what changes occur in the cardiovascular when you are participating in physical activity?
When participating in physical activity, several changes occur in the cardiovascular system to meet the increased demand for oxygen and nutrients by the muscles. These changes include:
1. Increased heart rate: The heart beats faster to pump more blood to the working muscles. This ensures that more oxygen and nutrients are delivered to the muscles and waste products, such as carbon dioxide, are removed.
2. Increased stroke volume: The amount of blood pumped by the heart with each beat (stroke volume) increases in response to physical activity. This further boosts the amount of blood, oxygen, and nutrients delivered to the working muscles.
3. Increased cardiac output: The overall volume of blood circulated through the body per minute (cardiac output) increases during physical activity. This is due to the combined effects of increased heart rate and increased stroke volume.
4. Redistributed blood flow: The blood vessels in the muscles dilate (widen), allowing more blood to flow to the working muscles. In contrast, blood vessels in non-essential organs such as the stomach and intestines constrict (narrow), reducing blood flow to those areas temporarily.
5. Increased oxygen extraction: As the blood delivers more oxygen to the working muscles, these muscles are able to extract and use more oxygen from the bloodstream.
6. Lower peripheral resistance: The body's blood vessels, particularly those supplying the muscles, are more effective at delivering blood during physical activity. This reduces the resistance the blood faces as it flows through the circulatory system.
7. Increased venous return: The movement of blood back to the heart (venous return) is enhanced during physical activity due to the action of skeletal muscles compressing veins and the rhythmic changes in pressure within the thoracic cavity.
These cardiovascular changes help to ensure that the body's muscles receive the necessary oxygen and nutrients to perform the physical activity while also allowing for efficient removal of waste products from the working muscles.