Heart and Circulation

Question 1

What are the functions of the cardiovascular system?

Answer 1

• transport of nutrients, oxygen and hormones throughout the body and removal of metabolic waste
• protection of the body by white blood cells, antibodies and complement proteins that circulate in the blood and defend the body against foreign microbes and toxins. (Clotting agents are also present that protect the body from loss of blood)
• regulation of body temperature, fluid pH, and water content of cells

Question 2

What is the arterial system?

Answer 2

the vessels that carry blood around the body

Question 3

What is microcirculation?

Answer 3

Where transfer of nutrients, waste and water occurs - capillaries, arterioles, venules

Question 4

What is the function of the heart?

Answer 4

pumps blood around the cardiovascular system

Question 5

What are the two circuits in the cardiovascular system?

Answer 5

• Pulmonary - carries deoxygenated blood away from the right ventricle of the heart to the lungs and returns oxygenated blood to the left atrium of the heart
• systemic - carries blood away from heart and delivers to tissues and organs, then returns blood back to heart - distinct form pulmonary circuit

Question 6

Where does the functional aspect of the cardiovascular system occur?

Answer 6

In the capillaries where the exchange of gasses and nutrients occurs

Question 7

Where is most blood in the heart found?

Answer 7

the left side

Question 8

What side of the heart has higher muscle mass and why?

Answer 8

left side because it is used to pump blood around the body

Question 9

What lines the walls of the heart

Answer 9

squamous epithelial cells

Question 10

How does contraction work?

Answer 10

atria contract just before ventricles

Question 11

What organ regulated blood volume? Why is blood volume important? What adds resistance to blood pressure?

Answer 11

the kidneys and to maintain blood pressure

arteries add pressure

Question 12

What is the location of the heart?

Answer 12

lies centrally in the chest, between the lungs and pleura, in the middle mediastenum

Question 13

What surrounds the heart?

Answer 13

pericardial sac of fibrous tissue that is lined by a serous, slippery membrane that secretes a small amount of lubricating fluid - mesothelial layers - allows free movement

Question 14

What is the front of the heart called?

Answer 14

sternocostal surface

Question 15

Where are the auricles found?

Answer 15

anterior surface of the outer walls of the atria

Question 16

What is the function of the auricles?

Answer 16

increase the volume of blood the heart can hold

Question 17

What is the bottom of the heart called?

Answer 17

diaphragmatic surface (mainly left ventricle)

Question 18

How does deoxygenated blood return to the heart?

Answer 18

vena cavae (superior and inferior) (veins) into the right atrium

Question 19

What valve lies between the right atrium and right ventricle?

Answer 19

tricuspid valve

Question 20

Where does blood go from the right ventricle?

Answer 20

pulmonary trunk where it divides into right and left pulmonary arteries to the lungs where blood is oxygenated (pulmonary circulation)

Question 21

How does blood return from the lungs?

Answer 21

via the left and right, superior and inferior pulmonary veins to the left atrium

Question 22

What valve lies between the left atrium and left ventricle?

Answer 22

mitral/bicuspid valve

Question 23

Where does blood go from the left ventricle?

Answer 23

aorta which pumps blood around the body

Question 24

What lines all blood vessels?

Answer 24

endothelial cells

Question 25

What is the coronary sinus?

Answer 25

a collection of veinsjoined together to form a large vessel that collects blood from the heart muscle (myocardium). It delivers deoxygenated blood to the right atrium, as do the superior and inferior vena cavae. It is present in all mammals, including humans.

Question 26

What enters the right atrium?

Answer 26

deoxygenated blood via the superior and inferior vena cava and coronary sinus

Question 27

What is the fossa ovals?

Answer 27

vestige of the foramen ovale which is a shunt in embryo that allows oxygenated foetal blood (coming from mother) to bypass non ventilated foetal lungs

Question 28

What nodes are present in the right atrium?

Answer 28

Sino-atrial node and atrio-ventricular node

Question 29

What is also known as the natural pace maker of the heart?

Answer 29

the Sino-atrial node - electrically conductive tissue that generates action potential spontaneously

Question 30

What does the left atrium consist of?

Answer 30

left and right pulmonary veins (superior and inferior) left auricle (receives blood from pulmonary veins no nodes

Question 31

What are papillary muscles?

Answer 31

muscles located in the ventricles, they attach to the cusps of antrioventricular valves to prevent prolapse of the valves on systesol - along with tendinous cords

Question 32

What is laminar blood flow?

Answer 32

the normal condition for blood flow throughout most of the circulatory system

Question 33

What ensures laminar blood flow into the pulmonary trunk and aorta?

Answer 33

smooth ventricle walls near its outflow

Question 34

What is systole?

Answer 34

when ventricles contract

Question 35

What is diastole

Answer 35

when ventricles relax

Question 36

Where does the heart receive its blood supply from?

Answer 36

coronary arteries (left and right)

Question 37

What controls the speed of the S-A node (pacemaker)?

Answer 37

the autonomic nervous system

Question 38

What is the Bundle of His?

Answer 38

part of the electrical conduction system of the heart, that transmits impulses from the atrioventricular node, located at the inferior end of the interatrial septum, to the ventricles of the heart. - it is the only route in which conduction can pass from the AV node - it continues into the right and left bundle branches that spread conduction through each ventricle

Question 39

Where does the wave of conduction (and contraction) in the heart occur?

Answer 39

passes from Sino-atrial node (SA node) through the atria to the atrioventricular node (AV node)