Maintaining fluid balance in the body Flashcards
(18 cards)
What structures are contained in the renal cortex?
The cortex contains the glomerulus, the renal capsule, the PCT, and the DCT.
What structures are found in the renal medulla?
The medulla contains the loop of Henle and the collecting duct.
Where does the ureter join the kidney?
The renal pelvis is where the ureter joins the kidney.
What is the role of nephrons in the kidneys?
Each kidney contains a thousand tiny tubes known as nephrons, which are responsible for the formation of urine.
What is the primary function of the nephron?
The function of the nephron is to filter the blood, remove waste, and selectively reabsorb useful substances back into the blood.
What occurs during ultrafiltration in the glomerulus?
Blood enters through the afferent arteriole, creating high hydrostatic pressure that forces water and small minerals out of the capillaries to form glomerular filtrate.
What happens to large proteins and blood cells during ultrafiltration?
Large proteins and blood cells are too big to pass through the small gaps, so they remain in the blood.
What is the process of selective reabsorption in the PCT?
In the PCT, filtrate is reabsorbed back into the blood, leaving urea and excess minerals behind.
How does the structure of the PCT facilitate reabsorption?
The PCT has microvilli that provide a larger surface area for reabsorption and contains many mitochondria for energy.
What is the sodium ion concentration in the PCT and why?
The concentration of sodium ions in the PCT is low because sodium ions are actively transported out into the bloodstream.
How do sodium ions and glucose get reabsorbed in the PCT?
Sodium ions diffuse into the PCT cells through co-transport proteins, carrying glucose with them, which then diffuses into the bloodstream.
What is the structure of the loop of Henle?
The loop of Henle is made up of two limbs: the ascending limb and the descending limb.
What occurs in the ascending limb of the loop of Henle?
The ascending limb walls are impermeable to water and actively transport sodium ions out.
What happens in the descending limb of the loop of Henle?
The descending limb is permeable and allows water to move out by osmosis.
what is the role of mitochondria in the ascending limb cell wall and how does the ascending limb contribute to the sodium ion gradient?
Mitochondria in the walls of the ascending limb provide energy to actively transport sodium ions out, leading to an accumulation of sodium ions in the medulla.
What happens to water in the descending limb due to the sodium ion gradient?
Water moves out of the descending limb by osmosis and is absorbed into the blood.
What is the state of the filtrate when it reaches the DCT and collecting duct?
When the filtrate reaches the DCT and collecting duct, the solution is very dilute.
What happens to the remaining filtrate in the collecting duct?
Whatever filtrate remains in the collecting duct will go on to form urine.
