Biology 20 - Excretory vocabulary Flashcards
Excretory System
Regulate the volume and composition of body fluids by removing wastes and returning needed substances to the body for reuse.
Excretion
The process of separating wastes from the body fluids and eliminating them.
Kidneys
- Located in the mid-lower back
- Cushioned by fat and protected by the ribcage
- Humans can function with only one kidney – if one is removed the other will increase in size to handle the increased workload
Ureters
Muscular tubes that move urine by peristaltic action to the urinary bladder, where it is temporarily stored
Urethra
Tube by which urine enters the body. 20cm long in males and merges with the vas deferns. 4cm long in females and remains separate from the reproductive tract
Nephrons
Closely associated with blood vessels and filter various substances from the blood, transforming it into urine.
Renal arteries
Enters each capsule and splits into a fine network of capillaries called the glomerulus.
Bowman’s Capsule
Located at the top of each nephron.
Filtrate
Water, small molecules, iron, and urea proceeded further into the nephron.
Collecting Duct
Functions as a water conservation device, reclaiming water from the filtrate so that very little is lost from the body.
Renal Veins
Solutes and water reclaimed during reabsorption are returned to the body via renal veins.
Tubular Reabsorption
Removes useful substances such as sodium from the filtrate and returns them to the blood for reuse.
Glomerular filtration
Moves water and solutes, except proteins, from blood plasma into the nephron (this filtered fluid is called filtrate).
Tubular Secretion
Moves additional wastes and excess substances from the blood into the filtrate.
Water reabsorption
Removes water from the filtrate and returns it to the blood for reuse by body systems.
