Cardiovascular - Heart

Question 1

What is the pericardium?

Answer 1

• Triple-layered sac that encloses the heart
• Simple squamous epithelium (mesothelium) and some loose C.T.
• Separated by serous fluid which decreases friction
• Consists of 2 layers:
• parietal layer
• visceral layer

Question 2

What is the pericardial cavity?

Answer 2

• Between the parietal and visceral layers of serous pericardium is a slitlike space
• filled with pericardial fluid

Question 3

What are the tunics of the heart?

Answer 3

1) endocardium (tunica intima)
2) myocardium (tunica media)
3) epicardium (tunica adventitia)

Question 4

What are the chambers of the heart?

Answer 4

4 chambers:
2 atria
2 ventricles

Question 5

Where does the right side of the heart pump to?

Answer 5

pulmonary circulation

Question 6

Where does the left side of the heart pump to?

Answer 6

systemic circulation

Question 7

How do veins reach the heart?

Answer 7

enter through the atria

Question 8

How do arteries reach the heart?

Answer 8

exit at the ventricles

Question 9

What is the position of the heart?

Answer 9

• Behind body of sternum
• Anterior to vertebrae T5 to T8
• Anterior and slightly to left in thorax
• Region: mediastinum (between 2 lungs)

Question 10

How is the “lub” sound produced in the heart?

Answer 10

by the closing of the AV valves at the start of ventricular contraction

Question 11

How is the “dup” sound produced in the heart?

Answer 11

by the closing semilunar valves at the end of ventricular contraction

Question 12

Where is the aortic valve heard?

Answer 12

2nd intercostal space at right sternal margin

Question 13

Where is the pulmonary valve heard?

Answer 13

2nd intercostal space at left sternal margin

Question 14

Where is the mitral valve heard?

Answer 14

over heart apex (in 5th intercostal space) in line with middle clavicle

Question 15

Where is the tricuspid valve heard?

Answer 15

right sternal margin of 5th intercostal space

Question 16

How is blood supply to the muscular walls and tissues of the heart delivered?

Answer 16

through the right and left coronary arteries

Question 17

What are the left coronary artery branches and their functions?

Answer 17

• Anterior interventricular (left anterior descending): sends branches into and supplies the interventricular septum and anterior walls of both ventricles.
• circumflex branch: follows the coronary sulcus posteriorly and supplies the left atrium and the posterior part of the left ventricle

Question 18

What are the right coronary artery branches?

Answer 18

• Marginal branch: along inferior border/margin

- Posterior interventricular branch: In interventricular sulcus

Question 19

What do the cardiac veins do?

Answer 19

carry deoxygenated blood from the heart wall into the right atrium, also occupy the sulci on the heart surface

Question 20

What are the cardiac veins and their location?

Answer 20

1) great cardiac vein: anterior interventricular sulcus
2) middle cardiac vein: posterior interventricular sulcus
3) small cardiac vein: along inferior margin

Question 21

What is the coronary sinus?

Answer 21

Where are all 3 cardiac veins meet.

• found in posterior atrioventricular groove (coronary sulcus)
• empties into right atrium

Question 22

What are the 4 chambers of the heart?

Answer 22

1) right atrium
2) right ventricle
3) left atrium
4) left ventricle

Question 23

What is the right atrium?

Answer 23

forms the entire right border of the human heart. receiving chamber for oxygen-poor blood returning from the systemic circuit

Question 24

How does the right atrium receive blood?

Answer 24

superior vena cava, inferior vena cava and coronary sinus

Question 25

What is the fossa ovalis?

Answer 25

A depression in the location of foramen ovale Foramen ovale = opening through the interatrial septum which opens to left atrium in fetus Valve of IVC directs blood through foramen ovale during fetal life Foramen closes after birth

Question 26

What are tricuspid valves?

Answer 26

3 Triangular cusps, attach by cordae tendineae to papillary muscles Prevent backflow during ventricular contraction

Question 27

What are trabeculae carnae?

Answer 27

Muscle ridges throughout wall

Question 28

What are the openings of the right ventricle?

Answer 28

- Right atrioventricular orifice | - orifice to pulmonary trunk

Question 29

What are the pulmonary semilunar valves?

Answer 29

3 pouches Opens during ventricular contraction due to flow of blood pushing pouches against wall Closes due to backflow of blood caused by elastic recoil in pulmonary artery, filling pouches

Question 30

What is the left atrium?

Answer 30

- makes up most of the heart’s posterior surface, or base. It - receives oxygen-rich blood returning from the lungs through two right and two left pulmonary veins - Wall structure similar to Right Atrium with pectinate muscle in auricle; - Mitral valve = bicuspid = left AV valve - Chamber = confluence of 4 vessels, therefore smooth wall

Question 31

What is the left ventricle?

Answer 31

Forms the apex of the heart and dominates the heart’s inferior surface - same as right but walls are 3X as thick as right to overcome systemic resistance.

Question 32

What is the right ventricle?

Answer 32

The right ventricle forms most of the anterior surface of the heart

Question 33

What are the elements associated with the conduction system of the heart?

Answer 33

- Sinoatrial (SA) node - Atrioventricular - Bundle of His - Purkinje fibers - Skeleton of heart

Question 34

What is the sinoatrial node?

Answer 34

- Pacemaker of heart - In wall of right atrium near opening of SVC - Cardiac fibers with the lowest threshold, therefore have fastest rhythm - Impulse spreads over 2 atria via gap junctions between cardiac muscle cells

Question 35

What is the atrioventricular node?

Answer 35

In floor of atrium near coronary sinus | After a short delay (millisecond) an impulse is conducted along interventricular septum via Bundle of His

Question 36

What is the skeleton of the heart?

Answer 36

- Fibrous rings around AV and semilunar valves - Muscle of atria and ventricles attach to rings - Prevent conduction of impulse from atria to ventricles

Question 37

What is the Bundle of His?

Answer 37

bundle of Purkinje cells passes through cardiac skeleton, down interventricular septum

Question 38

What are the fetal circulation and changes at birth?

Answer 38

``` Foramen ovale – Passage between RA and LA – Becomes fossa ovalis • Ductus Arteriosus – Passage between pulmonary trunk and aortic arch – Becomes ligamentum arteriosum • Umbilical Arteries – Inside anterior body wall to umbilicus – Become medial umbilical ligaments • Umbilical Veins – From umbilicus to liver – Become ligamentum teres • Ductus Venosus – Continuation of umbilical veins through liver to inferior vena cava – Becomes ligamentum venosum ```

Question 39

What is coronary circulation?

Answer 39

Circulation of blood in the blood vessels of the heart.