Chapter 50: Circulatory Systems

Question 1

cardiovascular system

Answer 1

heart, blood, and vessels

Question 2

hearts

Answer 2

muscular chambers that move extracellular fluids around the body

Question 3

extracellular fluid

Answer 3

fluid in the circulatory system and the fluid outside it

Question 4

open circulatory system

Answer 4

heart helps move hemolymph through vessels leading to different regions of the body
inefficient

Question 5

closed circulatory system

Answer 5

a system of vessels keeps circulating blood separate from the interstitial fluid

Question 6

advantage of closed circulatory system vs open circulatory system

Answer 6

fluid can flow more rapidly, and therefore transport waste and nutrients faster
can control the flow of blood to tissues by the diameter of the vessels

Question 7

pulmonary circuit

Answer 7

blood is pumped from the heart to the lungs and back to the heart

Question 8

systemic circuit

Answer 8

blood pumped from the heart to the body, and then back to the heart

Question 9

arteries

Answer 9

blood vessels that carry the blood away from the heart

Question 10

arterioles

Answer 10

small arteries that feed blood into capillary beds

Question 11

capillaries

Answer 11

tiny, thin walled vessels where materials are changed by tissue fluid and blood

Question 12

venules

Answer 12

small vessels that drain capillary beds

Question 13

veins

Answer 13

deliver the blood back towards the heart

Question 14

sinus venosus (fish)

Answer 14

blood returning from all parts of the body collect here

Question 15

bulbus arteriousus (fish)

Answer 15

highly elastic chamber, last part of fishes heart

Question 16

aorta

Answer 16

large dorsal artery

Question 17

atrioventricular valve

Answer 17

one-way valve between the atria and ventricles

prevent blood flow of blood into the atria when the ventricles contract

Question 18

pulmonary valve

Answer 18

separates the right ventricle and pulmonary circuit, preventing blood flow

Question 19

aortic valve

Answer 19

separates the left ventricle and systemic circuit, prevents blood flow

Question 20

cardiac cycle

Answer 20

contraction of two atria, then contraction of two ventricles, and then relaxation

Question 21

systole

Answer 21

when the ventricles contract

Question 22

diastole

Answer 22

ventricles relax

Question 23

pacemaker cells

Answer 23

can initiate action potentials without stimulation from the nervous system

Question 24

sinoatrial node

Answer 24

primary pacemaker
modified cardiac muscle cells
located at the junction of superior vena cava and right atrium

Question 25

atrioventricular node

Answer 25

stimulated by the depolarization of the atria
located between the atria and ventricles
with slight delay, generates AP which are conducted to the ventricles via the bundle of His
slight delay ensures that the atria contract before ventricles do

Question 26

bundle of His

Answer 26

modified cardiac fibers that do not contract but conduct APs

Question 27

Purkinje fibers

Answer 27

conducting fibers ensure cardiac potential spreads rapidly and evenly throughout the ventricular muscle mass

Question 28

electrocardiogram

Answer 28

measured electrical events in the cardiac muscle during the cardiac cycle by placing electrodes on skin

Question 29

plasma

Answer 29

fluid matrix of the blood

Question 30

erythropoietin

Answer 30

hormone that controls the production of RBC

released by cells in the kidney

Question 31

hypoxia

Answer 31

insufficient oxygen

Question 32

spleen

Answer 32

recycles old RBC, they get ruptured b/c flexibility is lost

Question 33

platelets

Answer 33

tiny fragment of cell without any organelles, but packed with enzymes and chemicals necessary for sealing leaks in blood vessels and initiating blood clotting

Question 34

steps of blood clotting

Answer 34

1. prothrombin converted to thrombin
2. thrombin cleaves fibrinogen
3. forms insoluble threads of fibrin
4. fibrin forms the meshwork for clotting

Question 35

Starling’s forces

Answer 35

1. blood pressure squeezes water and small solutes out of the capillaries
2. osmotic pressure pulls water back into the capillaries

Question 36

edema

Answer 36

tissue swelling

Question 37

histamine

Answer 37

mediator of inflammation released by certain WBC
increases capillary permeability and relaxes the smooth muscles of arterioles, raising blood pressure of the capillaries and leading to fluid into tissues

Question 38

fenestrations

Answer 38

holes in the capillary walls

Question 39

Frank-Starling law

Answer 39

if the cardiac muscle cells are stretched, they contract more forecefully

Question 40

lymphatic system

Answer 40

returns interstitial fluid to the blood

Question 41

lymph

Answer 41

interstitial fluid once it has returned to lymphatic system

Question 42

thoracid duct

Answer 42

empty into large veins at the base of the neck

Question 43

plaque

Answer 43

deposits formed at sites of endothelial damage

Question 44

thrombus

Answer 44

intravascular blood clot

formed when blood platelets stick to the plaque

Question 45

coronary arteries

Answer 45

pathway of blood supply to the heart muscle

Question 46

myocardial infarction

Answer 46

heart attack

Question 47

embolus

Answer 47

piece of a thrombus that breaks loose

Question 48

stroke

Answer 48

embolism in an artery in the brain causes the cels fed by that artery to die