Module 6 Flashcards
What percentage of cardiac output do the kidneys receive when the body is at rest?
20 - 25% (1.0 - 1.25 litres blood min-1 )
. Identify two structural differences between the AFFERENT and EFFERENT arterioles?
- Lumen of the efferent arteriole is much narrower. 2. Afferent arteriole contains the granular cells Juxtaglomerular Apparatus
What are the main functions of the kidneys and the urinary system?
Excretion: Filters blood (plasma) to remove wastes & foreign substances and maintain blood volume. Helps to regulation blood ionic composition, blood pH & osmolality. Waste (urine) flows from each kidney, down its ureter to the bladder (temporarily stored)
How are KIDNEY FUNCTION and BLOOD PRESSURE HOMEOSTASIS related to each other?
Because the kidneys are able to adjust extracellular fluid volumes by varying sodium and water loss in the urine this in turn affects the plasma volume and ultimately blood volume and pressure
Identify the components of the nephron. What is the main general function of each component?
Bowman’s capsule:
PCT:
Loop of Henle
DCT:
Collecting ducts:
: Filtration
Majority of the reabsorption & secretion of solutes
Sets up salt gradient in the medulla
Some (less than PCT) reabsorption & secretion of solutes
Water reabsorption
Where are the kidneys located?
Kidneys are located between T12 and L3. The hilum of each is in line with L2. The right kidney is slightly lower due to the position of the liver.
Note: all the adipose tissue surrounding the kidney this is called the perirenal fat, what function does it serve?
It protects and supports the kidney attaching it to the posterior wall of the abdomen
Are the kidneys anterior or posterior to the parietal peritoneum?
Posterior
The kidneys are referred to as being retroperitoneal, what does this mean?
Located behind the peritoneum
What structures are found POSTERIOR to the kidneys?
Diaphragm, ribs, posterior body wall
this is the outer kidney region, which is light red and has a granular appearance. Notice the thin, transparent membrane that covers the surface of the kidney; this is the renal capsule.
Kidney cortex:
: deep to the cortex; a darker region. The medulla is segregated into triangular regions that have a striped, or striated, appearance - the medullary pyramids. The base of each pyramid faces toward the cortex; its apex, or papilla, points to the innermost kidney region.
Medullary region
areas of tissue, more like the cortex in appearance that segregate and dip downward between the pyramids
Renal columns:
medial to the hilus; a relatively flat, basin-like cavity that is continuous with the ureter, which exits from the hilus region. Finger-like extensions of the pelvis should be visible. The larger, or primary extensions are called the major calyces; subdivisions of the major calyces are the minor calyces. Note that the minor calyces terminate in cuplike areas that enclose the apices of the medullary pyramids and collect urine draining from the pyramidal tips into the pelvis.
Renal pelvis:
What structures constitute the renal corpuscle?
Glomerulus and Bowman’s Capsule
What structures contribute to the striated appearance of the medullary pyramids?
The long loops of Henle, collecting ducts and the loops of the vasa recta
Where is the juxtaglomerular apparatus located? Use a coloured pen to show its position on the diagram above:
Where the DCT meets the afferent arteriole of the nephron
What are the relative percentages of cortical & juxtamedullary nephrons in a kidney?
85% cortical; 15% juxtamedullary.
List some distinguishing features between cortical & juxtamedullary nephrons in this table:
Write down the correct sequence of tubules and ducts a drop of urine passes from its point of formation in the nephron collecting duct to be stored in the urinary bladder.
In which body cavity does the bladder lie?
Pelvic
. Into which body cavity does the bladder protrude when full?
Abdominal