Renal System Flashcards
What does the word Renal mean
Kidney
Function of Kidneys (broad)
handle the stuff found in plasma
maintain plasma volume*
What is plasma composed of
Water Ions Organic molecules Trace elements and vitamins Waste material
Functions of the kidneys (5)
- regulate blood volume and pressure
- water conc and fluid volume
- inorganic ion concentration - acid/base balance
- excretion
- synthesis of glucose
- secretion of hormones
Gluconeogenesis
synthesis of glucose via the kidneys (when fasting)
Hormones the kidney secretes
Erythropoietin (EPO)
Renin
1,25-dihydroxy Vitamin D
Causes of fluid volume changes
health disorders (dehydration) rapid movement of water (osmosis)
ICF
Intracellular fluid - fluid inside the cell
Ions predominant in ECF
Na+, HCO3-, Cl-
Ions predominate in ICF
K+
Mg2+, Pi, Protein
ECF
extracellular fluid - fluid found outside the cell; plasma, interstitial fluid, CSF
Plasma
non-cellular part of blood, fluid inside blood vessels
Body Fluid Components
ICF
ECF
Plasma
What does the kidney excrete
Urea Uric acid Creatinine (muscle metabolism) Bilirubin (Hb breakdown) Foreign chemicals (drugs, food additives, pesticides)
How does water diffuse across membrane?
Aquaporins - water channels
Water concentration
Osmoles - 1 osm is equal to 1 mole of solute particles
Osmolarity
number of solutes per unit volume of solution expressed in mol/L
T/F: Pure water has low osmolarity
TRUE
Diffusion
movement of molecules from one location to another as a result of random thermal motion
Diffusional Equilibrium
movement of water and solutes has equalized; water and solute concentration are equal on both sides of the petition
Osmosis
diffusion of water across a selectively permeable membrane from region of high water concentration to one with lower water concentration
Semi-permeable membrane
permeable to water, not solutes
Osmotic pressure
increases when water moves to create osmotic EQb
Pressure applied to stop movement of water
Required to stop cells from bursting
Tonicity
determined by the concentration of non-penetrating solutes of an extracellular solution relative to the intracellular environment of the cell.
The solute concentrations may influence changes in cell volume
Three conditions of tonicity
- Isotonic (isosmotic) - same osmolarity outside and inside the cell - shape stays constant shape
- Hypertonic (hyperosmotic) - outside envrionment has higher osmolarity than inside the cell - cell would shrink
- Hypotonic (hypoosmotic) - lower osmolarity than inside the cell - cell would swell/bulge
Changes in cell volume
fate of the RBC:
Hypotonic solution
Isotonic solution
Hypertonic solution
Hypo - cell bulge/swell
Iso - no change
Hyper - cell shrinkage
Penetrating solute
urea
can cross cell membranes
What is given in an emergency
Isotonic saline
Absorption
movement of solute/water INTO blood (plasma)
Filtration
Movement of solute/water OUT of blood (plasma)
Net filtration pressure
Startling Forces
Capillary hydrostatic pressure (Pc)
pushes fluid OUT OF capillary into interstitial fluid
Interstitial fluid hydrostatic pressure (Pif)
fluid push INTO capillary from interstitial fluid
Pic
Osmotic force INTO capillary
due to plasma protein concentration
Pi IF
Osmotic force OUT OF capillary
due to interstitial fluid protein concentration
Arterial end of capillary
Favours FILTRATION - fluid pushed out of capillary
Venous end of capillary
Favours ABSORPTION - fluid flows INTO capillary
Homeostasis
Total body balance of any substance
Fixed volume of water in body
Gain- ingestion, metabolism product
Loss- excretion, metabolized
Kidneys - retroperitoneal
Ureter - drain urine from kidneys
Bladder
Urethra
micturition
release of urine outside body (urination)
Anatomy of the Kidney
Outer cortex Inner cortex Nephron --> renal corpuscle --> renal tubule
Structure of a Nephron
Bulb like renal corpuscle
Components of Renal Corpuscle
Glomerulus
Bowman’s Capsule
Components of Renal Tubule
convoluted - twisted Proximal convoluted tubule (PCT) Loop of Henle Distal convoluted tubule (DCT) Collecting duct
Loop of Henle segments
descending limb - downward
Ascending limb - upwards
Renal Corpuscles
Initial blood filtering component
First making of urine
Glomerulus
Interconnected capillaries in the renal corpuscle
First filtration of blood
Development of Renal Corpuscle
Parietal and Visceral layers important**
Glomerular capillary
- fenestrated endothelial layers
- basement membrane
- podocyte (foot) with filtration slits
Two types of nephrons:
Cortical (85%) - closer to cortex
Juxtamedullary (15%) - closer to medulla, corpuscle is in cortex