Urinary System Flashcards
The urinary system maintains the homeostasis of
Water and electrolytes
What are the main functions of the kidneys
- Formation of urine, maintaining water, electrolyte and acid-base balance
- Excretion of waste products
- Production and secretion of erythropoietin, the hormone that stimulates formation of the red blood cells
- Production and secretion of renin
Why is the right kidney lower than the left?
The space is occupied by the liver
What are the three processes involved in the formation of urine?
Filtration
Selective reabsorption
Secretion
The walls of the glomerulus and the glomerular capsule consist of
A single layer of flattened epithelial cells
The structure of the glomerulus and the glomerular capsule makes them?
Very permeable to facilitate filtration
The filtrate taken from the bloodstream at the glomerular capsule consists of what?
Water and other small molecules
Blood cells, plasma proteins and other large molecules are too large to filter through and stay in the capillaries
What causes filtration to take place
A pressure gradient between the glomerulus blood pressure and the pressure of the filtrate in the glomerular capsule
What is the glomerular filtration rate?
The volume of filtrate formed by both kidneys per minute
Describe how glomerular filtration is protected by auto regulation
Renal blood flow is maintained across a wide range of systolic blood pressures, because glomerular filtration is dependant upon blood pressure, which varies significantly due to various factors; renal blood pressure must be locally controlled.
Most reabsorption from the filtrate back into the blood takes place in?
The proximal convoluted tubule
The epithelial lining of the proximal convoluted tubule possesses microvilli, what is the function of this?
To increase the surface area for absorption
Describe selective reabsorption in the tubule
Different segments of the tubules have different types of sodium cotransporters and channels in the apical membrane
