Ch 17 Kidneys

The compound NaCl ________ pass through the membrane of the descending limb.

does not

Water passes through the membrane of the descending limb and into the interstitial fluid through

osmosis

Sodium exits the ascending limb and enters the interstitial fluid through

active transport

As salt leaves the tubular fluid in the ascending limb, the interstitial fluid becomes _______ concentrated.

more

In response to the sodium levels in the interstitial fluid around it, water leaves the tubular fluid in the descending limb, causing the tubular fluid to become __________ concentrated.

more

The countercurrent multiplier system is an example of

positive feedback

1. Outer region of the kidney; reddish brown color; contains many capillaries

2. Inner region of the kidney; striped appearance; composed of renal pyramids

3. Collects urine from the calyces and transports it to the ureters

4. Long duct that leads to the urinary bladder

5. Functional unit of the kidneys; responsible for the formation of urine; contains tubules

1. Cortex

2. Medulla

3. Renal Pelvis

4. Ureter

5. Nephron

In the kidneys, blood goes from the afferent arterioles to the _____, and then enters the _____, which then delivers the blood to the _____.

glomerulus; efferent arterioles peritubular capillaries

True or False

1. Most of the reabsorption of glomerular filtrate occurs in the proximal tubules and descending limbs of nephron loops.

2. The active transport of salt in the descending limb is responsible for the increase in concentration of tubular fluid.

3. In the proximal tubules, sodium is actively transported out of the filtrate, and water follows by osmosis.

4. Salt is actively transported across the membrane of the ascending loop of Henle, into the interstitial fluid.

1. True

2. False

3. True

4. False

When the reabsorption rate of a substance increases, its renal plasma rate is _____ the GFR (glomerular filtration rate); conversely, when the secretion of a substance increases, its renal plasma rate is _____ the GFR.

less than; greater than

Check all that apply when there is an increase in aldosterone secretion in response to an increase in renin by the juxtaglomerular apparatus.

1) Potassium secretion increases.

2) Sodium reabsorption increases.

NOT

Sodium secretion increases

Potassium reabsorption increases.

The kidneys help regulate blood pH by excreting _____ in the urine and by reabsorbing ______.

H+; bicarbonate

The following can occur as a result of renal insufficiency?

salt and water retention

uremia (high plasma urea concentrations)

elevated plasma H+ concentrations

elevated K+ concentrations

Filtration occurs when __________.

blood fluids leave the glomerulus and enter the Bowman's capsule

Reabsorption occurs when __________.

the filtrate passes from the nephron tubules back to the peritubular capillaries

Secretion occurs when __________.

the filtrate passes from the peritubular capillaries back to the nephron tubules

When the urinary bladder becomes stretched, there is an increase in the frequency of action potentials traveling from...

the urinary bladder to the sacral region

In response to these impulses, smooth muscle on the urinary bladder contracts due to _____.

the parasympathetic neurons from the spinal cord to the urinary bladder

When urination is desired, decreased action potentials along which of the following causes relaxation of the external urinary sphincter?

somatic motor neurons

The calculation for renal clearance includes _____.

The amount of waste added by tubular secretion and reclaimed by tubular reabsorption

The units for renal clearance are _____.

ml/min

Choose the correct statement that is true about inulin.

All inulin filtered by the glomerulus remains in the renal tubule and appears in the urine.

Place the following parts of the kidney in order of urine flow.

1. Collecting ducts

2. Renal papilla

3. Minor calyx

4. Major calyx

5. Renal pelvis

6. Ureter

7. Urinary bladder

8. Urethra

Which of the following factors will increase the glomerular filtration rate?

constriction of the efferent arteriole

All of the following will cause the juxtaglomerular cells of the kidney to secrete renin except

EXCEPT :increased parasympathetic activity

these will: decreased blood pressure

low blood volume

a need to conserve sodium, and chloride ions

How much fluid filters through the glomerulus in a 24-hour period?

45 gallons

Which of the following substances are normally present in glomerular filtrate but not in urine?

glucose

Most of tubular reabsorption takes place in the

proximal convoluted tubule

Water reabsorption from the kidney tubule is a passive process dependent on the reabsorption of

sodium

The permeability of the distal segment of the tubule to water is regulated by

anti-diuretic hormone (ADH)

Which of the following is a result of aldosterone secretion?

reduced potassium levels in the blood

The mechanism by which greater amounts of a substance may be excreted in urine that were filtered from the plasma is

tubular secretion

Substances that are secreted into the kidney tubules include all but

EXCEPT : Chloride ions

They do include:

penicillin

hydrogen ions

histamine

The normal output of urine for an adult in an hour is

50-60ml

Urine moves along the ureters to the bladder via

peristalsis

The third layer of the bladder wall is composed of smooth muscle fibers and is called the

detrusor muscle

Which of the following structures is under conscious control?

external urethral sphincter

Shigatoxin, produced by Eschericheria coli, can be transported by the blood to the kidney where the toxin destroys cells of the kidney's filter system.

True

The left kidney is slightly higher than the right one.

True

The kidney is composed of three layers connected by the renal columns.

False

-The kidney has two main layers, the cortex and medulla.

Venous blood leaves the kidney via the renal vein which joins the inferior vena cava in the abdomen.

True

The renal corpuscle is comprised of the glomerulus, a tangled cluster of capillaries.

False

The peritubular capillary system is a high-pressure system.

False

-All kidney capillaries, like others, are under relatively low pressure

The glomerular filtration rate is inversely proportional to filtration pressure.

False

- Filtration through the glomerulus is directly controlled by blood or filtration pressure.

The average glomerular filtration rate for both kidneys in healthy adults is 125ml/minute.

True

Angiotensin II stimulates release of aldosterone, which stimulates reabsorption of sodium in the tubules.

True

- Angiotensin II will cause the release of aldosterone from the adrenal cortex which targets the kidneys to cause sodium reabsorption and potassium elimination.

Different segments of the renal tubule are specialized to reabsorb specific substances and a variety of transport mechanisms are used throughout the tubule.

True

-Each part of the nephron functions under unique physiological control systems such as pressure laws and hormones.

There is a ceiling on the amount of glucose that can be reabsorbed because its reabsorption is dependent on a carrier mechanism.

True

-Glucose will appear in the urine when blood levels reach around 160-180mg/dl.

The amount of urea in the plasma is directly proportional to the amount of protein in the diet.

True

-Urea is a waste product of protein metabolism.

The inner layer of the ureters or the mucous coat is continuous with the linings of the renal tubules and the urinary bladder.

True

- The inner lining is a continuous epithelium.

Renal pyramids are separated by the

renal columns

Blood is supplied to the vasa recta by the

efferent arterioles

Glomerular filtration

is increased by increased afferent arteriole diameter.

During the processing of the glomerular ultrafiltrate

compounds present in excess of the transport maximum for the transport protein will appear in the urine.

Which of the following is not true regarding the renal tubule?

NOT TRUE: The vasa recta functions as a countercurrent multiplier.

TRUE:

The vasa recta functions as a countercurrent multiplier.

c) Tight junctions exist between adjacent tubular epithelial cells.

d) The reabsorption of Cl- tends to be passive.

Antidiuretic hormone

is not secreted in great enough amounts in individuals with diabetes insipidus.

lomerular filtration rate can be determined by calculating renal clearance of

inulin.

Aldosterone

is secreted in response to increased plasma potassium.

Which of the following is true regarding renal bicarbonate reabsorption?

Alkalosis induces increased bicarbonate excretion.

carbonic anhydrase inhibitors act primarily on the

proximal convoluted tubule.

The kidneys regulate

the volume of blood plasma (and thus contribute significantly to the regulation of blood pressure);

the concentration of waste products in the plasma;

the concentration of electrolytes (Na+, K+, and other ions) in the plasma; and

the pH of plasma.

kidney stones

hard objects formed in the kidneys containing crystalized minerals or waste products. About 80% are calcium stones, composed of calcium phosphate or calcium oxalate.

Struvite stones

are crystals of magnesium ammonium phosphate that may result from certain urinary tract infections.

Uric acid stones

occur in people with gout,

The major stimulus for bladder emptying is

acetylcholine (ACh) released by parasympathetic axons, which stimulate muscarinic ACh receptors in the detrusor muscle.

The glomerular (Bowman's) capsule

surrounds the glomerulus. The glomerular capsule and its associated glomerulus are located in the cortex of the kidney and together constitute the renal corpuscle. The glomerular capsule contains an inner visceral layer of epithelium around the glomerular capillaries and an outer parietal layer. The space between these two layers is continuous with the lumen of the tubule and receives the glomerular filtrate, as will be described in the next section.

proximal convoluted tubule

In the process of reabsorption, salt, water, and other molecules needed by the body are transported from the lumen, through the tubular cells and into the surrounding peritubular capillaries.

juxtamedullary nephrons

-longer and more numerous

- next to the medulla

-help concentrate urine

Where is the loop of henle located?

the medulla

The glomerular (Bowman's) capsule and the proximal and distal convoluted tubules are located

in the cortex

podocytes

the cells that compose the inner layer of the glomerular (Bowman's) capsule.

The GFR can be regulated by constriction or dilation of the afferent arterioles.

Sympathetic innervation causes constriction of the afferent arterioles.

Intrinsic mechanisms help to autoregulate the rate of renal blood flow and the GFR.

Sodium is actively transported, chloride follows passively by electrical attraction, and water follows the salt out of the proximal tubule.

Salt transport in the proximal tubules is not under hormonal regulation.

Sodium is actively extruded from the ascending limb, followed passively by chloride.

Because the ascending limb is impermeable to water, the remaining filtrate becomes hypotonic.

The layers (tunics) of the GI tract are, from the inside outward, the mucosa, submucosa, muscularis, and serosa.

The mucosa consists of a simple columnar epithelium, a layer of connective tissue called the lamina propria, and a thin layer of smooth muscle called the muscularis mucosae.

The submucosa is composed of connective tissue; the muscularis consists of layers of smooth muscles; the serosa is connective tissue covered by the visceral peritoneum.

The submucosa contains the submucosal plexus, and the muscularis contains the myenteric plexus of autonomic nerves.

The parietal cells of the gastric glands secrete HCl

the chief cells secrete pepsinogen.

the most important function of the stomach is the secretion of intrinsic factor,

which is needed for the absorption of vitamin B12 in the intestine.

The common bile duct and pancreatic duct empty into

the duodenum