Functions of the Cardio-Respiratory System

The cardio-respiratory system consists of two main parts: the cardiovascular system which circulates blood, and the respiratory system which oxygenates blood and removes carbon dioxide.
The main function of the cardiovascular system is to transport nutrients, gases and waste products around the body, to protect from disease and to regulate the body temperature and pH.
The heart is a key organ in the cardio-respiratory system. Its job is to pump oxygenated blood around the body to all the working tissues.
This oxygen and nutrient rich blood supply is required by the body’s cells for aerobic respiration; a process which produces the energy required for all bodily functions and physical activity.
The circulatory system also transports hormones, which are chemicals produced by different organs to regulate body functions.
The respiratory system has the main function of getting oxygen from the air we breathe into the bloodstream, and getting rid of carbon dioxide, which is a waste product of the cells.
This is achieved through a process called gaseous exchange which occurs in the lungs, specifically in tiny air sacs called alveoli.
When we exercise, our muscle cells need more energy. This means that both the cardiovascular and respiratory systems need to work harder to supply more oxygen and nutrients, and to remove waste products more quickly.
The cardiovascular and respiratory systems work together to maintain a stable internal environment in the body – one of the main principles of homeostasis.
Both of these systems are capable of adapting to the ongoing demands placed on them. For example, regular exercise will improve the efficiency and capacity of these systems.
Important terms to remember: Cardiac output (the amount of blood the heart pumps through the circulatory system in a minute), stroke volume (the amount of blood pumped out of the heart per beat), heart rate (number of heart beats per minute), arteries (blood vessels which carry blood away from the heart), veins (blood vessels that carry blood towards the heart), capillaries (tiny blood vessels), oxygen uptake (amount of oxygen muscle can extract from blood), and also familiarise yourself with common diseases and disorders.

Remember, understanding these functions and how they relate to physical activity is crucial in answering questions about the cardio-respiratory system’s role in exercise and overall health.