Excretory System Flashcards
Kidney
Key organ of the urinary system
Responsible for Water and Electrolyte Balance as well as the excretion of nitrogenous wastes.
Renal Artery
carries oxygenated blood that contains nitrogenous waste from the aorta to the kidney
Renal Vein
carries deoxygenated blood free of nitrogenous waste from the kidney to the inferior vena cava
Ureter
carries urine from the kidneys to the bladder.
Urethra
tube leading from the urinary bladder to the outside of the body
Nephron
the functional unit of the kidney
starts in the cortex and ends in the medulla
filter the blood, remove waste, and re-sorb ions, nutrients and water
Cortex
outer layer of the kidney
Medulla
inner region of the kidney
Major Nephron Regions (5)
Renal Corpuscle
Proximal Tube
Loop of Henle
Distal Tube
Collecting Duct
Renal Corpuscle
glomerulus and bowman’s capsule,
forms filtrate (pre-urine) consisting of ions, nutrients, waters and water
Proximal Tube
Has epithelial cells that reabsorb nutrrinst, ions and water from the filtrate into the blood
Loop of Henle
establishes strong osmotic gradient in the interstitial fluid surrounding the loop
Distal Tube
Reabsirbs ions and water in regulated manner
Help maintain water and electrolyte balance according to the body’s needs
Collecting Duct
reabsorbs more water to maintain homeostasis
Urea moves from urine to the interstitial fluid at the base of the collecting duct
Glomerulus
cluster of capillaries in the renal corpuscle that brings blood to the nephron from the renal artery
Bowman’s Capsule
region of the nephron that surrounds the glomerulus.
Aldosterone
steroid hormone released from the adrenal gland
central role in the regulation of blood Na+ and K+ levels (-> of blood pressure )
antidiuretic hormone (ADH)
also called vasopressin
is a peptide hormone released from the pituitary gland
that controls water retention
Ion and Water movement in the proximal fluid
How does the Loop of Henle work?
- As the fluid travels down the descending limb, water passively transports out of the loop and into the interstitial membrane.
At the bottom of the loop, the inside and outside have a high osmolarity. Water does not leave because the membrane of the ascending limb is almost impermeable to water. - Fluid loses Na+ and Cl- ions through passive transport in the thin ascending limb.
- Near the cortex, osmolarity in the surrounding fluid is low, so the ions need to be actively transported out of the loop
Malpighian tubules form pre-urine, which is further processed by which of the following anatomical structures?
hindgut
Proximal Tube vs Distal Tube
The function of the proximal tubule is essentially the reabsorption of filtrate in accordance with the needs of homeostasis (equilibrium),
The distal part of the nephron and collecting duct are mainly concerned with the detailed regulation of water, electrolyte, and hydrogen-ion balance.
What is Diabetes Insipidus?
