LECTURE 32 11/28/22 (LECTURE 17 SLIDES: RENAL PHYSIOLOGY) Flashcards
Secretion from the blood vessels into the renal tubule is driven by ________________.
Secondary Active Transporters that rely on the sodium gradient (11:33)
Fluid that is left over at the end of the nephron tubule will be ___________.
Excreted (11:52)
What is formula for Excretion?
Excretion = Filtration - Reabsorption + Secretion (12:46)
Label 1-4
- Filtration
- Reabsorption
- Secretion
- Excretion
(14:40)
Describe what is happening in A, B, C, D
Which substance will most closely represent PAH?
What will be the clearance rate of PAH?
Substance D.
600 cc/min (equivalent to renal plasma flow)
(19:00)
In a healthy individual, how many ways can creatinine enter the nephron?
In a healthy individual, how many ways can creatinine get reabsorbed?
2 (creatinine is mainly filtered and slowly secreted into the nephrons)
0 (creatinine does not get reabsorbed)
(20:20)
Rank the filterability of a neutral dextran, polycationic dextran, and polyanionic dextran from most filterable to least filterable.
Most filterable: Polycationic Dextran
Neutral Dextran
Least filterable: Polyanionic Dextran
*dextrans with the highest relative filterability will have a small radius and positive charge. (23:33)
Which substance can be filtered?
Which substance can not be filtered?
What are two reasons albumin can not be filtered?
- Albumin is too big.
- Albumin has a negative charge
(24:00)
Glomerular Anatomy: Label A through D
How many layers are there in the glomerulus?
What kind of charge are in each layer?
3 Layers:
Endothelium
Basement Membrane
Epithelium
All three layers have negative charges and repel things that shouldn’t be filtered (ie: albumin) (27:28)
Endothelium contains _______________ to allow filtration of huge amounts of fluid.
Fenestrations (25:28)
What is the basement layer of the glomerulus composed of?
Connective Tissue, Collagen, Proteoglycan, Filaments. (26:00)
What is outer layer of the glomerulus?
What is the outer layer of the glomerulus composed of, what is the purpose of these structures?
Epithelial Layer (26:20)
Podocytes. They provide support, allow large amounts of fluids to pass through the slit pores, and prevent proteins from leaving the glomerulus. The blood pressure of the glomerulus is 60 mmHg, the podocytes helps maintain the integrity of the glomerulus. (30:30)
What can cause proteins to be filtered through the glomerulus?
Can proteins be reabsorbed from the tubule?
- Infection
- High Blood Pressure
No, there are no specific transporters for protein reabsorption.
(28:00)
How much pressure is lost when blood goes from the glomerular capillaries to the peritubular capillaries?
What causes the drop in blood pressure in the peritubular capillaires?
47 mmHg lost.
Glomerular capillary blood pressure (60 mmHg)
Peritubular capillary blood pressure (13 mmHg)
High resistance in the efferent arterioles.
(35:00)
What is the difference in oncotic pressure between the glomerular capillaries and the peritubular capillaries?
0 mmHg
Glomerular capillary oncotic pressure (32 mmHg)
Peritubular capillary oncotic pressure (32 mmHg)
(36:00)
What is the peritubular capillary hydrostatic pressure?
What is the peritubular capillary oncotic pressure?
What is the interstitial fluid hydrostatic pressure?
What is the interstitial fluid oncotic pressure?
13 mmHg (Peritubular hydrostatic pressure)
32 mmHg (Peritubular oncotic pressure)
6 mmHg (Interstitial fluid hydrostatic pressure)
15 mmHg (Interstitial fluid oncotic pressure)
What are the pressures that favor reabsorption to the peritubular capillaries?
What are the pressures that opposes reabsorption to the peritubular capillaries?
What is the Net Reabsorption Pressure?
Forces that favor reabsorption:
Peritubular oncotic pressure (32 mmHg)
Interstitial fluid hydrostatic pressure (6 mmHg)
Forces that oppose reabsorption:
Peritubular hydrostatic pressure (13 mmHg)
Interstitial oncotic pressure (15 mmHg)
10 mmHg
(38mmHg - 28mmHg)
(39:00)