Cardiovascular

Question 1

What is the cardiovascular system?

Answer 1

Essentially a transportation system - uses blood to carry oxygen, nutrients, cell waste, hormones and other substances vital for body homeostasis

Question 2

Location of the heart

Answer 2

Central chest cavity - mediastinum one the anterior, base sits near the 2nd intercostal space, posterior to the sternum

Question 3

Explain the heart wall layers

Answer 3

Outer layer = epicardium

Myocardium - hearts muscle fibres.

Inner layer = endocardium. Thin sheet that lines the hearts layers

Heart is also enclosed by a double walled sac called pericardium

Question 4

What is pericarditis

Answer 4

Inflammation of the pericardium. Often results in a decrease in the already small amount of serous fluid - causes the pericardial layer to bind & stick together, forming painful adhesions that interfere with heart movements

Question 5

Explain the pericardium layers

Answer 5

Parietal = lines the internal surface of the fibrous pericardium

Visceral = lines the surface of the heart

Question 6

Explain blood flow around the heart

Answer 6

Should know this

Question 7

Where is the atrioventricular valves?

Answer 7

Lies between the atria and ventricles. Prevents back flow into the atria when ventricles contract

Question 8

Purpose of chordae tendineae?

Answer 8

Anchors AV valves to papillary muscles

Question 9

Where is the semi lunar valve

Answer 9

Lies between the left ventricle and aorta

Question 10

Function of heart valves

Answer 10

Allows blood to flow in only one direction through the hearts chambers

Question 11

What is valvular stenosis ?

Answer 11

Valve flaps become stiff, forces the heart to contract more vigorously than normal to create pressure to drive the blood through the narrowed valve

Question 12

What is a heart block?

Answer 12

Depolarisation waves can only reach the ventricles by travelling through the AV node - thus, any damage to it can cause the ventricles to beat at their own rate, which is a lot slower

Question 13

Diastole vs systole

Answer 13

Relaxation

Contraction

Question 14

What are the two things that act to regulate heart activity?

Answer 14

Nerves of the autonomic nervous system

Intrinsic conduction system: sets the basic rhythm

Question 15

Cardiac output equation

Answer 15

Multiply the number of times the heart beats per minute by the volume it ejects on each beat (minute volume)

Question 16

What is starlings law of the heart

Answer 16

The more a muscle fibre is stretched - the greater the force of subsequent contraction

Question 17

What four factors that influence starling law

Answer 17

Amount of blood that returns to the threat

Diastolic filling time - 70% of the cardiac cycle is the diastolic phase

Atrial systole - adds further 20-25% BV to the ventricles; greatly increases their stretch

Structural competence (mechanical competence)

Question 18

What are the electrical properties of the cardiac cells?

Answer 18

Automaticity
Excitability
Conductivity
Contractility

Question 19

Describe the electrical conduction of the heart

Answer 19

SA node - 60-80 bpm

AV node; 40-60

Bundle of his - BBB (innervates contraction of ventricles)

Purkinje fibres - 20-40

Question 20

What do muscle fibres contract in response to?

Answer 20

An electrical stimulus

Question 21

What is the P wave?

Answer 21

Atria depolariSation