The Urinary System is a group of organs in the body concerned with filtering out excess fluid and other substances from the bloodstream. The substances are filtered out from the body in the form of urine.
Urine is a liquid produced by the kidneys, collected in the bladder and excreted through the urethra. Urine is used to extracting excess minerals or vitamins as well as blood corpuscles from the body.
The Urinary organs include the kidneys, ureters, bladder, and urethra. The Urinary system works with the other systems of the body to help maintain homeostasis.
The kidneys are the main organs of homeostasis because they maintain the acid-base balance and the water-salt balance of the blood. If the kidneys fail, these functions are compromised or lost altogether, with devastating effects on homeostasis.
The affected individual might experience weakness, lethargy, shortness of breath, anemia, widespread edema (swelling), metabolic acidosis, rising potassium levels, heart arrhythmias, and more.
Each of these functions is vital to your well-being and survival. The urinary system, controlled by the nervous system, also stores urine until a convenient time for disposal and then provides the anatomical structures to transport this waste liquid to the outside of the body.
Failure of nervous control or the anatomical structures leading to a loss of control of urination results in a condition called incontinence.
Functions of the urinary system
- Excretion – removal of waste material from the blood plasma and the disposal of this waste in the urine.
- Elimination – removal of waste from other organ systems. From the digestive system – undigested food, water, salt, ions drugs. From respiratory system – CO2, H+, water, toxins. From skin – water, NaCl, nitrogenous wastes (urea, uric acid, ammonia, creatinine).
- water balance – kidney tubules regulate water reassertion and urine concentration.
- Regulation of pH – volume, and composition of body fluids.
- Production of erythropoietin: for hematopoiesis, and renin for blood pressure regulation.
Anatomy of the Urinary System
The urinary system consists of the kidneys, ureters, urinary bladder and urethra. The kidneys form the urine and account for the other functions attributed to the urinary system.
The ureters carry the urine away from kidneys to the urinary bladder, which is a temporary reservoir for the urine. The urethra is a tubular structure that carries the urine from the urinary bladder to the outside.
- kidneys – a pair of bean-shaped organs located retroperitoneal, responsible for blood filtering and urine formation.
- Renal capsule – a layer of fibrous connective tissue covering the kidneys.
- Renal cortex – the outer region of the kidneys where most enthrones are located.
- Renal medulla – an inner region of the kidneys where some enthrones is located, also where urine is collected to be excreted outward.
- Renal calyx – duct-like sections of renal medulla for collecting urine from nephrons and direct urine into the renal pelvis’
- Renal pyramid – connective tissues in the renal medulla binding various structures together.
- Renal pelvis – central urine collecting area of the renal medulla.
- Hilum – concave notch of kidneys where renal artery, renal vein, ureter, nerves, and lymphatic vessels converge.
- Ureter – a tubule that transports urine (mainly by peristalsis) from the kidney to the urinary bladder.
- Urinary bladder – a spherical storage organ that contains up to 400 ml of urine.
- Urethra – a tubule that excretes urine out of the urinary bladder to the outside, through the urethral orifice.