Thorax 3 (The heart)

Question 1

what does cardiovascular system consist of?

Answer 1

double circulatory system driven by both left and right sides of the heart
-pulmonary and systemic

Question 2

what is the pulmonary system

Answer 2

low pressure system to lungs - therefore arteries and veins cannot be identified by thickness of walls)

Question 3

what is the pressure like in systemic system

Answer 3

high

Question 4

what is the structure of the heart

Answer 4

4 chambered muscular pump that squeezes blood around the body

• left and right atria
• left and right ventricles

Question 5

what is the sac that surrounds the heart?

Answer 5

pericardium

Question 6

what are the three layers of the pericardium

Answer 6

fibrous
parietal
visceral

Question 7

pericardium - fibrous layer

Answer 7

tough and inelastic - on the outside of pericardium therefore is fused to the central tendon of the diaphragm
- connected by fibrous tissue to the upper and lower parts if the sternum (sternopericardial ligaments)

Question 8

pericardium - parietal layer

Answer 8

fused to fibrous pericardium

Question 9

pericardium - visceral layer

Answer 9

attached to the surface of the heart

Question 10

where does the pericardial cavity lie? and what does it contain?

Answer 10

between two layers - contains thin film of lubricant that allows frictionless movement of the heart within the pericardium

Question 11

pericardial cavity - what is the transverse sinus

Answer 11

recess in between the aorta and pulmonary artery in front and the superior vena cava behind

Question 12

pericardial cavity - what is the oblique sinus

Answer 12

posterior recess behind the left atrium, where it is reflected ack around the inside of the inner serous pericardial sac

Question 13

pericardium - what happens at the roots of the great vessels

Answer 13

the serous pericardium runs up them for a short way and then reflects back on itself

• superior vena cava has a sleeve of its own
• aorta and pulmonary trunk share a sleeve

Question 14

what is the heart protected by

Answer 14

bony thoracic cage - ribs, manubrium, sternum, vertebral column

Question 15

what the heart sounds and where do they come from

Answer 15

lub-dub
lub - from mitral and tricuspid valves closing at the beginning of ventricular systole
dub - closing of both semilunar valves at the beginning of diastole

Question 16

anatomical positioning of the heart

Answer 16

located in the middle mediastinum
- anterior mediastinum between heart and sternum
- superior mediastinum above the heart and behind the manubrium
- posterior mediastinum is between heart and vertebral column
apex of heart located in 5th intercostal space

Question 17

shape of the heart

Answer 17

left side is thicker than right as it has to pump blood against a much higher resistance
- heart lies obliquely

Question 18

what are the inflow and outflow channels

Answer 18

right atrial inflow
left atrial inflow
right ventricular outflow
left ventricular outflow

Question 19

inflow and outflow channels

- right atrial

Answer 19

• superior vena cava from upper parts of the body
  inferior vena cava from lower parts of the body
  coronary sinus drains majority of blood from the heart muscle itself

Question 20

inflow and outflow channels

- left atrial

Answer 20

• four pulmonary veins (2 right and 2 left) - lie at the back of the heart which carries oxygenated blood from the lungs

Question 21

inflow and outflow channels

- right ventricular

Answer 21

• pulmonary trunk (bifurcates into 1 left and 1 right pulmonary artery which both split again) - carries deoxygenated blood to lungs

Question 22

inflow and outflow channels

- left ventricular

Answer 22

• aorta - forms aortic arch and this splits off al over the body

Question 23

what is the difference between inflow outflow angle in left ventricle compared to right

Answer 23

more acute