cardiovascular anatomy

Question 1

branches off the arch of the aorta

Answer 1

• brachiocephalic trunk
• right subclavian
• right common carotid
• left common carotid
• left subclavian

Question 2

what are the layers of the heart (external-internal)

Answer 2

• epicardium
• myocardium
• endocardium

Question 3

epicardium

Answer 3

• thin layer
• outermost layer
• formed by visceral and serous pericardium
• composed of connective tissue and fat
• connective tissue secretes small amount of lubricating fluid into the pericardial cavity
• where nerves and blood vessels of the heart are found
• functions as an additional layer under the pericardium to help protect the heart

Question 4

myocardium

Answer 4

• thick later
• cardiac muscle
• responsible for contraction and relaxation
• provides structure
• conducting electrostimulation
• composed of cardiac muscle
• is an involuntary striated muscle

Question 5

endocardium

Answer 5

• thin layer
• lines cavities and valves
• lines inner surface
• main function is to provide protection
• comprised of lose connective tissue and simple squamous epithelial tissue
• regulates contractions and aids cardiac embryological development

Question 6

what is cardiac tamponade

Answer 6

compression of the heart due to a build up of fluid around the heart
- fluid build up in the pericardial cavity compromises the heart volume

Question 7

where are the main parts of the hearts conducting system found

Answer 7

in the septum
- the interatrial septum and the interventricular septum

Question 8

flow of blood through the heart

Answer 8

1. enters through the superior and inferior vena cava and coronary sinus
2. blood enters into the right atrium
3. blood passes through the tricuspid valve
4. blood enters the right ventricle
5. blood is pumped up through the pulmonary artery through the pulmonary valve
6. blood enters the lungs where it is oxygenated
7. blood re-enters the heart through 1 of 4 pulmonary veins
8. entering into the left atrium
9. blood is passed through the mitral valve into the left ventricle
10. blood is then pumped through the aortic valve into the aorta

Question 9

what prevents back flow of blood in addition to the valves

Answer 9

• the papillary muscles
• the chordae tendineae

Question 10

veins of the heart

Answer 10

• superior and inferior vena cava (deoxygenated blood too heart)
• pulmonary veins (oxygenated blood to the heart from the lungs)

Question 11

arteries of the heart

Answer 11

• pulmonary artery (deoxygenated blood from heart to the lungs)
• aorta (oxygenated blood away from heart to rest of body)

Question 12

sections of the main part of the aorta

Answer 12

• ascending aorta
• arch of aorta
• descending aorta

Question 13

what is an aneurysm

Answer 13

a dilation of the artery

Question 14

pulmonary arteries/ trunk

Answer 14

• pulmonary trunk splits in 2 around T5-T6
• the pulmonary trunk is a think short vessel
• two branches of the left and right pulmonary arteries enter each lung

Question 15

pulmonary veins

Answer 15

• 4 pulmonary veins
• there is one superior and one inferior vein arriving from each lung
• superior vena cava returns blood from the upper lobes
• the inferior vena cava returns blood from the lower lobes

Question 16

superior vena cava formation

Answer 16

• formed through the merging of the brachiocephalic veins
• drains into the right atrium at the 3rd rib

Question 17

inferior vena cava formation

Answer 17

• formed in the pelvis by the joining of the common iliac veins
• collects blood from the hepatic, lumbar, gonadal, renal and phrenic veins
• enters the pericardium at T8

Question 18

what are the great vessels of the heart

Answer 18

• the 4 main vessels that transport blood to and from the heart
• aorta, pulmonary artery, pulmonary vein, (superior and inferior) vena cava

Question 19

what separates the two sides of the heart

Answer 19

• the interatrial septum (between the atriums)
• the interventricular septum (between the ventricles)

Question 20

stages of electrical conduction of the heart

Answer 20

1. excitation signal is created by the sinoatrial node
2. the wave of excitation spreads across the atria causing them to contract
3. the signal then reaches the atrioventricular node where the signal is delayed
4. it is then conducted into the bundle of His down the interventricular septum
5. the bundle of His and the Purkinje fibres spread the wave of impulses along the ventricles
6. this causes the ventricles to contract

Question 21

what are the effects of the nervous system on the SA node

Answer 21

• sympathetic = increases the firing rate of the SA node, increasing the heart rate
• parasympathetic = decrease firing rate of the SA node, decreasing the heart rate

Question 22

what are the connecting layers in the heart

Answer 22

• subepicardial layer - between the myocardium and epicardium
• subendocardial layer - between and joins the endocardium and myocardium

Question 23

what layer of the heart are the purkinje fibres located in

Answer 23

the subendocardial layer

Question 24

what are the main layers of the pericardium

Answer 24

• fibrous pericardium (external)
• serous pericardium

Question 25

fibrous pericardium

Answer 25

- made of tough connective tissue - relatively non-distensible - rigid structure prevents rapid overfilling of the heart

Question 26

serous pericardium

Answer 26

- separated into 2 layers: outer parietal layer and the internal visceral layer

Question 27

what is the purpose of the pericardial cavity

Answer 27

to hold lubricating serous fluid that helps to minimise friction from heart contractions

Question 28

what is the function of the pericardium

Answer 28

- fixes the heart in the mediastinum, limiting its motion - prevents overfilling of the heart - lubrication - protection from infection

Question 29

what is the innervation of the pericardium

Answer 29

phrenic nerve is responsible for somatic innervation of the pericardium

Question 30

what are the names of the valves in the heart

Answer 30

- atrioventricular valves - tricuspid and mitral - semilunar - pulmonary and aortic

Question 31

what are the names of the coronary arteries that supply the heart

Answer 31

- right coronary and left coronary arteries - arise from the left and right aortic sinuses within the aorta

Question 32

what vessels does the left coronary artery give off

Answer 32

- left anterior descending artery - left marginal artery - left circumflex artery

Question 33

what vessels does the right coronary artery give off

Answer 33

- right marginal artery - posterior interventricular artery

Question 34

what is the venous drainage of the heart

Answer 34

the coronary sinus

Question 35

what are the tributaries of the coronary sinus

Answer 35

- great cardiac vein - small cardiac vein - middle cardiac vein - posterior cardiac vein