Cardiovascular System Flashcards
What does the cardiovascular system consist of?
-heart, blood vessels, blood
What is the functions of the cvs?
-Mediates continuous movement of all body fluids
-Transport of O2 and nutrients to tissues and waste and CO2 from tissues
-Temp regulation - vessel dilation/contraction
-Distribution of molecules
What are the 3 layers of the blood vessels?
- Tunica Adventitia (externa) - outer supporting tissue layer
- Tunica Media - intermediate muscular layer
- Tunica Intima - inner lining of epithelial cells (endothelium), basement membrane and collagenous tissue
What is the name given zto tiny blood vessels that supply the tunica externa and media?
Vaso vasora
What layer does the pericsrdial membrane and heart wall share?
The epicardium
What is the pericardium and what is it composed of?
-Membraneous structure surrounding the heart
-Composed of fibrous pericardium and serous pericardium
What is the fibrous pericardium?
-Outer layer
-Composed of collagen bundles - tough and anchor heart to diaphragm and vessels
-Doesnt change shape or size much - prevents overfilling w blood - not alot of elastin
What is the serous pericardium?
Thin inner serous membrane that produces serous fluid
-Parietal pericardium- fused to fibrous pericardium- encases heart like a sac
-Visceral pericardium- innermost layer also known as epicardium (layer shared by heart wall)
Where is the pericardial cavity found?
-Brween parietal and visceral percardia - contains thin layer of serous fluid (pericardial fluid) acts as lubricant, decreasing friction as heart moves
What happens in cardiac tamponade?
Excess fluid builds within pericardial space - with each contraction more fluid accumulates in pericardial cavity
What is the heart wall composed ofß
-Epicardium - outermost layer of heart wall is also innermost layer of pericardium
-Myocardium - thickest layer - cardiac muscle - responsible for beating of heart
-Endocardium - lines lumen of heart - composed of squamous epithelium- endothelium and elastic and collagen fibres - direct contact with circulating blood
What is myocardial infarction?
-Heart attack
-Results from lack of blood flow (ischemia) amd oxygen (hypoxia) to a region of the heart resulting in death of cardiac muscle cells
What are the 2 blood circuits in the body?
-Pulmonary circuit - right side of heart to lungs to heart (blood becomes oxygenated)
-Systematic circuit - left side of heart to head and body to return to right side of heart
What ki nds of arteries and veins are there?
Arteries - elastic, muscular, arterioles-capillaries
Veins - venules and small, medium and large
What are elastic arteries?
-Conducting artieries because larges diameter
-E.g aorta, pulmonary artery and intermediate branches
-Tunica intima - sub-endothelial layer w incomplete internal elastic lamina
-Tunica media - 40-70 fenestrated elastic membranes - smooth muscle - thin external elastic lamina w vaso vasorum in outer half
-Tunica adventitia - thin layer of fibroelastic ct
What are muscular arteries?
-Distributing arteries - thick tunica media of smooth muscle - higly contractile
-E.g all other arteries e.g femoral artery
-Tunica intima - sub endothelial layer w thick internal elastic lamina
-Media - up to 40 layers smooth muscle cells, internal elastic lamina and thick external elastic lamina at junctions of tm with ti and ta
-Adventitia - thin layer of fibroelastic ct
What are arterioles?
-Arteries w diameter of less than 0.1mm
-Tunica intima - subendothelial layer not prominent- some elastic fibres isntead of defined internal elastic lamina
-Tunica media - 1-2 layers of smooth muscle cells
-Tunica adventitia - sparse loose ct, very little ta
What are the 2 classifications of capillaries?
- Continuous capillaries
-have no pores of fenestrae in their walls - most common type - Fenestrates capillaries
-possess pores in their walls that are covered by pore diaphragms
-found in GI mucosa, endocrine glands and renal glomeruli
Why and where do veins contain valves?
Thin tunica intima of veins contain valves to prevent the backflow of blood since bloodglow is so slow
