Nephron and Glomerular Filtration Rate

Flashcards about Nephrons and Glomerular Filtration Rate (GFR)

Name the components of a nephron.

Nephron Loop, Collecting Duct, Afferent Arteriole, Vasa Recta, Peritubular Capillaries, Efferent Arteriole, Proximal Convoluted Tubule, Glomerular Capsule, Cortical Radiate Artery and Vein, Distal Convoluted Tubule

What is the main function of the nephrons and collecting ducts?

To control the composition of body fluids and remove wastes from the blood, producing urine.

What processes result in urine formation?

Glomerular filtration, tubular reabsorption, and tubular secretion.

Name the components of the Filtration Barrier.

Fenestrae, Podocytes

What is the normal volume of fluid filtered into the Bowman's capsule per unit of time?

125 ml/min or 180 liters/day

What are the primary determinants of Glomerular Filtration Rate (GFR)?

Net filtration pressure (NFP), surface area, and porosity/permeability.

How do the physical determinants affect GFR ?

↓K →↓ GFR, ↑ PB →↓ GFR, ↑ πG → ↓ GFR

Give examples of Physiologic/Pathophysiologic Causes of GFR.

Renal disease, diabetes mellitus, hypertension, urinary tract obstruction, ↓ Renal blood flow, increased plasma proteins, ↓Arterial pressure, ↓ Angiotensin II, ↑ Sympathetic activity, vasoconstrictor hormones

How does sympathetic stimulation affect GFR?

Sympathetic stimulation causes a decrease in renal blood flow, glomerular hydrostatic pressure, and GFR.

Name Hormones that decrease GFR.

Norepinephrine, Epinephrine, and Endothelin decrease renal blood flow, glomerular hydrostatic pressure, and GFR.

Name Hormones that Increase GFR.

Endothelial derived nitric oxide and Prostaglandins increase renal blood flow, glomerular hydrostatic pressure, and GFR.

What affect does Angiotensin II have on GFR?

Angiotensin II increases Glomerular hydrostatic pressure and GFR.

Name a component of Tubulo-glomerular feedback.

Macula densa NaCl, Renin Angiotensin II , Afferent arteriolar resistance, Proximal NaCl reabsorption, Adenosine , Calcium release , Efferent arteriolar resistance

Which Hormonal/ Autacoids affect GFR and how?

Norepinephrine, Epinephrine, and Endothelin Decrease GFR, Prostaglandins, Nitric oxide, and Angiotensin II Increase GFR

Name a component of Autoregulation.

Tubulo-glomerular feed back regulation and Myogenic autoregulation.