Physiology Exam 2 Quizzes and Practice Quizzes

The duodenal mucosa secretes ___________________. This substance inhibits stomach's secretory activity, potentiates secretin's actions, increases output of enzyme-rich pancreatic juice, stimulates the gall bladder to contract and expel stored bile and relaxes the sphincter to allow entry of bile and pancreatic juice into duodenum.

Cholecystekinin

Lipid products are converted into triglycerides and packaged with lecithin and lipoproteins, forming:

Chylomicrons

6. What two pressures oppose filtration and what are their values?

1. Capsular hydrostatic pressure (15 mmHg) 2. Glomerular osmotic pressure (30 mmHg)

How does ADH (antidiuretic hormone) affect the collecting duct membrane, and how does this influence water reabsorption?

ADH causes aquaporins to be inserted into the membrane, which increases water reabsorption into the peritubular capillaries

What effect does aldosterone have on the membranes of the kidney tubule, and how does this effect sodium reabsorption?

Aldosterone stimulates the synthesis and retention of more Na+ channels in the apical membrane and more Na-K pumps in the basolateral membrane. This increases resorption of sodium in the kidney tubule.

Antidiuretic hormone helps conserve total body water by incorporating water channels in what part of the kidney tubular system?

Collecting Ducts

The defecation reflex consists of an involuntary and voluntary control mechanism over defecation. Which sphincter is associated with volitional control?

External Anal Sphincter

Which of the following has no significant/least significant role in maintaining the acid-base balance in the blood?

Liver

Which of the following is a major buffer in the kidney tubule lumen?

Phosphate

The cells located at the distal tubules of the nephron secrete:

Potassium

Of the following electrolytes, which is more abundant in the intracellular fluid compartment than in the extracellular fluid compartment?

Potassium Ion

_______________ is the movement of water and valuable solutes from the filtrate in the renal tubules into the blood. In which part of the renal tubule does this take place? In which part of the renal tubules does most of it take place?

Reabsorption

______________ is the movement of selected solutes from the blood of the peritubular capillaries into the renal tubule for excretion.

Secretion

When non-adjacent segments of the alimentary canal contract and relax, food is moved forward and backward. This action is done primarily to mix and mechanically break down food and is called:

Segmentation

What is the purpose of reabsorption in the kidney tubule?

The purpose of reabsorption is to allow the body to reclaim water and valuable solutes (glucose, amino acids, ions, etc.) from the filtrate and keep them from being excreted.

Which of the following is not an aspect of the small intestine? duodenum, cecum, ileum jejunum

cecum

Which of the following can produce metabolic acidosis? decreased respiration, vomiting, hyperventilation, diarrhea

diarrhea

Name 2 pathways whereby water and solutes can be reabsorbed from the lumen of the renal tubule to the blood of the peritubular capillaries. Which pathway is the most commonly used?

a. Transcellular pathway - most commonly used b. Paracellular pathway

For each part of the renal tubule listed, tell whether reabsorption, secretion, or both processes happen there. a. Proximal tubule b. Nephron loop c. Distal tubule d. Collecting duct

a. both reabsorption and secretion b. reabsorption c. both reabsorption and secretion d. both reabsorption and secretion

In dehydration and overhydration, what would be the levels of: a. ADH ___________ dehydration ___________ overhydration (↑ or ↓) b. Aldosterone __________ dehydration ____________ overhydration (↑ or ↓)

a. ↑/↓ b. ↑/↓

The ______________ arteriole feeds into the glomerulus, while the ______________ arteriole exits the glomerulus.

afferent, efferent

Bile is produced by the (1.________________) and stored in the (2.__________________) until needed in the postprandial period. Bile acids, important components of bile, are biological detergents that solubilize the products of lipid digestion.

1. Liver 2. GB

Common components of the glomerular filtrate are divided into four categories. Identify these categories.

1. water 2. ions 3. nitrogenous wastes 4. organic molecules

What is the normal net filtration pressure? _____ mmHg

10

Glomerular hydrostatic pressure in the glomerulus is about _____ mmHg.

55

The tubular filtrate has the greatest osmolarity at what site?

@ tip of the loop of henle

The total amount of filtrate formed by all the renal corpuscles in both kidneys per minute is called the _________________ ________________ ______________.

Glomerular filtration rate

Glomerular filtration would be decreased by what condition?

Increased plasma protein

The enteric nervous system participates in both short and long reflex arcs. _____________reflexes respond to stimuli arising inside or outside of gut, such as from autonomic nervous system; Parasympathetic system enhances digestive process and the Sympathetic system inhibits digestion.

Long

This cell type makes HCL acid and a substance that allows for proper absorption of B12:

Parietal Cells

Considering the concept of transport maximum, why would a patient with uncontrolled diabetes mellitus have glucose in their urine?

Patients with diabetes mellitus have an inability to make, or, an inability to respond to insulin. Since insulin allows cell to take up glucose from the blood, patients with uncontrolled diabetes mellitus have high blood glucose levels. This excess glucose in the blood proceeds to the filtrate where it "fills up" all of the glucose transporters in the kidney tubule fairly quickly. The remaining glucose does not get reabsorbed and becomes part of the urine.

"As in the salivary glands, the pancreas has a structure that consists of ducts and acini. The pancreatic acinar cells line the blind ends of a branching ductular system that eventually empties into the main pancreatic duct and from there into the small intestine under control of the ______________."

Sphincter of Oddi

List at least 4 solutes that are secreted into the filtrate. With these items in mind, explain why secretion is so important in generating urine.

Substances secreted: H+, K+, uric acid, creatinine, toxins, drugs Secretion allows waste products that do not pass through the filtration membrane of the glomerulus to be excreted. It also allows for precise control fluid, electrolyte and acid/base balance.

How does the Na-K pump affect the reabsorption of sodium and water in the renal tubule?

The Na-K pump actively transports sodium from the lumen of the renal tubule transcellularly into the interstitial fluid. This increases the osmolarity of the interstitial fluid and draws water from the renal tubule into the interstitial fluid by osmosis. The bulk flow of the water sweeps sodium and other solutes into the peritubular capillaries.

How does sodium reabsorption by the proximal tubule drive the reabsorption of other solutes such as glucose?

The Na-K pump actively transports sodium from the tubular cell into the interstitial fluid. This lowers the concentration of sodium in the tubular cell and causes additional sodium to use facilitated diffusion to move into the tubular cell from the filtrate. As sodium diffuses into the tubular cell down its concentration gradient, other solutes such as glucose are "dragged" into the cell with the sodium.

Which of the following is true of diuretics?

They often act on the distal convoluted tubule

Explain the concept of transport maximum

Transport maximum is the maximum amount of a solute that can be reabsorbed due to saturation of carrier proteins. Any substances that can't bind to the appropriate carrier proteins are not reabsorbed and proceed through the tubule to be excreted in urine.

Which of the following substances has the greatest renal clearance?

Urea

The filtration membrane consists of three layers: the__________________ glomerular endothelium, the _______________ membrane, and the ___________________ processes (which contain filtration slits). This filtration membrane permits (large or small) molecules to be filtered.

fenestrated, basement, podocyte foot, small

Glomerular filtration is a process driven by the _____________________________ of the blood.

hydrostatic pressure

Consuming a salty meal would increase / decrease water reabsorption from the filtrate

increase

10. Cells within the ascending nephron loop that are chemoreceptive to sodium chloride concentrations are known as the ____________ ___________.

macula densa

The kidneys autoregulate GFR via the ____________________ and _______________________ _______________ mechanisms.

myogenic, tubuloglomerular feedback

Chief cells produce:

pepsinogen