Anatomy and Physiology 1 FINALS

• The skeletal system provides support and structure to the body, protects internal organs, and allows for movement.
• The heart is approximately the size of a fist and is located on the superior surface of the diaphragm, left of the midline, anterior to the vertebral column, and posterior to the sternum

  
• The coverings of the heart include the pericardium, which is a double-walled sac composed of a superficial fibrous pericardium and a deep two-layer serous pericardium
• The pericardium protects and anchors the heart, prevents overfilling of the heart with blood, and allows for the heart to work in a relatively friction-free environment
• The heart wall consists of the epicardium (visceral layer of the serous pericardium), myocardium (cardiac muscle layer), fibrous skeleton of the heart (connective tissue), and endocardium (endothelial layer of the inner myocardial surface)
• Vessels returning blood to the heart include the superior and inferior venae cavae, right and left pulmonary veins, while vessels conveying blood away from the heart include the pulmonary trunk, which splits into right and left pulmonary arteries, and the ascending aorta with its branches
• The coronary circulation is the functional blood supply to the heart muscle itself, with collateral routes ensuring blood delivery to the heart even if major vessels are occluded
• Heart valves ensure unidirectional blood flow through the heart, with atrioventricular (AV) valves lying between the atria and the ventricles to prevent backflow when ventricles contract, and semilunar valves preventing backflow of blood into the ventricles
• The pathway of blood through the heart and lungs involves the right atrium, tricuspid valve, right ventricle, pulmonary semilunar valve, pulmonary arteries, lungs, pulmonary veins, left atrium, bicuspid valve, left ventricle, aortic semilunar valve, and aorta for systemic circulation
• The cardiac cycle includes systole (contraction) and diastole (relaxation), with phases like ventricular filling, ventricular systole, isovolumetric contraction, ventricular ejection, isovolumetric relaxation, and the dicrotic notch
• The heart and lungs diagram

  
• Diagram of the layers of the heart

  
• Illustration of the heart

  
• Labeled diagram of the posterior view of the heart

  
• Labeled diagram of the human heart

  
• Illustration of the heart's coronary arteries

  
• The coronary sinus and the great cardiac vein

  
• Cross-sectional view of the heart showing the interior of the right ventricle and the right atrium

  
• Diagram showing the atrioventricular valves

  
• Image of the semilunar valves in the heart

  
• Illustration of the mitral valve

  
• Blood vessels are channels that carry blood throughout the body, forming a closed loop that begins and ends at the heart
• The circulatory system consists of the heart, vessels, and blood vessels, with the human body containing about 60,000 miles of blood vessels
• Three types of blood vessels: arteries carry blood away from the heart, veins carry blood back toward the heart, and capillaries connect arteries and veins
• Arteries are strong, muscular vessels that carry oxygen-rich blood from the heart to the body, handling a large amount of force and pressure but not carrying a large volume of blood
• Arteries branch into smaller vessels called arterioles, which are very flexible and help maintain the body's blood pressure
• Capillaries, the smallest blood vessels, have thin walls allowing for the exchange of oxygen, nutrients, carbon dioxide, and waste products between the blood and tissues
• Veins carry deoxygenated blood back to the heart, with thin, less elastic walls to handle high volumes and low pressure, and most veins have valves to control blood flow
• Blood vessels have three layers of tissue: tunica intima, media, and adventitia, each serving different functions in regulating blood flow and providing structure and support
• Vasa vasorum are small blood vessels that supply the walls of larger arteries and veins, ensuring their nourishment when diffusion through the lumen becomes insufficient
• Vascular nerves (nervi vasorum) control vasodilation and vasoconstriction, regulating temperature and homeostasis in blood vessels
• Conditions affecting blood vessels include aneurysms, arterial diseases like atherosclerosis, blood clots, high blood pressure, Raynaud's disease, varicose veins, vascular malformations, vasculitis, with risk factors including age, weight, smoking, and family history
• Hemodynamics refer to how blood flows through arteries and veins, with factors like vessel size, friction, expansion, and contraction affecting blood flow efficiency
• Hemodynamic factors include vessel size, friction, vessel expansion and contraction, pressure differences, cardiac output, heart rate, and ventricle function, all influencing blood flow to organs and tissues
• Neurons are the basic functional units of the nervous system, receiving and transmitting signals to different parts of the body

  
• Neurons consist of a body (soma) and processes (neurites), with the nerve cell body where neural impulses (action potentials) are generated
• Axons are long and conduct impulses away from the neuronal body, while dendrites are short and receive impulses from other neurons, conducting the electrical signal towards the nerve cell body
• Efferent neurons (motor or descending) send neural impulses from the CNS to peripheral tissues, while afferent neurons (sensory or ascending) conduct impulses from peripheral tissues to the CNS
• Neurons function through synapses where neurotransmitters are released from axons to trigger responses in effector cells according to CNS orders
• Glial cells, located in the central and peripheral nervous systems, provide physical and chemical support to neurons and maintain their environment