Skeletal, Muscular, and Circulatory System Study Notes

Skeletal System Disorders

• Osteoarthritis: Occurs when protective cartilage wears down.
• Juvenile arthritis: Arthritis affecting individuals under 16 years old.
• Rheumatoid arthritis: An autoimmune disorder that causes joint inflammation.
• Osteoporosis: Occurs when new bone formation does not keep up with the removal of old bone.
• Rickets: Softening of bones due to a lack of calcium or vitamin D.
• Gout: The buildup of uric acid in the blood and joints.

Types of Bone Fractures

• Greenstick: Incomplete break of the bone.
• Spiral: Caused by excessive twisting.
• Comminuted: Bone is crushed into pieces.
• Transverse: Fracture in a straight line.
• Compound: Exposure of bone through the skin.

Types of Muscle Tissue

1. Smooth muscle: Contracts slowly. Found in blood vessels and intestines. Control is involuntary.
2. Skeletal muscle: Contracts rapidly. Found in the trunk, limbs, head, and neck. Control is voluntary.
3. Cardiac muscle: Contracts rapidly. Found in the heart. Control is involuntary.

Muscular System Injuries

• Tendinitis: Inflammation of tendons that connect muscles to bones.
• Dystrophy: Hereditary disease in which the muscle becomes weaker over time.
• Strain and tears: Caused by overstretching the muscle.

Blood Composition

Blood is a fluid that carries gases, nutrients, and wastes through the body.

Cardiovascular vs. Lymphatic Systems

• Cardiovascular: Transports blood around the body.
• Both: Carry fluids through the body.
• Lymphatic: Collects fluid that leaks from blood and returns it to the bloodstream.

Function of Lymph Capillaries

They absorb fluids from around the body tissues.

Parts of the Lymphatic System

1. Bone marrow: Where blood cells are produced.
2. Thymus: Where T-cells finish developing.
3. Lymph nodes: Small organs that remove pathogens and dead cells.
4. Tonsils: Defend the body against infections.
5. Spleen: Stores white blood cells and allows them to mature.

Parts of the Circulatory System

1. Heart: Contracts to pump blood to the body.
2. Blood: Carries chemical messages and removes waste.
3. Arteries: Carry oxygen-rich blood away from the heart.
4. Veins: Carry oxygen-poor blood back to the heart.
5. Capillaries: Deliver oxygen-rich blood and collect oxygen-poor blood.

Components of Blood

Blood is composed of four main components: plasma, platelets, white blood cells, and red blood cells.