Human Anatomy - First Grade PDF

HUMAN ANATOMY OSOL ALDEEN UNIVERSITY COLLEGE FIRST GRADE DEPARTMENT OF PHARMACY  The Urinary System The urinary system consists of several key structures: 1. Kidneys 2. Ureters 3. Urinary Bladder 4. Urethra  Blood supply Renal Arteries Segmental...

HUMAN ANATOMY OSOL ALDEEN UNIVERSITY COLLEGE FIRST GRADE DEPARTMENT OF PHARMACY  The Urinary System The urinary system consists of several key structures: 1. Kidneys 2. Ureters 3. Urinary Bladder 4. Urethra  Blood supply Renal Arteries Segmental Arteries Interlobar Arteries  Kidneys Location: The kidneys are two bean-shaped organs located retroperitoneally on either side of the spine, between the levels of T12 and L3.  Structure of kidneys Cortex: The outer region containing glomeruli and convoluted tubules. Medulla: The inner region with renal pyramids, loops of Henle, and collecting ducts. Renal Pelvis: The funnel-shaped structure that collects urine from the pyramids and passes it to the ureter.  Kidneys The kidneys are the primary organs of the urinary system. the kidneys are the organs that filter the blood, remove the waste and excrete the wastes in the urine. They are the best organs that perform the functions of the urinary system. the other components are accessory structures to eliminate the urine from the body. The right kidney usually is slightly lower than the left because the liver displace it downward. The kidneys, protected by the lower ribs. Each kidney is held in place by connective tissue and is surrounded by a thick layer of adipose tissue, which helps to protect it. A tough, fibrous, connective tissue renal capsule closely envelopes each kidney  Ureters Structure: pair of muscular tubes about 25-30 cm long convey urine from the kidney to the bladder. The walls of the ureters are made up of an outer fibrous tissue layer, two central layers of smooth muscle and a mucous membrane lining.  Urinary Bladder Location: A hollow, muscular reservoir organ located in the anterior part of pelvis. Structure: Can expand to hold about 400- 500 ml of urine. Function: Stores urine until it is excreted. It has four parts: apex, base, superior surface, two inferolateral surfaces.  Urethra Structure: A tube that carries urine from the bladder to the outside of the body. Length: About 4 cm in females and 20 cm in males. Function: Passageway for urine excretion.  Sphincters Internal Urethral Sphincter: Involuntary control, located at the bladder-urethra junction. External Urethral Sphincter: Voluntary control, located in the urogenital diaphragm.  Nephrons The nephron is the functional unit of the kidney, responsible for filtering blood and forming urine. Each kidney contains about one million nephrons. Nephrons contain a network of tubes, veins, and arteries that intertwine to exchange salts, wastes, and fluids to remove them from the bloodstream.  Nephron diagram and different parts The nephron consists of the following parts: Renal Corpuscle Glomerulus: A network of capillaries where blood filtration begins. The walls of the glomerular capillaries are highly permeable, allowing water and solutes to pass through. Bowman's Capsule (Glomerular Capsule): A cup-like structure that surrounds the glomerulus and collects the filtrate (filtered fluid).  Renal Tubule The renal tubule is a long, convoluted tube that processes the filtrate to form urine. It consists of several segments: Proximal Convoluted Tubule (PCT) Loop of Henle (Nephron Loop) Distal Convoluted Tubule (DCT) Collecting Duct