Human Physiology Overview

The relative constancy of the internal environment of the body.

The internal environment surrounding cells.

The liquid components within the body, including their volume, distribution, characteristics, and functions.

The percentage of water in the body varies significantly between individuals.

Body water acts as the medium for dissolving solutes and hosting metabolic reactions.

The process where glucose is broken down in the presence of oxygen to release energy (ATP), carbon dioxide, and water.

The balance between the intake and output of water in the body.

Water loss that is essential for body function and cannot be controlled, such as through respiration and urine.

Water loss that can be adjusted based on the body's needs, such as sweating.

Water loss that is noticeable, such as through urination and sweating.

Water loss that is not noticeable, such as through respiration and skin evaporation.

The kidneys regulate the amount of water excreted in urine, which helps maintain overall water balance in the body.

Sweating is a deliberate water loss to cool down the body and involves electrolytes, while insensible perspiration is passive water loss through the skin and lungs.

The concentration of a solution expressed as the number of moles of solute per liter of solution.

The concentration of a solution expressed as the number of moles of solute per kilogram of solvent.

The amount of a substance that will react with or replace one mole of hydrogen ions (H+).

The cell membrane acts as a barrier between the intracellular fluid (ICF) and the extracellular fluid (ECF).

The capillary wall acts as a barrier between the plasma and the interstitial fluid (ISF).

The internal environment immediately surrounding cells in the body. Think of it as the 'soup' where all the cells live and function.

A 70 kg male typically has 60% body water, which equals approximately 42 liters.

A 70 kg female typically has 50% body water, approximately 35 liters.

A stable state that is constantly adjusting to maintain balance, like the temperature in your house.

Dosage calculation for water-soluble medications considers body water volume.

Administering 100 mg to a 70 kg male results in a final concentration of about 2.4 µg/mL in the body.

Administering 100 mg to a 70 kg female leads to a final concentration of approximately 2.9 µg/mL.

Processes that move substances across cell membranes, such as diffusion, osmosis, and active transport.

A quiz that tests your understanding of the concepts covered in a particular section of the course.

29 µg (micrograms) is equal to 29 x 10⁻⁶ grams.

The fluid that circulates throughout the body, carrying oxygen, nutrients, and waste products.

0.0029 mg is equivalent to 2.9 µg (micrograms).

For a 70 kg elderly female with 45% body water, administering 100 mg results in 3.2 µg/mL.

A 70 kg very thin male with 75% body water (52.5 L), a 100 mg dosage yields 1.9 µg/mL.

A 7 kg infant with 75% body water (5.25 L), 10 mg treatment leads to 1.9 µg/mL.

Body water remains constant (dynamic steady state) due to internal water fluctuations between compartments and the surrounding environment.

Water intake (oral) comprises oral fluids, food, and water from metabolism.

Body water loss is through various routes, including urine and perspiration.

Understanding body water percentage is essential for accurately calculating drug dosages in water-soluble medications.

The volume of Intracellular Fluid (ICF) is calculated by subtracting the volume of Extracellular Fluid (ECF) from the total body water volume.

The volume of Interstitial Fluid (ISF) is calculated by subtracting the volume of Plasma from the volume of Extracellular Fluid (ECF).

Hematocrit refers to the percentage of blood volume occupied by red blood cells (RBCs).

Total blood volume can be calculated using the hematocrit value and the plasma volume.

Body fluids are primarily aqueous solutions containing inorganic ions with varying amounts of protein.

Extracellular Fluid (ECF) is rich in sodium (Na+) and chloride (Cl-) ions, but low in potassium (K+).

Intracellular Fluid (ICF) is high in potassium (K+) and magnesium (Mg++) but low in sodium (Na+) and chloride (Cl-) ions.

Artificial solutions like physiological saline, Ringer's solution, and Locke-Ringer solution are used to mimic the composition of body fluids and can be used to replace plasma or ISF.