Urinary System. Functions of Urinary System. Filter Blood Regulation of Blood Volume/Pressure [renin] Regulation of the solute concentration of the Blood: Na + , Cl - , K + , Ca +2 , HPO 4 -2 pH regulation of extracellular fluid Regulation of RBC synthesis [erythropoietin]
Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.
Blood enters the nephron from a network that begins with the renal artery. This artery branches into smaller and smaller vessels –and enters each nephron as an afferent arteriole. The afferent arteriole ends in a specialized capillary called the Glomerulus. Each kidney has a glomerulus contained in Bowman’s Capsule. Any cells that are too large to pass into the nephron are returned to the venous blood supply via the efferent arteriole. The efferent arteriole will divides to become the peritubular capillaries.
At least 500 mL (17 oz) of urine must be eliminated every day because this amount of fluid is needed to remove potential toxic materials from the body to maintain homeostasis.
A normal adult eliminates from 1.5 L (1.6 qt) to 2.3 L (2.4 qt) of Urine a DAY, depending on the amount of water taken in and the amount of water lost through Respiration and Perspiration.
Urine flows from the nephron to the collecting ducts, which extend to the tips of the pyramids, and empty into the calyces. All the urine will leave the kidney via the ureters.
Each ureter is about 25 cm long and carries urine from the renal pelvis to the urinary bladder via peristaltic waves.
The wall of the ureter consists of three layers. The outermost is a fibrous coat, middle layer is muscular [ circular & longitudinal] and the innermost layer is called the mucosa, a transitional epithelium that is continuous with the lining of the renal pelvis and bladder, also secretes a protective mucus.
A triangular region, called the trigone, is formed by three openings in the floor of the bladder. Two are from the ureters, and third from the urethra. There are flaps of mucosa covering the openings of the ureters and act as valves.
A band of muscles encircles the opening to the urethra forming the internal urethral sphincter.
The second layer is called the submucosa. It contains elastic connective tissue fibers.
The third layer is the muscularis: this collection of smooth muscle is known as the detrusor muscle. Contraction of this muscle expels urine from the bladder.
The outermost layer is dense connective tissue.
20 cm long [7-8 in]
Transports both urine & semen
Eternal urethral orifice opens at tip of penis
3-4 cm long [1.5 in]
External urethral orifice opens just anterior to the vaginal opening
Urethrathin walled tube – conveys urine from bladder to external environment. Similar structure to ureterSphincters: internal urethral [involuntary] & external urethral [ voluntary]
Kidney stones affect more than a million Americans each year. Twelve to 24 million Americans will develop stones in their lifetime and the incidence rate has increased dramatically over the last 20 years with approximately 350,000 new stone cases reported each year.
In the United States, 7 to 10 of every 1,000 hospital admissions are due to kidney stones.
The stones can be as small as a grain of sand or as large as a golf ball. The size, shape, and location of the stone can cause many different symptoms.