Test 3 - Quiz 8 - Renal Physiology (Colombo) Flashcards
Kidneys manage both the __________ of urine and the ___________ or expulsion of various components of the serum.
Outflow
Retention
The kidneys are regulators of three things. Name them.
BP
Blood plasma constituents
pH
The fluid in the body is distributed across 4 compartments. Name them and roughly how much is in each.
Plasma - 3 L - Least
Interstitial - 11 L
Transcellular (ECF) - 14 L
Intracellular - 28 L - Most
How is fluid volume disposed of and about how much per day for each mechanism?
Kidneys - 0.5-20 L/day
Skin/Respiratory - 700 mL/day
Sweat - 100 mL/day (1-2 L/hour in heavy exercise)
Poop - 100 mL/day
Increased volumes of blood means what for blood pressure?
How is this alleviated via the kidneys?
Increased blood pressure
By controlling urine volume, they can rapidly shed excess pressure
*The opposite is also true, urine volume can be restricted in dehydration, preserving pressure
__________ _____________ is regulated by the kidney, which also serves to regulate tonicity.
Electrolyte balance
The kidneys excrete metabolic __________ products and ____________ chemicals.
Waste
Foreign (Pharmaceuticals)
*They also excrete systemic hormones
Waste products are highly ____________ and poorly ____________.
Filtered
Reabsorbed
What are 4 metabolic wastes?
Urea
Uric acid
Creatinine
Bilirubin
What are 4 foreign substances?
Pesticides
Food additives
Toxins
Drugs
Excreting 1 HCO3- is basically the same as adding what?
1 H+
What are three important “other” renal functions?
Production of erythropoietin (RBCs)
Gluconeogenesis
Adrenal glands
The kidney can be divided into 2 basic parts. Name and describe them.
Renal cortex - Outer section
Renal medulla - Innermost section
In the renal medulla, what are the specialized regions of tissues and what make up those tissues?
Renal pyramids
-Nephrons
What is the renal pelvis and how are the pyramids connected to it?
Urine drainage tube
Papilla
*Pic on slide 11 of his presentation, if needed
Where are the capillary beds located in the kidneys?
Renal pyramids (nephrons)
**THIS IS WHERE FILTRATION OCCURS
What are the 3 processes of the kidney?
Filtration - What gets there and how it is taken into the nephron
Modification - What is done to filtrate in the nephron
Excretion - Micturition
What is the vessel that supplies blood to the kidneys?
Renal a.
Renal arteries then branch into what 3 aa.?
Interlobar a.
Arcuate a.
Radial a.
The 3 arteries after the renal artery then lead to what?
Afferent arterioles
Afferent arterioles lead to what?
Glomerular capillaries
The glomerular capillaries lead into what?
Nephron
AND
Efferent arterioles
Filtration occurs here
The efferent arterioles lead to what?
Peritubular capillaries
This is where reabsorption/secretion occurs
Peritubular capillaries send their blood where?
Renal vein
What is the part of the kidney where vessels go in and out?
Hilum
What is the basic functional unit of the kidney?
Nephron
How many nephrons are in a single kidney?
1 million
Each nephron is fed by glomerular capillaries that are referred to as what?
Glomerulus
The glomeruli are covered by what?
Epithelial cells and encased in Bowman’s capsule
What is the route plasma takes going from glomerulus to ureter?
Glomerulus -> Bowman’s capsule -> Proximal tubule -> Loop of Henle (concentrates urine) -> Distal tubule -> Collecting duct (part the body can control) -> Renal pelvis -> ureter
Cortical nephrons are different than juxtamedullary nephrons how?
More common (70% of nephrons)
Found in cortical region primarily
Loop of Henle only penetrating the medulla
More superficial
Juxtamedullary nephrons differ from cortical nephrons how?
Less common (30% of nephrons)
Primarily w/in medulla
Long loops of Henle that penetrate deep into the medulla
*These nephrons are very good at concentrating the urine
What is the vasa recta?
In juxtamedullary nephrons, efferent arterioles extend part of the way down the Loop of Henle and form special peritubular capillaries (called the vasa recta)
Urinary excretion rate is equal to what?
Filtration rate - reabsorption + secretion
(Out of proximal tubule minus what’s taken back by peritubular capillaries plus what comes out of the peritubular capillaries
Example of a substance filtered but not reabsorbed at all?
Waste