renal 1 Flashcards
Why can’t we drink ocean water for hydration?
Because it has high salt content, which leads to dehydration as kidneys excrete excess salt by producing more urine.
List the six major kidney functions in mammals.
Regulation of plasma volume, osmotic balance, ion balance, pH balance, excretion of wastes/toxins, hormone production.
What are the four key processes in the mammalian urinary system?
Filtration, reabsorption, secretion, and excretion.
What are the two layers of the mammalian kidney?
Outer cortex and inner medulla.
What is the nephron and what is its role?
A tubular structure that filters blood and forms urine; it’s the kidney’s functional unit.
How do kidneys help regulate blood pressure?
Through plasma volume control and renin secretion, which influences arterial pressure.
What are the three main processes that occur in nephron function?
Glomerular filtration, tubular reabsorption, and tubular secretion.
What is the difference between reabsorption and secretion in the nephron?
Reabsorption moves substances from filtrate to blood; secretion moves substances from blood to filtrate.
What is transcellular transport?
Transport of substances across epithelial cells, through both membranes.
What is paracellular transport?
Transport of substances between adjacent epithelial cells.
What is the role of ion channels, pumps, and cotransporters in the nephron?
They regulate water and solute movement across epithelial membranes.
How many nephrons are in a human kidney?
Hundreds of thousands per kidney, with millions across both kidneys.
What is the glomerulus?
A tuft of capillaries that performs the initial filtration of blood in the nephron.
Differentiate between cortical and juxtamedullary nephrons.
Cortical: short loops, majority of nephrons; Juxtamedullary: long loops, help concentrate urine.
What are mesangial cells and their function?
Cells that regulate glomerular blood flow and filtration pressure.
How much blood do kidneys filter per minute?
Approximately 1200 mL/min passes through glomeruli.
What is glomerular filtration rate (GFR)?
The volume of filtrate formed per minute by the kidneys (~125 mL/min).
How much filtrate is produced daily?
Approximately 180 liters per day.
What percentage of the filtrate is reabsorbed by the nephron?
About 99%.
List the three pressures influencing glomerular filtration.
Glomerular hydrostatic pressure (GHP), Bowman’s capsule hydrostatic pressure (BCHP), Blood oncotic pressure (BOP).
How does GHP influence filtration?
It pushes water and solutes out of the blood and into the capsule, favoring filtration.
How does BCHP affect filtration?
It opposes filtration by pushing fluid back into the blood from the capsule.
What is the function of blood oncotic pressure (BOP)?
Draws water back into glomerular capillaries, opposing filtration.
What is the formula for net hydrostatic pressure (NHP)?
NHP = GHP – BCHP.
