Cardiovascular Physiology and Hematology Flashcards

Vocabulary flashcards covering Blood, Heart, and Blood Vessels based on human anatomy and physiology lecture materials.

Whole Blood

The fluid connective tissue of the cardiovascular system consisting of plasma and formed elements, with a normal temperature of $38^\circ\text{C}$ and a slightly alkaline pH of $7.35\text{--}7.45$.

Plasma

The liquid matrix of blood, making up $46\text{--}63\%$ (averaging $55\%$) of whole blood volume, composed primarily of water ($92\%$), plasma proteins ($7\%$), and other solutes ($1\%$).

Hematocrit

The percentage of whole blood volume occupied by formed elements (packed cell volume, PCV), averaging $46$ in adult males and $42$ in adult females.

Albumins

The most abundant plasma proteins (approximately $60\%$), primarily synthesized by the liver, which maintain plasma osmotic pressure and transport fatty acids, thyroid hormones, and steroid hormones.

Globulins

Plasma proteins making up approximately $35\%$ of total plasma proteins, including immunoglobulins (antibodies) for immune defense and transport globulins for hormone and lipid binding.

Fibrinogen

A soluble plasma protein ($4\%$ of total plasma proteins) produced by the liver that is converted into insoluble fibrin threads during blood clot formation.

Erythropoietin (EPO)

A hormone secreted primarily by the kidneys (and liver) during tissue hypoxia (low $O_2$) to stimulate red blood cell production (erythropoiesis) in red bone marrow.

Pernicious Anemia

A type of anemia resulting from a deficiency in vitamin $B_{12}$ (cobalamin), often caused by a lack of intrinsic factor from the stomach required for its absorption in the ileum.

Oxyhemoglobin

A form of hemoglobin bound to oxygen ($HbO_2$), formed when iron in the heme group interacts with oxygen.

Carbaminohemoglobin

A form of hemoglobin bound to carbon dioxide ($CO_2$), formed when $CO_2$ binds to the N-terminal amino group of hemoglobin rather than to the heme iron.

Biliverdin

An organic green compound formed when iron is stripped from the heme unit of broken-down hemoglobin inside macrophages.

Bilirubin

An orange-yellow pigment produced by the reduction of biliverdin, which is transported bound to albumin in the bloodstream to the liver for excretion in bile.

Neutrophils

Phagocytic granulocytes constituting $50\text{--}70\%$ of circulating white blood cells that engulf pathogens, contain myeloperoxidase (MPO) in pale granules, and release 20-carbon inflammatory mediators like prostaglandins and leukotrienes.

Eosinophils

Phagocytic granulocytes making up $2\text{--}4\%$ of circulating white blood cells with bright red-staining granules, which attack large parasites with toxic compounds (nitric oxide, cytotoxic enzymes) and reduce inflammation in allergic reactions.

Basophils

Granulocytes comprising less than $1\%$ of circulating white blood cells that enter damaged tissues to release histamine (dilating blood vessels) and heparin (preventing blood clotting).

Monocytes

Large agranulocytes with kidney bean-shaped nuclei constituting $2\text{--}8\%$ of white blood cells that enter peripheral tissues to transform into aggressive tissue macrophages.

Lymphocytes

Agranulocytes accounting for $20\text{--}40\%$ of circulating white blood cells, primarily located in lymphatic organs, consisting of T cells, B cells, and natural killer (NK) cells.

Megakaryocytes

Giant polyploid cells located in red bone marrow that produce platelets by shedding cytoplasm packets into blood sinusoids under the influence of thrombopoietin (TPO).

Hemostasis

The multi-phase process responsible for stopping bleeding, consisting of the vascular phase, platelet phase, and coagulation phase, followed by clot retraction.

Fibrinolysis

The gradual process of dissolving a blood clot, wherein thrombin and tissue plasminogen activator (t-PA) convert plasminogen into active plasmin, which digests fibrin strands.

Pericarditis

Inflammation of the pericardial surfaces caused by pathogens, leading to restricted heart movement, excess pericardial fluid, a distinctive scratching sound, and potential cardiac tamponade.

Pulmonary Circuit

The cardiovascular circuit that carries deoxygenated blood from the right ventricle to the gas exchange surfaces of the lungs and returns oxygenated blood to the left atrium.

Systemic Circuit

The cardiovascular circuit that carries oxygenated blood from the left ventricle to supply tissues throughout the rest of the body and returns deoxygenated blood to the right atrium.

Coronary Circulation

The intrinsic blood supply network to the heart muscle, originating at the aortic sinuses via coronary arteries and draining into the right atrium via the coronary sinus.

Coronary Artery Disease (CAD)

A condition characterized by partial or complete blockage of coronary circulation, most commonly caused by the formation of an atherosclerotic plaque or thrombus.

Angina Pectoris

Temporary chest pain or constriction caused by transient myocardial ischemia, often brought on by exertion or stress, which may radiate to the left arm or left side of the neck.

Myocardial Infarction (MI)

Tissue death (infarction) of heart muscle resulting from prolonged severe coronary ischemia and oxygen deprivation, commonly triggered by coronary thrombosis.

Autorhythmicity

The ability of specialized cardiac muscle cells to spontaneously initiate and distribute electrical impulses that stimulate contraction without direct neural or hormonal input.

Sinoatrial (SA) Node

The primary natural pacemaker of the heart located in the right atrium, establishing a baseline spontaneous depolarization rate of $60\text{--}100\,\text{action potentials/min}$.

Commotio Cordis

Sudden cardiac death caused by a non-penetrating precordial blow to the chest occurring strictly within a $20\,\text{msec}$ window on the upstroke of the T wave, triggering ventricular fibrillation.

Bradycardia

An abnormally slow heart rate defined as less than $60\,\text{beats per minute (bpm)}$.

Tachycardia

An abnormally fast heart rate defined as greater than $100\,\text{beats per minute (bpm)}$.

Cardiac Output (CO)

The total volume of blood pumped by a ventricle per minute, calculated as the product of heart rate and stroke volume ($CO = HR \times SV$).

Stroke Volume (SV)

The volume of blood ejected by a ventricle during a single heartbeat, calculated as the difference between end-diastolic volume and end-systolic volume ($SV = EDV - ESV$).

Preload

The degree of myocardial stretching experienced by ventricular muscle cells prior to contraction during diastole, which is directly proportional to end-diastolic volume (EDV).

Contractility

The intrinsic force generated by cardiac muscle during a contraction at any given preload, increased by positive inotropic factors and decreased by negative inotropic factors.

Afterload

The amount of arterial pressure and vascular resistance the contracting ventricles must overcome to open the semilunar valves and eject blood.

Frank-Starling Principle

The physiological rule stating that an increase in end-diastolic volume (EDV) produces increased myocardial stretch, resulting in a more forceful contraction and larger stroke volume.

Bainbridge Reflex

An autonomic reflex in which an increase in venous return stretches receptors in the right atrium, stimulating sympathetic activity to increase heart rate.

Digoxin

A positively inotropic drug derived from Digitalis (foxglove) that inhibits the $Na^+/K^+$ ATPase pump in myocardium, increasing intracellular calcium concentration to boost cardiac contractility.

Atropine

A competitive antagonist of muscarinic acetylcholine receptors used as a positively chronotropic drug to treat severe bradycardia by blocking parasympathetic inhibition of heart rate.

Tunica Intima

The innermost layer of a blood vessel wall, consisting of an endothelial lining, underlying connective tissue, and an internal elastic membrane in arteries.

Tunica Media

The middle layer of a blood vessel wall, containing concentric sheets of smooth muscle in loose connective tissue that control vessel diameter via vasoconstriction or vasodilation.

Tunica Externa

The outer connective tissue sheath of a blood vessel composed of collagen and elastic fibers that anchors the vessel to adjacent tissues and contains the vasa vasorum in large vessels.

Vasa Vasorum

A network of small blood vessels located within the tunica externa and media of large arteries and veins that supply nutrients to the vessel wall tissue.

Continuous Capillaries

Capillaries with a complete endothelial lining found in most tissues (except epithelia and cartilage) that permit diffusion of water, small solutes, and lipid-soluble materials.

Fenestrated Capillaries

Capillaries containing microscopic pores in their endothelial lining that permit rapid exchange of water and larger solutes, found in the choroid plexus, endocrine organs, kidneys, and small intestine.

Sinusoids

Capillaries featuring large gaps between adjacent endothelial cells that permit free exchange of water, large plasma proteins, and blood cells in the liver, spleen, bone marrow, and lymphoid organs.

Blood Colloid Osmotic Pressure (BCOP)

The osmotic force generated by suspended non-diffusible plasma proteins (primarily albumin) that pulls water out of interstitial space back into capillaries.

Net Filtration Pressure (NFP)

The net pressure driving fluid movement across capillary walls, calculated as the difference between capillary hydrostatic pressure and blood colloid osmotic pressure ($NFP = CHP - BCOP$).

Edema

An abnormal accumulation of excess fluid in interstitial tissues, commonly caused by increased capillary hydrostatic pressure (e.g., hypertension) or decreased blood colloid osmotic pressure (e.g., liver failure).

Mean Arterial Pressure (MAP)

The average blood pressure within systemic arteries throughout an entire cardiac cycle, estimated as diastolic pressure plus one-third of pulse pressure ($\text{MAP} \approx \text{diastolic} + \frac{1}{3}\text{pulse pressure}$), normally ranging between $70\text{--}100\,\text{mmHg}$.

Angiogenesis

The physiological process of forming new blood vessels from pre-existing vessels, stimulated by vascular endothelial growth factor (VEGF) in response to tissue hypoxia or embryonic development.