The Heart

Question 1

what is the heart?

Answer 1

Cone shaped, muscular pump

Question 2

where is the heart located?

Answer 2

in the thorax between lungs (medium sternum)

Question 3

what protects the heart?

Answer 3

the ribcage (ribs 2-5)

Question 4

where is the apex of the heart located?

Answer 4

5th intercostal space

Question 5

what’s the heart wrapped in?

Answer 5

pericardium (layers of tissue)

Question 6

how many types of pericardium are there?

Answer 6

2

Question 7

what are the 2 types of pericardium?

Answer 7

fibrous pericardium (outer)
serous pericardium (inner)

Question 8

what is the fibrous pericardium, physically?

Answer 8

non-elastic sac of dense elastic tissue

Question 9

How is the fibrous pericardium attached to its surroundings?

Answer 9

fuses inferiorly with the diaphragm and superiorly with the great vessels

Question 10

what’s the function of the fibrous pericardium? (2)

Answer 10

to prevent the heart from overfilling with blood

anchors it in position

Question 11

where is the serous pericardium located?

Answer 11

between the heart and the fibrous pericardium

Question 12

Is the serous pericardium a single or double membrane?

Answer 12

double

Question 13

what are the 2 portions of the serous pericardium double membrane?

Answer 13

visceral (inner)

parietal (outer)

Question 14

what does the serous pericardium secrete?

Answer 14

serous fluid

Question 15

what does serous fluid do?

Answer 15

allows the 2 membranes to glide on top of each other in the pericardial cavity (preventing friction)

Question 16

What are the 3 layers of the thick muscular heart wall made up of?

Answer 16

• endocardium (inner layer)
• myocardium (middle layer)
• epicardium (outermost layer)

Question 17

what’s the endocardium made up of?

Answer 17

endothelium (simple squamous epithelia)

Question 18

what’s the myocardium made up of?

Answer 18

spiral bundles of cardiac muscle

Question 19

what’s the epicardium the same as?

Answer 19

the visceral pericardium

Question 20

what does the epicardium contain?

Answer 20

blood vessels which the the heart with blood

Question 21

Which ventricular wall is thicker?

Answer 21

left

Question 22

why is the left ventricular wall thicker?

Answer 22

has to pump at a greater pressure

Question 23

What’s the fibrous skeleton of the heart?

Answer 23

bands of fibrous connective tissue that are found between the atria and ventricles

Question 24

How does the fibrous skeleton separate the atria from the ventricles?

Answer 24

electrically (so only the atria or ventricles are contracting at any one time)

Question 25

How many ways to heart valves open in?

Answer 25

1

Question 26

what's the purpose of heart valves?

Answer 26

to prevent backflow of blood

Question 27

What are the 2 types of valves found in the heart?

Answer 27

Atroventricular (AV) | Semilunar (SV)

Question 28

Which side of the heart is the tricuspid AV?

Answer 28

right

Question 29

which side of the heart is the bicuspid AV?

Answer 29

left

Question 30

Where are AV valves found?

Answer 30

between atria and ventricles

Question 31

what opens the AV valves?

Answer 31

the pressure of the blood flowing from the atria to the ventricles

Question 32

What prevents the valves from everting?

Answer 32

they are anchored by chordae tendnae to papillary muscles

Question 33

what are the 2 types of semilunar valves?

Answer 33

pulmonary and aortic

Question 34

where's the pulmonary SV found?

Answer 34

between the right ventricle and the pulmonary trunk

Question 35

where's the aortic SV found?

Answer 35

between the left ventricle and the aorta

Question 36

What opens the SV?

Answer 36

the force of the ventricles contracting

Question 37

what keeps the SVs shut?

Answer 37

during ventricular diastole, blood flows backwards into the aorta and pulmonary trunk which pools in the cusps to hold the SV shut

Question 38

What is the coronary circulation made up of?

Answer 38

vessels running in the epicardium, usually surrounded by fatty tissue

Question 39

How much blood per minute is delivered to the heart by the coronary circulation?

Answer 39

250ml

Question 40

When is coronary blood delivered to the myocardium?

Answer 40

during ventricular relaxation

Question 41

where do most cardiac veins drain?

Answer 41

into the coronary sinus which empties into the right atrium

Question 42

what's an angiography?

Answer 42

an imaging technique used the examine the patency (condition) of vessels

Question 43

generally, what does the conducting system do?

Answer 43

coordinates heart contraction

Question 44

what do the cells of the conducting system do?

Answer 44

initiate electrical impulse (they don't contract themselves)

Question 45

draw a flow diagram showing the movement of electrical impulse through the heart

Answer 45

Sinoatrial Node (SN)--> Atrioventricular Node --> Atrioventricular bundle--> branches off to left and right heart--> ends at Perkinje fibres

Question 46

what does an Electrocardiogram (ECG) do?

Answer 46

records the electrical activity of the heart

Question 47

How are oxygen and nutrients delivered to a foetus?

Answer 47

from the placenta via the umbilical cord

Question 48

what does foetal circulation bypass?

Answer 48

the non-functional lungs and the liver

Question 49

What allows the non-functional lungs and the liver in the foetus to be bypassed? (2)

Answer 49

Ductus Venosus | Gap in the heart's septum- Foramen Ovale

Question 50

What does the Ductus ateriosus connect?

Answer 50

the pulmonary trunk to the arch of the aorta

Question 51

What changes occur at birth when the newborn takes their first breath?

Answer 51

- lungs expand--> blood rushes into pulmonary circulation --> O2 levels rise--> ductus arteriosus constricts - Left Arterial pressure increases causing the foramen ovale to become the fossa ovalis - The umbical cord is tied--> umbilical vessels closes --> ductus venosus closes

Question 52

what does the ductus venosus become?

Answer 52

ligamentum venosum

Question 53

what does the foramen ovale become?

Answer 53

fossa ovalis

Question 54

what does the ductus arteriosus become?

Answer 54

ligamentum arteriosum