Valves ensure blood flows toward your heart. Vein valves work to bring the blood that flowed down via arteries back up to your heart.
Allan already had a heart attack and can try to prevent another one by changing the diet, exercising, or even quit smoking, but there are non-modifiable risks such as age, sex and generic heritage, so If Allan is over 40 years old, male or comes from a family with heart diseases, Allan needs to be extra careful because those factors cannot be changed no matter how the way of life is changed.
Capillaries<span> are </span>small<span>, thin </span>blood vessels<span> that connect the </span>arteries<span> and the veins. Their thin walls allow oxygen, nutrients, carbon dioxide and waste products to pass to and from the tissue cells.</span>
Your answer is B "Pituitary"
Brainliest Please
