Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key


Play button


Play button




Click to flip

18 Cards in this Set

  • Front
  • Back
Function of the
Urinary System
regulate volume, electrolyte composition, pH of the internal environment
Components of the
Urinary System
- pair of kidneys: forms urine
- pair of ureters: carries urine to the urinary bladder
- urinary bladder: stores urine
- urethra: empties the bladder of urine
Function of the
- Maintaining H2O balance in the body

- Regulating the quantity and concentration of most extracellular (ECF) fluid ions

- Maintaining proper plasma volume

- Helping maintain proper acid-base balance of the body

- Maintaining the proper osmolarity of body fluids

- Excreting the end products of bodily metabolism such as urea and uric acid

- Excreting foreign compounds such as drugs, food additives, pesticides

- Secreting erythropoietin, a hormone that stimulates red blood cell production

- Secreting renin, a hormone important in salt conservation by the kidneys

- Converting vitamin D into its active form
Blood enters the kidney via:

Blood leaves the kidney via:
- rernal artery

- renal vein
Define nephron.
def. functional unit of the kidney
- consists of 3 components:
+ vascular component
+ tubular component
+ combined vascular/
tubular component
3 components of a nephron
- vascular component
- tubular component
- combined vascular/tubular component
Parts of the Vascular Component
- Afferent arteriole : brings blood to the glomerulus

- Glomerulus : tuft of capillaries that filters plasma into the tubular component

- Efferent arteriole : carries blood from the glomerulus; only arteriole in body post capillary

- Peritubular capillaries : supply the renal tissue; involved with exchanges with tubular lumen
Parts of the Tubular Component
- Bowman’s capsule - collects the glomerular filtrate

- Proximal tubule - uncontrolled reabsorption and secretion of selected substance

- Loop of Henle - establishes osmotic gradient that is important for concentrating urine

- Distal tubule and collecting duct - variable control of Na+ and H2O reabsorption and K+ and H+ secretion
Parts that are Combined Tubular and Vascular Components
Juxtaglomerular apparatus:
- region where the glomerulus and the ascending limb of the Loop of Henle are close to each other
- also region where ascending limb passes through the fork formed between the affereent and efferent arteriole
- secretes substances involved in the control of kidney function.
2 layers composing the kidney
- renal cortex : outer, granular layer
- renal medulla: inner, striated appearing
2 types of nephrons
1) cortical nephron
- 80%
- glomeruli located in outer layer of the cortex
2) juxtamedullary nephron
- 20%
- Glomeruli located in inner layer of renal cortex
- Loop of Henle present
3 Processes in the
Formation of Urine
1. Glomerular filtration – nondiscriminant filtration (except for red blood cells) of a protein-free plasma from the glomerulus into the Bowman’s capsule
2. Tubular reabsorption - selective movement of filtered substances from the tubular lumen into the peritubular capillaries
3. Tubular secrtetion - selective movement of nonfiltered substances from the peritubular capillaries into the tubular lumen
Of the 180 liters of plasma filtered per day, how much is reabsorbed?
178.5 liter
3 Layers of the
Glomerular membrane
1. Wall of the glomerular capillaries
- consists of large pores called genestrae
- >100 x permeable to H20 & solute than other capillaries

2. basement membrane : acellular gelatinous layer
- consists of collagen to provide structural support & glycoproteins which is negatively charged, repelling proteins(ex. albumin)

3. inner layer of Bowman's capsule
- consist of podocytes that intertwine w/foot processes to form filtration slits
3 physical forces involved in glomerular filtration
(1) glomerular capillary blood pressure : the fluid pressure exerted by blood within the glomerular capillaries (favors filtration)
*most susceptible to changes for GFR

(2) plasma-colloid osmotic pressure
- caused by unequal distribution of plasma proteins across the plasma membrane. H2O wants to move down osmotic gradient from Bowman’s capsule into glomerulus (opposes filtration)

(3) Bowman’s capsule hydrostatic pressure
- the fluid pressure exerted by filtrate in the Bowman’s capsule (opposes filtration)
Factors affecting Glomerular filtration Rate (GFR)
1) the net filtration pressure
2) the amount of glomerular surface area available for penetration
3) the permeability of the glomerular membrane
2 Mechanism of GFR regulation
1) Sympathetic Control - involves baroreceptor reflex

2) Autoregulation
In glomerular filtration, what percentage of plasma is filtered and where are the destination of each type of plasma (filtered or unfiltered)?
1) 20% filtered; excreted as urine
2) 80% unfiltered; exit via efferent arteriole to the venous system