Our tireless urinary system acts as a filtration factory, keeping our blood clean. The two bean-shaped kidneys, located just below the ribcage, are the stars of the show. Millions of microscopic filtering units called nephrons within each kidney work overtime. Blood travels through these nephrons, where waste products like urea, a byproduct of breaking down proteins, and excess water are separated out. Essential elements and water are meticulously reabsorbed back into the bloodstream, while the leftover liquid waste becomes urine. Thin tubes called ureters, one for each kidney, then act as pipelines, transporting the urine down to the bladder. The bladder, a muscular sac in the lower abdomen, acts as a reservoir, comfortably storing urine until you feel the urge to eliminate it. When it's time, muscles in the bladder contract, and urine travels down the urethra, a tube leading out of the body, to be voided.

1. The Urinary/Excretory
System, Fluid, Electrolytes,
and Acid-Base Balance
SED SCI 212: Anatomy and Physiology

2. Learning Objectives:
a)Recall the Gross Anatomy of Urine
Transport and Kidney
b)Explain the components and functions of
the urinary system and how it regulates
fluid, electrolyte, and acid-base balance.
c)Identify Disorders of the Urinary System

3. 1.1 The Urinary/Excretory System

4. Numerous metabolic
processes occurring within various
cells of the body give rise to a
plethora of waste products. The
urinary system, by filtering and
purifying the blood that passes
through the kidneys, rids the body
of these waste substances.

5. Furthermore, the urinary system is
instrumental in regulating the
volume, acidity, salinity, concentration,
and chemical composition of blood, lymph,
and other bodily fluids. Guided by
hormones, the kidneys continually
monitor the substances they release into
urine to maintain a healthy chemical
equilibrium.

6. Any signs of urinary issues should
be promptly reported, as disorders
within this system can be subtle.

7. Four (4) Components of the Urinary System

8. 1.Kidneys: These
bean-shaped organs
filter blood to remove
waste and excess
substances, forming
urine.

9. 2. Ureters: Tubes
that carry urine
from the kidneys
to the bladder.

10. 3. Bladder: A
muscular sac that
stores urine until it
is ready to be
expelled.

11. 4. Urethra: A
tube that carries
urine from the
bladder out of the
body

12. Kidney Structure and Function

14. The kidneys sit at the back of the
abdominal wall and at the start of
the urinary system. These organs are
constantly at Work:
 Nephrons, tiny structures in
the renal pyramids, filter
Gallons of blood each day.
 The kidneys reabsorb vital
Substances, remove unwanted
ones, and return the filtered
Blood back to the body.
 As if they weren’t busy
enough, the kidneys also
create urine to remove all the
waste.

19. Two (2) Primary
Functions of the Kidney:
1. Filtration
2. Regulation

20. Formation and
Transportation of
Urine in the Urinary
System

21. Formation of
the Urine

22. 1. Filtration
2. Reabsorption
3. Secretion
Formation of the Urine

24. Transportation
of the Urine

25. 1.Collection
2. Ureter
3. Bladder
4. Urethra
Transportation of the Urine

26. 1.2 FLUID BALANCE

27. The Significance of Maintaining
Proper Fluid Balance

28. • Cellular Function
• Blood Pressure Regulation
• Thermoregulation
• Nutrient Transport
The Significance of Maintaining
Proper Fluid Balance:

29. The Role of the Kidneys in Regulating
Fluid Levels:
1.Filtration
2.Reabsorption
3.Excretion
4.Hormonal Regulation

30. In summary,proper fluid balance s essential for
maintaining health and homeostasis in the body. The
kidneys, through their filtration, reabsorption, and
excretion functions, play a pivotal role in achieving
and sustaining this balance. They ensure that the
body retains adequate fluid when needed and
eliminates excess fluids when the body is adequately
hydrated, contributing to the stability of the body’s
internal environment and supporting various
physiological functions.

31. 1.3 ELECTROLYTES BALANCE

32. Electrolytes are essential
minerals in the body that carry
an electric charge. They play a
crucial role in various
physiological functions and are
vital for maintaining health.
Electrolytes are primarily found
in bodily fluids such as blood,
urine, and sweat.
What are Electrolytes?

33. Role of Electrolytes in the Body:
• Nerve Function
• Muscle Function
• Fluid Balance
• Acid-Base Balance

34. Electrolyte Regulation:
Selective Reabsorption: As blood is filtered through
the kidneys, electrolytes are selectively reabsorbed or
excreted based on the body’s needs. The kidneys
regulate the balance of key electrolytes like sodium,
potassium, calcium, and chloride through this process.
Hormonal Control: Hormones, such as aldosterone,
influence electrolyte balance by affecting the
reabsorption or excretion of specific ions. For example,
aldosterone prompts the kidneys to reabsorb sodium and
excrete potassium.

35. Common Electrolytes:
1. Sodium (Na+):
 Role: Sodium is essential for maintaining fluid balance, nerve
function, and muscle contractions.
 Imbalance: High sodium levels can lead to hypertension,
while low levels can result in hyponatremia.
2. Potassium (K+):
 Role: Potassium is vital for normal heart rhythm, muscle
function, and nerve signaling.
 Imbalance: Elevated potassium levels (hyperkalemia) can
lead to cardiac arrhythmias, while low levels (hypokalemia)
can cause muscle weakness.

36. 3. Calcium (Ca2+):
Role: Calcium is necessary for bone health, blood
clotting, muscle function, and nerve transmission.
Imbalance: High calcium levels can lead to kidney
stones, while low levels can result in muscle cramps
and osteoporosis.
4. Chloride (Cl-):
Role: Chloride is closely associated with sodium and
helps maintain fluid balance and regulate pH.
Imbalance: Abnormal chloride levels can affect
acid-base balance in the body.

37. In summary, electrolytes are critical
minerals that play pivotal roles in various
physiological processes, including nerve and
muscle function, fluid balance, and pH
regulation. The kidneys, through their selective
reabsorption and excretion mechanisms,
ensure that electrolyte balance is maintained
within narrow, healthy ranges, contributing to
overall homeostasis in the body.

38. 1.4 ACID-BASE BALANCE

39. ACID-BASE BALANCE:
Maintaining the right
balance between acidity
and alkalinity in the
body’s fluids is critical
for normal function.
Think of it like
maintaining the right
temperature in your
home – not too hot, not
too cold.

40. Why It Matters?
1.Enzymes: Just like the right temperature is
needed for your oven to cook food properly, the
right pH is needed for enzymes in your body to
work correctly.
2.Cell Function: Cells need the right pH to do
their jobs. If it’s too acidic or too alkaline, cells
can’t function properly.
3.Breathing and Heart: Your body’s pH affects
your breathing and heart rate. An imbalance
can mess things up.

41. Kidney’s Role:
Your kidneys act like the body’s pH managers:
1.Acid Excretion: If your blood is too acidic,
they help by getting rid of extra acid in your
pee.
2.Bicarbonate Reabsorption: If your blood is
too alkaline, they bring back bicarbonate ions
from your pee into your bloodstream to
balance things out.

42. In simple terms, your kidneys are
like the body’s pH controllers, making
sure the body’s acidity or alkalinity stays
just right for everything to work
properly. When things get too far off
balance, you can feel unwell, much like
when your home is too hot or too cold.

43. 1.5 COMMON DISORDER OF
THE URINARY SYSTEM

44. 1. Urinary Tract Infections (UTIs):
 Identification: UTIs are bacterial infections that can affect
any part of the urinary system, including the bladder
(cystitis) or kidneys (pyelonephritis).
 Causes: Bacterial invasion is often the root cause, typically
from Escherichia coli (E. coli) bacteria.
 Symptoms: Frequent, painful urination, cloudy or bloody
urine, and lower abdominal discomfort.
 Treatment: Antibiotics are the primary treatment. Drinking
plenty of fluids and maintaining good hygiene can also help
prevent UTIs.

46. 2. Kidney Stones (Nephrolithiasis):
 Identification: Kidney stones are hard mineral deposits that
form in the kidneys and can obstruct the urinary tract.
 Causes: Factors like dehydration, diet, and genetic
predisposition can contribute to stone formation.
 Symptoms: Severe back or abdominal pain, blood in urine,
nausea, and vomiting.
 Treatment: Smaller stones may pass naturally with
increased fluid intake. Larger stones may require medical
intervention, such as lithotripsy (sound wave treatment) or
surgical removal.

48. 3. Renal Failure:
 Identification: Renal failure occurs when the kidneys are
unable to adequately filter waste and excess fluids from the
blood.
 Causes: It can result from various factors, including chronic
conditions like diabetes, high blood pressure, or acute events
like severe infections or injury.
 Symptoms: Fatigue, swelling, changes in urination patterns,
and imbalances in electrolytes.
 Treatment: Treatment varies depending on the type and
severity of renal failure, ranging from medication and dietary
changes for chronic kidney disease to dialysis or kidney
transplant for end-stage renal disease.

50. 4. Incontinence (Enuresis):
 Identification: Incontinence is the involuntary loss of urine,
often due to weakened bladder or pelvic floor muscles.
 Causes: Ageing, childbirth, nerve damage, or certain
medical conditions can contribute.
 Symptoms: Leakage of urine, ranging from mild to severe.
Treatment: Treatment options include lifestyle changes, pelvic
floor exercises (Kegels), medications, or surgical procedures,
depending on the underlying cause

52. Kangaroos have a remarkable
urinary/excretory system that sets them
apart from other animals? In their arid
Australian habitats, where water is
scarce, kangaroos have evolved unique
adaptations to conserve water. One key
adaptation is in their kidneys. Kangaroo
kidneys are specialized to concentrate
urine effectively, resulting in a waste
product that contains very little water.
This means they can excrete waste
without losing precious fluids
Did you know?

53. Thank You!