The immune system fights off the pathogen by Leukocytes also known as white blood cells. When a pathogen enters the body the immune system becomes alert to it and sends out sends out the Phagocytes (a type of Leukocytes) which engulfs the pathogens.
The answer is the last option.) All of the above. When working out at a higher intensity, you burn more calories which can cause weight loss, increased heart rate giving you a stronger aerobic workout, and breathe more b=deeply due to the intensity of the workout.
Answer:
The circulatory system is divided into systemic circulation and pulmonary circulation.
Explanation:
Systemic circulation carries oxygenated blood from the left ventricle to the rest of the body while pulmonary circulation carries deoxygenated blood away from the right ventricle.