Module 11: Renal System 1st Half Flashcards
What is Tonicity? (3)
Hypotonic Solution:
-Lower concentration of solute than compared solution
Isotonic Solution:
-Same concentration of solute than compared solution
Hypertonic Solution:
-Higher concentration of solute than compared solution
What is included in the Renal System? (4 things)
Kidneys
Ureters
Bladder
Urethra
What does the Renal system regulate? (4 things)
1.Water balance
2. Electrolyte levels
3. pH of the blood
4. Long-term regulation of arterial pressure
Basic function of kidneys is to? (3 things)
- Remove nonessential substances (like waste metabolites, excess water, and electrolytes)
- Recover any essential substance (e.g., glucose)
- Kidney is an endocrine gland -> produces hormones or components of hormonal systems (EPO, renin, vitamin D)
Kidney Anatomy: What are the functional units?
Nephrons
-each nephron spans the cortex and medulla
What does the Kidney consist of? (7 things)
-Cortex (outer renal)
-Medulla (middle renal)
-Calyces (collect waste from the collecting ducts of nephrons)
-Renal Pelvis (collects urine and drains into the ureter)
-Ureter (travels into the bladder)
-Renal Artery and Vein
Nephrons function?
To filter the blood, reabsorb essential substances, and excrete nonessential molecules and waste
Vasculature of the Nephron (Blood Travel Path)
-Blood from the renal artery branches into several interlobar arteries that branch into arcuate arteries
-Blood from arcuate arteries flows through interlobular arteries and into the afferent arteriole
-Afferent arteriole gives rise to the glomerulus (where filtration occurs)
-Blood from the glomerulus enters the efferent arteriole
-Blood that enters the peritubular capillaries (network of capillaries surrounding the nephron) drains into the interlobular vein, arcuate vein, interlobar vein and back into the renal vein
What are the processes along the Nephron? (4 things)
Filtration:
-Movement of the fluid through the glomerular capillary due to hydrostatic pressures
Reabsorption:
-Movement of a substance from lumen of the nephron back INTO the blood
Secretion:
-Movement of a substance from the blood INTO the lumen of the nephron
Excretion:
-Removal of a substance from the body
Putting together:
Excretion = Filtration + Secretion - Reabsorption
What is Filtrate?
Is the solution created by filtration. Is composed of: water + all the dissolved solutes in blood (except large proteins)
-Contains same substances as plasma with exception of large proteins and RBCs
What does the Renal Corpuscle consist of?
-Glomerular capsules (Bowman’s capsule): surrounds a very small, high permeable capillary bed called the glomerulus
-Glomerulus
Glomerular Filtration?
Is facilitated by extremely permeable capillaries, which make up the glomerulus, and Starling Forces
What are Podocytes?
Special epithelial cells that surround the capillaries. They have large filtration slits that are formed between pedicles
What are Starling Forces?
Are the physical forces that determine the movement of fluid between capillaries and tissue fluid
Starling Forces in Renal System: (4 things)
- Hydrostatic pressure of Glomerular Capillary (or PGC) is ~60 mmHg, casing filtration of fluid into the glomerular capsule
- Colloid osmotic pressure of Glomerular Capillary (πGC) due to plasma proteins in glomerulus is -32 mmHg, causing reabsorption of fluid into the plasma.
- Hydrostatic pressure of Bowman’s Capsule (or PBC) is -18 mmHg, causing reabsorption of fluid
- Colloid osmotic force of Bowman’s capsule (πBC) causes filtration by presence of proteins in Bowman’s space (pressure = 0 since very few proteins are filtered)
Net Filtration Pressure = 60 + (-32) + (-18) = +10 mmHg out -> Positive number = filtration