Anatomy and Function of the Cardiovascular System and Blood

Vocabulary practice cards covering the anatomy of the heart, blood vessel structures, cardiac physiology, and blood composition based on the HUBS 1401 Human Bioscience lecture.

Arteries

Blood vessels that transport blood away from the heart.

Veins

Blood vessels that carry oxygen-poor blood back to the heart, with the exception of the pulmonary vein.

Capillaries

Small vessels with a diameter of $5-10\,μm$ that permit nutrient, waste, and gas exchange between blood and interstitial fluid.

Pericardium

A double-walled sac containing serous fluid that encases the heart.

Epicardium

The outer layer of the heart wall that is also known as the visceral pericardium.

Myocardium

The muscular wall of the heart containing cardiac muscle tissue, vasculature, and nerves.

Endocardium

The inner layer of the heart wall, consisting of a lining of epithelial cells.

Atrioventricular (AV) valves

Valves that separate each side's atrium and ventricle to prevent blood backflow.

Semilunar valves

The aortic and pulmonary valves that prevent back-flow of blood from the arteries into the ventricles.

Coronary sinus

A structure that delivers oxygen-poor blood from the heart wall into the lower portion of the right atrium.

Interventricular septum

The internal wall that separates the left and right ventricles.

Trabeculae carneae

The ridged inner surface of the heart ventricles.

Tunica media

The middle layer of a blood vessel wall containing smooth muscle and elastic fibers.

Cardiac output

The amount of blood pumped out by each ventricle in $1\,min$, calculated as $heart\,rate \times stroke\,volume$.

Sinoatrial (SA) node

The pacemaker located in the right atrium that initiates cardiac muscle contraction by depolarizing $70-80$ times per minute.

Atrioventricular (AV) node

A component of the conduction system where a signal is delayed for $100\,msecs$ to prevent ventricular contraction from disrupting atrial emptying.

Purkinje fibers

Specialized cardiac muscle cells that rapidly conduct electrical signals to the contractile cells of the ventricles.

Hemocytoblast

The primary stem cells from which all formed elements of blood develop through hematopoiesis.

Erythrocytes

Red blood cells that have a biconcave shape, lack a nucleus and mitochondria, and are approximately $8\,μm$ in diameter.

Hemoglobin

A quaternary protein in RBCs composed of heme and globin, where each molecule can bind $4$ oxygen molecules.

Agglutination

The clumping of red blood cells that occurs when surface antigens react with specific antibodies in the blood plasma.

Neutrophils

The most abundant leukocytes ($60-70\%$) that have a 2-5 lobed nucleus and are the 'first on the scene' to engulf pathogens via phagocytosis.

Eosinophils

Leukocytes ($2-4\%$) with a two-lobed nucleus and granules that stain red; they are effective against parasitic worms and play a role in allergic reactions.

Basophils

Leukocytes accounting for $0.5-1\%$ of WBCs that release histamine and heparin to promote localized inflammation.

Monocytes

Large leukocytes ($3-8\%$) with kidney-shaped nuclei that travel to tissues to differentiate into highly phagocytic macrophages.

Lymphocytes

Agranular leukocytes ($20-25\%$) involved in adaptive immunity, categorized into T-cells, B-cells, and Natural Killer (NK) cells.

Platelets

Nucleus-free cell fragments containing vesicles with chemicals that promote blood clotting and form platelet plugs.

Systole

The phase of the cardiac cycle where high pressure in the ventricle causes blood to be pumped into the arteries.

Mean Arterial Pressure (MAP)

The average pressure within the arterial circuit.

Arterioles

Small diameter arteries where smooth muscle regulates blood flow across the capillary beds.