How Oxygen is Transported in the Blood and how Physiological Measurements can be Applied

Oxygen Transport in Blood

Oxygen is carried in the blood in two main ways: bound to haemoglobin within red blood cells and dissolved directly in blood plasma.

Red Blood Cells (RBCs) are specially adapted to carry oxygen around the body. Each RBC contains millions of haemoglobin molecules.
Haemoglobin is a protein containing iron that gives RBCs their red colour. Haemoglobin can bind to oxygen and forms oxyhaemoglobin when in regions of high oxygen concentration such as the lungs.
This oxygen-bound haemoglobin (oxyhaemoglobin) is carried to tissues around the body where oxygen levels are lower. Here, the haemoglobin releases the oxygen, reverting back to its deoxygenated form.
A small amount of oxygen stays dissolved directly in the blood plasma. Even though this is only about 2% of the total oxygen transport, it’s important for regulation of breathing rate.

Physiological Measurements and Their Applications

Physiological measurements are key for assessing overall health, fitness levels, and progression or status of various diseases. The correct interpretation of these measurements can help in the diagnosis and management of health problems.

Heart Rate: This is the number of times the heart beats in one minute. Normal resting heart rate for a healthy adult ranges between 60-100 beats per minute. Lower resting heart rates often signal better cardiovascular fitness and heart function.
Blood Pressure: Measured as systolic pressure over diastolic pressure, this indicates the pressure exerted on artery walls during (systolic) and between (diastolic) heartbeats. Normal blood pressure typically falls below 120/80 mmHg. Regular measurement is crucial in diagnosing and monitoring hypertension.
Respiratory Rate: This is the number of breaths taken in one minute. A healthy adult usually has a respiratory rate between 12-20 breaths per minute. Changes might indicate respiratory or metabolic disease.
Oxygen Saturation: Using a device called a pulse oximeter, this measures the percentage of haemoglobin saturated with oxygen. A healthy individual should typically have an oxygen saturation of 95-100%. Lower levels may indicate various health issues, such as lung diseases.

Measurement of these physiological parameters can be used in various fields: sports science to monitor athlete performance, clinical settings to monitor patient health status, and in research to investigate the effects of interventions on human physiology.