Endocrine System: The endocrine system is a network of glands that release hormones into the bloodstream to regulate processes like metabolism, growth, reproduction, and homeostasis.
Baroreceptor Reflex Flow Art: The baroreceptor reflex helps maintain blood pressure homeostasis by detecting changes in arterial stretch and triggering heart rate and vessel tone adjustments via the autonomic nervous system.
The Hematopoietic System of the Bone Marrow new: The bone marrows hematopoietic system consists of stem cells that differentiate into various blood cell types, providing a continuous supply of cells vital for immunity, oxygen transport, and clotting.
Renin Aldosterone Angiotensin: The renin-angiotensin-aldosterone system (RAAS) regulates blood pressure and fluid balance by promoting vasoconstriction and sodium retention in response to decreased blood volume or pressure.
Cardiac Cycle vs Heart Sounds: The cardiac cycle corresponds with heart sounds, where the “lub” (S1) is caused by AV valve closure during systole, and the “dub” (S2) marks semilunar valve closure during diastole.
Automatic Innervation: Autonomic innervation involves the sympathetic and parasympathetic nervous systems, which regulate involuntary functions like heart rate, digestion, and respiratory rate through motor neurons.
Dual System of Human Circulation: The human circulatory system has two circuits: the pulmonary circuit carries deoxygenated blood to the lungs, while the systemic circuit distributes oxygenated blood to the body.
Cardiac Cycle vs Electrocardiogram: The cardiac cycle represents mechanical heart activity, while the electrocardiogram shows its electrical activity; both correlate to diagnose rhythm and timing issues.
The Enzyme Renin Converts The Pro Enzyme Angiotensin I: Renin, secreted by the kidneys, catalyzes the conversion of angiotensinogen to angiotensin I, which is further converted to angiotensin II, a vasoconstrictor that raises blood pressure.
The Hypothalamus Controls Thermoregulation: The hypothalamus monitors body temperature and triggers responses like sweating or shivering to maintain homeostasis through its control of the autonomic nervous system.
Net Filtration Pressure: Net filtration pressure (NFP) is the balance of hydrostatic and osmotic pressures in the glomerulus, determining the movement of fluid into the nephron for urine formation.
Conduction System of Heart: The hearts conduction system includes the SA node, AV node, bundle of His, bundle branches, and Purkinje fibers, coordinating the electrical impulses that drive rhythmic contractions.
Factors in Cardiac Output: Cardiac output depends on stroke volume and heart rate, influenced by preload, afterload, contractility, and autonomic nervous system regulation.
Cardiac Conduction: The heart’s electrical system begins with the sinoatrial (SA) node, spreading impulses through the atria, to the atrioventricular (AV) node, and down the bundle branches and Purkinje fibers to coordinate contraction.
Neonatal Circulatory System: At birth, the neonatal circulatory system undergoes major changes as fetal shunts close and the lungs take over oxygen exchange, resulting in the adult-like pattern of blood flow.
Carbon Digestion: Carbohydrate digestion starts in the mouth with salivary amylase and continues in the small intestine with pancreatic enzymes, breaking polysaccharides into monosaccharides like glucose for absorption.
Action Potential Heart Contraction: A cardiac action potential initiates when the SA node fires, spreading electrical impulses that trigger calcium influx, leading to coordinated contraction of the atria and ventricles.
Blood Flow Relaxed Ventricles: When the ventricles relax during diastole, blood flows passively from the atria into the ventricles through the open AV valves, preparing the heart for the next contraction.
Phases of the Cardiac Cycle: The cardiac cycle includes atrial systole, ventricular systole, and diastole, each phase coordinating contraction and relaxation to maintain continuous blood flow through the heart and circulatory system.
Depolarization in Sinus Rhythm: In normal sinus rhythm, depolarization originates in the SA node and spreads uniformly through the atria and ventricles, resulting in coordinated heartbeats seen as distinct P, QRS, and T waves on an ECG.
