Railway Science (Biology – Excretory System)

Out of 180L, due to reabsorption by the kidneys, only 1 - 2 L of filtrate is excreted out as urine. The amount of filtrate generated by the glomerulus each minute is known as the glomerular filtration rate.

(sonography) is a non-invasive imaging test. It uses high-frequency sound waves to create real-time pictures or videos of internal organs or other soft tissues, such as blood vessels.
Electrocardiography is the process of producing an electrocardiogram (ECG) to check the heart's rhythm and electrical activity. Magnetic Resonance Imaging (MRI) is a non - invasive imaging technology that produces three - dimensional detailed anatomical images.
It is often used for disease detection, diagnosis, and treatment monitoring. Echocardiography is a test that uses sound waves to produce live images of your heart. The image is called an echocardiogram.

It is an excretory product that requires a minimum amount of water (1 gm of Uric Acid requires 10 ml of water). It is produced by the ‘Inosinic pathway’ in the liver. For example - Reptiles, Birds, Insects excrete Nitrogenous waste as Uric acid. Creatine is an important amino acid present in muscles. Ammonia is the most toxic Excretory Product. Urea is a medium toxic excretory product.

Dialysis :- It is a treatment to remove waste products and excess fluid from the blood when the kidneys stop working properly. Two main types of dialysis: Hemodialysis - The blood is cleaned outside the body to an artificial kidney machine and then sent back into the body. Peritoneal dialysis - The lining of the abdomen or belly is used to filter the blood inside the body.

Bowman's capsule is a part of the nephron that forms a cup-like sack surrounding the glomerulus. It encloses a space called “Bowman's space”. Some other Part of KIdney - Arteriole, renal pelvis, renal cortex, Ureter, medulla,renal pyramid, capillaries, venule.

Path of urine in human body: Kidney → ureter → urinary bladder → urethra. Urinary bladder stores the urine. Filtration takes place in Nephron (in Kidneys). Ureter is a tube that carries urine. Urethra a passage to let the urine out of the body. Steps involved in urine formation are - Glomerular filtration, Tubular reabsorption and Tubular secretion.

Nephrons: Each of it filters a small amount of blood. Nephrons are also called the functional units of the kidney. These produce urine in the process of removing waste and excess substances from the blood.
These are composed of a renal corpuscle, a proximal tubule, an intermediate tubule, a distal convoluted tubule, a connecting tubule, and cortical, outer medullary, and inner medullary collecting ducts.

Urethra - Tube that connects the urinary bladder to the urinary meatus for the removal of urine from the body. Prostate gland: An Exocrine gland (glands with ducts), walnut-sized gland located underneath the bladder and in front of the rectum. Function - produce the fluid that nourishes and transports sperm (seminal fluid). Testis: Male reproductive gland. Function - produces spermatozoa, synthesizes testosterone.

In human male, the urethra originates from the urinary bladder and extends through the penis to its external opening called urethral meatus. Testicles: These are the male reproductive organs responsible for sperm production.

The prostate gland, about the size of a walnut, sits between the bladder and penis, with the urethra passing through its center. As you age, changes in hormone balance can cause your prostate gland to enlarge.