Term
| Kidneys - function and purpose |
|
Definition
– make urine
– help maintain homeostasis in the body by manipulating the composition of the blood plasma (ex: body acid-base, fluid-electrolyte balances)
– filter waste products out of the bloodstream, allow elements needed by the body to stay in the bloodstream |
|
|
Term
| ureters - function and purpose |
|
Definition
| - carry urine to urinary bladder |
|
|
Term
| urinary bladder - function and purpose |
|
Definition
| - collects, stores, and releases urine |
|
|
Term
| urethra. - function and purpose |
|
Definition
|
|
Term
| Main processes by which the kidneys maintain homeostasis: |
|
Definition
- blood filtration, reabsorption, and secretion
- fluid balance regulation
- acid-base balance regulation
- hormone production |
|
|
Term
|
Definition
| the basic functional unit of the kidney |
|
|
Term
|
Definition
- to regulate water and soluble matter (esp electrolytes) in the body
- does this by filtering the blood under pressure, reabsorbing necessary fluid and molecules back into the blood, while secreting other unneeded molecules |
|
|
Term
| List the components of the nephron, in order as urine flows through them. |
|
Definition
Renal corpuscle
Proximal convoluted tubule
Loop of Henle
Distal convoluted tubule |
|
|
Term
| Proximal convoluted tubule (PCT) |
|
Definition
- a continuation of the capsular space of Bowman’s capsule
- the longest part of tubular system of the nephron
- lined w/ cuboidal epithelial cells that have a brush border (1000s of tiny projections of cell membrane) on their lumen side
- brush border increases the cellular surface area exposed to the fluid in the tubule by a factor of about 20. this is esp important to the PCT’s reabsorption/secretion fxns.
- PCT follows a twistin path through cortex
- The tubular filtrate (or primitive urine)(prev called the glomerular filtrate) behins trip thru tubular part of nephron in the PCT |
|
|
Term
|
Definition
- continues from PCT, descends into medulla of kidney, makes a u-turn, and heads back up into the cortex
- the descending part of the LOH has epi cells similar to the PCT cells, incl brush border
- as it makes its u-turn, the wall becomes thinner and the epi cells flatten to simple squamous epithelial cells and lose their brush border, lumen gets narrower
- LOH ascends back up into the cortex, wall becomes thicker again but cells don’t regain brush border
- Lumen expands as the LOH ascends toward the cortex |
|
|
Term
|
Definition
- a continuation of the ascending part of the loop of Henle
- follows a twisting path through the cortex
- although it is called a convoluted tubule, the DCT is not as twisted as the PCT
- the DCT from all the nephrons empty into a series of tubules called collecting ducts
- the CDs carry tubular filtrate through the medulla and eventually empty into the renal pelvis that will become the ureter
- they also play an important role in urine volume, because they are the primary site of action of antidiuretic hormone.
- Potassium regulation and acid-base balance control are 2 other important fxns that take place in the collecting ducts |
|
|
Term
| What are the 3 basic processes a nephron uses to form urine? IOW |
|
Definition
Filtration of the blood
Reabsorption of useful substances back into the bloodstream
Secretion of waste products from the blood into the tubules of the nephron |
|
|
Term
| List the blood components that cannot be kept in balance if the kidneys fail. |
|
Definition
| Electrolytes, nitrogenous wastes |
|
|
Term
| What is the GFR and why is it important to kidney function? |
|
Definition
Glomerular filtration rate
– the term used to describe how fast plasma is filtered as it passes through the glomerulus.
– The GFR depends on the rate of blood flow (and thus plasma flow) to the kidnet, expressed in ml/min.
– ~ 25% of the plasma is removed from circulation each minute.
– Another mechanism, reabsorption, is used to reduce the volume of glomerular filtrate |
|
|
Term
|
Definition
6 basic steps
- blood enters glomerulus via the afferent glomerular arteriole
- high BP in the glomerular capillaries forces some plasma (minus lg proteins and blood cells) out of the capillaries and into the capsular space of Bowman’s capsule. Fluid known as glomerular filtrate. From there, it moves into the proximal convuluted tubule and is then called tubular filtrate
- balance of the plasma not forced out of the glomerular capillaries leaves the glomerulus via the efferent glomerular capillaries and enters a peritubular capillary network around the rest of the nephron.
- while the tubular filtrate travels through the tubules of the nephron, some of its useful substances are reabsorbed back into the peritubular capillaries
- waste products are secreted back from the peritubular capillaries into the tubular filtrate as it travels through the tubules.
- by the time the tubular filtrate reaches the collecting ducts, it has decreased in volume, has changed chemical composition many times, , and is now ready to leave the kidney on its way to being eliminated. When the tubular filtrate enters the renal pelvis, it is urine, and nothing more will be done to alter its composition. (One exception here is that mucus may be added to horse urine after it reaches the renal pelvis) |
|
|
Term
| How much kidney function must be lost before renal dysfunction is evident? |
|
Definition
| 2/3 of the total nephrons in both kidneys must be nonfunctional before clinical signs of renal dysfunction start to become evident |
|
|
Term
| How is renal damaged classified and categorized? |
|
Definition
Renal damage
- prerenal
- renal
- postrenal
Renal failure
- acute
- chronic
- end-stage |
|
|
Term
|
Definition
| used to remove excess extracellular fluid by increasing urine flow and sodium excretion and reduing hypertension |
|
|
