MLT 111 Chapters 2 & 3 Exam

Glucosuria is the medical term used to describe the presence of glucose in the urine. This condition occurs when the kidneys are unable to reabsorb all the glucose from the filtrate, leading to its excretion in the urine. Glucosuria can be a sign of uncontrolled diabetes or kidney dysfunction. It is important to diagnose and treat the underlying cause of glucosuria to prevent further complications.

The kidney serves multiple functions in regard to the blood. Firstly, it helps maintain fluid volume by regulating the amount of water reabsorbed into the bloodstream. Secondly, it maintains solute concentration by selectively reabsorbing certain substances and excreting others. Lastly, the kidney eliminates waste products from the blood through the formation of urine. Therefore, all of the given options are correct as they represent the different functions of the kidney in relation to the blood.

The nephron is the basic functional unit of the kidney. It is responsible for filtering the blood and producing urine. The nephron consists of a glomerulus, which filters waste products and excess water from the blood, and a tubule, which reabsorbs necessary substances back into the bloodstream and excretes waste products as urine. The nephron plays a crucial role in maintaining the body's water and electrolyte balance and regulating blood pressure.

The specific gravity of a fluid is a measure of its density compared to the density of water. A specific gravity of 1.010 indicates that the fluid leaving the glomerulus is slightly more dense than water. This suggests that there may be some solutes or substances present in the fluid, such as waste products or excess ions, which contribute to its increased density. Therefore, the statement is true.

The kidney is responsible for several functions in the body, such as excretion of water and wastes, as well as conservation of water. However, the conjugation of bile is not a function of the kidney. Bile is produced by the liver and stored in the gallbladder, and it plays a role in the digestion and absorption of fats in the small intestine. The kidney's main function is to filter waste products from the blood and regulate fluid balance in the body.

The correct answer is Ureters. The ureters are the structures that transport urine from the kidneys to the bladder. They are long, narrow tubes that connect the renal pelvis of each kidney to the bladder.

Oliguria is the correct answer because it matches the definition of "poor output of urine." Oliguria is a medical term used to describe a condition where the body produces abnormally small amounts of urine. This can be caused by various factors such as dehydration, kidney damage, or certain medications.

The correct answer is "taking back of needed substances from the tubules into the body." Reabsorption refers to the process in which substances that are needed by the body, such as water, glucose, and electrolytes, are transported from the tubules in the kidneys back into the bloodstream. This process helps to maintain the body's balance of fluids and electrolytes.

A properly labelled urine specimen for routine urinalysis should not be delivered to the lab in a gray top blood collection tube because the gray top tube is specifically designed for collecting and preserving blood samples, not urine samples. Using the wrong type of tube may affect the accuracy and reliability of the test results. Therefore, it is not true that a urine specimen can be tested if it is delivered in a gray top blood collection tube.

Aldosterone is a hormone produced by the adrenal glands that regulates the balance of electrolytes in the body, including sodium. It acts on the kidneys to increase the reabsorption of sodium, thereby promoting sodium retention. Therefore, the statement that aldosterone is responsible for sodium retention is true.

The glomerular filtration rate refers to the rate at which blood is filtered by the glomerulus in the kidneys. It is a measure of kidney function and is typically expressed in milliliters per minute (ml/min). A normal GFR for a healthy adult is around 125 ml/min. This means that approximately 125 milliliters of fluid are filtered by the kidneys every minute. Therefore, the correct answer is 125 ml/min.

Urea is found in the highest concentration in the urine. Urea is a waste product formed in the liver from the breakdown of proteins. It is then filtered by the kidneys and excreted in the urine. Uric acid is also a waste product, but its concentration in urine is typically lower than that of urea. Glucose is not normally found in urine, as it is reabsorbed by the kidneys. Creatinine is a waste product of muscle metabolism and its concentration in urine is lower than that of urea.

Each kidney contains approximately 1 million nephrons. Nephrons are the functional units of the kidneys responsible for filtering waste products and excess water from the blood. The large number of nephrons in each kidney allows for efficient filtration and maintenance of fluid balance in the body.

The plasma concentration of a substance at which active transport stops and increased amounts are excreted in the urine is called the renal threshold. This is the point at which the kidneys can no longer reabsorb the substance and it starts to be eliminated from the body through urine. At concentrations below the renal threshold, the substance is reabsorbed by the kidneys, while at concentrations above the threshold, it is excreted. This threshold varies for different substances and can be influenced by factors such as age, health conditions, and medications.

The Loop of Henle and the collecting tubules are located in the medulla. The medulla is the innermost region of the kidney, located between the renal cortex and the renal pelvis. This is where the urine concentration and reabsorption occur, as the Loop of Henle is responsible for creating a concentration gradient that allows for the reabsorption of water and solutes. The collecting tubules then further concentrate the urine before it is transported to the renal pelvis and eventually eliminated from the body.

The descending loop of Henle is responsible for the re-absorption of water by osmosis. As the filtrate flows down the descending limb, the surrounding interstitial fluid becomes increasingly hypertonic. This creates an osmotic gradient that causes water to passively diffuse out of the filtrate and into the interstitial fluid. This re-absorption of water helps to concentrate the urine and conserve water in the body.

ADH (antidiuretic hormone) increases water re-absorption in the distal convoluted tubule. This hormone is released by the posterior pituitary gland in response to low blood volume or high blood osmolality. When ADH binds to receptors in the distal convoluted tubule, it stimulates the insertion of aquaporin channels into the tubular cells. These channels allow water to move from the tubular lumen into the cells and then into the bloodstream, increasing water re-absorption. This leads to a decrease in urine volume and an increase in urine concentration.

The correct answer is "Vasa recta." The capillary loops located in the medulla of the kidneys are called vasa recta. These blood vessels play a crucial role in maintaining the concentration gradient in the renal medulla, which is important for the reabsorption of water and solutes. The vasa recta also helps in the removal of waste products from the medulla and ensures proper blood flow to the renal medulla.

The normal serum osmolarity is not 50 - 100 mOsm. The normal range for serum osmolarity is typically between 275 - 295 mOsm. Therefore, the given statement is false.

During tubular re-absorption, the movement of a solute attached to a carrier protein is called active transport. This process requires energy and is responsible for the selective reabsorption of specific solutes from the filtrate back into the bloodstream. Passive transport, on the other hand, does not require energy and occurs down a concentration gradient. The statement that it only occurs in the glomerulus is incorrect, as tubular reabsorption occurs in the renal tubules throughout the nephron.

The correct answer is the afferent arteriole. The afferent arteriole is the blood vessel that carries blood into the glomerulus, which is a network of capillaries in the kidney. This arteriole is responsible for supplying blood to the glomerulus, where filtration of waste products and excess fluid occurs. The aorta is the main artery that carries oxygenated blood from the heart to the rest of the body. The efferent arteriole carries blood away from the glomerulus. The juxtaglomerular apparatus is a structure involved in regulating blood pressure and kidney function.

The renal medulla is composed of tissue called renal pyramids. These pyramids are cone-shaped structures located in the innermost part of the kidney. They contain the loops of Henle and collecting ducts, which are responsible for the reabsorption and concentration of urine. The renal pyramids play a crucial role in maintaining the osmotic balance and regulating the volume and composition of urine.

Disposable containers with a capacity of 25 ml or less are not recommended for the collection of specimens for routine urinalysis.

Bowman's capsule and both convoluted tubules are located in the cortex of the kidney. The cortex is the outer region of the kidney, and it contains the glomerulus and the convoluted tubules. Bowman's capsule is a cup-like structure that surrounds the glomerulus and is responsible for the initial filtration of blood. The convoluted tubules are responsible for reabsorbing water and important molecules from the filtrate. Therefore, both Bowman's capsule and the convoluted tubules are located in the cortex of the kidney.

Juxtaglomerular cells combine with macula densa cells to form the juxtaglomerular apparatus in the kidney. The juxtaglomerular apparatus is a specialized structure located in the nephron, specifically at the point where the distal convoluted tubule comes into contact with the afferent arteriole. The macula densa cells are located in the wall of the distal convoluted tubule and play a role in regulating blood pressure and filtration rate in the kidney.