiber.
• Cellular respiration, creatine phosphate breakdown, and fermentation are three sources of ATP for muscle contraction.

1. What is the role of the sarcoplasmic reticulum in muscle fiber contraction?
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2. How does a muscle fiber receive the message to contract?
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3. Which of the three sources of energy for muscle contraction supplies the greatest amount of energy?
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Essential Study Partner
    Muscle Cell Function
    Neuromuscular Junction
    Sliding Filament Theory

Art Quizzes
    Muscle Fiber
    Interaction of Thick and Thin Filaments
    Cross-Bridge Cycle in Muscle Contraction

Animation Quizzes
    Muscle Contraction Action Potential
    Striated Muscle Contraction
    Detailed Striated Muscle Contraction
    Actin-Myosin Crossbridges

19.5 Whole Muscle Contraction

• In the body, muscles have tone, vary in the strength of contraction, and can be isometric.
• Muscle fibers differ and help us perform in one sport as compared to another.
• Exercise has many health benefits aside from strength and endurance of muscles.

1. Describe the three phases of a muscle twitch as recorded as a myogram.
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2. What sports are better suited to individuals with more slow-twitch fibers?
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3. List some of the ways that exercise is beneficial to health.
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Essential Study Partner
    Muscle Twitch Physiology

Art Quiz
    Muscle Stimulation Pattern

Case Study
    Sports & Fitness