Lecture 14 & 15 - Cardiovascular System Flashcards
What are the components of the cardiovascular system?
The heart and blood vessels
What is the function of the cardiovascular system?
The function is to circulate blood throughout the
body to meet the changing needs of the body
cells.
– Cells need:
1. Continuous delivery of oxygen and nutrients
2. Continuous removal of carbon dioxide and waste
What are the 3 main types of blood vessels? Explain them.
- Arteries: carry blood AWAY from the heart
- Veins: carry blood TOWARD the heart
- Capillaries: sites of exchange between the two
What are the three significant features that the heart contains?
- Two sides: allows separation of oxygenated and deoxygenated blood
- Great vessels: bring blood to or from the heart
- Two sets of valves: ensure unidirectional flow of blood through the heart
Where is the heart located?
– In the thoracic cavity within the mediastinum between the lungs
– Extending between the 2nd and 6th ribs
Explain the orientation of the heart.
The heart is rotated slightly so that the right side is more anterior and the left side is positioned more posteriorly
Explain what the Pericardium is.
The heart is enclosed in three layers of tissues collectively called the Pericardium.
From most superficial to deep:
1. Fibrous pericardium
2. Serous pericardium:
- Parietal pericardium
- Visceral pericardium
What is Fibrous Pericardium?
- Dense irregular connective tissue that encloses but does not attach to the heart
- Anchors the heart and prevents over-filling of the chambers
What is Serous Pericardium?
Serous pericardium: Double-layered covering, each consisting of simple squamous epithelium
- Parietal pericardium: Adherent to the inner surface of the fibrous pericardium
- Visceral pericardium: Adherent heart surface
The two are continuous and have a pericardial cavity between them filled with pericardial fluid
Explain the layers of tissue of the heart wall.
Three layers of tissue
– Epicardium: Serous membrane; smooth outer surface of the heart
– Myocardium: Middle layer composed of cardiac muscle cells and responsible for the heart contracting
– Endocardium:
* Smooth the inner surface of the heart chambers
* Continuous with blood vessels
Explain the Anatomy of the Heart.
- The Heart has:
– 4 Chambers
– 4 Valves
– 4 Great Vessels
– Coronary Arteries
– Coronary Veins
Explain Coronary Arteries.
2 main types, they both exit from the aorta
Right Coronary artery: has 2 main branches
- Right marginal artery: supplies the right ventricle
- Posterior interventricular artery: supplies posterior and inferior parts of the heart
Left Coronary artery: had 3 main branches
- Anterior interventricular artery (LAD): supplies the anterior part of the heart
- Left marginal artery: supplies the lateral wall of the left ventricle
- Circumflex artery: extends to and supplies the posterior aspect of the heart
Explain Coronary Veins.
2 main types: Great cardiac vein and small cardiac vein
- They drain the left and right margins of the heart into the coronary sinus in the Coronary Sinus
Explain the Right Atrium.
- Posterior wall is smooth
- Anterior wall exhibits muscular ridges called pectinate muscles
- Contains 3 openings
- Superior Vena Cava
- Inferior Vena Cava
- Coronary Sinus
What is the trabeculae carnae?
They are large irregular muscular ridges on the internal surface of the right and left ventricles
Explain papillary muscles.
They are in the right and left ventricles of the heart
- Anchor the tricuspid valve to the ventricle via the chordae tendinae
Explain the Left Atrium.
- The posterior wall is smooth
- Anterior wall exhibits muscular ridges called pectinate muscles
- Openings
- Pulmonary Veins
What are Atrioventricular valves?
– Each valve has leaf-like cusps that are attached to cone-shaped papillary muscles by tendons (chordae tendinae).
– Right has three cusps (tricuspid).
– Left has two cusps (bicuspid).
What are Semilunar valves?
– Each cusp is shaped like a cup.
– When cusps are filled, the valve is closed; when cusps are empty, the valve is open.
– Pulmonary (Right)
– Atrial (Left)
Explain the right and left sides of the heart.
Right side:
- Deoxygenated blood pumped to the lungs
- Called the Pulmonary Circuit
Left side:
- Oxygenated blood pumped to the body
- Called the Systemic Circuit
Both pumps:
- Contract at the same rate
- Pump the same volume of blood each minute
Explain Pulmonary and Systemic Circulation.
Pulmonary: circulation through the lungs
Systemic: circulation through the body
Explain the Aorta and its different parts.
Aorta: The aorta is the largest artery of the body and carries blood from the heart to the circulatory system.
– Ascending aorta: right and left coronary arteries branch from here
– Aortic arch: arching posteriorly and to the left and has three
* Brachiocephalic artery
* Left common carotid
* Left subclavian artery
– Descending aorta
* Thoracic aorta: portion in the thorax
* Abdominal aorta: inferior to diaphragm. It ends as two common iliac arteries
Explain the Brachiocephalic trunk artery.
It’s the first branch of the aortic arch. It forms 2 branches
- Right Common Carotid Artery: transports blood to the right side of the head and neck
- Right Subclavian Artery: transports blood to the right upper limbs
Explain the Left common carotid artery.
It’s the second branch of the aortic arch.
- Transports blood to the left side of the head and neck.
