nephrons and kidneys Flashcards
What are the functions of the mammalian kidneys?
serve both excretory and osmoregulatory functions. consist of a network of tubules that process and filter blood.
How does hormone regulation affect blood osmolarity?
When blood osmolarity increases, osmoreceptors in the hypothalamus trigger the release of ADH (antidiuretic hormone).
ADH causes thirst and helps bring blood osmolarity back down to the normal range
What are the two main regions of the kidney?
Renal cortex: The outer layer of the kidney
Renal medulla: The inner layer of the kidney
How does blood flow through the kidneys?
Blood enters the kidney via the renal artery, which branches into capillaries
Materials from the blood are passed into excretory tubules for processing.
Processed fluid exits via the renal vein.
What is the role of the renal pelvis in the kidney?
collects the urine produced by the kidneys, which then travels through the ureter to the urinary bladder.
What are the two types of nephrons in the kidneys?
Cortical nephrons: Reach only a short distance into the medulla.
Juxtamedullary nephrons: Extend deep into the medulla
What is the role of juxtamedullary nephrons?
juxtamedullary nephrons are essential for producing hyperosmotic urine, which helps conserve water. more abundant in terrestrial animals. Kangaroo rats excrete the most hyperosmotic urine
What is the basic structure of a nephron?
a long tubule and a ball of capillaries called the glomerulus. The Bowman’s capsule surrounds the glomerulus.
How is filtrate formed in the glomerulus?
formed when blood pressure forces fluids from the blood in the glomerulus into the lumen of the Bowman’s capsule. The glomerulus is permeable to water and small solutes
What happens during reabsorption in the nephron?
filtrate passes through three main regions of the nephron:
Proximal tubule (closest to glomerulus).
Loop of Henle.
Distal tubule, which connects to the collecting duct.
What is the role of the collecting duct?
The collecting duct receives processed filtrate from the distal tubule and delivers it to the renal pelvis for excretion.
How does the urinary bladder function?
As urine accumulates in the urinary bladder, it expands, and the cells flatten to accommodate more space. Stretching of the bladder initiates the feeling of the need to urinate.
