Physiology Chapter 19

Approximately how much plasma moves through the kidneys of an adult during a 24-hour period?

180 Liters

Calculate the net filtration pressure if capillary hydrostatic pressure is 60 mm Hg, capillary osmotic pressure is 25 mm Hg, and capsular hydrostatic pressure is 10 mm Hg.

25 mm Hg (60 - (25 + 10) = 25 mm Hg. The two pressures that oppose filtration must be subtracted from the force favoring filtration.)

The hairpin-shaped segment of the nephron is the

loop of Henle

The segment of the nephron between the proximal and distal tubules that loops down into the medulla of the kidney and returns back to the cortex is called the ________

loop of Henle

The functional unit of the kidney is the ____

nephron

If the osmotic pressure in the glomerular capillaries increased from 28 mm Hg to 35 mm Hg, would net filtration increase or decrease?

net filtration would decrease (because osmotic pressure opposes filtration, increasing osmotic pressure would decrease net filtration)

In normal kidneys, blood cells and plasma proteins are

not filtered

In a normal kidney, which of the following conditions would cause an increase in the glomerular filtration rate (GFR)?

A decrease in the concentration of plasma proteins in the blood

Which combination of changes would increase the glomerular filtration rate (GFR) the most?

Vasodilation of the afferent arteriole and vasoconstriction of the efferent arteriole

Which chemical can stimulate ventilation by binding both peripheral and central chemoreceptors?

plasma CO2

Which unique epithelial cells of Bowman's capsule are involved in filtration?

podocytes

Which substance would be found in higher concentration if the membrane were damaged?

protein

Most reabsorption of fluid from the filtrate back into the blood occurs from the ______.

proximal convoluted tubule

What is the term for the movement from the glomerulus to the nephron lumen?

filtration

The amount of filtrate entering the proximal tubules of the kidneys each minute is the ________ rate.

glomerular filtration

What is the term for the movement from the nephron lumen to the blood?

reabsorption

The primary function of the proximal tubule is ________

reabsorption of ions, organic molecules, and water.

The kidneys function to produce hormones, excrete wastes, regulate blood pressure, and maintain ion balance. Which of the following is another function of the kidneys?

regulate osmolarity

Functions of the kidneys include all but one of the following. Identify the exception.

regulation of blood protein levels

The ________ branch off the ________ and supply blood to the kidneys.

renal arteries, abdominal aorta

The ____ carries blood from the kidneys back to the ____

renal vein, inferior vena cava

Glomerular filtration rate is determined by the net filtration pressure and the filtration coefficient. Which two factors determine the filtration coefficient?

glomerular surface area and the permeability of the filtration barrier

Where does filtration take place in the kidneys?

glomerulus

What is the primary driving force that produces glomerular filtration?

hydrostatic pressure of blood (blood pressure)

What causes the internal urethral sphincter to open?

increasing urine pressure due to contraction of the full bladder

Urine is produced by the ___?

kidney

Contents in the peritubular capillaries are actively transported into proximal and distal convoluted tubules in a process known as:

secretion

What is the term for the movement from the peritubular capillaries to the nephron lumen?

secretion

Which word means to selectively move molecules from the blood and add them to the tubule lumen?

secretion

If blood flow through the afferent arterioles increases, __________ ?

stretch reflexes trigger vasoconstriction to reduce the flow

Neural control of GFR is mediated by ________ that innervate ________ receptors on vascular smooth muscle causing ________

sympathetic neurons, alpha, vasoconstriction

Urine is carried to the urinary bladder by____

the ureters

Urine is carried to the external environment by the ____

urethra

After it is formed, urine is temporarily stored in the ____

urinary bladder

The characteristic yellow color of urine is attributed to the presence of

urobilinogen

What is the order of the blood vessels that carry blood to and within the kidney? (order in which blood passes through them)

Afferent arteriole -> glomerulus -> efferent arteriole -> peritubular capillary

Which of the following correctly indicates the direction of the different forces causing filtration in the renal corpuscle (of fluid flow into or out of Bowman's capsule from the glomerular capillaries)?

Blood hydrostatic pressure - (out), blood colloid osmotic pressure - (in), hydrostatic fluid pressure of the Bowman's capsule - (in)

The portion of the nephron that attaches to the collecting duct is the ____

Distal tubule

Why is inulin administration an effective way of measuring renal clearance rates?

Inulin is neither secreted nor reabsorbed.

Why is the regulation of extracellular fluid osmolarity so important?

It strongly influences cell volume.

Approximately what percent of the total filtered volume is excreted as urine each day?

Less than 1%

Ions directly regulated by the kidney include all EXCEPT which of the following?

OH- (hydroxide)

A glomerulus is

a "knot" of capillaries that lies within the Bowman's capsule.

Which of the following substances is not normally found in filtrate?

blood cells and large particles (blood cells and large particles, such as proteins, are not allowed to filter through a healthy glomerular membrane)

The force for glomerular filtration is the ____

blood pressure in the glomerular capillaries

An obstruction in a glomerulus would affect the flow of blood into the

efferent arteriole

All of the following will normally be found in the filtrate EXCEPT

erythrocytes

Which equation correctly describes the relationship between excretion, filtration, reabsorption, and secretion?

excretion = filtration - reabsorption + secretion