EXCRETORY SYSTEM including renal kindly

For gnm students excretory system includes renal function and Ne

1. EXCRETORY SYSTEM BY: Sunaina B handari (clinical instructor)

2. INTRODUCTION DEFINITION : The excretory system is responsible for the removal of waste products from the body, helping maintain homeostasis. MAIN ORGANS : kidneys Ureters Bladder Urethra

3. Positions Right kidney Left Kidney Superiorly R.Adrenal gland L. Adrenal gland Anteriorly R.lobe of liver,duodenum Spleen,Stomach , &hepatic flexure of pancreas, jejunum the colon & splenic flexure of the colon. Posteriorly D iaphragm &posterior Diaphragm& abdominal wall muscles Posterior abdominal wall Muscles.

4. GROSS STRUCTURE OF KIDNEY MICROSCOPIC STRUCTURE OF KIDNEY

5. Gross Structure Of Kidney Kidney Is Surrounded By An Outer Fibrous Capsule There Are Three Major Regions Of The Kidney : 1. Renal cortex 2. Renal medulla 3. Renal pelvis urine formed passes through the renal papilla at the apex of the pyramid into a minor calyx>major calyx>renal pelvis

6. RENAL CORTEX RENAL MEDULLA RENAL PELVIS Reddish brown tissue, it is a space between the medulla and the outer capsule . Contains some parts of nephron. Innermost layer made up of parenchymal cells, Contain RENAL PYRAMIDS. Renal pyramids contains dense network of nephrons. Funnel shaped structure that connects the kidney wwith the circulatory and nervous system. Contains hilum ( concave part of the bean –shape where blood vessels and nerves enter and exit the kidney )

7. Microscopic structure of kidney the renal structures that conduct the essential work of the kidney can not be seen by naked eyes.only electron microscopes can reveal them. The nephrons is the smallest unit of the kidney , also called the microscopic structure of the kidney. Each kidneys contains around 1-2 millons of nephrons and a lot of collecting ducts.

8. Proximal convoluted tubule This is the first site for water reabsorption into the blood stream . This is the first segment after the Bowman's capsule. It reabsorbs about 65-70% of the filtered sodium, water, and other solutes such as glucose, amino acids, and bicarbonate. The proximal tubule also secretes substances like hydrogen ions and certain drugs into the urine .

9. The loop of henle The loop of henle is a u-shaped tube that consists of descending limb and ascending limb. 1.Descending Limb : Function: The wall of the descending limb allows water to leave but doesn't let salt (sodium and chloride ions) pass through. Process: As the filtrate (the fluid being processed into urine) travels down, water moves out into the surrounding tissue because the surrounding tissue is saltier. This makes the filtrate inside the descending limb more concentrated (saltier ).

10. 2.Thin Ascending Limb: - Function: This part doesn't allow water to leave, but it does allow salt to move out. Process: As the filtrate moves up, salt moves out into the surrounding tissue, but water stays in. This starts to make the filtrate less concentrated . 3.Thick Ascending Limb: Function: Like the thin ascending limb, this part also doesn't let water pass through, but it actively pumps out salt (using energy). Process: This part pumps out even more salt into the surrounding tissue, making the filtrate even less concentrated by the time it reaches the end of the Loop of Henle . #over all role : Creating a gradient: the LOH creates a difference in salt concentration between inside of the nephron and the surrounding tissue.the tissue around the loop becomes very salty,especially deep in the medulla.

11. Purpose: This salt gradient is essential because it helps the kidney conserve water. When the filtrate eventually reaches the collecting duct, the salty environment around the Loop of Henle allows water to be reabsorbed back into the body, concentrating the urine. THE DISTAL CONVOLUTED TUBULE *Distal Tubule*: This segment comes after the loop of Henle . The distal tubule further adjusts the composition of the urine, primarily by reabsorbing sodium and calcium while secreting potassium and hydrogen ions. It plays a crucial role in regulating electrolyte balance and blood pH . Anti-diuretic hormone (secreted from the pituitary gland as a part of homeostasis) will act on the distal tubule to increase the permeability of the tubule to water to increase reabsorption. Which results in increased blood volume and increased blood pressure.

12. PARTS.. FUNCTION GLOMERULAR CAPSULE Filtratio n of molecules and water from blood. PROXIMAL CONVOLUTED TUBULE Selective reabsorption of many substances from glomerular filterate,eg glucose,amino acids and ions. LOOP OF HENLE Creates a hypertonic environment in the medula to facilitate water reabsorption by collecting ducts. DISTAL CONVOLUTED TUBULE Selective reabsorption of ions and secretion of hydrogen ions. DISTAL CONVOLUTED TUBULE Final concentration of urine.

13. Blood supply to kidney The renal veins drain the kidney and the renal arteries supply blood to the kidney. Kidney recieves the highest amount of blood. RENAL ARTERY The renal arteries split into several segmental arteries upon entering the kidneys, which then split into several arterioles . Carries oxygen rich blood in the kidney. AFFERENT ARTERIOLES The renal arteries branches into smaller arterioles called afferent arterioles. And these bring blood to the nephron .

14. GLOMERULUS: The afferent arterioles lead to a tiny ball of capillaries called the glomerulus . Here , blood is filtered. Small molecules and water pass through, while larger molecules and blood cells stay in the blood. EFFERENT ARTERIOLES : After filtration, the remaining blood exits the glomerulus through efferent arterioles.These arterioles are narrower, which helps maintain pressure in the glomerulus for efficient filtration. PERITUBULAR CAPILLARIES AND VASA RECTA: The efferent arterioles then form a network of capillaries around the nephron, called peritubular capillaries, and a special set of capillaries called the vasa recta around the Loop of Henle . These capillaries help in the reabsorption and secretion of various substances, ensuring that the right balance of electrolytes and fluids is maintained .

15. RENAL VEIN Finally, the filtered blood, now oxygen-poor but clean, is collected by the renal vein . The renal vein carries this blood back to the heart, completing the circuit. GLOMERULAR NEPHRITIS an inflammatory condition of kidney characterized by increased permeability of glomerular filtration barrier, causing filtration of protiens (especially albumin) and RBSs,resulting in protieinuria and hematuria.

16. Functions of kidneys A cid base balance W ater balance E lectrolyte balance T oxins removal B lood pressure control E rythropoeitin VITAMIN D metabolism