Endocrine
These chemical messengers are secreted into the bloodstream by endocrine glands to regulate body processes.
Hormones
This fluid matrix of blood makes up about 55% of total blood volume and is mostly water.
Plasma
This hollow, muscular organ pumps blood through the body via the cardiovascular system.
Heart
These blood vessels carry blood away from the heart and typically have thick, elastic walls.
Arteries
This adrenal cortex hormone regulates sodium and potassium balance by promoting sodium reabsorption and potassium excretion in the kidneys.
Aldosterone
This “master gland” regulates many other endocrine glands and is controlled by the hypothalamus.
Pituitary Gland
These oxygen-carrying cells contain hemoglobin and lack a nucleus when mature.
Erythrocytes (RBCs)
This chamber of the heart receives oxygenated blood from the lungs via the pulmonary veins.
Left Atrium
These microscopic vessels are the primary sites of nutrient and gas exchange between blood and tissues.
These cell fragments play a key role in clot formation by forming a temporary plug at the site of injury.
Platelets (Thrombocytes)
This hormone from the anterior pituitary stimulates the thyroid gland to release thyroid hormones.
Thyroid Stimulating Hormone (TSH)
This blood type is known as the universal donor because it lacks A, B, and Rh antigens on red blood cells.
O Negative (O-)
This valve lies between the left atrium and left ventricle and prevents backflow during ventricular contraction.
Mitral (Bicuspid) Valve
This is the force exerted by blood against the walls of blood vessels, usually measured in arteries.
This structure carries electrical impulses from the atria to the ventricles, acting as the only normal electrical connection between them.
Atrioventricular (AV) Node
This autoimmune disorder results in hyposecretion of thyroid hormones and is characterized by symptoms such as weight gain, fatigue, and cold intolerance.
Hashimoto's
This protein within red blood cells binds oxygen and gives blood its red color.
Hemoglobin
This structure, known as the heart’s natural pacemaker, initiates the electrical impulses that set the rhythm of the heart.
Sinoatrial (SA) Node
This process involves the narrowing of blood vessels, increasing blood pressure.
Vasoconstriction
This large artery distributes oxygenated blood from the left ventricle to all systemic arteries and is the main pressure reservoir of the systemic circulation.
Aorta
This condition results from hypersecretion of growth hormone in adults, leading to thickened bones and enlarged hands, feet, and facial features.
Acromegaly
This hormone, primarily produced by the kidneys, stimulates red blood cell production in response to low oxygen levels.
Erythropoietin (EPO)
This phase of the cardiac cycle involves ventricular contraction and the ejection of blood into the aorta and pulmonary trunk.
Ventricular Systole
This circuit carries oxygen-poor blood from the heart to the lungs and returns oxygen-rich blood back to the heart.
Pulmonary Circuit
This plasma protein, produced by the liver, plays a major role in maintaining blood osmotic pressure and transporting some hormones and drugs.
Albumin