Collagen.
A fluid connective tissue knwon as Blood carries oxygen and food
Your pulse rate increases when you exercise because your heart is pumping faster. Your heart is trying to provide your tissue with more oxygen as your muscles will require more oxygen when you're being active.
Red blood cells
In the lungs, oxygen saturation of hemoglobin is close to 100% due to high oxygen levels in alveoli. In exercising tissue, oxygen saturation can drop to around 70-75% as oxygen is released to supply energy for muscle contraction.
The heart is the muscle that functions as the circulatory pump within the body. It is responsible for pumping blood throughout the circulatory system to deliver oxygen and nutrients to the body's tissues and organs.
Heart disease can affect body tissues by decreasing the amount of oxygen available for metabolism. For example, CHF may lead to fatigue because the heart is pumping less effectively.
The heart is an organ made up of cardiac muscle tissue, nerve tissue, and blood vessel tissue. It is responsible for pumping blood throughout the body, delivering oxygen and nutrients to cells and removing waste products.
the heart pumps oxygenated blood round the body so that the muscles get oxygen to help them be used in energetic exercises
atrial and ventricular systole occur at the same time
Myoglobin acts as an oxygen reserve in muscle tissue. It is a protein that binds to oxygen and releases it when needed during periods of low oxygen availability, such as during exercise.
Muscular tissue is found throughout the body, attached to bones for movement (skeletal muscle), around internal organs for contraction (smooth muscle), and making up the heart for pumping blood (cardiac muscle).
The circulatory system is responsible for delivery of oxygen and nutrients to the tissue in the organs. All cells in the body require oxygen for cellular reactions. This oxygen, along with the biomolecules from the foods we eat, are used to produce energy. The heart is also a part of this system. The heart is responsible for retrieving deoxygenated blood, pumping it to the lungs and then sending it through the arteries throughout the body.