Overview of Excretory Systems of Body Anatomy of Kidney Dr. Muhammad Rafique Anatomy, DIMC Objectives Define the Excretion Enumerate the different excretory organs of Body Know facts about the renal system Discuss the external features of kidney, ureters, urinary bladder and urethra Describe the longitudinal section of kidney Definition Excrete Word made up of to components Ex means out Crete means to flow That means to flow out of waste product from the body Different organs for Excretion Kidneys: Are the primary and major sources, to excrete out water and electrolytes from the body in form of urine Intestinal Tract: The undigested food excreted from the body as the feces through anus Skin: Water, salt & other metabolic products also excreted from skin as the sweat which secreted sweat glands Glands of Skin Sweat Glands Sweat glands are long tubular glands, coiled at their ends, located in the dermis of the skin. They produce a watery fluid called sweat which consists of 98% water and 2% solid residue. Organic : Urea, uric acid, creatinine, volatile fatty acids Inorganic: Sodium chloride, potassium chloride and glucose. Glands of Skin Cont… Sebaceous Glands Sebaceous glands are attached to the hair follicle. Each gland consists of a small branched alveoli which produces an oily or waxy substance called sebum. Excretory substances like waxes, sterols, fatty acids and traces of other hydrocarbons are eliminated along with the sebum. Different organs for Excretion Lungs: CO2 and water vapors are the metabolites and excreted from the body through nostrils Liver: Dead and debris, toxicants and excess of amino acids are removed from the body through different source with help of blood Overview of Gross Anatomy of Excretory System The Excretory System consists of: Kidneys Ureters Urinary bladder Urethra Facts About Renal System The kidneys function as a pair of filters through which about one liter of blood circulates each minute. The entire blood in the body passes through them in 5 - 6 minutes. In a day it filters 1800 liters of blood which is 400 times the blood volume. Tea, coffee and alcohol are beverages that increase the formation of urine. They are termed diuretics. Each human kidney contains more than 1.2 million nephrons. Facts About Renal System When a kidney is damaged or diseased, the other kidney is able to compensate for it. So a person can lead a normal life with only one kidney. A normal adult excretes 1 - 1.8 litres of urine per day. An artificial kidney (dialysing machine) is used for dialysis. When the kidneys of a patient stop functioning, life can be prolonged through dialysis. Kidney transplants have had good success rates and have given fresh lease of life to patients. Kidneys Kidneys are the paired the paired organs Bean shaped, located into right and left lumbar regions The right kidney is slightly at the lower level as compared to left kidney due to presence of liver in left hypochondrium Kidneys Cont….. Kidney has: Two border: Lateral; Convex Medial; Concave, has depression at the middle called as Hilum. Hilum means opening through structures enter and leave the kidney. The structures which entered the kidney are Renal artery & renal nerve fibers. The structures which leave kidney are the renal vein, renal pelvis and ureter and lymphatic vessels Kidneys Cont….. Kidneys has: Two Poles: Superior pole; on the medial and posterior aspect of superior pole there is a supra-renal gland on each kidney Two Surfaces: Anterior Surface related to different viscera Posterior Surface; related to muscles of posterior abdominal wall and lower two ribs Ureters The ureters are long tubes like structures convey the urine from the kidneys to the urinary bladder. Superiorly the ureter begins at the dilated part called as the Renal Pelvis. The renal pelvis is the beginning of ureter within the mass of kidney, it first receives the urine and becomes narrow to form the Ureter. Urinary Bladder Urinary bladder is situated within the hypogastrium, below the pubic symphysis, in the pelvic cavity It receives the urine with help of two ureters and stores urine form some period. Urinary bladder is a triangular shaped organ has an apex, a base and two lateral and a posterior surfaces Urinary Bladder Cont…. Empty bladder entirely located below the pubic symphysis, but urinary bladder distended it can be palpated per abdomen The urinary bladder continuous downward as the base which gives another tube like structure the urethra Urethra Urethra is a tube like structure which excretes the urine from the body. The urine is stored with in the urinary bladder and when desired occurred the urinary bladder expels the urine within the urethra. In the female the urethra is short and has only one part which opens into vulva of female that is to the exterior Urethra Cont… In the male the urethra has three parts 1. Porstatic part 2. Membranous part 3. Penile Part Ultimately urine excreted to exterior through urethra Longitudinal Section of Kidney A longitudinal section of the kidney shows three distinct regions: Renal Cortex Renal Medulla Renal Pelvis Renal Cortex This is the outer pale red colored layer. It contains the malphigian corpuscles, the proximal and distal parts of the renal tubule. Renal Medulla This forms the inner dark red zone and contains the Henle's loop and the collecting tubules, present in the form of renal pyramids. The conical pyramids project into the renal pelvis. Renal Pelvis This is a large funnel- shaped region behind the renal medulla. Urine flows into the renal pelvis through minute openings at the tips or papillae of the pyramids. The urine that is collected is passed down to the ureters into the bladder.