Like other muscles, it needs oxygen and nutrients to function. The heart receives its oxygen and nutrients from blood pumped from a large blood vessel called the aorta, through smaller blood vessels called arteries (coronary arteries), then through even smaller vessels called arterioles and capillaries.ike other muscles, it needs oxygen and nutrients to function. The heart receives its oxygen and nutrients from blood pumped from a large blood vessel called the aorta, through smaller blood vessels called arteries (coronary arteries), then through even smaller vessels called arterioles and capillaries.
What is PDF? Portable Document Format (PDF) is a file format used to present and exchange documents reliably, independent of software, hardware, or operating system. Invented by Adobe, PDF is now an open standard maintained by the International Organization for Standardization (ISO).
PDF Today. Today, PDF is an open standard maintained by the International Organization for Standardization (ISO). The format has expanded over the years and now PDF files can contain elements including links, form fields, audio and can also be signed electronically to collect e-signatures that are legally binding.