Kidneys and Fluid Homeostasis Flashcards
1
Q
What are the functions of the kidney?
A
- Part of the urinary system.
- Act as a filtration unit, clearing waste products from the body produced during the body’s metabolism.
- Regulate and maintain water, electrolyte and acid-base balance.
- Activate vitamin D.
- Produce and secrete erythropoietin (the hormone that stimulates the formation
of red blood cells). - Produce and secrete renin (an enzyme involve in blood pressure regulation)
- Clear medications/drugs from the body.
2
Q
Where are the kidneys located?
A
- Lie on posterior abdominal wall
- One on each side of spine
- Below diaphragm
- Right kidney is usually slightly
lower than the left one - Held in position by a mass of
fat
3
Q
What are the 3 different areas of tissue that form the gross structure of the kidney?
A
- An outer fibrous capsule:
covers the kidney - The cortex: a reddish-brown layer immediately below the capsule (surrounds the renal pyramids)
- The medulla: the inner most layer
4
Q
What is the anatomy of a nephron?
A
- The nephrons are the structural
and functional unit of the kidney - Each kidney contains over 1 million
nephrons. - There are thousands of collecting
ducts (which collect fluid from
several nephrons). - Each nephron consist of a renal
corpuscle and a renal tubule.
5
Q
How do the kidneys work?
A
Urine formation and the adjustment of blood composition involve
three processes:
1. Glomerular filtration (“dumping into the waste container”)
2.Tubular reabsorption (“reclaiming what the body needs to keep”)
3. Tubular secretion (“selectively adding to the waste
container”).
6
Q
What is Glomerular Filtration Rate (GFR)?
A
- GFR = volume of filtrate formed by both kidneys each minute.
- In a healthy adult, the GFR is about 125 mL/min
- Nearly all filtrate is later reabsorbed from the tubules.
- Less than 1% of filtrate eventually becomes urine (i.e. 1 to 1.5 litres excreted as urine).
