Kidney Function and Structure Quiz

The study of kidney function.

Paired organs located on either side of the spine, just above the waist.

A smooth muscle tube that carries urine from the kidneys to the bladder.

The process of expelling urine from the bladder.

The outer layer of the kidney where the nephrons (blood-filtering units) are located.

A protective layer of connective tissue and fat surrounding the kidney.

A large blood vessel that supplies blood to the kidneys.

The kidneys receive approximately 20-25% of the cardiac output despite comprising only 0.4% of body weight.

The kidneys' mechanism for regulating blood pressure, involving renin, angiotensin, and aldosterone.

An enzyme produced by the kidneys that initiates the RAAS by converting angiotensinogen to angiotensin I.

A hormone produced by the adrenal glands that regulates sodium and potassium balance, leading to increased blood pressure.

A hormone produced by the kidneys in response to low oxygen levels, stimulating red blood cell production.

The process by which the kidneys convert inactive vitamin D to its active form, essential for calcium absorption.

The process where the kidneys synthesize glucose from non-carbohydrate sources, like amino acids, during fasting or stress.

Tiny filtering units within the kidneys responsible for blood purification.

The process where blood pressure forces fluid from the glomerulus into Bowman's capsule.

The process by which water and solutes move from the glomerular capillaries into Bowman's capsule.

The movement of substances from the renal tubules back into the blood.

The pressure driving fluid out of the glomerular capillaries into Bowman's capsule.

The hydrostatic pressure in Bowman's capsule, opposing filtration.

The osmotic pressure exerted by proteins in the glomerular capillaries, opposing filtration.

The ability of the glomerulus to filter blood.

The ability of the kidneys to maintain a relatively constant GFR despite fluctuations in blood pressure.

The intrinsic ability of vascular smooth muscle to respond to pressure changes.

The process by which substances from the blood are selectively added into the filtrate in the nephron tubule.

The pressure exerted by the blood flowing through the glomerular capillaries, pushing fluid out into Bowman's capsule.

The pressure exerted by the fluid within Bowman's capsule, resisting the movement of fluid into the capsule.

The pressure created by plasma proteins in the blood, drawing water back into the capillaries.

The percentage of plasma that flows through the kidneys that gets filtered into the nephrons.

The small blood vessels surrounding the nephron tubules, where reabsorption and secretion occur.

The force that drives fluid out of the glomerular capillaries into Bowman's capsule. It is the difference between the hydrostatic pressure in the capillaries and the opposing pressures (colloid osmotic pressure and hydrostatic pressure in Bowman's capsule).

The pressure exerted by the fluid within Bowman's capsule. It opposes the movement of fluid from the capillaries into the capsule.

The pressure created by the presence of proteins in the blood plasma. It draws fluid back into the capillaries.

The pressure exerted by the blood within the glomerular capillaries. It pushes fluid out of the capillaries and into Bowman's capsule.

The surface area of the glomerular capillaries available for filtration and the permeability of the filtration slits. These factors determine how easily fluid can pass through the capillary walls.

The afferent arteriole is wider than the efferent arteriole, leading to increased pressure in the glomerulus, which drives filtration.

A paracrine signaling mechanism in the kidney where the flow of fluid through the Loop of Henle influences the glomerular filtration rate (GFR).

A mechanism that helps regulate blood flow through the afferent arteriole, similar to autoregulation in other arterioles.

The afferent arteriole constricts in response to increased blood pressure, reducing blood flow to the glomerulus and preventing a rise in GFR.

The afferent arteriole dilates when blood pressure decreases, increasing blood flow to the glomerulus to help maintain GFR. However, dilation is less effective than constriction.

A specialized structure in the kidney where the end of the ascending limb of the loop of Henle comes close to the afferent and efferent arterioles, enabling communication between them.

A specialized group of cells in the juxtaglomerular apparatus located in the thick ascending limb of the loop of Henle. They sense changes in fluid flow and deliver signals to the afferent arteriole.

Specialized smooth muscle cells found in the walls of the afferent arteriole, adjacent to the macula densa. They release renin in response to certain stimuli.

When the macula densa detects increased fluid flow, it signals the afferent arteriole to constrict, reducing GFR. This is part of autoregulation and helps maintain stable glomerular filtration.