Renal Physiology Flashcards
Kidney regulates the __________ of blood
Plasma
Renal (kidney) functions (5)
- Regulate our blood volume and pressure
- Maintain the acid-base balance
- Excrete waste products
- Synthesis of new glucose molecules to provide energy
- Secrete hormones
Primary function of renal(kidney)
Regulate our blood volume and pressure
- Maintain the water concentration and fluid volume
- Maintain the inorganic ion composition within a constant range
Example of waste products that the kidneys excrete
- urea
- uric acid
- creatinine
- bilirubin
- foreign chemicals
Example of hormones the kidneys secrete
- Erythropoietin (EPO): synthesized by fibroblasts in the kidney
- Renin
- 1,25- dihydroxyvitamin D: an active metabolite of Vitamin D
Kidneys regulate fluid volume, which affects ________________ and _______________
Blood volume and blood pressure
The function of the kidneys is to maintain the volume of the plasma within a very ______ range
narrow
Changes that occur where the plasma volume is affected happen due to the rapid movement of water form the plasma component by the process of __________
osmosis
Kidney regulates the extracellular fluid. What are the three extracellular fluid?
- plasma
- interstitial fluid
- cerebrospinal fluid
These ions have higher concentration in the extracellular fluid compartment (3)
- sodium
- chloride
- bicarbonate
These ions have higher concentration in the intracellular fluid compartment (2)
- potassium
- phosphate
__________ are specialized water-selective channels in the plasma membrane of cells. They are responsible for the rapid diffusion of water
Aquaporins
Water concentration does not just take into account the number of water molecules only but also the ___________________
solutes dissolved in the water
One _______ is equal to one mole of solute particle that is dissolved in water
Water concentration is always recorded in this
osmole
___________ is defined as the number of solutes per volume of solution expressed in moles per litre
Osmolarity
Pure water= high water concentration
The more solute, the more it will raise the osmolarity
A region of lower osmolarity has a _________ water concentration
higher
A region with higher osmolarity has a ______ water concentration as it contains more solute molecules
lower
In _________, solute molecules move from an area of higher concentration to an area of lower concentration due to random thermal motion
diffusion
This is the net diffusion of water across a selectively permeable membrane from a region of high water concentration to one with a lower water concentration
Osmosis
This is a membrane which is permeable to water but does not allow solutes to cross
Semi-permeable membrane
_____________ will push and prevent water from coming into the cell, to prevent them from taking on water and bursting.
Opposing pressure required to stop osmosis completely
Osmotic pressure
__________ is determined by the concentration of non-penetrating solutes of an extracellular solution.
Tonicity
3 classes of tonicity that one solution could have relative to another
- Isotonic solution
- Hypertonic solution
- Hypotonic solution
In this class of tonicity, the inside of the cell and the extracellular environment have the same osmolarity.
The cell volume or shape does not change
Isotonic solution
In this class of tonicity, the extracellular medium has a higher osmolarity than inside the cell
A living cell in this medium will shrink
Hypertonic solution
In this class of tonicity, the extracellular medium has a lower osmolarity that inside the cell.
A living cell in this medium will swell up or bulge out
Hypotonic solution
Water always flows from a region of _________ osmolarity to a region of _______ osmolarity
lower, higher
Movement of water and solutes from the interstitial fluid compartment to the plasma is called __________
absorption
Movement of water and solutes from the plasma to the interstitial fluid is called ____________
filtration
How does fluid move between the plasma and the interstitial fluid compartments?
- The capillary hydrostatic pressure pushes some of the fluid out of the capillary into the interstitial fluid
- Interstitial fluid hydrostatic pressure pushes fluid into the capillaries
Hydrostatic pressure
the pressure exerted by a fluid; every fluid has this property (Pc)
What is the contribution of the plasma proteins to fluid movement?
- Proteins are large and sometimes charged; cannot move in and out of capillaries easily
- Inside the plasma there are many plasma proteins and these plasma proteins contribute to the osmolarity
Osmotic force due to plasma protein concentration
- a lot pf plasma proteins means there are more plasma proteins in the plasma and less water concentration inside the capillary than outside the capillaries
- water will try to move into the capillary as these plasma proteins tend to pull water into the capillary
Osmotic force due to interstitial fluid protein concentration
- proteins do have a difficult time crossing the capillary, but some plasma proteins will escape and are found in the interstitial space
- these plasma proteins will try to draw fluid out of the capillary into the interstitial space
The net pressure determines the direction of fluid movement. How do you determine the net pressure?
Sum the two outgoing forces and subtract the two ingoing forces
The four factors that determine the net filtration pressure are termed the __________________
Starling forces
At the arterial end of a capillary, there’s more filtration of fluid as the net filtration pressure is positive; fluid moves _______ of the capillary
out
At the venule end of the capillary, there’s more absorption of fluid, as the net filtration pressure is negative; fluid moves _____ the capillary
into
Kidneys are ___________ in location (found behind the peritoneum)
retroperitoneal
What are the other structures associated with the urinary system? (3)
- ureters
- bladder
- urethra
This is the inner concave part of the kidney
Hilum
These drain the formed urine form the kidneys and empty into the bladder
Ureters
This is the storage organ or a sac for the formed urine.
This receives innervation from the autonomic nervous system; emptying of this is controlled by parasympathetic and sympathetic inputs
Bladder
Bladder empties out of the body through the _________
urethra
Micturition
the process of releasing the urine outside the body, or urination
2 regions of the kidney
Outer portion: cortex
Inner portion: Medulla
Nephron
- functional units of the kidney
- where the urine is made
- contains renal corpuscle and renal tubule
Renal corpuscle
bulb-like structure
Attached to the renal corpuscle is a long tube called the ______________
renal tubule
Urine starts forming in the ___________ which fuse together and form collecting ducts
nephrons
Collecting ducts empty their contents into the ______________
renal pelvis
The formed urine enters into the ureter to be taken away to the ___________
bladder
This part of the nephron is a cup-like shaped structure with a tuft (loops) of capillaries.
The glomerulus and the Bowman’s capsule is known as this
Renal corpuscle
What are the renal tubule segments
- proximal convoluted tubule
- Loop of Henle (descending and ascending limbs)
- distal convoluted tubule
- collecting ducts
This segment of renal tubule is close to the renal corpuscle
proximal convoluted tubule
The distal convoluted tubule drains its contents into a main tube called the ________________
collecting duct
This is the initial blood filtering component of a nephron
Renal corpuscle
_____________ are cells closest to which come in contact with the glomerular capillaries;
These cells have foot-like processes
Podocytes
What is the ultimate outcome of the development of the renal corpuscle?
Development of a hollow tube which becomes the Bowman’s cup and continues on as the tubule