Renal Structure and Function Flashcards
What are the main functions of the Kidney?
- Regulation of H2O and Electrolyte Balance
- Metabolic Waste Excretion
- Bioactive Substance Excretion (drugs and hormones)
- Regulation of Arterial Blood Pressure
- Regulation of RBC Production
- Regulation of Vitamin D Production
- Metabolism
What is Metabolic Waste?
Product of something that you metabolize/make in your own body
How do the kidneys maintain homeostasis due to the variable input of H2O and electrolytes?
By varying the output of water and minerals in the urine
What are some examples of Metabolic Waste that are excreted by the Kidneys and where do they come from?
- Urea (from Proteins)
- Uric Acid (from Nucleic Acids)
- Creatinine (from Muscle Creatine)
- Products from Hemoglobin breakdown
- Various Hormone metabolites (from Endocrine system)
Blood Pressure ultimately depends on what?
Blood Volume
How do the Kidneys regulate Arterial Blood Pressure?
- Regulating Blood Volume via maintenance of Na and H2O balance
- Releasing Vasoconstrictors that regulate smooth muscle in peripheral vasculature
How does the Kidney regulate RBC Production?
Releases Erythropoietin that controls erythrocyte production by the bone marrow
–Secretion of EPO is regulated by the partial pressure of O2 in Kidneys
What actions are performed by Vitamin D?
Tells Gut to increase Ca absorption
Where does the last step in producing Vitamin D occur?
Kidney
CNS is an obligate user of blood glucose meaning?
CNS can ONLY use Blood glucose as a fuel source
What metabolic process occurs in the Kidney?
Renal Ammonioagenesis which is a key way to excrete excess Acid from the body and is crucial to maintaining Acid-Base Homeostasis
What are Renal Columns?
Portions of the Renal Cortex that stretch into the Medulla and break it up
What has more surface area in the Kidney, Renal Cortex OR Renal Medulla?
Renal Cortex (ligher in color)
Where does a majority of Filtration occur in the Kidney?
Renal Cortex (lighter in color)
Where does a majority of Reabsorption happen in the Kidney?
Renal Cortex (darker in color) because most of the Distal and Proximal Tubules are located in the Renal Cortex
What is the functional unit of the Kidney and where are they found?
- The Nephron
2. Found majority in the Renal Cortex and a small part in the Renal Medulla
How many Nephrons does each Kidney have?
Roughly 1 million each so 2 million total
Describe Filtration in the Kidney and where it occurs:
Filtration of PLASMA occurs in the Glomerulus
About 180 L/day of plasma is filtered in the Nephron
About how much Plasma is excreted in Urine?
2 L/day
What is the Renal Corpuscle
“Balloon around the capillary”
- FILTERS BLOOD
- The Glomerulus (compact tuft of interconnected capillary loops) is surrounded by Bowman’s Space (balloon-like hollow capsule filled with fluid) that
What do you call the blood that is filtered from the Glomerulus into the Bowman’s Space and where does it go?
- Filtrate
2. Drains into Proximal Tubule
In what part of Nephron does a majority of reabsorption occur?
Proximal Tubule