Urinary System Flashcards
The urinary system consists of two kidneys (although it is possible to live with one), two ureters, and a urethra. What is the function of the urinary system.
In short, the function of the urinary system is to filter the blood. In doing so, the kidney is the only organ in the urinary system that does so. In general, the kidney receives blood from the renal artery, plasma and blood components are separated, filtrate is sent along the renal tubule to be excreted in the urine, and good nutrients are reunited with the blood components in the peritubular capillaries to travel back to the body.
Trace the pathway of blood through the kidney. Be sure to describe what happens in both filtrate excretion and nutrient reabsorption.
Blood enters the kidney through the renal artery where it then is sent to the nephron. In the nephron, the first site blood passes through is the glomerulus. The glomerulus is a cluster of capillaries responsible for separating blood plasma and blood components. The plasma carries both nutrients and filtrate:
FILTRATE escapes and travels through the proximal convoluted tubule, through the nephron loop, and through the distal convoluted tubule. From the distal convoluted tubule, filtrate empties into the collecting duct (aka the renal tubule) where it can be excreted as urine. Although plasma is carrying filtrate through this process, large amounts of plasma is reabsorbed back into the body via the peritubular capillaries. Filtrate then exits the kidney into the renal pelvis; after this, the filtrate is out of the kidney where it moves to the ureter.
BLOOD COMPONENTS travel into the efferent tubule, then into the peritubular capillaries where it is reunited with plasma being reabsorbed. Blood then exits the kidney via the renal vein.
Explain the difference between the pyramids and columns in the kidney.
Pyramids are also known as the renal medulla. They are “pyramid” shaped and provide a cavity to water resorption and secretion. columns are the areas between the pyramids and function to provide blood to the nephron.
What is the functioning unit of the kidney?
The nephron is the functioning unit of the kidney. In short, the nephron is the filtering component of the kidney; it filters blood, separates its components from filtrate, allows reabsorption or secretion to occur (at this point, the nephron is responsible for creating urine with waste products or allow nutrients in the blood to reabsorb for distribution to the body’s systems.
Other than filtering blood, what is the kidney responsible for?
The kidney is able to determine blood viscosity and, therefore, blood pressure.
The kidney is also responsible for detecting dehydration; in this case, stimulating the hypothalamus, the posterior pituitary gland is then stimulated causing a release of anitdiuretic hormone. This hormone promotes water reabsorption.
Blood is filtered in the kidney to help purge the “system” of waste. What are the waste products found in urine?
Waste products, also referred to as filtrate, in the urine consist of chemicals like hemoglobin, ammonia, urea, NaCl, KCL, creatine, and uric acid.
When the body is well hydrated, we can expect the content of the urine to be…
An individual who is well hydrated will produce hypotonic urine, while an individual who is dehydrated will produce urine that is hypertonic. The normal volume of urine produced per day is approximately 1-2 liters.
