Support and Movement
Tuesday, November 19, 2024 10:36 PM
Support and Movement
• Adaptation in Animals: Animals have physical adaptations to thrive in different habitats. These adaptations enable them to secure food, shelter, and
protection.
• Difference Between Movement and Locomotion:
o Movement: Involves changing the position of body parts.
o Locomotion: Refers to the movement of the entire body, often for activities like food search and avoiding threats.
16.1 Human Skeleton
• Definition: The human skeleton serves as a framework for the body, termed as an endoskeleton. It is composed of bones and cartilage.
• Functions:
o Protects internal organs.
o Facilitates movement through coordination with muscles.
o Supports body shape and mineral storage.
• Osteology: The study of bones.
N
• Human Bones Count: Approximately 300 at birth, later fusing to form 206 bones in adulthood.
16.1.1 Structure of Bone
• Composition: Bones are composed of living cells, collagen fibers, and mineralized components (10-20% water content).
• Bone Regions:
o Epiphysis: Terminal ends, consisting of spongy bone and marrow.
o Diaphysis: Shaft of the bone.
o Metaphysis: The region connecting diaphysis and epiphysis.
• Bone Formation Processes: Includes calcification or ossification.
• Bone Types:
SK
o Compact Bone: Dense and strong.
o Spongy Bone (Cancellous): Contains spaces, lighter, and aids in blood cell production.
Cortical (Compact) Bone:
• Forms the outer layer of the diaphysis and makes up about 80% of the skeletal structure.
• Composed of dense and strong matrix, which is organized into cylindrical structures called osteons (Haversian systems). These osteons contain a central
canal (Haversian canal) that houses blood vessels and nerves, ensuring nourishment and communication.
Spongy (Cancellous) Bone:
• Found in the epiphyses and some areas within flat bones.
• Contains trabeculae, a network-like structure that supports and houses red bone marrow, important for the production of blood cells.
➢ Medullary Cavity:
• Located in the diaphysis and contains yellow bone marrow that stores fat.
➢ Periosteum:
• The outer layer of the bone, a fibrous membrane covering that plays a role in nourishment, growth, and repair.
• Rich with blood vessels, nerves, and bone-forming cells (osteoprogenitor cells), supporting bone health and attachment for tendons and ligaments.
Endosteum:
• A thin membrane lining the inner surface of the bone, including the medullary cavity.
• Contains bone-forming cells and plays a role in bone growth and repair.
Osteogenic Layer:
• The inner layer of the periosteum and endosteum is highly cellular, containing osteoblasts and osteoclasts.
• Osteoblasts are responsible for bone formation, while osteoclasts break down bone tissue during bone remodeling.
Bone Cells
• Osteoblasts:
Responsible for forming new bone by secreting matrix materials and minerals.
Support and Movement Page 1
, o Responsible for forming new bone by secreting matrix materials and minerals.
o Once surrounded by the matrix, they become osteocytes.
• Osteocytes:
o Mature bone cells located in lacunae (small spaces within the bone matrix).
o Maintain and monitor the bone tissue.
• Osteoclasts:
o Large cells responsible for breaking down bone tissue, enabling bone remodeling and mineral release.
16.1.2 Structure of Cartilage
• Definition:
o Cartilage is a flexible connective tissue surrounded by the perichondrium (a layer providing nourishment and structural support).
• Function:
o Provides cushioning at joints, reduces friction, and offers protection from compressive forces.
• Types of Cartilage:
o Hyaline Cartilage: Found in joints, the rib cage, nose, and respiratory structures. It reduces friction and absorbs shock.
o Fibrocartilage: The toughest type, found in intervertebral discs and menisci. It offers strong support and the ability to withstand pressure.
o Elastic Cartilage: The most flexible type, found in structures such as the ear and epiglottis, offering elasticity and shape maintenance.
N
Comparison of Bone and Cartilage
Bone
• Strength: Hard and strong, providing structural support.
• Formation: Developed by osteocytes (bone cells).
• Calcification: Undergoes calcification, meaning minerals such as calcium are deposited to harden the bone tissue.
• Covering: Covered by a protective layer called the periosteum.
• Function: Provides protection to internal organs and supports body movements through muscular attachment.
• Water Content: Contains 10-20% water.
• Blood Cells: Bone marrow is involved in the production of blood cells.
SK
Cartilage
• Strength: Soft and flexible, providing support and cushioning at joints.
• Formation: Formed by chondrocytes (cartilage cells).
• Calcification: Not calcified, making it more flexible compared to bones.
• Covering: Covered by a protective layer called the perichondrium.
• Function: Protects joints and reduces friction during movement.
• Water Content: Contains approximately 80% water, contributing to its cushioning properties.
• Blood Cells: Does not form blood cells.
16.1.3 Division of the Human Skeleton
The human skeleton is divided into two major parts:
1. Axial Skeleton
2. Appendicular Skeleton
Axial Skeleton
• Description: Forms the central axis of the body and includes:
o Skull: Composed of cranial bones that protect the brain and facial bones that form the structure of the face.
▪ Cranial Bones: Include the frontal, parietal, temporal, occipital, ethmoid, and sphenoid bones.
▪ Facial Bones: Protect soft tissues of the face, facilitate breathing, eating, and contribute to facial expressions.
o Vertebral Column (Spine): Protects the spinal cord and supports the head and torso. It consists of:
▪ Cervical Vertebrae (7): Located in the neck.
▪ Thoracic Vertebrae (12): Form the upper back and attach to ribs.
▪ Lumbar Vertebrae (5): Lower back region.
▪ Sacrum (5 fused bones) and Coccyx (4 fused bones): Form the base of the spine.
o Rib Cage (Thoracic Cage): Composed of ribs and the sternum, it protects the heart and lungs and plays a role in respiration.
▪ True Ribs (1-7): Directly connected to the sternum.
Support and Movement Page 2
Tuesday, November 19, 2024 10:36 PM
Support and Movement
• Adaptation in Animals: Animals have physical adaptations to thrive in different habitats. These adaptations enable them to secure food, shelter, and
protection.
• Difference Between Movement and Locomotion:
o Movement: Involves changing the position of body parts.
o Locomotion: Refers to the movement of the entire body, often for activities like food search and avoiding threats.
16.1 Human Skeleton
• Definition: The human skeleton serves as a framework for the body, termed as an endoskeleton. It is composed of bones and cartilage.
• Functions:
o Protects internal organs.
o Facilitates movement through coordination with muscles.
o Supports body shape and mineral storage.
• Osteology: The study of bones.
N
• Human Bones Count: Approximately 300 at birth, later fusing to form 206 bones in adulthood.
16.1.1 Structure of Bone
• Composition: Bones are composed of living cells, collagen fibers, and mineralized components (10-20% water content).
• Bone Regions:
o Epiphysis: Terminal ends, consisting of spongy bone and marrow.
o Diaphysis: Shaft of the bone.
o Metaphysis: The region connecting diaphysis and epiphysis.
• Bone Formation Processes: Includes calcification or ossification.
• Bone Types:
SK
o Compact Bone: Dense and strong.
o Spongy Bone (Cancellous): Contains spaces, lighter, and aids in blood cell production.
Cortical (Compact) Bone:
• Forms the outer layer of the diaphysis and makes up about 80% of the skeletal structure.
• Composed of dense and strong matrix, which is organized into cylindrical structures called osteons (Haversian systems). These osteons contain a central
canal (Haversian canal) that houses blood vessels and nerves, ensuring nourishment and communication.
Spongy (Cancellous) Bone:
• Found in the epiphyses and some areas within flat bones.
• Contains trabeculae, a network-like structure that supports and houses red bone marrow, important for the production of blood cells.
➢ Medullary Cavity:
• Located in the diaphysis and contains yellow bone marrow that stores fat.
➢ Periosteum:
• The outer layer of the bone, a fibrous membrane covering that plays a role in nourishment, growth, and repair.
• Rich with blood vessels, nerves, and bone-forming cells (osteoprogenitor cells), supporting bone health and attachment for tendons and ligaments.
Endosteum:
• A thin membrane lining the inner surface of the bone, including the medullary cavity.
• Contains bone-forming cells and plays a role in bone growth and repair.
Osteogenic Layer:
• The inner layer of the periosteum and endosteum is highly cellular, containing osteoblasts and osteoclasts.
• Osteoblasts are responsible for bone formation, while osteoclasts break down bone tissue during bone remodeling.
Bone Cells
• Osteoblasts:
Responsible for forming new bone by secreting matrix materials and minerals.
Support and Movement Page 1
, o Responsible for forming new bone by secreting matrix materials and minerals.
o Once surrounded by the matrix, they become osteocytes.
• Osteocytes:
o Mature bone cells located in lacunae (small spaces within the bone matrix).
o Maintain and monitor the bone tissue.
• Osteoclasts:
o Large cells responsible for breaking down bone tissue, enabling bone remodeling and mineral release.
16.1.2 Structure of Cartilage
• Definition:
o Cartilage is a flexible connective tissue surrounded by the perichondrium (a layer providing nourishment and structural support).
• Function:
o Provides cushioning at joints, reduces friction, and offers protection from compressive forces.
• Types of Cartilage:
o Hyaline Cartilage: Found in joints, the rib cage, nose, and respiratory structures. It reduces friction and absorbs shock.
o Fibrocartilage: The toughest type, found in intervertebral discs and menisci. It offers strong support and the ability to withstand pressure.
o Elastic Cartilage: The most flexible type, found in structures such as the ear and epiglottis, offering elasticity and shape maintenance.
N
Comparison of Bone and Cartilage
Bone
• Strength: Hard and strong, providing structural support.
• Formation: Developed by osteocytes (bone cells).
• Calcification: Undergoes calcification, meaning minerals such as calcium are deposited to harden the bone tissue.
• Covering: Covered by a protective layer called the periosteum.
• Function: Provides protection to internal organs and supports body movements through muscular attachment.
• Water Content: Contains 10-20% water.
• Blood Cells: Bone marrow is involved in the production of blood cells.
SK
Cartilage
• Strength: Soft and flexible, providing support and cushioning at joints.
• Formation: Formed by chondrocytes (cartilage cells).
• Calcification: Not calcified, making it more flexible compared to bones.
• Covering: Covered by a protective layer called the perichondrium.
• Function: Protects joints and reduces friction during movement.
• Water Content: Contains approximately 80% water, contributing to its cushioning properties.
• Blood Cells: Does not form blood cells.
16.1.3 Division of the Human Skeleton
The human skeleton is divided into two major parts:
1. Axial Skeleton
2. Appendicular Skeleton
Axial Skeleton
• Description: Forms the central axis of the body and includes:
o Skull: Composed of cranial bones that protect the brain and facial bones that form the structure of the face.
▪ Cranial Bones: Include the frontal, parietal, temporal, occipital, ethmoid, and sphenoid bones.
▪ Facial Bones: Protect soft tissues of the face, facilitate breathing, eating, and contribute to facial expressions.
o Vertebral Column (Spine): Protects the spinal cord and supports the head and torso. It consists of:
▪ Cervical Vertebrae (7): Located in the neck.
▪ Thoracic Vertebrae (12): Form the upper back and attach to ribs.
▪ Lumbar Vertebrae (5): Lower back region.
▪ Sacrum (5 fused bones) and Coccyx (4 fused bones): Form the base of the spine.
o Rib Cage (Thoracic Cage): Composed of ribs and the sternum, it protects the heart and lungs and plays a role in respiration.
▪ True Ribs (1-7): Directly connected to the sternum.
Support and Movement Page 2
