Lecture 7 Anatomy of the Heart

Question 1

Describe the structure of the heart

Answer 1

Cone shaped muscular pump

Located in the thorax between the lungs.

Question 2

Which ribs protect the heart

Answer 2

ribs 2-5

Question 3

Which structure protects the heart

Answer 3

The rib cage

Question 4

In relation to the rib cage, where can the apex of the heart be found

Answer 4

In the 5th intercostal space, in the midclavicular line.

Question 5

Describe the structure of the fibrous pericardium

Answer 5

• An inelastic sac/bag of dense connective tissue.
• FP fuses interiorly with the diaphragm and superiorly with the great vessels (aorta etc that project out of top of heart)

Question 6

What is the function of the fibrous pericardium

Answer 6

function of this big bag/sac like structure is to prevent over filling of the heart, and to anchor it into its position so it doesnt get loose in the body!

Question 7

Describe the structure of the serous pericardium

Answer 7

This is a double membrane located underneath the fibrous pericardium.
It contains both parietal and visceral sections.

Question 8

Describe the location of the heart

Answer 8

• located in thorax, between the two lungs
• protected by the ribs
• lies behind the sternum
• between ribs 2-5 (left of midline)

Question 9

Where is the apex (bottom) of the heart found

Answer 9

Apex lies in the midclavicular line and is found in the 5th intercostal space,

Question 10

What does pericardium mean

Answer 10

Around the heart

Question 11

What is the serous pericardium

Answer 11

It is a double layered serous membrane that lies deep to the fibrous pericardium. Contains visceral and parietal portions.

Question 12

What are the names of the 4 valves, and which chambers do they exist between

Answer 12

Tricuspid and bicuspid valve are the AV valves.

Question 13

What is the name of the left AV valve

Answer 13

The bicuspid valve (mitral valve

Question 14

What is the name of the right AV valve

Answer 14

The tricuspid valve

Question 15

What is the name of the valve that connects the left right ventricle to the pulmonary trunk

Answer 15

The pulmonary semi lunar valve

Question 16

What is the name of the valve that connects the left ventricle to the aorta

Answer 16

Aortic semi lunar valve

Question 17

What is the fibrous skeleton of the heart, and what is its function

Answer 17

Bands of fibrous tissue that separate the atria and ventricles from each other electrially. Fibrous skeleton represents area of non contractile tissue.

Question 18

Where would you find fibrous skeleton of the heart

Answer 18

Bands of fibrous tissue encircle the pulmonary artery and the aorta, AV valves and semi lunar valves.

Question 19

Which valves are anchored by the chordae tendinae

Answer 19

The tricupsid and biscupid valves.

Question 20

What is the role of the chordae tendinae

Answer 20

They anchor the bicuspid and tricuspid valves to the papillary muscles.

Question 21

What causes the AV valves to open

Answer 21

• AV valves are anchored to papillary muscles by chordae tendinae
• AV valve will open when the atrial pressure exceeds the ventricular valve
This pressure difference occurs when blood has filled into atria from superior and inferior VC

Question 22

What causes the AV valves to close

Answer 22

• AV valves will close when the ventricular pressure exceeds the atrial pressure
The contraction of papillary muscles prevents eversion of AV valves and prevents blood flowing back.

Question 23

What is the role of the papillary muscles

Answer 23

These muscles prevent eversion of the AV valves, and hence prevents backflow of blood into the atria.

NB the papillary muscles have no role in opening of the AV valves.

Question 24

Cardiac veins of the coronary circulation empty into which vessels/chambers of the heart.

Answer 24

Cardiac veins drain into the coronary sinus first.This empties into the right atrium.

Question 25

How much blood does the heart recieve per minute

Answer 25

The heart recieves 250 ml of blood per minute.

Question 26

During which phase of the cardiac cycle is blood delivered to the heart

Answer 26

Blood is delivered to the myocardium during ventricular relaxation.

Question 27

What is an angiography

Answer 27

A medical imaging technique used to examine how open or closed the blood vessels are, if there is any restriction to the flow of blood.

Question 28

Describe the conducting system of the heart

Answer 28

* f(x) to coordinate heart contraction * Consists of non contractile cells that initiate electrical impulses * SA node is located in the right atrium * AV node is located in the * AV bundle (bundle of his) * Right and left bundle branches * Purkinje fibers

Question 29

What is an ECG trace used for

Answer 29

ECG trace records the electrical activity of the heart.

Question 30

Describe three shortcuts of the fetal circulation

Answer 30

ductus venosus takes blood from umbilical vein to inferior VC. Foramen ovale is

Question 31

Which vessel carries blood from the placenta to the ductus venosus

Answer 31

The umbilical vein

Question 32

What is the foramen ovale, what does it allow

Answer 32

Foramen ovale allows blood to bypass the lungs. It is a small hole in the wall of the heart - septum, that allows blood to flow directly from the right atria to the left atria.

Question 33

What is the ductus arteriosus

Answer 33

This is a vessel that allows the blood to bypass the lungs. It is a vessel that connects the pulmonary artery to the aorta.

Question 34

What is the ductus venosus

Answer 34

Ductus venosus connects the umbilical vein to the inferior vena cava.

Question 35

Summarize the changes at birth in the fetal circulation when a newborn takes its first breath

Answer 35

1) Ductus venosum forms the ligamentum venosum 2) Foramen ovale closes to become Fossa ovalis 3) Umbilical cord it ties to produce ductoses fibroses. 4) Constriction of the ductus arteriosus to form the liagamentum arteriosum

Question 36

Which structures are involved in allowing blood to bypass the lungs

Answer 36

The foramen ovale and the ductus arteriosus.

Question 37

Explain what happens for constriction of the ductus arteriosus

Answer 37

- Lungs expand - blood rushes into the pulmonary circulation - Oxygen levels rise - Ductus arteriosus is constricted.

Question 38

What is the fibrous pericardium

Answer 38

• An inelastic sac of dense connective tissue Fuses interiorly with the diaphragm and superiorly with the great vessels F(x) is to prevents over filling of the heart and anchors it into position

Question 39

If the diaphragm moves, the heart will also move. True or false

Answer 39

True, because the heart is encased in a dense inelastic sac of connective tissue, called the fibrous pericardium. Fibrous pericardium is fused with the diaphragm.

Question 40

Describe the layers of the heart wall

Answer 40

• Endocardium is the inner most layer • Myocardium is the middle layer made up of cardiac muscle tissue Epicardium is the outer layer made of visceral pericardium

Question 41

Which layer of the heart wall is the thickest q

Answer 41

The myocardium, muscle layer. Also known as the tunica media.

Question 42

Describe and explain the structure of the serous pericardium

Answer 42

• Parietal pericardium lines the inner surface of the fibrous pericardium • The Visceral pericardium (epicardium) adheres tightly to the surface of the heart. • The pericardial cavity is the space that forms between the parietal and visceral layers which contains tissue fluid. f(x) of the serous pericardium is to prevent friction.