Kidney Function 1 Flashcards
Give the 3 main functions of the kidney and some information on each
- Excretion of metabolites or ingested substances
- urea from protein catabolism
- uric acid from nucleic acid breakdown
- creatinine from muscle creatine
- hormone metabolites
- foreign chemicals
- end products of haemoglobin breakdown - Control of body fluid composition
- volume regulation (linked to sodium concentration)
- osmoregulation
- pH regulation (can secrete/excrete H+) - Endocrine
- Hormones that act on the kidney e.g. ADH, aldosterone
- Hormones produced by the kidney e.g. Vitamin D3, renin
What is the role of the ureter?
Brings urine from the kidney to the bladder to be stored.
What does the glomerulus sit in?
A fluid filled space
What are the 3 layers that the fluid has to pass through in the bowmans capsule to get to the rest of the nephron?
- Fenestrated capillary endothelium
- Basement membrane
- Tubular epithelium (podocytes)
Why is the capillary endothelium fenestrated?
What is the basement membrane a site of?
What do podocytes have?
To increase permeability
Negative charges
Filtration slits
What are 3 important parts of a podocyte?
Podocyte cell body
Primary process of podocyte
Branching pedicels
What is the name of two important filtration slit proteins?
Nephrin and Podocin
What are the 2 sections of the renal corpuscle?
- Glomerulus
2. Bowmans space in Bowmans capsule
What are the 8 sections of the renal tubule?
- Proximal convoluted tubule
- Proximal straight tubule
- Descending thin limb of Henle’s loop
- Ascending thin limb of Henle’s loop
- Thick ascending limb of Henle’s loop
- Distal convoluted tubule
- Cortical collecting duct
- Medullary collecting duct
When do the nephrons merge together?
In the collecting duct
What percentage of the nephrons are cortical and which are juxtamedullary?
Give some info on each
Cortical - 85%
Juxtamedullary - 15%
Cortical - outer 2/3 of cortex
Short loop of Henle
Juxtamedullary - inner 1/3 of cortex
Long loop of Henle
Produces concentrated urine
What parts of the nephron are juxtaglomerular apparatus?
Extraglomerular mesangial cells (responsible for generating extracellular matrix) Juxtaglomerular cells (secretes renin which is an enzyme to regulate blood pressure) Mucula densa (cells lining the distal tubule at the point where the thick ascending limb meets the distal convoluted tubule)
What are the two sets of capillary beds we have in series in the kidney?
The glomerulus and the peritubular (arise from the efferent arteriole).
What are the peritubular capillaries in the loop of Henle called?
Vasa recta
What are the three basic renal processes?
- Glomerular filtration
- Tubular reabsorption
- Tubular secretion
Explain glomerular filtration
The movement of fluid and solutes from the glomerular capillaries to the Bowmanss space.
20% of the plasma that enters the glomerulus is filtered
Explain tubular secretion
The secretion of solutes from the peritubular capillaries into the tubules