Wk 4: Cardiovascular System Flashcards
5 functions of cardiovascular system
- Maintains continuous movement of all body fluids
- Transports O2 & nutrients into tissues
- Transports CO2 & metabolic waste out of tissues
- Temp regulation
- Distribution of molecules: hormones & cells of immune system - e.g: secretions of pituitary gland into bloodstream
What are the 3 tunics (3 coats) of the blood vessels
- Tunica Adventitia (externa) - outer
- Tunica Media - middle
- Tunica Intima - inner
What are the tiny vessels supplying the tunica externa & tunica media
Vaso vasora
Describe the Tunica Externa
Outer supporting tissue layer
Describe the Tunica Media
Intermediate muscular layer
Describe the Tunica Intima
Inner lining of epithelial cells, basement membrane & collagenous tissue
Where is the pericardial membrane positioned
It surrounds the heart
What are the 3 layers of the pericardium & which of these 3 is shared with the heart wall
3 layers:
1. Fibrous pericardium
2. Parietal layer of serous pericardium
3. Visceral layer of serous pericardium (epicardium)
* The visceral layer of the serous pericardium (epicardium) is the layer shared with the heart wall
What is the fibrous pericardium composed of & what does this mean for the function
- Composed of collagen bundles
- Due to lack of elastin in composition, this layer doesn’t change shape/size which prevents overfilling w blood
Function of fibrous pericardium (2)
- Tough
- Anchors heart to diaphragm & vessels
What does the serous pericardium produce
Serous fluid
What is the positioning of the parietal pericardium
It is fused to the fibrous pericardium. It encases the heart like a sac
What is the innermost layer of the pericardium
The visceral pericardium/epicardium
Where is the pericardial cavity positioned
Between the parietal & visceral layers of the serous pericardium
Function of pericardial cavity
Contains a layer of serous/pericardial fluid which acts as a lubricant, decreasing friction as heart moves
What is cardiac tamponade
- Excess fluid build up in the pericardial space
- More fluid accumulates w each contraction
- Puts pressure on heart, prevents full relaxation, heart contains less blood at beginning of each heart cycle, death
What are the 3 layers of the wall of the heart
- Epicardium (tunica adventitia) - outer, shared w pericardium
- Myocardium (tunica media)
- Endocardium (tunica intima) - inner
Which layer of the heart wall contains the cardiac muscle tissue
The myocardium
What is endocardium composed of
- Special squamous epithelium called endothelium
- Elastic fibres
- Collagen fibres
What is myocardium responsible for (1)
Beating of the heart
Describe the blood flow through the pulmonary circuit
- Blood flows from the right side of the heart (deoxygenated)
- Blood flows to the lungs to become oxygenated
- Blood flows to the heart
Describe the blood flow through the systemic circuit
- Blood flows from the left side of the heart (oxygenated)
- Blood flows to the head & rest of body
- Blood flows back to the right side of the heart (deoxygenated)
Why do arteries have smaller lumens than veins
To maintain the pressure of blood flow
What are the 3 layers of both arteries & veins
- Tunica externa - outer
- Tunica media - middle
- Tunica intima - inner
