Flashcards in Pathophysiology Exam #4 Deck (105)
What are the ten functions of the Renal System?
REVIEW OF KIDNEY FUNCTIONS
• EXCRETE END PRODUCTS OF METABOLISM FROM THE BLOOD, such as urea, creatinine, metabolic acids, others
• In coordination with antidiuretic hormone (ADH), REGULATE VASCULAR, INTERSTITIAL, AND INTRACELLULAR OSMOLALITY
AND VOLUME by regulating urine volume and osmolality
• REGULATE ELECTROLYTE AND OTHER SOLUTE BALANCE of body fluids
• REGULATE ACID-BASE BALANCE OF BODY FLUIDS, in conjunction with body buffers in the lungs
• REGULATE BLOOD PRESSURE by controlling vascular volume and by secreting renin, which causes synthesis of
angiotensin II (potent vasoconstrictor) and aldosterone secretion and the lungs
• REGULATE BONE MARROW PRODUCTION OF RBCS BY secreting erythropoietin (from the peritubular endothelial
cells) in response to hypoxia
• SYNTHESIZE VITAMIN D TO it’s most active form, 1,25-DHCC, which helps regulate calcium and phosphate
balance and bone formation
• SYNTHESIZE VARIOUS HORMONES that help regulate renal blood flow, such as PGs (prostaglandins, which is a
vasodilator), endothelin (vasoconstrictor), and nitric oxide (vasodilator)
• PERFORM GLUCONEOGENESIS (only the liver performs more than the kidneys)
o Gluconeogenesis is the production of glucose from non-carbohydrates such as, amino acids
• EXCRETE DRUGS AND TOXINS from the body fluids
What is the anatomic location and size of the Kidneys, and what organ sits on top of them?
• The kidney location is in the retroperitoneal (behind the peritoneal cavity), underneath ribcage (protected by
• The kidneys should be about the same size; the average adult kidney size is 11 – 13 cm (longitudinally)
• There should be NO MORE THAN A 1.5 cm difference or greater difference between the kidneys
• If there is a ≥1.5 cm difference between the two kidneys; one is to large or one is to small (you need to investigate why)
• Adrenal gland sits on top of the kidneys; they have their own blood flow (BF), autonomic innervation, and lymphatic circulation
o The adrenal glands are actually completely separate organs from the kidneys
***** If the patient has a nephrectomy, its very important that the surgeon dissects and removes just the kidney
and not the adrenal gland that is sitting on top of the kidneys*****
Describe the blood flow to and from the kidneys and the indications related to them.
• Blood flow:
o You can see the abdominal aorta; and the abdominal aorta is where the renal arteries divide and branch off to provide BF to the kidneys
o So as soon as the LV ejects blood, there is not to far of a distance before the kidneys are perfused
o The kidneys receive 20 – 25% of CO/ minute
o Based on size, the kidneys (that are about the size of your fist) receive a lot of BF and are very vascular
o You also see the renal veins coming off the kidneys and emptying into the inferior vena cava (IVC)
§ It is just as important to have unobstructed out-flow of blood as it is to have unobstructed in-flow of
blood (from the renal arteries)
§ If you have a tumor that obstructs the inferior vena cava and the renal veins, that increases the
pressure within the kidney; when the pressure within the kidney increases, that decreases that amount of BF to that kidney
o Another mechanism that helps propel urine from the kidneys to the bladder is?
Describe the urinary bladder.
• Urinary bladder
o Smooth muscle pouch
o As urine fills up the urinary bladder, it causes a reflex dilation; so the pressure does not rise in the urinary bladder in direct relation with the volume
o At some point the volume is going to cause such a pressure that it sends afferent impulses to your brain
that says you need to urinate
o Then you have the parasympathetic nervous system which contracts the bladder and relaxes the internal
o The external sphincter is (hopefully/ usually) in voluntary control
• The R kidney does sit a little ___ than the L kidney (because of the liver)
• Renal fraction: _____ of CO perfuses
kidneys each minute
• With average CO:
Renal blood flow – _____ ml/min.
• Altered RBF = altered renal function
*20 - 25%
*1000 - 1200 ml/min
The kidneys are enclosed in this thick fibrous
tissue called the _____ _____.
What is the function of the renal capsule?
o Helps enclose and protects the kidney
o If the kidney bleeds (like from a percutaneous renal biopsy), that renal capsule will hold that blood in; that can
be very detrimental to the kidney because that blood increases and puts pressure on the tissue (of that kidney) that will ultimately lead to ischemia
Kidneys are divided into the ___ and
cortex and medulla
Renal artery branches off of the ___ ___.
The renal artery branches into what other arteries?
segmental arteries (superior, middle, and inferior)
o Superior provides BF to the superior
aspect of the kidney; middle to middle;
inferior to inferior
The renal vein delivers ___ blood back to the IVC.
If you look at the renal pyramid here (urine is formed) you see these little dots in the membrane called the ___ ___.
• Urine empties thru the papilla into a ___ ___; and the minor calyces empty into their own ___ ___.
o That urine is then transported in thru the ureter down to the urinary bladder
Trace blood flow from the left ventricle through the kidneys and then back to the mitral valve.
FROM THE LV BACK TO THE RA **** YOU WILL SEE THIS AGAIN ****
LEFT VENTRICLE ->AORTIC VALVE -> ASCENDING AORTA -> ARCH OF THE AORTA ->DESCENDING THORACIC AORTA (PIERCES THE DIAPHRAGM) ->ABDOMINAL AORTA->BRANCHES INTO THE L & R RENAL ARTERIES ->SEGMENTAL ARTERIES (SUP, MID, INF) ->INTERLOBAR ARTERIES -> ARCUATE ARTERIES -> INTERLOBULAR ARTERIES -> AFFERENT ARTERIOLES -> GLOMERULUS -> EFFERENT ARTERIOLES -> PERITUBULAR CAPILLARIES ->VASA RECTA -> INTERLOBULAR VEINS -> ARCUATE VEINS -> INTERLOBAR VEINS ->RENAL VEIN -> INFERIOR VENA CAVA -> RIGHT ATRIUM -> TRICUSPID VALVE ->RIGHT VENTRICLE -> PULMONIC VALVE -> PULMONARY ARTERIES -> PULMONARY CIRCULATION -> PULMONARY VEINS -> LEFT ATRIUM -> MITRAL VALVE
What is the blood flow specifically through the kidneys?
1ST RENAL A.
2ND SEGMENTAL A.
3RD INTERLOBAR A.
4TH ARCUATE A.
5TH INTERLOBULAR A.
6TH AFFERENT ARTERIOLES
8TH EFFERENT ARTERIOLES
9TH PERITUBULAR CAPILLARIES
10TH VASA RECTA
11TH INTERLOBULAR V.
12TH ARCUATE V.
13TH INTERLOBAR V.
14TH RENAL V.
What is the functional unit of the kidneys?
• Starting at the BOWMANS CAPSULE (completely surrounds those glomerular capillaries)
• The Bowman’s capsule then becomes the ___ ___.
o First you have the ___ proximal tubule
o Convoluted proximal tubule then becomes the ___ proximal tubule
• It then thins out and becomes the ___ ___ ___ ___ ___
o AKA the ______?
• The loop of Henle makes a hairpin turn; this is the ___ ___ ___ ___ ___.
o AKA the _________?
-THIN DESCENDING LOOP OF HENLE
-THIN ASCENDING LOOP OF HENLE
-passive diluting segment
• The lumen of the tube then gets larger; this is the _____ _____ _____ _____.
o AKA the ____________?
• Then the ___ ___
o not really discussed much because the ___ distal tubule is very similar in function and structure to
the thick ascending limb of the loop of Henle
o and the ___ distal tubule is very similar in function and structure to the ___ ___ ___.
-THICK ASCENDING LIMB OF THE LOOP OF HENLE
-active diluting segment
-CORTICAL COLLECTING TUBULE
AFTER THE DISTAL TUBULE WE HAVE THE ___ ___ ___?
• What is the result once the tubular filtrate leaves the medullary collecting duct?
• MEDULLARY COLLECTING DUCT
• In the adult, the kidney has how many nephrons?
- 1 – 1.25 million nephrons (2 – 2.5 million if you have both kidneys)
The kidney is divided into a ___ and the ___
cortex and medulla
There are two types of nephrons, what are they?
There are two types of nephrons
o CORTICAL nephrons (on the R side)
o JUXTAMEDULLARY nephrons (on the L side)
What is the characteristics of Cortical nephrons?
§ They are called the cortical nephrons because the
majority of the components of that nephron are located within the cortex of the kidney
§ 85% of nephrons are cortical
What is the characteristics of Juxtamedullary nephrons?
§ These nephrons (as you notice) have long thin
loops of Henle that dive deep deep down into the
§ Account for the other 15% of our nephrons
§ Responsible for determining the final urine
volume and concentration
Vasa recta lie right next to those long thin ___ ___ ___.
- loops of Henle
The glomerulus contains how many capillaries?
The glomerulus is ~ 12 – 24 capillaries
The Bowman’s capsule is the beginning of the___ ___ ___; it completely surrounds the glomerular
-lumen of the tubule
The distal tubule (on each nephron) lies right in between the ___ ___ ___.
o The distal tubule actually comes into contact with the ___ arteriole
-afferent and efferent arterioles