Urine is formed in the kidneys through filtration of blood. The urine is then passed through the ureters to the bladder, where it is stored. During urination, the urine is passed from the bladder through the urethra to the outside of the body.

1. Urine Formation
B A S I C S O F B I O M E D I C A L
P R E P A R E D B Y A T H E E N A P A N D IA N

2. 01
Urinary System
Functions
Steps
Mechanism
1.
2.
3.
4.
Key Discussion Points
Tableof
Contents

3. The purpose of the urinary
system is to eliminate waste
from the body, regulate
blood volume and blood
pressure, control levels
of electrolytes and
metabolites, and regulate
blood pH. 02
UrinarySystem

4. 03
Each kidney
consists of
functional units
called nephrons.

5. 04
EXCRETION
Following filtration of
blood and further
processing, wastes (in the
form of urine) exit the
kidney via the ureters

6. The female and male urinary system are very
similar, differing only in the length of the urethra

7. Function
Regulate blood volume and composition
(e.g. sodium, potassium and calcium)
Regulate blood pressure
Regulate pH homeostasis of the blood
Contributes to the production of red blood cells by
the kidney
Helps synthesize calcitrol the (active form
of Vitamin D)
Stores waste product (mainly urea and uric acid)
before it and other products are removed from the
body.
The main functions of the urinary system and its
components are to

8. Average urine production in adult humans is
about 1–2 litres (L) per day, depending on
state of hydration, activity level,
environmental factors, weight, and the
individual's health
Producing too much or too little urine
requires medical attention
Polyuria is a condition of excessive urine
production (> 2.5 L/day)
Oliguria when < 400 mL (millilitres) are
produced, and anuria one of < 100 mL per
day.
07
Urineformation

9. 08
Steps-FormationofUrine
1. The Glomerulus Filters
Water and Other
Substances from the
Bloodstream

10. 09
Steps
STEP 2
2. The Filtration Membrane Keeps Blood
Cells and Large Proteins in the
Bloodstream
STEP 3
3. Reabsorption Moves Nutrients and
Water Back into the Bloodstream

11. 10
STEP 4
4. Waste Ions and Hydrogen Ions
Secreted from the Blood Complete the
Formation of Urine
STEP 5
5. Urine Is 95% Water
STEP 6
6. Urine Excreted outside through
Urethra

13. 12
MechanismofUrineFormation

14. 13
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