Human Anatomy Notes – Blood, Brain, Skeleton & Nutrition Guide

  1. Definition The blood circulatory system is a network of the heart, blood, and blood vessels that transports nutrients, gases, hormones, and waste products throughout the body. 2. Main Components Heart – the muscular pump. Blood – the fluid that carries oxygen, nutrients, hormones, and waste. Blood Vessels – the channels for blood flow: Arteries – carry blood away from the heart (usually oxygen-rich). Veins – carry blood toward the heart (usually oxygen-poor). Capillaries – tiny vessels where exchange of substances occurs between blood and tissues. 3. Circulation Types Pulmonary circulation – blood flow between heart and lungs : Right side of the heart pumps deoxygenated blood to the lungs. Blood picks up oxygen and returns to the left side of the heart. Systemic circulation – blood flow between heart and the rest of the body : Left side of the heart pumps oxygenated blood to all body tissues. Blood returns deoxygenated to the right si...

 # Anatomy of the Kidney and Kidney Diseases The kidneys are a pair of bean-shaped organs, each about the size of a fist, located just below the rib cage, one on each side of the spine. They play a crucial role in maintaining overall health by filtering waste products from the blood, balancing electrolytes, regulating blood pressure, and producing hormones. ## Gross Anatomy of the Kidney Each kidney is encased in a tough, fibrous capsule and surrounded by a layer of adipose tissue (perirenal fat) for protection. Internally, the kidney is divided into three main regions: *   **Renal Cortex:**  The outermost layer, light reddish-brown in color. It contains the renal corpuscles (glomeruli and Bowman's capsules) and the convoluted tubules of the nephrons. *   **Renal Medulla:**  The inner region, darker and composed of cone-shaped structures called renal pyramids. The base of each pyramid faces the cortex, and its apex, the renal papilla, points towards th...