Introduction to the kidney Flashcards
List 3 substances secreted by the kidneys.
Erythropoietin
Active form of vitamin D
Renin
What are the 3 key processes of the kidney that allow it to contribute to homeostasis?
Filtration
Reabsorption
Secretion
Give 2 things that the kidneys regulate in terms of body fluid.
Body fluid volume
Body fluid composition
What are the components of the uriniferous tubule?
Nephron + collecting duct
What is the functional unit of the kidney?
Nephron
What comprises the renal corpuscle?
Glomerulus + Bowman’s capsule
What are the two types of nephron?
Cortical
Juxtamedullary
What are the 2 arterioles of each nephron?
Afferent arteriole
Efferent arteriole
What are the 2 capillary networks of each nephron?
Glomerular capillaries
Peritubular capillaries
Describe the pressure of the glomerular capillaries and what function they allow the kidneys to carry out.
High pressure
Filtration
Describe the pressure of the peritubular capillaries and what functions they allow the kidneys to carry out.
Low pressure
Reabsorption and secretion
Describe the outer layer of Bowman’s capsule in terms of its name, function, and epithelium.
Parietal layer
Structural function
Simple squamous
Describe the inner layer of Bowman’s capsule in terms of its name, function, and epithelium.
Visceral layer
Filtration function
Modified simple squamous cells - podocytes
Which cells provide support between the glomerular capillary loops?
Mesangial cells
Give the 3 layers of the filtration barrier and a special feature they each have that aids their function.
Glomerular capillary endothelium (fenestrated)
Basement membrane (negatively charged)
Epithelial cells (podocytes) with interdigitating foot processes & filtration slits
The filtration barrier limits the passage of substances from the blood based on what 3 things?
Size
Charge
Shape
What is the epithelium of the PCT?
Simple cuboidal with microvilli
Give the 3 main cell types found in the juxtaglomerular apparatus.
Macula densa
Granular or juxtaglomerular cells in the afferent arteriole
Mesangial (Lacis) cells
What do the granular / juxtaglomerular cells secrete?
Renin
Describe the water permeability of the collecting duct.
Under hormonal control by ADH
What percentage of body weight is water?
60%
How many litres is intracellular fluid?
28 litres
How many litres is extracellular fluid?
14 litres
Which 2 compartments can extracellular fluid be divided into and how many litres in each?
Interstitial fluid - 11 litres
Plasma - 3 litres
