L1 - Heart & Cardiovascular System

Question 1

what is the heart?

Answer 1

the largest organ of the mediastinum of thorax

Question 2

what is the apex beat?

Answer 2

point of maximal impulse of heart
5th left intercostal, midclavicular line

Question 3

what are the 2 layers of cardiac pericardium?

Answer 3

1. Fibrous Pericardium - fibrous tissue (CT) adherent to central tendon of diaphragm
2. Serous Pericardium - 2 layers - parietal and visceral (epicardium) pericardium

Question 4

what is pericarditis?

Answer 4

inflammation of pericardium

Question 5

what is pericardial effusion?

Answer 5

excess fluid in pericardial cavity - constricts cardiac movement

Question 6

what are the two circulations and where do they go?

Answer 6

pulmonary: RV -> pulmonary arteries -> lungs -> pulmonary veins -> LA

systemic: LV -> aorta -> body -> vena cava -> RA

Question 7

what is the function of the heart valves?

Answer 7

prevent backflow

Question 8

what are the types of valves?

Answer 8

atrioventricular valves: between atria and ventricles
right = tricuspid
left = bicuspid
semilunar valves: at junction of ventricles & great arteries

Question 9

describe three features of the atria?

Answer 9

• irregularly shaped
• auricle = tapering shape
• interatrial septum

Question 10

what is the fossa ovalis?

Answer 10

depression in the interatrial septum of right atria
remains of foramen ovale in embryo

Question 11

give two features of the right ventricle’s interventricular septum? (upper and lower)

Answer 11

muscular/thick major part and membranous (thin upper part)

Question 12

give three features of the internal wall of the ventricles?

Answer 12

• trabeculae carneae (muscular ridges)
• papillary muscles
• chordae tendineae (connects tricuspid valves to papillary muscles)

Question 13

name three features of the left ventricle?

Answer 13

• apex
• mitral valve
• semilunar valves

Question 14

in the atrioventricular valves, what are the chordae tendineae attached to?

Answer 14

1. free margin & ventricular surface of leaflet
2. papillary muscles (project into ventricles)

Question 15

what is ventricular diastole?

Answer 15

valve relaxed and open

Question 16

what is ventricular systole?

Answer 16

papillary muscles contract - pulling cusps together - chordae tendineae prevent cusps being blown backward into atrium - valve closed

Question 17

what are the two semilunar valves?

Answer 17

pulmonary and aortic

Question 18

what is valve stenosis?

Answer 18

valve doesn’t open properly, narrow opening, reduced blood flow

Question 19

what is valve incompetence/leak?

Answer 19

valve does not close properly = backflow
normal amount of blood pumped at one time 55%
leaking valve = 25%

Question 20

where do coronary arteries arise from?

Answer 20

aorta sinuses located in coronary sulcus

Question 21

what is ischemic heart disease?

Answer 21

inadequate oxygenation of myocardium

Question 22

what drains the right atrium?

Answer 22

coronary sinus - main vein in coronary sulcus tributaries

Question 23

what are the layers of the heart wall?

Answer 23

1. epicardium (visceral pericardium)
2. myocardium (cardiac muscle)
3. endocardium (inner lining)

Question 24

what is the sino-atrial node?

Answer 24

• pacemaker
• wall of RA at junction of superior vena cava

Question 25

what is the atrioventricular node?

Answer 25

aka Bundle of His
in septum -> right bundle -> Purkinje Fibres
-> left bundle -> Purkinje Fibres

Question 26

how is the heart innervated?

Answer 26

parasympathetic nerve fibres - vagus nerve, inhibit heart
sympathetic nerve fibres - stimulate

Question 27

what is the dermatone?

Answer 27

strip of skin supplied by single spinal nerve

Question 28

what is referred pain?

Answer 28

pain from location interpreted by brain as coming from other location as they are innervated by the same spinal cord zone
Heart - T1 - T4