Lecture 15

Question 1

Location and orientation of the heart

Answer 1

1/3 to the right, 2/3 to the left. Bottom ‘pointy’ end of heart is apex and in the 5th intercostal space on left. The right and left lung occupy the two lateral pulmonary cavities of the thorax

Question 2

Superior mediastinum

Answer 2

above the heart

Question 3

anterior mediastinum

Answer 3

in front of heart

Question 4

Middle mediastinum

Answer 4

at heart

Question 5

posterior mediastinum

Answer 5

behind heart

Question 6

transverse thoracic plane

Answer 6

conceptual line that is defined by the inferior boarder of T4

Question 7

sternal angle

Answer 7

Manubriosternal joint

Question 8

Aorta

Answer 8

ascending aorta (comes from LV), aortic arch (gives rise to other vessels) and descending aorta

Question 9

Pulmonary trunk

Answer 9

Blood from RV to lungs

Question 10

superior vena cava

Answer 10

Blood to RA

Question 11

Inferior vena cava

Answer 11

Blood to RA

Question 12

4x pulmonary veins

Answer 12

very posterior

Question 13

Arteries

Answer 13

large arteries to head, neck, upper limb and thorax. From aortic arch, brachiocephalic trunk (RS only), common carotid and left subclavian artery on LHS. Brachiocephalic trunk branches into right common carotid and subclavian artery.

Question 14

Veins

Answer 14

Right subclavian meets with jugular vein to RA (forms brachiocephalic vein). On left, same thing. Left BCV is longer than right as it if further from superior VC.

Question 15

pulmonary vessels

Answer 15

Exception that arteries carry O2 blood and veins carry deO2 blood. Pulmonary arteries carry deO2 blood to lungs and pulmonary veins carry O2 to heart.

Question 16

Spatial orientation of heart

Answer 16

When looking at heart from anterior POV, mostly right ventricle and atrium. LV and LA are more posterior.

Question 17

Pericardium

Answer 17

3 layered fibroserous membrane that covers the heart. Has a single inelastic outer layer (fibrous pericardium) which fuses with sternum, great vessels and diaphragm. Keeps heart in place and prevents over-distension.

Question 18

Auricles

Answer 18

Atrial projections (L and R) anterior surface of heart

Question 19

Apex

Answer 19

Formed by LV

Question 20

Atrioventricular sulcus

Answer 20

Anterior interventricular groove between ventricles

Question 21

Posterior external features

Answer 21

posterior sulci, SVC, IVC, L and R PA, branches of pulmonary trunk.

Question 22

internal features of right atrium

Answer 22

Anterior wall and right auricle have musculi pectinati which attach to a thick posterior ridge called cristae terminalis forming a line between SVC and IVC and between rough and smooth atrial wall. The coronary sinus brings deO2 blood from heart to RA to join oxygenation cycle, SVC and IVC bringing deO2 blood from body and right atrioventricular orifice which is the opening between RA and RV

Question 23

Internal features of RV

Answer 23

Right atrioventricular orifice is guarded by tricuspid valve which is attached to ventricular valve by tough tendons called chordae tendineae papillary muscles. Has muscular ridges called carneae. Pulmonary trunk guarded by semilunar valve.

Question 24

Internal features of LA

Answer 24

Most of the LA wall is smooth with only the auricle having musculi pectinati. No crista terminalis on LHS. 4 PV and left atrioventricular orifice.

Question 25

Internal features of LV

Answer 25

Left atrioventricular orifice guarded by bicuspid valve. Cusps attached to papillary muscles via chordae tendinae. Has tuberculae carneae.

Question 26

Atrioventricular valves

Answer 26

2 atrioventricular valves in heart. Thin leaflets at the atrioventricular boundary joined to papillary muscles in ventricle wall by chirdae tendineae which hold tension on the valve leaflets preventing them from opening into the atrium on ventricular contraction risking backflow of blood. The tricuspid atrioventricular valve between RA and RV has 2 leaflets. Bicuspid allows O2 blood to travel into LV.

Question 27

Semilunar valves

Answer 27

2 in the heart. Have 3 crescent shaped cusps in walls of pulmonary trunk and aorta at the exit of their ventricles. Stops backflow. Pulmonary SLV sends deO2 blood to lungs and aortic SLV sends O2 blood from LV to aorta. When ASLV closes and blood enters ascending aorta, any leftover in ascending aorta flows down into cusps due to gravity and flows into coronary arteries.

Question 28

Coronary circulation

Answer 28

Coronary arteries and cardiac veins. Aortic sinuses located above each semilunar cusp and they fill with blood which enter coronary arteries. Recoil of aorta closes valves and that's when it fills coronary arteries

Question 29

coronary arteries

Answer 29

R and L coronary arteries branch and fill from ascending aorta. RCA travels in anteriorventricular sulcus continuing posteriorly as the right posterior interventricular artery in the posterior interventricular sulcus. LCA wraps around behind pulmonary trunk, continuing as the left interventricular branch of the LCA. In anterior interventricular sulcus.

Question 30

Pulmonary veins

Answer 30

Exits: Oxygenated blood exits the lungs through pulmonary veins. Enters: These veins drain into the left atrium of the heart.

Question 31

Pulmonary arteries

Answer 31

Exits: The pulmonary artery exits the right ventricle of the heart through the pulmonary valve. Enters: It then carries deoxygenated blood to the lungs.