The Excretory System: Structure, Function, and Importance by chetan rana
- 2. Introduction Excretion - Excretion is the removal of the metabolic wastes of an organism. Wastes removed include carbon dioxide, water, salt, urea, and uric acid. All excreted wastes travel at some time in the blood. Organs of the Excretory System- • Lungs - removal of excess carbon dioxide. • Liver - produces urea and uric acid as a by-product of the breakdown of proteins. • Skin - removal of excess water, salt, urea, and uric acid. • Urinary System - kidneys filter the blood to form urine, which is excess water, salt, urea, and uric acid.
- 3. Introduction Lungs • The lungs are another part of the excretory system. • Lungs are part of the respiratory system, also. • Wastes removed by the lungs include carbon dioxide and water vapor produced by cellular respiration.
- 4. Introduction Skin • The skin also functions in excretion. • Sweat glands in the skin produce perspiration. • When a person perspires, the skin excretes water and salts.
- 5. Introduction Liver The liver plays a role in the body's excretory system by breaking down harmful substances and excreting the by- products in the blood and bile: • Ammonia to urea: The liver converts ammonia into urea, a less toxic substance, which is then released into the blood. • Bile: The liver produces bile, a fluid that helps digest fats and carries away waste. Bile by-products enter the intestines and leave the body in feces. • Blood filtration: The kidneys filter blood by-products, which leave the body in urine.
- 6. Importance 1. Humans produce waste products that must be removed from their body. 2. Most animals have a system that deals with nitrogen-rich wastes from the breakdown of proteins and nucleic acids. 3. Ammonia (NH3) is toxic. 4. Homeostasis: The excretory system helps maintain the body's internal chemical balance. 5. Blood pressure: The excretory system helps regulate blood pressure. 6. Electrolyte balance: The excretory system helps maintain the body's electrolyte balance.
- 7. Organs of the Urinary System
- 8. Organs of the Urinary System The major organs involved in the excretory/ urinary system include 2 Kidney, 2 Ureters, 1 Bladder 1 Urethra.
- 9. Kidney Location • The kidneys are located Trusted just below the rib cage, with one on each side of the spine. The right kidney is generally slightly lower than the left kidney to make space for the liver. • Each kidney is approximately 3cm thick, 6 cm wide, and 12 cm long. The left kidney is 10 g heavier than the right kidney.
- 10. Kidney structure • The kidneys are two bean-shaped organs that are roughly the size of a fist. A tough, fibrous renal capsule surrounds each kidney and provides support for the soft tissue inside. Beyond that, two layers of fat serve as further protection. The adrenal glands lie on top of the kidneys. • Inside the kidneys are several pyramid-shaped lobes. Each consists of an outer renal cortex and an inner renal medulla. Nephrons flow between these sections. Each nephron includes a filter, called the glomerulus, and a tubule.
- 11. Kidney structure
- 12. Kidney structure • The glomerulus filters blood, which enters the kidneys through the renal arteries and leaves through the renal veins. The kidneys are relatively small organs, but they receive 20% to 25% trusted Source of the heart’s output. • The tubule returns necessary substances to the blood and removes waste that then becomes urine. The kidneys excrete urine through the ureter, a tube that leads to the bladder.
- 13. Kidney structure • Internally, the kidney has three regions— 1. an outer cortex, 2. a medulla in the middle, and 3. The renal pelvis in the region called the hilum of the kidney. The hilum is the concave part of the bean shape where blood vessels and nerves enter and exit the kidney. it is also the point of exit for the ureters.
- 14. Kidney structure
- 15. Urinary System Functions 1. Removing waste- The excretory system removes harmful substances and waste products from the body, such as urea, sweat, and feces. 2. Maintaining fluid balance- The excretory system helps maintain the body's fluid balance by regulating the water in the urine. 3. Regulating blood pressure- The excretory system helps regulate blood pressure by secreting the enzyme renin and releasing the hormone erythropoietin. 4. Controlling electrolyte levels- The excretory system helps control the levels of electrolytes in the body.
- 16. Urinary System Functions 5. Maintaining chemical homeostasis- The excretory system helps maintain the body's internal chemical homeostasis. 6. Preventing damage to the body- The excretory system helps prevent damage to the body by removing excess and unnecessary materials from the body fluids.