Renal Physiology and Renal Function Tests (1) Flashcards
Which of the following parts of the nephron acts a sieve?
a) DCT
b) PCT
c) Glomerulus
d) Loop of Henle
c) Glomerulus
Each kidney contains approximately 1 to 1.5 million functional units called
- Basic functional unit of the kidney
- When the kidney filters the blood, the filtrate will go to the bowman’s capsule. The filtrate will stay here
nephrons
two types of nephrons
Cortical nephrons and Juxtamedullary nephrons
- make up approximately 85% of nephrons, are situated primarily in the cortex of the kidney.
- They are responsible primarily for removal of waste products and reabsorption of nutrients
Cortical nephrons
longer loops of Henle that extend deep into the medulla of the kidney.
- Their primary function is concentration of the urine.
Juxtamedullary nephrons
What is inside the PCT, blood or filtrate?
Filtrate
What is the inside afferent arteriole, blood or filtrate?
Blood
Total renal blood flow
1200 mL/min
Before returning to the renal vein, blood from the efferent arteriole enters the _____and flows slowly through the cortex and medulla of the kidney
close to the tubules.
peritubular capillaries and the vasa recta
- Innermost layer
- Lined by: Endothelial cells
- Contain numerous pores (fenestrae)
Capillary wall membrane
- <70,000 MW (66,000)
- negatively charged, the proteins are negatively charged as well when in contact with one another they will
repel.
Glomerular basement membrane (basal lamina)
- Slit membranes prevent filtration of proteins
Visceral epithelium (podocytes)
- acts as a filtration barrier.
- Another reason why proteins can’t go out is because of the outermost layer of the capillary membrane which is formed
by the - CONTAINS SHIELD OF NEGATIVITY ,
PODOCYTES
what are the three GLOMERULAR FILTRATION (layers)
- Capillary wall membrane
- Glomerular basement membrane (basal lamina)
- Visceral epithelium (podocytes)
Pressure that forces the fluid outside a vessel.
Hydrostatic pressure
Oncotic pressure
Pressure that maintains the fluid inside the vessel
- Increased hydrostatic pressure in the glomerular capillary
- Increased GFR
Constriction of the efferent arteriole
- Decreased hydrostatic pressure in the glomerular capillary
- Decreased GFR
Constriction of the afferent arteriole
Normal GF
120/min
- Must pass through three glomerular filtration barrier cellular layers
Plasma filtrate
by containing pores and
are referred to as______
- increase capillary permeability but do not allow the passage of large
molecules and blood cells.
fenestrated endothelium
What contains the barrier that repels molecules with a negative charge even through they are small enough to pass through the three layers of the barrier.
- It is very important because it is the place where albumin ( primary
protein associated with renal disease ) - has a negative charge and
is repelled
Shield of negativity
When blood pressure drops prevent a marked decrease in blood flowing through the kidney
- It prevents an increase in the blood level of toxic waste products.
Dilation or action of the afferent arterioles and constriction or pressure of the efferent arterioles
increase in blood pressure results in ______ to prevent overfiltration or damage to the glomerulus
constriction of the afferent arterioles
- Triggering factor or stimulant: l
- Decreases water retention within the circulatory system
- resulting in a decreased overall blood volume and subsequent decrease in blood pressure
Low plasma sodium
low plasma pressure and low
plasma sodium. This will be sensed by the_____
- an enzyme produced by the juxtaglomerular cells, is secreted and reacts with the bloodborne substrate angiotensinogen to produce the
inert hormone angiotensin I.
Renin