Renal System Flashcards
Role of renin
Regulates blood pressure
Role of erythropoietin
Stimulates red blood cells production in the bone marrow
Role of the right kidney
Formation of urine and the regulation of water balance in the body
Role of the ureter
Transports urine from the kidneys to the bladder
Role of the urinary bladder
Hold the urine until it is expelled from the body
Role of the urethra
Transport urine out of the body
Renal Fascia
Outermost, tough connective tissue layer
Anchors the adrenal glands to the surrounding structures
Perirenal fat capsule
Second layer which helps anchor the kidney in place
Cushions it against blows
Renal capsule
3rd and innermost layer
Gives the kidney a glistening appearance
3 regions of the kidney
Outer cortex
Medulla
Renal pelvis
What makes the renal cortex granular?
The presence of nephrons
What does the medulla consist of?
Renal pyramids
What is in-between the renal pyramids?
Renal columns through which the blood vessels pass
What makes up the lobes of the kidney?
The renal pyramids along with the adjoining cortical region
Where does the renal pelvis lead to?
The ureter on the outside of the kidney
What does each nephron consist of?
A renal corpuscle and a renal tubule
What does the renal corpuscle consist of?
Glomerulus
Glomerular
Where is the cortical nephron located?
Almost entirely within the cortex
Podocytes
Highly modified cells which make up the inner layer of the capsule
How long is the renal tubule?
3cm
Where are the juxtamedullary nephrons located?
Close to the cortex-medulla junction
Nephron loops dip deep into the medulla
Where are the collecting ducts located?
Run downward through the medullary pyramids
Where do the collecting ducts deliver the final urine product?
Into the calyces and renal pelvis
What 2 capillary beds is each nephron associated with?
Glomerulus
Peritubular capillary bed
What is the glomerulus fed by?
The afferent arteriole
What is the glomerulus fed and drained by?
Arterioles
Result of high blood pressure in glomerular capillaries
Forces fluid and small solutes out of the blood
What happens to most of the filtrate from the nephrons?
Reclaimed by the renal tubule cells and returned to the blood
What are peritubular capillaries adapted for?
Absorption
What is the fluid known as once it is in the glomerular capsule?
Filtrate
What is filtrate?
Essentially blood plasma without blood proteins
What can proteins and blood cells not pass through the filtration membrane?
They are too large
Glomerular filtration rate
The amount of fluid filtered from the blood into the glomerular capsule per minute
What happens to most of the fluid in the glomerular capsule?
Reabsorbed and reenters the plasma
Where does most resorption happen?
In the PCT
How is water reabsorbed?
Passively by osmosis
How are substances other than water reabsorbed?
By active processes, relying on ATP
Tubular secretion
Removal of hydrogen and potassium ions and creatine
Can help with controlling blood pH
Common nitrogenous wastes
Urea
Uric acid
Creatinine
Urea formation
Formed by the liver as an end product of protein breakdown
When is uric acid released?
When nucleic acids are metabolised
What is creatinine associated with?
Creatine metabolism in muscle tissue
What is the yellow colour in urine due to?
Urochrome, resulting from the body’s destruction of haemoglobin
Where are ureters located?
Runs behind the peritoneum from the renal hilum to the posterior aspect of the bladder
Role of Ureters
Carry urine from the kidneys to the bladder
How is urine propelled along the ureter
By peristalsis - an active process
Urinary bladder
Smooth, collapsible muscular sac
Role of the urinary bladder
Stores urine temporarily
Where is the urinary bladder located?
Retroperitoneally in the pelvis
Prostate location
Surrounds the neck of the bladder where it is empties into the urethra
What is the bladder wall made up of?
3 layers of smooth muscle
Micturition
Emptying of the bladder
What is micturition controlled by?
2 sphincters
How do kidneys keep blood composition relatively constant?
Exerting nitrogen-containing wastes
Maintaining water and electrolytes balance of the blood
Ensuring proper blood pH
What prevents excessive water loss in urine?
Anti-diuretic hormone
Main target of Antidiuretic hormone
Kidneys collecting ducts
What causes water to move from one compartment to another
Very small changes in electrolyte concentrations in various fluid compartments
Blood pH
7.4
How can lungs dispose of carbonic acid?
Eliminating carbon dioxide
What happens if blood pH rises?
Bicarbonate ions are excreted and hydrogen ions are retained by the tubule cells
What happens if blood pH falls?
Bicarbonate ions are reabsorbed and generated and hydrogen ions are excreted
Urine pH
4.5-8.0
Fundamental functions of renal excretion
Filtration
Reabsorption
Secretion
Kidney dialysis
The process of removing waste and excess fluid from the blood using an artificial kidney machine which filters or washes the blood
