Session 7 - Cardovascular And Lymphatic System

Question 1

What are the two blood circulations?

Answer 1

1. Pulmonary circulation
2. Systemic circulation

Question 2

Explain the pulmonary circulation

Answer 2

The right ventricle propels low-oxygen blood returning from the systemic circulation into the lungs via the pulmonary arteries. Carbon dioxide is exchanged for oxygen in the capillaries of the lungs, and then the oxygen-rich blood is returned via the pulmonary veins to the heart’s left atrium.

Question 3

Explain the systemic circulation

Answer 3

The left ventricle propels the oxygen-rich blood returned to the heart from the pulmonary circulation through systemic arteries, i.e. the aorta and its branches, exchanging oxygen and nutrients for carbon dioxide in the remainder of the bodies capillaries. Low-oxygen blood returns to the heart’s right atrium via systemic veins, i.e. tributaries of the superior and inferior vena cava

Question 4

Name the two parallel muscular pumps of the heart.

Answer 4

1. Systemic pump
2. Pulmonary pump

Question 5

What are the components of the systemic pump?

Answer 5

1. Left ventricle
2. Left atrium

Question 6

What are the components of the pulmonary pump?

Answer 6

Right ventricle
Right atrium

Question 7

Where is the heart located?

Answer 7

The heart lies in the middle mediastinum inside the pericardial sac between 4 segments of the sternum in front and the middle 4 thoracic vertebrae behind.

Question 8

Where is the apex of the heart located?

Answer 8

The apex of the heart lies in the fifth intercostal space.

Question 9

Describe the location of the base of the heart.

Answer 9

The base faces posterior, superiorly and to the right.

Question 10

What is the pericardium?

Answer 10

1. A fibroserous sac surrounding the heart and the roots of the great vessels.
2. It consists of the fibrous pericardium and the serous pericardium

Question 11

Describe the fibrous pericardium.

Answer 11

It is a tough connective tissue outer layer that defines the boundaries of the middle mediastinum.

Question 12

What are the functions of the fibrous pericardium?

Answer 12

1. Prevents overstretching
2. Provides protection
3. Anchors the heart

Question 13

What are the two constituents of the serous pericardium?

Answer 13

1. Parietal pericardium - lines the inner surface of the fibrous pericardium
2. Visceral pericardium - adheres to the heart and forms its outer covering

Question 14

Give the other name of visceral pericardium.

Answer 14

Epicardium

Question 15

Describe the surfaces of the heart

Answer 15

1. Diaphragmatic surface - faces inferiorly towards the diaphragm
2. Sterno-costal surface - also called anterior surfaces, is orientated anteriorly facing the sternum
3. Right pulmonary surface
4. Left pulmonary surface

Question 16

Which components make up the base of the heart?

Answer 16

1. Left atrium
2. Small portion of right atrium
3. Proximal parts of great veins

Question 17

Name the great veins

Answer 17

1. Inferior vena cava
2. Superior vena cava
3. Pulmonary veins

Question 18

What are the surface/external grooves of the heart called?

Answer 18

Sulci (sulcus for sing.)

Question 19

Describe where the coronary grove/sulcus is located

Answer 19

1. It circles the heart, separating the atria from the ventricle.
2. It contains the right coronary artery, the small cardiac vein, the coronary sinus and the circumflex branch of the the left coronary artery

Question 20

What is another name for the coronary groove?

Answer 20

Atrio-ventricular sulcus

Question 21

Describe the location of the anterior interventricular sulcus.

Answer 21

It is on the sterno-costal surface of the heart and contains the anterior interventricular artery and the great cardiac vein

Question 22

Describe the location of the posterior interventricular sulcus

Answer 22

It is on the diaphragmatic surface of the heart and contains the posterior interventricular artery and the middle cardiac vein

Question 23

Describe the characteristics of the right atrium

Answer 23

1. Has orifices of the superior vena cava from superior and inferior vena cava from inferior
2. The right auricle, an appendage, projects supero-medially over the origin of the ascending aorta.
3. The fossa ovalis, a shallow, oval scar characterizes the smooth posterior wall
4. Transverse muscular ridges called pectinate muscles or musculi pectinati run to a vertical ridge called the crista terminalis on the anterior wall.
5. The orifice of the coronary sinus lies between the orifices of the inferior vena cava and the tricuspid valve. It drains venous blood from the heart muscle.
6. The tricuspid opening is also found and is controlled by the tricuspid valve. It controls blood flow from the right atrium into the right ventricle.

Question 24

Describe the characteristics of the right ventricle.

Answer 24

1. Inner surface has muscular ridges called the trabeculae carneae except in the funnel-shaped infundibulum.
2. The infundibulum is a funnel-shaped opening of the right ventricle which extends upwards to the pulmonary trunk.
3. The orifice of the infundibulum is controlled by the pulmonary semilunar valve.
4. the tricuspid valve has 3 cusps which lie in the ventricle and are attached to cone-shaped papillary muscles by chordae tendinae.
5. Close to the apex lies a muscular bundle called the septo-marginal trabeculae or moderator band that stretches from the interventricular septum to the papillary muscle of the anterior wall

Question 25

What is the right auricle?

Answer 25

An appendage that projects supero-medially over the origin of the ascending aorta from the right atrium

Question 26

What is the fossa ovalis?

Answer 26

A shallow, oval scar on the posterior wall of the right atrium that formed from the fossa ovale

Question 27

What are pectinate muscles?

Answer 27

Transverse muscular ridges on the anterior walls of the atria

Question 28

What structure does the left auricle curl around?

Answer 28

The left border of the pulmonary trunk

Question 29

What is the function of papillary muscles?

Answer 29

They tense the chordae tendinae and prevent the cusps of the the tricuspid valve from flapping into the right atrium

Question 30

What is the septo-marginal trabeculae?

Answer 30

A muscular band bundle that stretches from the interventricular septum to the papillary muscles of the anterior wall of the right ventricle

Question 31

Describe the characteristics of the left ventricle.

Answer 31

1. The wall is approximately 3 times thicker than that of the right ventricle. 2. The inner wall demonstrates trabeculae carneae except in the aortic vestibule. 3. There is an aortic valve that is guarded by 3 semilunar valves 4. The interventricular septum is particularly thick and bulges into the right ventricle.

Question 32

Which 2 structures in the foetus provide detours by which blood bypasses the foetal lungs?

Answer 32

1. foramen ovale 2. ductus arteriosus

Question 33

What is the foramen ovale?

Answer 33

An opening in the septum between the right and left atria that diverts blood into the left atrium so that it bypasses the foetal lungs

Question 34

What is the ductus arteriosus?

Answer 34

A small vessel connecting the pulmonary artery with the aorta to divert blood into the systematic circulation without going through the lungs

Question 35

What is the function of arteriovenous anastomoses?

Answer 35

They permit direct transfer of blood from the arterial to venous channels, bypassing the capillary bed.

Question 36

Where do arteriovenous anastomoses occur?

Answer 36

Organs whose functions areintermitted