Anatomy of the cardiovascular system

Question 1

The mediastium

Answer 1

• Between the right and left lung
• Top of heart is the base of the heart and the point is the apex
• The mediastinum can shift if there is space or something s taking up space it can be shifted

Question 2

Describe the pericardium and layers of the heart

Answer 2

Pericardium:
- Fibrous pericardium: outermost layer of the pericardium
- Pericardial cavity: fluid filled to manage friction with the walls
- Parietal pericardium: the inner layer of the pericardium that goes in to the epicardium

3 layers of the heart:
- Epicardium: the outer layer of the heart a continuation of the inner layer of the pericardium
- Myocardium: contractile tissue responsible for the pumping action composed of myocytes (these do not reproduce)
- Endocardium: serous membrane that lines the inside of the heart, the valves and the chordae tendineae (tendinous chords)

Question 3

What are the types of myocytes

Answer 3

Contractile myocytes: more actin and myosin
Conductive myocytes: more Na/K channels

Question 4

Direction of blood flow through the heart

Answer 4

Superior/inferior vena cava
Right atrium (tricuspid valve)
Right ventricle
Pulmonary valve/artery
Lungs
Pulmonary vein
Left atrium (bicuspid valve)
Left ventricle
Aorta (aortic valve)

Question 5

What are the great vessels

Answer 5

1. Vena cava: Inferior and superior
2. Pulmonary artery:
   - Pulmonary trunk
   - Right and left pulmonary artery
3. Aorta:
   - Sits slightly to the left of midline, therefore not symmetrical
   - Right and left coronary artery come off of it
4. Pulmonary veins – two from each lung

Question 6

Heart valves

Answer 6

Atrioventricular valves (AV valves)
- Tricuspid (right)
- Bicuspid (left)

Semilunar valves:
- Aortic
- Pulmonic

Question 7

Chordae tendon

Answer 7

• Strong fibrous bands attached to the muscles within the ventricles that control the opening/closing of the AV valves
• Pressure and volume open/close the semilunar valves

Question 8

Coronary circulation

Answer 8

Right coronary artery
Left coronary artery:
- Splits into
~ Left anterior descending
~ Left circumflex
Coronary veins:
- They follow the artery
From these they split into arterioles and capillaries

Question 9

Arteries

Answer 9

• High pressure
• Muscular
• Propel blood
• About 30% of blood at any given moment

Question 10

Veins:

Answer 10

Has valves
Low pressure
Elastic
High capacity
At any given moment there will be 65% of blood in the veins

Question 11

What organs get the biggest blood supply

Answer 11

brain
muscles
kidneys
lungs
GI

Question 12

What does the lymphatic system do

Answer 12

• Picks up debris and excess fluid
• Runs with the vessels of the vascular system
• One way system
• Dumps in blood by right atrium

Question 13

Conduction system of the heart

Answer 13

• Heart can beat on its own
• Sinoatrial node SA
• Atrioventricular node (AV)
• Bundle of his
• Right and left bundle branches
• Purkinje fibers

Question 14

Vagus nerve control of the heart

Answer 14

• Parasympathetic: reduces heart rate to below 100
• Occurs at the SA node

Question 15

Sympathetic control of the heart

Answer 15

• Increases heart rate and force of contraction (contractility)
• Innervates at the septum and SA node