6a Cardiovascular System (Heart)

Question 1

What are the functions of the cardiovascular system?

Answer 1

Transportation of molecules using blood as a vehicle
1) delivering oxygen and nutrients to cells and tissues
2) removing carbon dioxide, ammonia and other metabolic waste from cells and tissues

Question 2

Where is the heart located?

Answer 2

In the thoracic cavity, between the lungs, inferior mediastinum

Question 3

Where does the apex of heart point and where is it approximately?

Answer 3

Towards the left hip , rests on the diaphragm, at approximately the 5th intercostal space

Question 4

Where is the base of the heart and where is it approximately?

Answer 4

Widest part of heart, points toward the right shoulder, behind the second rib
Where the great blood vessels emerge

Question 5

What kind of membranes cover both the lungs and the heart?

Answer 5

Serous membranes

Question 6

What is the serous membrane that surrounds the heart?

Answer 6

Pericardium

Question 7

Where is the parietal pericardium?

Answer 7

Outer layer of the pericardium, not directly in contact with the heart wall

Question 8

Where is the visceral pericardium?

Answer 8

Innermost layer of the pericardium, direct contact with the heart

Question 9

What is the space between the parietal and visceral pericardia?

Answer 9

The pericardial cavity, filled with serous fluid

Question 10

What is the purpose of the serous fluid filling the pericardial cavity?

Answer 10

Prevent friction, smooth gliding

Question 11

What does the pericardium do, other than prevent friction?

Answer 11

Anchors the heart to the surrounding structures like the diaphragm

Question 12

What are the components of the heart wall and their position?

Answer 12

Epicardium: outer layer
Myocardium: middle layer (muscle)
Endocardium: inner layer (direct contact with ventricle)

Question 13

What’s confusing about the relationship between the pericardium and the heart wall?

Answer 13

The outer most layer of the pericardium (parietal pericardium) and the outer most layer of the heart wall (epicardium) are actually the same structure but 2 names

Question 14

Where is the fibrous pericardium located?

Answer 14

Even more outer than the parietal epicardium
Parietal lines the inner surface of the fibrous pericardium

Question 15

What is the role of myocardium?

Answer 15

Cardiac muscle for contractions

Question 16

What is the role of endocardium?

Answer 16

Continuous with blood vessels
Simple squamous epithelium aka endothelium, makes sense cuz ENDOcardium
Serves to reduce friction of blood flow and prevent clotting

Question 17

Why is the myocardium of the left ventricle so much thicker than the myocardium of the right ventricle?

Answer 17

The right ventricle has to pump the blood to the lungs, a much shorter distance than the left ventricle, which has to pump throughout the whole body

Question 18

What are the two circuits that the heart pumps to? Briefly describe

Answer 18

Pulmonary circuit: right side of the heart pumping oxygen poor blood to lungs via the pulmonary artery
Systemic circuit: left side of the heart pumping oxygen rich blood to the rets of the body via the aorta and branches

Question 19

How does oxygen poor blood from the body makes its way back to the heart? Where does it enter?

Answer 19

Enters the right atrium
Comes from superior and inferior vena cava

Question 20

What separates the right atrium and right ventricle?

Answer 20

Right atrioventricular valve, or right AV valve

Question 21

Where does the blood from the right ventricle go next? What does it have to cross to get there?

Answer 21

Goes to the pulmonary artery, currently oxygen poor
Has to cross the pulmonary semilunar valve

Question 22

What kind of blood fills the left atrium and where does it come from?

Answer 22

Oxygen rich blood
Pulmonary vein

Question 23

What structure separates the left atrium and the left ventricle?

Answer 23

Left atrioventricular valve or left AV valve

Question 24

Where does the blood go from the left ventricle and what does it have to go through?

Answer 24

Goes to the aorta for distribution to the body
Must cross the aortic semilunar valve

Question 25

What do atria, generally speaking, do?

Answer 25

Receive blood from veins Assist in filling ventricles

Question 26

Does blood entering the atria enter at low or high pressure?

Answer 26

Low

Question 27

Generally speaking, what do the ventricles do?

Answer 27

Discharging chambers Propel blood to arteries Create that initial pressure

Question 28

What do arteries and veins do?

Answer 28

Arteries: carry blood away from heart Veins: carry blood to heart

Question 29

What can be said about the rate at which the heart pumps, specifically when do ventricles pumps and atria empty with respect to each other?

Answer 29

Ventricles pumps at the same time, atria empty into ventricles at same time

Question 30

What are the 3 little branches extending off the aortic arch?

Answer 30

Most right: brachiocephalic trunk Middle front ish: left common carotid artery Most left: left subclavian artery

Question 31

What do the arteries that branch from the aortic arch supple?

Answer 31

Brachiocephalic trunk: right arm and some branching to head Left carotid artery: head Left subclavian artery: left arm

Question 32

Where are the right and left coronary artery and what do they do?

Answer 32

Provides blood to the heart on either side Found in the right and left coronary sulcus (above the atrioventricular groove) For right: kind of traces the right atrium

Question 33

What do cardiac veins do?

Answer 33

Drain the myocardium of blood Small , great(left) and anterior cardiac veins

Question 34

Where is the coronary sinus located and what does it do?

Answer 34

Posterior end of heart Large vein that receives blood from cardiac veins Drains into the right atrium

Question 35

What are the 4 valves of teh heart?

Answer 35

Left and right atrioventricular valves: separating left and right atria from left and right ventricles Pulmonary semilunar valve: separating the right ventricle from the pulmonary artery Aortic semilunar valve: separating the left ventricle from the aorta

Question 36

What is the function of heart valves?

Answer 36

Allow blood to flow in 1 direction Prevent back flow Open and close in response to pressure changes

Question 37

What are the valves made of?

Answer 37

Cusps made of thin tough membrane

Question 38

Heart relation vs ventricular contraction?

Answer 38

Heart relaxation: ventricle is relaxed, not contracting Ventricle contraction… ventricle is in the process of pumping

Question 39

What holds the AV valves in place?

Answer 39

Chordae tendineae to the papillary muscles

Question 40

Describe AV valves when the heart is relaxed. What is happening?

Answer 40

Blood passively fills the ventricles Valves are therefore open

Question 41

How are the valves during ventricular contraction?

Answer 41

Closed to prevent backflow

Question 42

How are semilunar valves during heart relation?

Answer 42

Closed, not allowing the blood filling the ventricles to leave the other way

Question 43

How are semilunar valves during ventricular contraction?

Answer 43

Open, to let blood pass

Question 44

Describe the operation of AV valves?

Answer 44

Blood returning to the atria puts pressure on the valves, causing them to open into the ventricles The atrial pressure is greater than the ventricular pressure at this point, AV valves are limp Ventricles contract, forcing blood against the AV valve cusps, forcing it closed For a split second all valves are closed and there is very high pressure

Question 45

Describe the operation of semilunar valves.

Answer 45

Ventricles contract, intra ventricular pressure rises, semilunar valves are forces to open As the ventricles relax, the pressure falls, the valves close

Question 47

What are the sounds we hear during a heart beat? Where do they come from?

Answer 47

Lub-Dub Lub: AV valves closing Dub: semilunar valves closing

Question 48

What defines congestive heart failure?

Answer 48

Imbalance of pumping action between the two sides of the heart Many causes Heart inevitably fails

Question 49

What happens when teh right heart fails? (Chain reaction)

Answer 49

Results in peripheral congestion Then fluid accumulates in body tissues This causes edema (swelling of feet, ankles, fingers)

Question 50

What happens when teh left heart fails?

Answer 50

Leads to pulmonary congestion Then fluid accumulates in the lungs Then you drown and die

Question 51

What causes the heart to beat?

Answer 51

They make themselves beat Independent of nerve impulses They do this simultaneously

Question 52

What is the intrinsic conduction system?

Answer 52

Refers to teh network of specialized cardiac cells that ensure that the heart contract in a regular, continuous and synchronized fashion

Question 53

What special nervous tissues make up the intrinsic conduction system? Where?

Answer 53

Sinoatrial Node: right atrium, hearts pacemaker Atrioventricular Node: junction of atria and ventricles Atrioventricular Bundle: bundle branches are in the interventricular septum Purkinje fibers: spread within the ventricle wall muscles

Question 54

What is the path of electric signal responsible for our heartbeat?

Answer 54

SA node Atrial muscle AV node(delay), atria contracts Purkinje fibers Ventricular muscle Ventricles contract