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Flashcards in 7 structure of the heart Deck (37):
1

Where does the heart lie?

behind the sternum in the mediastinum. behind ribs 2-5.

2

Where is the apex of the heart located?

Behind the 5th rib along the midclavicular line

3

What protects the heart?

-ribs
-sternum
-fibrous periacardum

4

What is the job of the fibrous pericardium

-tough unstretchy bag that stops the heart from over filling
-attached to the diaphragm and fused to the great vessels
-to anchor the heart in place

5

What is the structure of the fibrous pericardium?

-visceral and parietal pericardium
-parietal attached to the fibrous
-FP made of dense CT
-visceral (epicardium) attached to the heart wall
-serous fluid between the membranes makes movement frictionless
-gap between membranes = parietal cavity

6

What are the layers of the heart wall?

-epicardium/visceral pericardium
-myocardium
-endocardium

7

What does the epicardium contain?

lots of fat and blood vessels

8

What does the myocardium contain?

Lots of muscle - very thick layer

9

What does the endocardium consist of?

simple squamous endothelial cells for a smooth interior of the heart wall

10

What is another name for the visceral pericardium?

Epicardium

11

What is the name of the gap between the visceral and parietal pericardium?

Parietal cavity filled with serous fluid so two pericardial layers can glide on each other with no friction

12

Where is the bi cuspid valve?

between the left ventricle and atria

13

Where are the mitral valves?

between the ventricles and atria

14

Where are the semilunar valves?

Between the ventricles and aorta/pulmonary artery

15

Where are the atrioventricular valves?

where do you think, stupid?

16

Where is the tricuspid valve?

between the right ventricle and atrium

17

Talk about the action of the AV valves...

-conncted to papillary muscles by chordae tendinae
-as atria fills and pressure builds they open into ventricles
-as ventricles fill and pressure builds they are pushed back up and try to open into the atria causing eversion
-papillary muscles tense up and pull chordae tendinae tight preventing them from doing this

18

Whats eversion?

Flow of blood back into the atria due to backwards valves

19

Action of the semilunar valves:

-pushed open when ventricular pressure exceed aortic pressure
-during diastole they are pushed shut by blood pooling in the cusps

20

How are the coronary vessels fed?

-when systole the semilunar valves cover the entrance to them
-during diastole blood pooled on the cusp flows into the vessels to feed heart
-better this way coz otherwise vessels would be all squeezed up

21

What are the coronary vessels?

LCA
-anterior inter ventricular vessel
-circumflex
RCA
-posterior interventricular vessel
-marginal

22

Which artery does the anterior interventricular vessel come off

LCA

23

Which artery does the posterior interventricular vessel come off

RCA

24

Where is the circumflex

vessel that wraps from the front of the hear round the back around aorta

25

Where do the coronary vessels drain to?

either into the coronary sinus and into the right atria or straight into the right atria

26

What happens if one of the coronary vessels is damaged?

Theres an anastamoses between the anterior and posterior interventricular vessel so they can share blood. otherwise tissue death and potential heart failure

27

How much blood per minute do the coronary vessels get?

250ml

28

What is the anterioventricular artery also known as?

The descending artery

29

What does the conducting system of he heart consist of?

Non contractile elements such as AVN SAN and bundle of his
-However they are adjacent to cells that do contract

30

Talk about contraction of the heart

-when one cell contracts all the cells around it do too so can cause contraction from a specific point
-starts at SAN --> spreads through atria but conat conduct through fibrous skeleton
-must continue through the AVN and down the R and L bundles of his to the apex

31

Foetal adaptations in circulatory system:

-Ductous venosus
-Ductus artereosis
-Foreman ovale

32

Flow of blood through the foetus:

-in through umbilical vein from placenta (o2 rich ish)
-either through the liver or ductous venousus to inferior vena cava (bringing blood from the legs to the heart) - into the heart where it all mixes through DA and FO
-out of the heart to body/lungs - some to feet and bladder but most back to placenta

33

Where is the Foreman ovale?

hole between right and left atria

34

Where is the ductous arteriosis?

linking pulmonary trunk to the aorta

35

What happens to the foreman ovale after birth

-left atrial pressure increases and causes it to slam shut producing the fossa ovale

36

What happens to the ductus venosus after birth?

it doesn't get blood from the umbilical vein anymore so it shrivels up and becomes ligamentum venosum

37

What happens to the ductous arteriosis after birth?

the baby takes its first breath which expands the lungs causing the pressure in them to drop. this draws more oxygenated blood up towards them causing it to constrict and become ligamentum arteriosum