Fluid and electrolytes

Question 1

Describe feedback mechanisms that regulate water intake

Answer 1

Thirst mechanism is the driving force for water intake
The hypothalamic thirst center osmoreceptors are
stimulated
* by a decline in plasma volume of 10-15%
* by increases in plasma osmolarity of 1-2%
* via baroreceptor input, angiotensin II and other
stimuli
Drinking water inhibits the thirst center
Inhibitory feedback signals: inhibit the thirst center as it
relieves a dry mouth and throat and activates stomach
and intestinal stretch receptor

Question 2

• Describe possible causes and consequences of dehydration.

Answer 2

Negative Fluid Balance: Causes and Effects

Causes of Negative Fluid Balance:

Hemorrhage
Severe burns
Prolonged vomiting or diarrhea
Profuse sweating
Water deprivation
Diuretic abuse

Signs and Symptoms:

Thirst
Dry, flushed skin
Oliguria (reduced urine output)
Potential Consequences:

Weight loss
Fever
Mental confusion
Hypovolemic shock
Loss of electrolytes
Summary:
Negative fluid balance occurs when water loss exceeds intake, commonly due to various factors. Recognizable signs and symptoms include thirst, dry skin, and reduced urine output. If unaddressed, it may lead to weight loss, fever, mental confusion, hypovolemic shock, and electrolyte imbalances.

Question 3

• Describe the importance of sodium in the body’s fluid and electrolyte balance, and indicate its relationship to normal cardiovascular system functioning.

Answer 3

Importance of Sodium:

Fluid Balance: Sodium plays a crucial role in maintaining the body’s overall fluid balance.
Electrolyte Balance: It is a key electrolyte, contributing to the balance of ions in bodily fluids.
Relationship to Cardiovascular System:

Blood Pressure Regulation: Sodium is integral to regulating blood pressure, a vital aspect of cardiovascular health.
Heart Function: Maintains proper heart muscle function, influencing the cardiovascular system’s overall performance.