CHAPTER 1: Fluids & Electrolytes / Acid–Base Balance 💧 Anatomy & Physiology Study Guide (Easy to Understand)

What percentage of the human body is made of water?

About 60%.

What is homeostasis?

The balance of water, electrolytes, and pH in the body.

Which organ is MOST responsible for fluid and electrolyte balance?

Kidneys.

What are the main functions of electrolytes in the body?

To send nerve signals, contract muscles, maintain heartbeat, balance fluids, and regulate blood pressure.

What is the normal blood pH range?

7.35–7.45.

What does acidosis mean in terms of blood pH?

Blood pH is below 7.35.

What does alkalosis mean in terms of blood pH?

Blood pH is above 7.45.

What is the bicarbonate buffer?

The most important buffer that consists of bicarbonate (HCO₃⁻) and carbonic acid (H₂CO₃), working within seconds to stabilize blood pH.

Where are the main electrolytes found in intracellular fluid (ICF)?

Potassium (K⁺), Magnesium (Mg²⁺), and Phosphate (PO₄³⁻).

Where are the main electrolytes found in extracellular fluid (ECF)?

Sodium (Na⁺), Chloride (Cl⁻), Calcium (Ca²⁺), and Bicarbonate (HCO₃⁻).

What hormone is also called vasopressin?

ADH (Antidiuretic Hormone).

What is the primary function of aldosterone?

To keep sodium and increase blood pressure.

What does ANP do when blood volume increases?

It removes sodium and water, lowering blood pressure.

What causes dehydration?

Causes include vomiting, diarrhea, sweating, fever, and not drinking enough water.

What are common symptoms of overhydration?

Headache, nausea, confusion, muscle weakness, and seizures (if severe).

What bodily function does calcium help with?

Strong bones, muscle contraction, blood clotting, and nerve function.

What is the main organ that controls blood pH?

Kidneys.

What is the RAAS system?

A hormone system that raises blood pressure when it gets too low.

What happens during overhydration?

There is too much water in the body, which can dilute sodium levels.

What do buffers do in the body?

They stop the blood from becoming too acidic or too basic.

What happens if there is too much potassium in the blood?

It can cause dangerous arrhythmias and cardiac arrest.

What function does sodium (Na⁺) serve in the body?

It controls water balance, blood pressure, and helps nerves send signals.