Intro to renal and filtration Flashcards
What percentage of cardiac output is attributed to the kidneys?
20%.
List the main functions of the kidney.
- Filtration of blood
- Detoxification (including drugs)
- Regulation of blood pressure
- Regulation of blood pH
- Regulation of haematopoiesis
- Making vitamin D.
What is the primary challenge in designing the kidney’s filter?
To create a very fine filter that does not clog while filtering a large volume of fluid in a small space.
What is the cut-off size for the kidney filter?
Approximately 4nm (40 Å).
What is the slit diaphragm?
A structural component of the kidney filter that allows for selective filtration.
True or False: Only about 3% of the total area of the slit diaphragm is actually slit.
True.
What happens when the afferent arteriole is restricted?
Blood pressure in capillaries drops and filtration rate decreases.
What happens when the efferent arteriole is restricted?
Blood pressure in glomerular capillaries rises and filtration rate increases.
What is one method the kidney uses to prevent clogging?
Pinocytosis of trapped proteins.
Fill in the blank: The typical blood flow to the kidneys is ______.
1.2L/min.
What is the typical plasma flow to the kidneys?
0.66L/min.
What is the rate of filtration through glomeruli summed across all?
0.13L/min.
Approximately what percentage of plasma is removed as filtrate?
20%.
What is the purpose of the fresh dialysate in an artificial glomerulus?
To be full of the ‘wanted’ small molecules of the blood to prevent net loss.
How many renal corpuscles are typically found in a human kidney?
50,000 – 1,000,000.
What hypothesis relates nephron number to a mother’s amino acid nutrition?
Barker hypothesis.
What is a major source of resistance to fluid flow in the kidney filter?
The slit diaphragm.
What is the role of mesangial cells in the kidney?
To clean the filter and renew it.
What is the significance of osmotic pressures in kidney filtration?
Pressure is needed to oppose the osmotic pressures from proteins and small molecule solutes.
What are the main parts of the nephron?
Renal corpuscle, Proximal tubule, Distal tubule, Henle’s loop
The nephron is divided into these four main sections.
What substances do nephron epithelia recover?
- Na+
- K+
- Ca2+
- Mg2+
- Cl-
- HCO3-
- PO42-
- H2O
- Amino acids
- Glucose
- Proteins
These are essential for various physiological processes.
What is the significance of understanding renal transport systems for medics?
Many components are drug targets used to control renal function and are vulnerable to damage by drugs
Knowledge of these transport systems aids in pharmacology and patient care.
What are Solute Carrier Family (SLC) proteins?
About 300 proteins, many are co-transporters powered by established concentration gradients
They are involved in secondary active transport.
What is the function of Aquaporins?
They are water channels that facilitate water transport across cell membranes
Essential for maintaining water homeostasis.