Circulatory System III

Question 1

where is the heart located?

Answer 1

the heart lies in the thoracic cavity between the lungs, it has a base, apex and it lies obliquely

Question 2

what organs are associated with the heart?

Answer 2

• diaphragm
• esophagus
• trachea
• L & R bronchus
• vertebrae
• ribs
• intercostal muscles

Question 3

what are the 3 layers of tissue which the heart is composed of?

Answer 3

• pericardium
• myocardium
• endocardium

Question 4

Describe the structure of the pericardium?

Answer 4

the pericardium has 2 sacs, an outer sac and an inner sac

Question 5

What is the structure & function of the pericardium’s outer sac?

Answer 5

the outer sac consists of fibrous tissue- preventing over distension of the heart

Question 6

What is the structure & function of the pericardium’s inner sac?

Answer 6

the inner sac is a double serous membrane, allowing smooth movement between layers when the heart beats

Question 7

Describe the structure and function of the myocardium?

Answer 7

myocardium is composed of specialised cardiac muscle, it is a sheet of muscle rather than individual cells as impulses spread across whole sheet, causing contraction

Question 8

Describe the structure of the Endocardium?

Answer 8

Endocardium consists of flattened epithelial cells, continuous with endothelium lining blood vessels

Question 9

What is the function of the Endocardium?

Answer 9

Endocardium lines chambers and valves of the heart, it is a smooth membrane allowing smooth flow of blood through the heart

Question 10

What is the top part of the heart called?

Answer 10

Atriums

Question 11

What is the bottom half of the heart called?

Answer 11

Ventricle

Question 12

How many semi lunar cusps does the right valve have?

Answer 12

The right valve has 3 semi lunar cusps

Question 13

How many semi lunar cusps does the left AV valve have?

Answer 13

The left AV valve has 2 cusps

Question 14

What are the 2 largest veins?

Answer 14

Superior and inferior vena cava

Question 15

What is the function of the superior and inferior vena cava?

Answer 15

They empty deoxygenated blood into the right atrium

Question 16

What is the movement of deoxygenated blood once it has entered the right atrium?

Answer 16

• It then travels via the right AV tricuspid valve into right ventricle
• its then pumped from here into the pulmonary artery

Question 17

What happens to the pulmonary artery once it leaves the heart?

Answer 17

it divides into L & R pulmonary artery which carries venous blood to lungs where gas exchange takes place

Question 18

what is the function of a pulmonary vein?

Answer 18

carries oxygenated blood back to the left atrium

Question 19

What is the movement of oxygenated blood once it has entered the left atrium?

Answer 19

• blood then passes through the left AV valve into left ventricle
• from here it is pumped into the aorta

Question 20

what is pulmonary circulation?

Answer 20

when blood passes from the RHS of the heart to the LHS via the lungs

Question 21

what are the branches of the ascending aorta?

Answer 21

right and left coronary arteries

Question 22

what is the function of the left and right coronary arteries?

Answer 22

supplies tissues of the heart with oxygenated blood

Question 23

what does the left and right coronary arteries form?

Answer 23

a network of capillaries which enclose the heart

Question 24

what are the 3 branches of the arch of the aorta?

Answer 24

1. left common carotid artery
2. left subclavian artery
3. brachiocephalic artery

Question 25

what is the function of the sinoatrial node?

Answer 25

it emits impulses which cause the heart to contract, each heartbeat is known as a cardiac cycle

Question 26

what is contraction known as?

Answer 26

systole

Question 27

what is the relaxed state of the heart called?

Answer 27

diastole

Question 28

what does the cardiac cycle range form in terms of BPM?

Answer 28

60-80 BPM

Question 29

how long does each cardiac cycle last?

Answer 29

0.8 seconds

Question 30

what is atrial systole?

Answer 30

contraction of atria

Question 31

what is ventricular systole?

Answer 31

contraction of ventricles

Question 32

what is complete cardiac diastole?

Answer 32

relaxation of atria and ventricles

Question 33

what nervous system controls the cardiac cycle?

Answer 33

autonomic nervous system (parasympathetic and sympathetic)

Question 34

what is the function of the parasympathetic nervous system in terms of cardiac cycle?

Answer 34

it slows HR and force of contraction

Question 35

what is the function of the sympathetic nervous system in terms of cardiac cycle?

Answer 35

it increases HR and force of contraction

Question 36

what is the nerve supply for the cardiac system?

Answer 36

vagus- 10th cranial nerve, arises in cardiac center of the medulla

Question 37

what is the function of the left pulmonary artery?

Answer 37

left PA runs into the left lung and divides into 2, one passing into each lobe

Question 38

what is the function of the right pulmonary artery?

Answer 38

right PA passes into the right lung and divides into 2, the larger branch carrying blood to middle and lower lobes, and the smaller branch to the upper lobe

Question 39

within each lung, what do arteries divide into?

Answer 39

arterioles and capillaries

Question 40

what does the brachiocephalic artery supply?

Answer 40

supplies right arm and right side of head and neck

Question 41

what does the left common carotid artery supply?

Answer 41

supplies left side of head and neck

Question 42

what does the left subclavian artery supply?

Answer 42

supplies left arm, part of head and neck

Question 43

what supplies most of the lower limbs with blood?

Answer 43

right and left common iliac arteries

Question 44

describe internal respiration?

Answer 44

- oxygen is carried from lungs to tissues in hemoglobin as oxyhemoglobin - interchange if gasses between capillaries - carbon dioxide is removed

Question 45

describe portal circulation?

Answer 45

- blood circulating in stomach and intestines is conveyed to liver via portal vein - blood with high concentration of nutrients goes to liver first where modifications of nutrients takes place before supplying the rest of the body