Which skin structures are responsible for fingerprints?

The left ventricle of the heart normally has the thickest wall, which is composed mainly of cardiac muscle tissue (myocardium). The left ventricle has to generate enough force to pump oxygen-rich blood to the rest of the body through the systemic circulation, which requires greater muscular effort than the right ventricle, which pumps blood only to the lungs via the pulmonary circulation. The thickness of the left ventricular wall ensures that it can withstand the pressure required to generate this forceful contraction.

Blood then carries them to target cells or organs throughout the body. Hormones are chemical messengers that help to regulate various physiological processes such as growth, metabolism, and reproduction. Unlike exocrine glands (option a), which secrete their products into ducts that carry them to external surfaces such as the skin or digestive tract, endocrine glands have no ducts and release their secretions directly into the circulatory system. Salivary glands (option d) are exocrine glands that secrete saliva into ducts leading to the mouth. Option b is also incorrect as it does not accurately describe endocrine glands.