Week 12 - Urinary System Flashcards
(52 cards)
Locate the following structures on a diagram: • Glomerulus • Glomerular capsule • Proximal convoluted tubule (PCT) • Loop of henle • Distal convoluted tubule (DCT) • Collecting ducts
N/A
What is the glomerulus ?
Is a series of capillaries that allows the flow of blood into the glomerular capsule.
What two components make up the renal corpuscle?
- Glomerulus
* Glomerulus capsule
What are the three components of the renal tubules and their respective functions?
- PCT - Bulk absorption of nutrients and fluids (passive)
- Loop of henle - concentration and dilution of filtrate
- DCT - Fine tuned absorption of substances (hormonal)
What are the role of collecting ducts?
To receive filtrate from multiple nephrons and transport them to the renal pelvis.
What are the functional units of the kidneys?
Nephrons
What are the different cell types found in: • Glomerular capsule: • PCT • Loop of Henle: • DCT:
• Glomerular capsule:
• Parietal layer - simple squamous that from the
capsule
• Visceral layer - podocytes to allow passage of
filtrate
• PCT - simple cuboidal (increased SA)
• Loop of Henle - simple squamous (water reasbsorption)
• DCT - simple cuboidal
What are the two types of capillaries associated with nephrons and briefly describe them
- Glomerular capillaries - Arise from the afferent arteriole, responsible for producing filtrate from the blood stream
- Peritubular capillaries - arise from the efferent arterioles and are responsible for reclaiming filtrate back into the blood from the renal tubules.
What is the difference between filtrate and urine?
Filtrate is what enters the glomerular capsules from the glomerular capillaries, whereas urine is what is actually secreted from the body.
List the 3 processes performed by nephrons to produce urine
1) Glomerular filtration
2) Tubular reabsorption
3) Tubular secretion
Why is glomerular filtration a passive process?
Substances move passively into the glomerular capsule due to differences in pressure - moves down the pressure gradient.
Why are large molecules such as blood cells and plasma proteins excluded from the filtrate?
The are too large to pass from the capillaries into the glomerular capsule
How is glomerular pressure regulated?
The dilation and constriction of the afferent and efferent arterioles.
Glomerular filtration depends on 3 main pressures. List them and indicate whether they promote or oppose the formation of filtrate
- Glomerular hydrostatic pressure - Promote
- Capsualr hydrostatic pressure - Oppose
- Blood colloid osmotic pressure - Oppose
The ascending loop concentrates filtrate and thus is permeable to _______ but is impermeable to ______
- Water
* Solutes
The ascending loop dilutes the filtrate and thus is permeable to _______ but is impermeable to ______
- Solutes
* Water
The reabsorption of filtrate in the PCT is under what kind of control?
passive
The reabsorption in the DCT is under what kind of control?
hormonal
What hormones are associated with the DCT and what are there functions?
- Aldosterone - promotes sodium reabsorption and thus the reabsorption of water
- ADH - promotes water reabsorption by inserting aquaporins into the kidney tubules.
Why is Na+ reabsorption the driving force for water and solute reabsorption.
Na+ is the main extracellular ion and this its concentration gradient drives the movement of water and consequently other ions.
Where is the nephron does tubular secretion occur?
PCT and DCT
Why is tubular secretion important?
Allows for the disposing of unwanted waste products and for the regulation of various substances in the body.
What structure carried the urine from the kidneys to the bladder?
ureters
What structure stores urine?
bladder
