Chapter 5 Flashcards

Question

Atrioventricular node

Answer 1

SA node travel to The AV node is located on the floor of the right atrium near the interatrial septum (Figure 5.7). From here, it transmits the electrical impulses onward to the bundle of His.

Answer 2

is a group of fibers located within the interventricular septum. These fibers carry an electrical impulse to ensure the sequence of the heart contractions (Figure 5.7). These electrical impulses travel onward to the right and left ventricles and the Purkinje fibers

Answer 3

are specialized conductive fibers located within the walls of the ventricles. These fibers relay the electrical impulses to the cells of the ventricles, and it is this stimulation that causes the ventricles to contract. This contractionof the ventricles forces blood out of the heart and into the aorta and pulmonary arteries

Answer 4

which are only one epithelial cell in thickness, are the smallest blood vessels in the body. The capillaries form networks of expanded vascular beds that have the important role of delivering oxygen and nutrients to the cells of the tissues (Figure 5.11). n The capillaries further slow the flow of blood to allow plasma to flow into the tissues. It is here that the exchange of oxygen, nutrients, and waste materials occur within the surrounding cells. n After leaving the cells, 90% of this fluid, which is now oxygen poor and contains some waste products, enter the opposite end of the capillary bed through the venules. n The 10% of this fluid that is left behind in the tissues becomes lymph.

Answer 5

form a low-pressure collecting system to return oxygen-poor blood to the heart (Figures 5.10 through 5.12). n Venules (VEN-youls) are the smallest veins that join to form the larger veins. n The walls of the veins are thinner and less elastic than those of the arteries. n The venous blood continues its flow at an increased speed as it continues its return journey to the heart. Venous means relating to, or contained in, the veins. n Veins have valves that enable blood to flow only toward the heart and to prevent it from flowing away from the heart (Figure 5.12). n Superficial veins are located near the body surface. n Deep veins are located within the tissues and away from the body surface.

Answer 6

largest veins, return blood into heart

Answer 7

contraction of the heart

Answer 8

relaxation of the heart

Answer 9

plasma fluid after the blood cells | and the clotting proteins have been removed.

Answer 10

are the clotting proteins found in plasma. They have an important role in clot formation to control bleeding

Answer 11

which are formed in red bone marrow, are the most common type of WBC. Through phagocytosis, neutrophils play a major role in the immune system’s defense against pathogens, including bacteria, viruses, and fungi

Answer 12

is the process of destroying pathogens by surrounding and swallowing them

Answer 13

which are also formed in red bone marrow, are the least common type of WBC. Basophils are responsible for causing the symptoms of allergies

Answer 14

are formed in red bone marrow and then migrate to tissues throughout the body. Here these cells destroy parasitic organisms and play a major role in allergic reactions

Answer 15

are formed in red bone marrow, in lymph nodes, and in the spleen. Lymphocytes identify foreign substances and germs (bacteria or viruses) in the body and produce antibodies that specifically target them

Answer 16

are formed in red bone marrow, lymph nodes, and the spleen. Through phagocytosis, monocytes provide immunological defenses against many infectious organisms

Answer 17

which are also known as platelets, are the smallest formed elements of the blood. They play an important role in the clotting of blood (thromb/o means clot, and -cytes means cells). n When a blood vessel is damaged, the thrombocytes are activated and become sticky. n This action causes the thrombocytes to clump together to form a clot to stop the bleeding

Answer 18

any substance the body regards as foreign

Answer 19

means | pertaining to the disruption of the blood supply.

Answer 20

is a condition in which there is an insufficient supply of oxygen in the tissues due to a restricted blood flow to a part of the body

Answer 21

is a condition in which severe episodes of chest pain occur due to an inadequate blood flow to the myocardium. These episodes are due to ischemia of the heart muscle and often progressively worsen as the blood flow continues to be compromised, until a myocardial infarction occurs.

Answer 22

sudden insufficnecy of blood

Answer 23

total blockage

Answer 24

expansion of a hollow structure

Answer 25

is the loss of the normal rhythm of the heartbeat. This can be a minor, temporary episode, or it can be a fatal event. The severity of this episode depends on how much the heart’s ability to pump blood is compromised. Rather than being an abnormality in the heart muscle, arrhythmias are usually caused by an abnormality in the electrical conduction system of the heart.

Answer 26

sudden occurence

Answer 27

the flow of blood through the vessels | of an organ

Answer 28

something inserted

Answer 29

is a fatty substance that travels through the blood and is found in all parts of the body. It aids in the production of cell membranes, some hormones, and vitamin D. Some cholesterol comes from dietary sources, and some is created by the liver. Excessively high levels of certain types of cholesterol can lead to heart disease

Answer 30

lso known as the pericardial sac, is the double-walled membranous sac that encloses the heart

Answer 31

carry blood towards the head

Answer 32

are the smaller, thinner branches of arteries that deliver blood to the capillaries. As it enters one end of the capillary bed, it is here that the rate of flow of arterial blood slows.

Answer 33

is the rhythmic pressure against the walls of | an artery caused by the contraction of the heart

Answer 34

is the measurement of the amount of systolic and diastolic pressure exerted against the walls of the arterie

Answer 35

which occurs when the ventricles contract, is the highest pressure against the walls of an artery. The term systole means contraction of the heart, and systolic means pertaining to this contraction phase.

Answer 36

sudden insufficiency of blood

Answer 37

localized area of dead tissue caused by a lack of blood

Answer 38

bad cholesterol | excessive quantities of ldl contribute to plaque buildup in arteries

Answer 39

good cholesterol because it carries unneeded cholesterol back to the liver for processing and does not contribute to plaque buildup.

Answer 40

are combinations of fatty acids attached to glycerol that are also found normally in the blood in limited quantities.

Answer 41

rapid uncontrollable heart beat

Answer 42

is a lower-than-normal number of erythrocytes (red blood cells) in the blood The severity of this condition is usually measured by a decrease in the amount of hemoglobin in the blood. When inadequate hemoglobin is present, all parts of the body receive less oxygen and have less energy than is needed to function properly.

Answer 43

high blood pressure

Answer 44

low blood pressure

Answer 45

is administered to stimulate the kidneys to increase the secretion of urine to rid the body of excess sodium and water. These medications are administered to treat hypertension and heart failure by reducing the amount of fluid circulating in the blood.

Answer 46

taken in a very small daily dose, such as 81 mg, which is commonly known as baby aspirin, may be recommended to reduce the risk of a heart attack or stroke by reducing the ability of the blood to clot.