Session 7 - Cardovascular And Lymphatic System Flashcards
What are the two blood circulations?
- Pulmonary circulation
- Systemic circulation
Explain the pulmonary circulation
The right ventricle propels low-oxygen blood returning from the systemic circulation into the lungs via the pulmonary arteries. Carbon dioxide is exchanged for oxygen in the capillaries of the lungs, and then the oxygen-rich blood is returned via the pulmonary veins to the heart’s left atrium.
Explain the systemic circulation
The left ventricle propels the oxygen-rich blood returned to the heart from the pulmonary circulation through systemic arteries, i.e. the aorta and its branches, exchanging oxygen and nutrients for carbon dioxide in the remainder of the bodies capillaries. Low-oxygen blood returns to the heart’s right atrium via systemic veins, i.e. tributaries of the superior and inferior vena cava
Name the two parallel muscular pumps of the heart.
- Systemic pump
- Pulmonary pump
What are the components of the systemic pump?
- Left ventricle
- Left atrium
What are the components of the pulmonary pump?
Right ventricle
Right atrium
Where is the heart located?
The heart lies in the middle mediastinum inside the pericardial sac between 4 segments of the sternum in front and the middle 4 thoracic vertebrae behind.
Where is the apex of the heart located?
The apex of the heart lies in the fifth intercostal space.
Describe the location of the base of the heart.
The base faces posterior, superiorly and to the right.
What is the pericardium?
- A fibroserous sac surrounding the heart and the roots of the great vessels.
- It consists of the fibrous pericardium and the serous pericardium
Describe the fibrous pericardium.
It is a tough connective tissue outer layer that defines the boundaries of the middle mediastinum.
What are the functions of the fibrous pericardium?
- Prevents overstretching
- Provides protection
- Anchors the heart
What are the two constituents of the serous pericardium?
- Parietal pericardium - lines the inner surface of the fibrous pericardium
- Visceral pericardium - adheres to the heart and forms its outer covering
Give the other name of visceral pericardium.
Epicardium
Describe the surfaces of the heart
- Diaphragmatic surface - faces inferiorly towards the diaphragm
- Sterno-costal surface - also called anterior surfaces, is orientated anteriorly facing the sternum
- Right pulmonary surface
- Left pulmonary surface