Urinary system One

• >Located on each sie of the vertebral column in the upper abdomen outside the peritoneal cavity
• >Major structures of kidney are medulla, cortex renal artery, renal vein, renal pyramid, renal calyx, renal pelvis, ureter, nephron

Cystitis - bladder infection

Pyelitis - inflammation of the renal pelvis

pyelonephritis - inflammation of renal parenchyma, calices and pelvis due to local bacterial infection

Uretitis - inflammation of ureter

Urethritis - Inflammation of urethra - caused by Ecoli or klebsiella, and some transmitted diseases including chlamydia, gonorrhea and ureplasma urealyticum infection

Renal artery branches off the abdoninal aorta and supplies blood to kidney

Renal vein - 99% of filtered blood is reabsorbed and circulated through renal vein back to general circulation and remaining 1%  of filtered blood contains waste product is processed further by kidney.

Outer layer of kidney containing 1.3 millions of nephrons that begin urine production

Inner portion of kidney, made of renal pyramids and tuvular structures

The functional unit of the kidney

Channels output to renal pelvis for excretion

After proessing the formed urine is channelled to the pelvis

Channels formed urine from the pyramids to the pelvis

Tube that transport urine to the bladder

Maintain homeostasis by regulating volume and composition of blood

Eliminate wast products

Regulate blood volume and BP

Regulate plasma ion concentrations

Stabilise blood Ph

Activation of Vit D

Production of erythropoietin

A hormone produced by the kidney that promotes the formation of red blood cells in the bone marrow

levels fall in chronic renal failure resulting in anaemia

Activation occurs in kidney

responsible for Ca absorption 

Patients with chronic renal failure have infufficient vit D requires oral supplements

Functional unit of kidney

each kidney contains approx 1 million nephron

• main activities include:
• selective reabsorption
• selective secreation
• mechanical filtration

Glomerulus are network of twisted caillaries which acts as a filter for the passage of protein and RBC free filtrate

Bowman's capsule surrounds the glomerulus and acts as a reservior fro the filtrate

Proximal convoluted tube are site of reabsorption of glucose, amino acids and electrolytes back to circulation

Loop of Henle U-shaped tubule located in mefulla and extending from proximal to distal convoluted tubule

Distal convoluted tube is the site of where filtrate enters the collection tubule 

Collecting tubule release urine

Are Nitrogenous wastes resulting from the end products of protein metabolism and muscle activity

UREA - most abundant. Produced during aminao acid breakdown

CREATININE is produced as a breakdown of muscle tissue

plasma concentrations are indicative of changes in renal function

Sterile, no bacteria

• >Nitrate in dipstick indicates bacterial metabolism
• >PH is slightly acidic
• >Specific gravity compares the concentration of urine with distilled water
• >Dilute urine has a low specific gravity due to excessive intake of water
• >Concentrated urine has a high specific gravity for example inadequate fluid intake.

• >Ureters is a long narrow fibro muscular tube 24-30cm that connects each kidney to the bladder. Urine that is formed within nephron flows into the ureter
• >Ureter originate at the lower portion of the renal pelvis and terminate in the trigone of the bladder wall
• >Movement of urine from the renal pelves through the ureters into the bladder is faciliated by peristalsis movement.

• >Highly muscular orgain that can store up to 1L of urine.
• >Ligaments hold the bladder in its place
• >Contraction of the detrusor muscle and relaxation  of the internal and external spincters com[resses the bladder to  expels urine into the urethra
• >Trigone funnels ruine into the urethra

• >Storage and emptying funtions of bladder is controlled by the nervous system
• >Promotes contration of the bladder wall and relaxation o fthe internal bladder sphincter
• >voluntary control of urination is provided by muscles in teh external sphincter and pelvic floor which is controlled by nervous system
• >Micturination occurs when the external sphincter i srelaxed and the detrusor muscle contracts. Both of these are controlled by the nervous system.

The urethra is a muscular tube that frains urine form the body. 3-4 cm long in female, close to 20cm long in male.

• Its arises from the base of the bladder
• In males the prostate gland which lies just below the bladder surrounds the urethra

Inability to voluntary control urination

• Causes: 
• > Immaturity
• >nocturnal enuresis- night bed wetting
• >stress incontinence - childbirth can stretch and damage sphincter muscles
• >Damage to central nervous system, nerves or spinal cord to the bladder or external urethral spincter eg stroke
• >

• >More common in women due to shortness of urethral and sits close to anus
• >Cause by E.coli
• >cause painful urination, frquency increases, loin pain and fever,  smelly urine.
• >Untreated can spread to ureter to the kidney and this is known as Pyelonephritis
• >Pyelonephritis results if bacteria invade corted and medulla causing high fever, intense pain vomiting and diarrhoes, blood cells and pus in urine.