XI Glossary

Abdominal aorta: The part of the descending aorta that passes through the abdominal cavity, supplying oxygenated blood to the abdominal organs, pelvis, and lower limbs. (Chapter 11.5)

Adrenal artery: Supplies blood to the adrenal glands and arises near the superior mesenteric artery. (Chapter 11.5)

Adrenal vein: The vein that drains blood from the adrenal (suprarenal) glands and empties into the inferior vena cava or the renal vein. (Chapter 11.5)

Anastomosis: A connection between two blood vessels that supply the same area, providing an alternate pathway for blood flow. (Chapter 11.2)

Aneurysm: An aneurysm is a weakened blood vessel wall that bulges or balloons. An aneurysm can break open, which is called a rupture. A ruptured aneurysm causes severe internal bleeding and can life threatening. (Chapter 11.6)

Angioplasty: A procedure in which the occlusion caused by plaque is mechanically widened with a balloon. (Chapter 11.6)

Anterior interventricular sulcus: A groove on the front (anterior) surface of the heart that marks the boundary between the left and right ventricles. (Chapter 11.2)

Anterior tibial artery: Located between the tibia and fibula and supplies blood to the muscles and skin of the anterior tibial region. (Chapter 11.5)

Anterior tibial vein: A vein that drains blood from the front (anterior) part of the lower leg (shin area) and carries it upward toward the heart, eventually joining larger veins in the leg. (Chapter 11.5)

Aorta: The largest artery in the body. (Chapter 11.5)

Aortic arch: The curved portion of the aorta, the largest artery in the body, which gives rise to major arteries that supply blood to the head, neck, and upper limbs. (Chapter 11.5)

Aortic hiatus: An opening in the diaphragm through which the descending aorta passes from the chest into the abdomen. (Chapter 11.5)

Apex: The pointed, inferior tip of the heart located just left of the sternum. (Chapter 11.2)

Arrhythmia: An abnormal heart rhythm due to disrupted electrical activity of the conduction system. (Chapter 11.6)

Arterial circle (circle of Willis): A circular network of arteries located at the base of the brain that provides collateral blood flow between the anterior and posterior cerebral circulations, helping ensure consistent blood supply to the brain. (Chapter 11.5)

Arteries: Blood vessels that carry blood away from the heart to the body’s tissues. Most arteries carry oxygenated blood, except for the pulmonary arteries, which carry deoxygenated blood to the lungs. (Chapter 11.2, Chapter 11.5)

Arteriole: A very small artery that leads to a capillary. (Chapter 11.5)

Arteriosclerosis: The thickening and stiffening of arterial walls that is commonly associated with normal aging. (Chapter 11.6)

Ascending aorta: Moves in an upward direction. (Chapter 11.5)

Atherosclerosis: A condition where cholesterol, low-density lipoprotein (LDL) deposits, and wastes build up within the lining of the arteries. (Chapter 11.6)

Atria: The two upper chambers of the heart that receive blood returning to the heart and pump it into the ventricles. (Chapter 11.2)

Atrial fibrillation (A-Fib): A common type of arrhythmia (irregular heartbeat) in which the atria (upper chambers of the heart) beat rapidly and irregularly, reducing the heart’s efficiency and increasing the risk of stroke. (Chapter 11.6)

Atrioventricular (AV): Relating to the connection between the atria and ventricles of the heart. (Chapter 11.3)

Atrioventricular (AV) bundle: A group of specialized heart muscle fibers that transmit electrical impulses from the AV node down to the ventricles. (Chapter 11.3)

Atrioventricular septum: The wall or partition that separates the atria (upper heart chambers) from the ventricles (lower heart chambers). (Chapter 11.2)

Atrioventricular valves: Valves located between the atria and ventricles (the tricuspid valve on the right and the mitral/bicuspid valve on the left) that prevent backflow of blood into the atria during ventricular contraction. (Chapter 11.2)

Auricles: Flaplike, thin-walled structures that can slightly expand to increase the volume of the atria, the upper chambers of the heart. (Chapter 11.2)

Autorhythmicity: The heart’s ability to generate its own electrical impulses without input from the nervous system, allowing it to contract in a regular, rhythmic pattern. (Chapter 11.2)

Axillary artery: A major artery that carries blood from the subclavian artery through the armpit (axilla) region to the upper limb. (Chapter 11.5)

Axillary vein: A large vein that drains blood from the upper limb and shoulder, running through the armpit (axilla) and continuing as the subclavian vein. (Chapter 11.5)

Basilic vein: A large superficial vein on the inner side of the arm that helps drain blood from the hand and forearm and eventually joins the brachial vein to form the axillary vein. (Chapter 11.5)

Blood flow: Initiated by the contraction of the ventricles of the heart and refers to the movement of blood through a vessel, tissue, or organ. (Chapter 11.5)

Blood pressure: The force exerted by blood on the walls of the blood vessels or the chambers of the heart. (Chapter 11.5)

Brachial artery: Supplies blood to much of the brachial region and divides at the elbow into several smaller branches, including the deep brachial arteries, which provide blood to the posterior surface of the arm, and the ulnar collateral arteries, which supply blood to the region of the elbow. (Chapter 11.5)

Brachial vein: A deep vein of the upper arm that drains blood from the arm and joins with the basilic vein to form the axillary vein. (Chapter 11.5)

Brachiocephalic artery: The first major branch of the aortic arch that supplies blood to the right arm, head, and neck. (Chapter 11.5)

Brachiocephalic vein: A large vein formed by the union of the subclavian and internal jugular veins; it drains blood from the head, neck, and upper limbs into the superior vena cava. (Chapter 11.5)

Bradycardia: A condition in which the resting heart rate for an adult drops below 60 bpm. (Chapter 11.4)

Broken heart syndrome: Also known as Takotsubo cardiomyopathy, stress-induced cardiomyopathy, or apical ballooning syndrome, it is a temporary heart condition triggered by intense emotional or physical stress. It mimics a heart attack but usually resolves within days or weeks. (Chapter 11.6)

Bundle branches: Pathways that split from the AV bundle and carry impulses down the left and right sides of the interventricular septum to the ventricles. (Chapter 11.3)

Bundle of His: A group of specialized heart muscle fibers that transmit electrical impulses from the AV node down to the ventricles. (Chapter 11.3)

Capillaries: The smallest blood vessels in the body, where the exchange of oxygen, nutrients, waste products, and other substances occurs between the blood and surrounding tissues. (Chapter 11.5)

Cardiac conduction system: A network of specialized heart cells that generate and transmit electrical impulses, controlling the heart’s rhythmic contractions. (Chapter 11.3)

Cardiac cycle: The period of time that begins with contraction of the atria and ends with ventricular relaxation. (Chapter 11.4)

Cardiac output (CO): The amount of blood pumped by each ventricle in one minute. (Chapter 11.4)

Cardiac tamponade: A medical emergency in which fluid builds up in the pericardial sac (the lining around the heart), putting pressure on the heart and preventing it from filling and pumping properly. (Chapter 11.6)

Cardiogenic shock: Results from the inability of the heart to adequately pump and maintain cardiac output. (Chapter 11.6)

Cardiologist: A physician who specializes in the diagnosis and treatment of heart disease. (Chapter 11.7)

Cardiology: The study of the heart. (Chapter 11.1)

Celiac trunk: A major branch of the abdominal aorta that quickly divides into the left gastric, splenic, and common hepatic arteries to supply blood to the stomach, spleen, liver, and other abdominal organs. (Chapter 11.5)

Cephalic vein: Begins in the antebrachium (between the elbow and wrist) and drains blood from the superficial surface of the arm into the axillary vein. (Chapter 11.5)

Chordae tendineae: Tough, fibrous cords that connect the valve flaps (cusps) of the tricuspid and mitral valves to papillary muscles in the ventricles. (Chapter 11.2)

Coarctation of the aorta: A congenital abnormal narrowing of the aorta that is normally located at the insertion of the ligamentum arteriosum, the remnant of the fetal shunt called the ductus arteriosus. (Chapter 11.6)

Common carotid arteries: Divide into internal and external carotid arteries. (Chapter 11.5)

Common hepatic artery: A branch of the celiac trunk that supplies oxygenated blood to the liver, stomach, duodenum, and pancreas. (Chapter 11.5)

Common iliac artery: One of the two large arteries that branch off from the abdominal aorta, supplying blood to the pelvis and lower limbs. (Chapter 11.5)

Common iliac vein: A large vein formed by the union of the internal and external iliac veins, which drains blood from the pelvis and lower limbs into the inferior vena cava. (Chapter 11.5)

Compliance: The ability to expand or stretch. (Chapter 11.5)

Congenital: Meaning the individual was born with the defect. (Chapter 11.6)

Congenital heart defects: Structural abnormalities in the heart or blood vessels that are present at birth and affect how blood flows through the heart and out to the rest of the body. (Chapter 11.6)

Coronary artery disease (CAD): The leading cause of death worldwide. It occurs when the buildup of plaque obstructs blood flow within coronary arteries and decreases compliance of the vessels. (Chapter 11.6)

Coronary sinus: A thin-walled vessel on the posterior surface of the right atrium that receives deoxygenated blood from the heart muscle and empties it into the right atrium. (Chapter 11.2)

Coronary sulcus: A deep groove located between the atria and ventricles of the heart. (Chapter 11.2)

Coronary veins: Systemic veins that collect deoxygenated blood from the heart muscle and drain it into the coronary sinus. (Chapter 11.2)

Deep femoral artery: A major branch of the femoral artery that supplies blood to the deeper muscles of the thigh. (Chapter 11.5)

Deep femoral vein: Drains blood from the deeper portions of the thigh. (Chapter 11.5)

Depolarization: The electrical activation of atrial muscle cells that triggers their contraction, increasing atrial pressure and pumping blood into the ventricles through open atrioventricular valves. (Chapter 11.4)

Descending aorta: The part of the aorta that extends downward from the aortic arch, carrying oxygenated blood to the chest, abdomen, and lower parts of the body. (Chapter 11.5)

Diastole: The period of relaxation that occurs as the chambers fill with blood. (Chapter 11.4)

Diastolic pressure: The lower number in a blood pressure reading; it measures the pressure in the arteries when the heart is resting between beats. (Chapter 11.5)

Digital arteries: Supply blood to the digits. (Chapter 11.5)

Digital veins: Veins that drain blood from the fingers and toes, returning it toward the heart. (Chapter 11.5)

Distributive shock: Characterized by peripheral vasodilation and includes conditions such as septic shock, anaphylactic shock, neurogenic shock or others. (Chapter 11.6)

Dorsal arch: An arterial network on the back (dorsal) side of the foot formed mainly by the dorsalis pedis artery, which supplies blood to the foot and toes. (Chapter 11.5)

Dorsalis pedis artery: An artery on the top of the foot that supplies blood to the foot and toes. (Chapter 11.5)

Dorsal venous arch: Complex series of anastomoses in the feet and ankles that the plantar veins flow into. (Chapter 11.5)

Ductus arteriosus: A fetal blood vessel that connects the pulmonary artery to the aorta, allowing blood to bypass the lungs before birth. It normally closes soon after birth. (Chapter 11.5)

Ductus venosus: A fetal blood vessel that shunts oxygen-rich blood from the umbilical vein directly to the inferior vena cava, bypassing the liver. (Chapter 11.5)

Edema: Swelling caused by excess fluid trapped in the body’s tissues, often occurring in the hands, feet, ankles, or legs. (Chapter 11.6)

Elastic artery: Arteries closest to the heart have the thickest walls, containing a high percentage of elastic fibers in all three of their tunics. (Chapter 11.5)

Electrocardiogram (ECG): A test that records the electrical activity of the heart over time using electrodes placed on the skin, producing a waveform that helps diagnose heart conditions. (Chapter 11.3)

End diastolic volume (EDV): The volume of blood in the ventricles at the end of ventricular filling (diastole), just before the heart contracts. (Chapter 11.4)

Endocardium: The innermost layer of the heart wall, connected to the myocardium by a thin layer of connective tissue. (Chapter 11.2)

Endothelium: A simple squamous epithelial tissue that makes up the endocardium, lining the inside of the heart. (Chapter 11.2)

End systolic volume (ESV): The amount of blood remaining in each ventricle after ventricular systole (contraction) and ejection of blood. (Chapter 11.4)

Epicardium: Also known as the visceral pericardium, it is the inner layer of the serous pericardium that is fused to the surface of the heart and forms part of the heart wall. (Chapter 11.2)

External carotid artery: Supplies blood to numerous structures within the face, lower jaw, neck, esophagus, and larynx. (Chapter 11.5)

External iliac artery: A continuation of the common iliac artery that supplies blood to the lower limbs; it becomes the femoral artery as it passes under the inguinal ligament. (Chapter 11.5)

External iliac vein: A large vein that drains blood from the leg to the common iliac vein. (Chapter 11.5)

External jugular vein: A vein that drains blood from the superficial areas of the head and neck and empties into the subclavian vein. (Chapter 11.5)

Femoral artery: A large artery in the thigh that supplies oxygenated blood to the lower limb. (Chapter 11.5)

Femoral circumflex vein: Forms a loop around the femur just inferior to the trochanters and drains blood from the areas in proximity to the head and neck of the femur. (Chapter 11.5)

Femoral vein: A large deep vein in the thigh that collects blood from the popliteal vein and the great saphenous vein, transporting it upward toward the external iliac vein and eventually back to the heart. (Chapter 11.5)

Fibrous pericardium: The tough outer layer of the pericardium made of dense connective tissue that protects the heart and anchors it in the chest. (Chapter 11.2)

Fibrous skeleton of the heart: Dense connective tissue that reinforces the heart muscle. It includes four rings surrounding the openings between the atria and ventricles, and the openings to the pulmonary trunk and aorta. (Chapter 11.2)

Fibular vein: A vein that drains blood from the lateral (outer) side of the lower leg and foot, returning it toward the heart. (Chapter 11.5)

Foramen ovale: An opening in the fetal heart that allowed blood to flow directly from the right atrium to the left atrium, bypassing the lungs before birth. (Chapter 11.2)

Fossa ovalis: A small oval-shaped depression on the interatrial septum, marking the spot of a fetal opening called the foramen ovale. (Chapter 11.2, Chapter 11.5)

Genicular artery: An artery that supplies blood to the knee joint and surrounding structures. (Chapter 11.5)

Gonadal artery: Supplies blood to the gonads, or reproductive organs, and is also described as either an ovarian artery or a testicular artery, depending upon the sex of the individual. (Chapter 11.5)

Gonadal vein: The vein that drains blood from the gonads (ovaries in females, testes in males) and returns it to the inferior vena cava or the left renal vein. (Chapter 11.5)

Great saphenous vein: The longest vein in the body, running along the inner leg from the foot to the groin, where it drains into the femoral vein; it is a superficial vein used often in vein grafts for surgeries. (Chapter 11.5)

Heart block: Refers to a disruption in the normal conduction pathway of electrical signals through the atria and ventricles. (Chapter 11.6)

Heart failure (HF): Occurs when the heart loses its effectiveness in pumping blood and is referred to as decreased cardiac output. (Chapter 11.6)

Heart rate (HR): The number of heart beats per minute, typically measured in beats per minute (bpm). (Chapter 11.4)

Heart sounds: Noises generated by the beating heart and the flow of blood, typically described as “lub-dub.” (Chapter 11.4)

Hepatic artery proper: A branch of the common hepatic artery that travels toward the liver and supplies it with oxygenated blood. (Chapter 11.5)

Hepatic portal system: A network of veins that carries nutrient-rich blood from the digestive organs and spleen to the liver for processing before it enters the general circulation. (Chapter 11.5)

Hepatic vein: The vein that carries deoxygenated blood from the liver to the inferior vena cava. (Chapter 11.5)

Hypertension: Refers to chronically elevated blood pressure greater than 120/80 mm Hg. (Chapter 11.6)

Hypervolemia: Excessive blood volume. (Chapter 11.5)

Hypovolemia: Low blood volume. (Chapter 11.5)

Hypovolemic shock: Caused by hemorrhage or significant fluid losses, often related to severe vomiting or diarrhea or extensive burns. (Chapter 11.6)

Inferior mesenteric artery: A branch of the abdominal aorta that supplies oxygenated blood to the distal part of the large intestine, including the descending colon, sigmoid colon, and rectum. (Chapter 11.5)

Inferior phrenic artery: A counterpart of a superior phrenic artery and supplies blood to the inferior surface of the diaphragm. (Chapter 11.5)

Inferior vena cava: A large vein that carries deoxygenated blood from the lower limbs and abdominopelvic region back to the right atrium of the heart. (Chapter 11.2, Chapter 11.5)

Intercalated disc: Specialized connections between cardiac muscle cells that contain gap junctions and desmosomes, allowing electrical impulses to pass quickly between cells and enabling the synchronized contraction of the heart muscle. (Chapter 11.2)

Internal carotid arteries: Major arteries that arise from the common carotid arteries and supply oxygenated blood to the brain, eyes, and other internal structures of the head. (Chapter 11.5)

Internal iliac artery: A branch of the common iliac artery that supplies blood to the pelvic organs, gluteal region, and medial thigh. (Chapter 11.5)

Internal iliac vein: A deep vein that drains blood from the pelvic organs and walls, joining with the external iliac vein to form the common iliac vein. (Chapter 11.5)

Internal jugular vein: A major vein that collects blood from the brain, face, and neck, and drains into the brachiocephalic vein. (Chapter 11.5)

Interventricular septum (ventricular septum): The wall or partition that separates the right and left ventricles of the heart. (Chapter 11.2)

Isovolumetric contraction: The phase in the cardiac cycle when the ventricles contract with no change in volume because all heart valves are closed, causing a rapid increase in ventricular pressure. (Chapter 11.4)

Isovolumetric ventricular relaxation phase: The early phase of ventricular diastole when the ventricles begin to relax, pressure falls, and all heart valves are closed, so no blood enters or leaves the ventricles. (Chapter 11.4)

Lateral circumflex artery: A branch of the deep femoral artery that supplies blood to the muscles on the front and side of the thigh and the hip joint. (Chapter 11.5)

Lateral plantar artery: An artery branching from the posterior tibial artery that supplies blood to the outer (lateral) side of the sole of the foot. (Chapter 11.5)

Left common carotid artery: Branches directly from the aortic arch. (Chapter 11.5)

Left gastric artery: A branch of the celiac trunk that supplies blood to the lower esophagus and the upper part of the stomach along its lesser curvature. (Chapter 11.5)

Left subclavian artery: Branches directly from the aortic arch. (Chapter 11.5)

Ligamentum arteriosum: A small ligament that is the remnant of the ductus arteriosus after it closes following birth. It connects the aortic arch to the pulmonary artery. (Chapter 11.5)

Ligamentum venosum: A fibrous remnant of the fetal ductus venosus found in the liver after birth. (Chapter 11.5)

Lumen: A hollow central passageway through which blood flows. (Chapter 11.5)

Maxillary vein: A vein that drains blood from the deep parts of the face, including the maxillary region, and joins with other veins to form the retromandibular vein. (Chapter 11.5)

Medial plantar artery: An artery that branches from the posterior tibial artery and supplies blood to the inner (medial) side of the sole of the foot. (Chapter 11.5)

Median antebrachial vein: Parallels the ulnar vein, is more medial in location, and joins the basilic vein in the forearm. (Chapter 11.5)

Median cubital vein: A superficial vein located in the front of the elbow (cubital fossa) that connects the basilic and cephalic veins. It is commonly used for drawing blood (venipuncture). (Chapter 11.5)

Median sacral artery: A small artery that arises from the posterior surface of the abdominal aorta just before it splits into the common iliac arteries; it supplies blood to the sacrum and coccyx. (Chapter 11.5)

Mediastinum: Central portion of the thoracic cavity. (Chapter 11.2)

Microcirculation: The flow of blood through the smallest blood vessels—arterioles, capillaries, and venules—where exchange of gases, nutrients, and waste products occurs between blood and tissues. (Chapter 11.5)

Middle sacral vein: A vein that drains blood from the sacrum and coccyx, typically emptying into the left or right common iliac vein. (Chapter 11.5)

Mitral regurgitation: The most common valve disorder, detected in approximately 2 percent of the population. (Chapter 11.6)

Mitral valve: The valve between the left atrium and left ventricle; it has two flaps (cusps) and prevents backflow of blood into the left atrium during ventricular contraction. Also called the bicuspid valve. (Chapter 11.2)

Moderator band: A muscular band of heart tissue found in the right ventricle that carries part of the conduction system (right bundle branch) to the anterior papillary muscle, helping coordinate ventricular contraction. (Chapter 11.2)

Murmur: Used to describe an unusual sound coming from a heart valve that is caused by the turbulent flow of blood. (Chapter 11.4)

Muscular artery: A medium-sized artery that contains a thick layer of smooth muscle, allowing it to regulate blood flow by constricting or dilating. (Chapter 11.5)

Myocardial infarction (MI): The medical term for what is commonly known as a heart attack. (Chapter 11.6)

Myocardium: The middle and thickest layer of the heart wall, composed mainly of cardiac muscle cells responsible for the heart’s contractions. (Chapter 11.2)

Obstructive shock: Caused by extracardiac conditions leading to a decrease in the left ventricular cardiac output and decreased delivery of oxygen to tissues. (Chapter 11.6)

Ovarian artery: Supplies blood to an ovary, Fallopian tube, and the uterus and is located within the suspensory ligament of the uterus. (Chapter 11.5)

Ovarian vein: The vein that drains blood from the ovaries and returns it to the inferior vena cava (right ovarian vein) or the left renal vein (left ovarian vein). (Chapter 11.5)

Palmar arches: Supply blood to the hand. (Chapter 11.5)

Palmar venous arches: Networks of interconnected veins located in the palm of the hand that collect blood from the fingers and hand, helping return it to the larger veins of the arm. (Chapter 11.5)

Papillary muscle: Small muscles inside the heart ventricles that attach to chordae tendineae and help prevent valve flaps from inverting during contraction. (Chapter 11.2)

Parietal pericardium: The outer layer of the serous pericardium that lines the inner surface of the fibrous pericardium. (Chapter 11.2)

Patent ductus arteriosus (PDA): A congenital condition in which the ductus arteriosus fails to close at birth. (Chapter 11.6)

Patent foramen ovale (PFO): A common congenital heart defect that occurs when the fossa ovalis in the interatrial septum that is present during fetal circulation does not fuse after birth. (Chapter 11.6)

Pectinate muscles: Muscular ridges found on the inner surface of the anterior right atrium of the heart. (Chapter 11.2)

Perfusion: The process of delivering blood to the body’s tissues and organs to supply oxygen and nutrients. (Chapter 11.5)

Pericardial cavity: The space between the heart and the pericardium, filled with serous fluid to reduce friction during heart contractions. (Chapter 11.2)

Pericarditis: Swelling and irritation of the pericardium, the thin, saclike tissue surrounding the heart. (Chapter 11.6)

Pericardium: The serous membrane that surrounds the heart and reduces friction caused by the beating of the heart. (Chapter 11.2)

Peripheral artery disease (PAD): Caused by atherosclerosis, with narrowed or blocked arteries, causing reduced oxygenated blood flow to the lower extremities. (Chapter 11.6)

Plantar arch: An arterial arch located on the sole (plantar surface) of the foot, formed mainly by the lateral plantar artery, providing blood supply to the foot’s plantar tissues. (Chapter 11.5)

Plantar veins: Veins located in the sole (bottom) of the foot that drain blood from the foot’s tissues and return it toward the heart. (Chapter 11.5)

Plantar venous arch: Complex series of anastomoses in the feet and ankles that the plantar veins flow into. (Chapter 11.5)

Plaque: A fatty material including cholesterol, connective tissue, white blood cells, and smooth muscle cells. (Chapter 11.6)

Popliteal artery: The main artery located behind the knee that supplies blood to the knee joint and lower leg. (Chapter 11.5)

Popliteal vein: A deep vein located behind the knee that collects blood from the lower leg and drains into the femoral vein. (Chapter 11.5)

Posterior interventricular sulcus: A groove on the back (posterior) surface of the heart that marks the boundary between the left and right ventricles. (Chapter 11.2)

Posterior tibial artery: Provides blood to the muscles and skin on the posterior surface of the tibial region. (Chapter 11.5)

Posterior tibial vein: A vein that drains blood from the back (posterior) part of the lower leg and foot, carrying it upward toward the heart. (Chapter 11.5)

Preload: The volume of blood in the ventricles at the end of ventricular filling (diastole), just before the heart contracts. (Chapter 11.4)

Pulmonary artery: The blood vessel that carries deoxygenated blood from the right ventricle of the heart to the lungs for oxygenation. (Chapter 11.2, Chapter 11.5)

Pulmonary capillaries: Tiny blood vessels surrounding the alveoli in the lungs where the exchange of oxygen and carbon dioxide takes place between the blood and the air in the lungs. (Chapter 11.5)

Pulmonary circulation: The portion of the circulatory system that carries deoxygenated blood from the right side of the heart to the lungs to pick up oxygen and release carbon dioxide and then returns oxygenated blood to the left side of the heart. (Chapter 11.2)

Pulmonary trunk: A large artery that carries blood out away from the right ventricle. (Chapter 11.2, Chapter 11.5)

Pulmonary valve (pulmonic valve): A semilunar valve located at the base of the pulmonary trunk that prevents backflow of blood into the right ventricle after it contracts. (Chapter 11.2)

Pulmonary veins: Blood vessels that carry oxygen-rich blood from the lungs back to the left atrium of the heart. (Chapter 11.5)

Pulse: The expansion and recoiling of an artery as blood is pumped through it with each heartbeat; it can be felt manually or measured electronically. (Chapter 11.5)

Purkinje fibers: Specialized fibers that spread the electrical impulse throughout the ventricles, causing them to contract. (Chapter 11.3)

Radial artery: A major artery of the forearm that runs along the thumb side, commonly used to measure the pulse at the wrist. (Chapter 11.5)

Radial vein: A vein that runs along the lateral (thumb) side of the forearm, draining blood from the hand and forearm back toward the heart. (Chapter 11.5)

Renal artery: A blood vessel that branches off from the abdominal aorta and supplies oxygen-rich blood to the kidneys. (Chapter 11.5)

Renal vein: The vein that carries deoxygenated blood filtered by the kidneys back to the inferior vena cava. (Chapter 11.5)

Repolarization: The process by which cardiac muscle cells restore their resting electrical state after depolarization, allowing the heart muscle to relax. (Chapter 11.4)

Resistance: Anything that slows blood or counteracts blood flow. (Chapter 11.5)

Respiratory pump: A mechanism where pressure changes in the thoracic cavity during breathing help move blood toward the heart through the veins. (Chapter 11.5)

Right atrium: The heart’s chamber that receives deoxygenated blood from the body’s systemic circulation and directs it to the right ventricle. (Chapter 11.2)

Right common carotid artery: A major artery branching from the brachiocephalic artery that supplies oxygenated blood to the right side of the head and neck. (Chapter 11.5)

Right subclavian artery: A major artery branching from the brachiocephalic artery that supplies blood to the right arm and parts of the chest and shoulder. (Chapter 11.5)

Saphenous vein: A large superficial vein in the leg that drains blood from the foot and leg and empties into the deep venous system. The great saphenous vein is the longest vein in the body. (Chapter 11.5)

Semilunar valves: Valves located at the openings of the heart leading to the pulmonary trunk (pulmonary valve) and the aorta (aortic valve); they prevent backflow of blood into the ventricles after contraction. (Chapter 11.2)

Septum: A wall or partition that divides a structure into separate parts, such as the walls separating the chambers of the heart. (Chapter 11.2)

Serous pericardium: A thin, double-layered membrane around the heart that reduces friction. It includes the parietal layer (outer) and the visceral layer (inner, also called the epicardium). (Chapter 11.2)

Shock: A life-threatening condition where the body’s tissues and organs don’t receive enough blood and oxygen. (Chapter 11.6)

Shunts: Alternative paths for blood flow. (Chapter 11.5)

Sinoatrial (SA) node: A specialized clump of conducting cells located in the wall of the upper right atrium close to the opening of the superior vena cava. (Chapter 11.3)

Skeletal muscle pump: Helps the lower-pressure veins counteract the force of gravity, increasing pressure to return blood to the heart. (Chapter 11.5)

Splenic artery: A major branch of the celiac trunk that supplies oxygenated blood to the spleen. (Chapter 11.5)

Stroke volume (SV): The amount of blood pumped by each ventricle. (Chapter 11.4)

Subclavian arteries: Supply blood to the arms, chest, shoulders, back, and central nervous system. (Chapter 11.5)

Subclavian vein: A large vein that drains deoxygenated blood from the arms and shoulders and transports it to the superior vena cava. (Chapter 11.5)

Subscapular vein: Drains blood from the subscapular region and joins the cephalic vein to form the axillary vein. (Chapter 11.5)

Sulcus: Fat-filled grooves along the superior surfaces of the heart. (Chapter 11.2)

Superior mesenteric artery: A major artery that branches from the abdominal aorta and supplies oxygenated blood to most of the small intestine and part of the large intestine. (Chapter 11.5)

Superior vena cava: A large vein that carries deoxygenated blood from the head, neck, upper limbs, and chest back to the right atrium of the heart. (Chapter 11.2, Chapter 11.5)

Systemic circulation: Transports oxygenated blood to almost all tissues of the body and returns deoxygenated blood to the heart to be sent through the pulmonary circulation. (Chapter 11.2)

Systole: Contraction of the heart. (Chapter 11.4)

Systolic pressure: The higher number in a blood pressure reading; it measures the pressure in the arteries when the heart contracts and pumps blood. (Chapter 11.5)

Tachycardia: A condition in which the resting heart rate for an adult is greater than 100 bpm. (Chapter 11.4)

Temporal vein: A vein that drains blood from the scalp and parts of the face, eventually contributing to the formation of the external jugular vein. (Chapter 11.5)

Testicular artery: A paired artery that arises from the abdominal aorta and supplies oxygenated blood to the testes in males. (Chapter 11.5)

Testicular vein: Flows from the scrotum, forming a portion of the spermatic cord. (Chapter 11.5)

Tetralogy of Fallot (ToF): A complex set of congenital heart defects that occurs in approximately 400 out of one million live births. (Chapter 11.6)

Thoracic aorta: The portion of the descending aorta located in the chest (thoracic) cavity that supplies blood to the chest wall and organs within the thorax. (Chapter 11.5)

Trabeculae carneae: Irregular ridges of cardiac muscle lining the inner walls of the ventricles, helping to reduce suction and improve heart efficiency during contraction. (Chapter 11.2)

Tricuspid valve: The valve between the right atrium and right ventricle that prevents backflow of blood when the ventricle contracts. (Chapter 11.2)

Trunk: A large artery. (Chapter 11.5)

Tunica externa: A sheath of connective tissue composed primarily of collagenous fibers. (Chapter 11.5)

Tunica interna: Composed of smooth epithelial and connective tissue layers. (Chapter 11.5)

Tunica media: The middle layer of the vessel wall. (Chapter 11.5)

Tunics: The three distinct layers that make up the walls of blood vessels. (Chapter 11.5)

Ulnar artery: A major artery of the forearm that runs along the little finger side, supplying blood to the medial aspect of the forearm and hand. (Chapter 11.5)

Ulnar vein: A vein that runs along the medial (pinky) side of the forearm, returning blood from the hand and forearm to the heart. (Chapter 11.5)

Umbilical arteries: Carry oxygen-depleted fetal blood, including wastes and carbon dioxide, to the placenta. (Chapter 11.5)

Umbilical vein: Carries oxygen-rich blood from the mother to the fetus. (Chapter 11.5)

Valve: A specialized structure that ensures one-way flow of blood. (Chapter 11.2)

Varicose veins: Occur in the superficial veins of the legs when defective valves allow blood to accumulate, causing them to distend, twist, and become visible on the surface of the skin. (Chapter 11.6)

Vasoconstriction: Decreases blood flow as the smooth muscle in the walls of the tunica media contracts, making the lumen narrower and increasing blood pressure. (Chapter 11.5)

Vasodilation: Increases blood flow as the smooth muscle relaxes, allowing the lumen to widen and blood pressure to drop. (Chapter 11.5)

Veins: Vessels that bring blood back to the heart. (Chapter 11.2, Chapter 11.5)

Ventricles: The two lower chambers of the heart that receive blood from the atria and pump it out to the lungs and the rest of the body. (Chapter 11.2)

Ventricular ejection phase: The second phase of ventricular systole when the ventricles contract fully, forcing blood out through the open semilunar valves into the pulmonary trunk and aorta. (Chapter 11.4)

Ventricular fibrillation (V Fib): A disorganized heart rhythm that causes the ventricles to quiver instead of contract. (Chapter 11.6)

Ventricular tachycardia (V Tach): Refers to a very rapid heartbeat that originates in the ventricles. (Chapter 11.6)

Venules: Small blood vessels that receive blood from capillaries and transport it into larger veins, beginning the return flow of blood back to the heart. (Chapter 11.5)

Vertebral arteries: Arteries travel through the cervical vertebrae to supply blood to the brain. (Chapter 11.5)

Viscosity: A measure of a fluid’s thickness or resistance to flow. (Chapter 11.5)