Human Tissues and Skeletal System: Definitions

Human Tissue Types and Skeletal Components

Muscle Tissue

• Muscle tissue: Cells that can contract.
• Skeletal muscle: Moves bones.
• Smooth muscle: Involuntary muscles found in the digestive system and blood vessels.
• Cardiac muscle: Makes up the heart.

Nervous Tissue

• Nervous tissue: Made of cells that receive and transmit messages.
• Neurons: Specialized nerve cells.

Epithelial and Connective Tissue

• Epithelial tissue: Layers of cells that line internal and external body surfaces.
• Connective tissue: Binds, supports, and protects structures in the body.
• Matrix: Intracellular substance that holds cells in tissue.

Body Cavities

• Cranial cavity: Contains the brain.
• Spinal cavity: Holds the spinal cord.
• Thoracic cavity: The upper part of the torso.
• Abdominal cavity: The lower compartment of the torso.
• Pelvic cavity: Contains organs of the reproductive and excretory systems.

Skeletal System Components

• Organ: A group of tissues that work together.
• Diaphragm: Dome-shaped muscle that divides the torso.
• Skeleton: The internal framework of the body.
• Periosteum: Tough membrane that covers the bone surface.
• Compact bone: Hard material composed of mineral crystals and protein fibers.
• Haversian canal: Narrow cylinder that holds blood vessels within bone.
• Osteocytes: Bone cells.
• Spongy bone: Connective tissue found below compact bone.
• Bone marrow: Soft tissue found in spongy bone.

Joints and Related Structures

• Fracture: A crack or break in a bone.
• Epiphyseal plate: The area where bone growth occurs.
• Joint: The place where two bones meet.
• Ligament: A tough band of connective tissue that holds bones together at a joint.
• Synovial fluid: Lubricating substance found at joints.

Joint Conditions

• Rheumatoid arthritis: Inflammation of a joint due to an autoimmune attack.
• Osteoarthritis: A degenerative condition where cartilage in joints becomes thinner and rougher.