PBL 3: Normal kidney function Flashcards
Which spinal level is the kidneys located?
T11 to L3
___ kidney is lower than the ___ kidney. Why?
Right kidney is lower than the left kidney as the right kidney is displaced by the liver
What is located on the superior surface of the kidneys?
The adrenal glands
The kidneys are encased in 4 layers.
Name these layers
- Renal capsule (inner layer)
- Perirenal fat
- Renal fascia
- Pararenal fat (outer layer)
Fill in the blanks regarding the layers of the kidney
Renal parenchyma can be divided into two main regions.
Name these regions
- Cortex (outer layer)
- Medulla (inner layer)
The outer cortex extends into the medulla, dividing it into?
Renal pyramids
Name these parts of the kidneys
What structures are located in the cortex of the kidney
Filled with glomeruli, associated blood vessels and their attached tubules.
Describe the composition of the renal medulla
- Highly salty as sodium chloride is pumped out of the ascending limp of the loop of Henle.
- Medulla is primarily composed of different tubule types.
- Medullary tissue is arranged in segments termed renal pyramids.
- As it becomes collecting ducts, they descend through the pyramids, draining through the renal papilla.
Describe the pathway of the urine from the collecting ducts?
The fluid descend through the renal pyramids, draining through the renal papilla.
Renal papilla into the minor calyx into the major calyx. Finishes by draining into the renal pelvis via the renal calyx.
What is the functional unit of the kidney?
Nephron
What is the function of the nephrons?
Responsible for filtration, excretion and resorption
What structures make up the Renal corpuscle
Bowman’s capsule and glomerulus
What are the two types of nephrons?
- Cortical nephrons
- Juxtamedullary nephrons
Compare the two types of nephrons
-
Cortical nephrons
- Short loop of Henle.
- Renal corpuscles in the outer part of the cortex
- 85% of all nephrons
-
Juxtamedullary nephrons
- Long loops, extending into the medulla
- Larger renal corpuscles in the inner third of the cortex
- 15% of all nephrons
The cortical nephrons contain a ____ loop of Henle. The renal corpuscles is located in the ______. Cortical nephrons make up _____% of all nephrons.
A) Short
B) Outer part of the cortex
C) 85%
The juxtamedullary nephrons contain a ____ loop of Henle. The renal corpuscles is located in the ______. Cortical nephrons make up _____% of all nephrons.
A) Long
B) Inner third of the cortex
C) 15%
Name the parts of the nephron
- Renal corpuscle (found in the renal cortex)
- Proximal convoluted tubule (found in the renal cortex)
- Loop of Henle (mostly in the medulla)
- Distal convoluted tubule (found in the renal cortex)
- Collecting tubule (in the medulla)
- Collecting duct (in the medulla)
What structures make up the juxtaglomerular complex
The beginning of the distal convoluted tubule is found close to the renal corpuscle, in a structure known as the juxtaglomerular complex
Define the glomerulus
A compact mass of looped fenestrated capillaries
Define the bowman’s capsule
- Blind ending of the nephron that encapsulates the glomerulus.
- This blind ending is the proximal end of the renal tubule
The ____ arteriole enter the renal corpuscle. The ___ arteriole leaves the renal corpuscle
A) Afferent
B) Efferent (E-exit)
The capillary loops selectively filtrate the blood across glomerular filtration barrier.
Which molecules does it permit the passage and which does it block?
Permits the passage of small and some medium sized molecules e.g. water and electrolytes, while blocking the passage of larger molecules e.g. RBCs.
What pressures drive the filtration across the glomerular filtration barrier
hydrostatic and oncotic pressure
Name the 3 layers of the glomerular filtration barrier
- Endothelium (inner layer)
- Glomerular basement membrane (middle layer)
- Podocytes (outermost layer)
Describe the endothelium of the glomerular filtration barrier
- Single layer of fenestrated endothelium
Describe the formation of the glomerular basement membrane of the glomerular filtration barrier
Product of the fusion of the basement membrane produced by endothelial cells and podocytes.
Which type of collagen is the glomerular basement membrane composed of?
Collagen type 4
Describe podocytes
- Epithelial cells
- Contain numerous processes with each process having many smaller processes known as foot processes/pedicles.
- The foot processes/pedicles are attached to the underlying glomerular basement membrane.
- The foot processes are interlock with its neighbouring foot processes from adjacent podocytes.
- The spaces between foot processes forms the filtration slits that act as a molecular sieve, providing an additional filtration barrier based mainly on size.
Name these parts of the glomerular filtration barrier
Name these parts of the glomerular filtration barrier
How many litres of filtrate move across the glomerulus into the tubular system per day?
180L per day
What substances are reabsorbed at the proximal covoluting tubule
- Water (via osmosis)
- Sodium chloride (65%)
- Bicarbonate (90%)
- Phosphate
- Glucose and amino acids (100%)
- Potassium (65%)
- Urea (50%) the rest are secreted as urine