Week 4 (cardiovascular system) Flashcards
What is the heart?
A pump that provides continuous linkage with the vascular components.
What is the arterial system?
A high-pressure distribution circuit
What are the capillaries?
Exchange vessels
What is the venous system?
A low pressure collection and return circuit
What is blood?
A body fluid that transports essential substances and metabolic waste products.
Name the layers of the heart
Pericardium
Epicardium
Myocardium
Endocardium
Describe the pericardium
Membrane that surrounds and protects the heart
Describe the epicardium
External layer composed of fibroelastic and adipose tissue and contains blood vessels, lymphatic and nerves that supply the myocardium.
Describe the myocardium
Middle layer composed of cardiac muscle tissue.
Describe the endocardium
Innermost layer of endothelium overlying thin layer of connective tissue.
What are the atria?
Two superior chambers receiving chambers
What are the ventricles?
Two inferior pumping chambers
What does the intraventricular septum do?
Separates the right and left sides
What do the atrioventricular valves do?
(Tricuspid and bicuspid)
Ensure one-way blood flow between the atria and ventricle.
What is the pulmonary circulation?
The right side which receives deoxygenated blood from the body (via the vena cava) and pumps blood to the lungs.
What is the systemic circulation?
The left side which receives oxygenated blood from the lungs (via the pulmonary vein) and pumps blood into the aorta for distribution throughout the body.
What is coronary circulation?
The myocardium’s own network of blood vessels.
What do the coronary arteries do?
Deliver oxygen and nutrients to the heart muscle and collects carbon dioxide and waste, and then moves into coronary veins.
What do arterioles do?
Control blood flow and feed capillaries.
Describe capillaries
Exchange vessels
Single layer of endothelium cells
500-2000 capillaries per mm2 of skeletal muscle tissue
Large surface area + slow rate of BF = effective oxygen and carbon dioxide exchange.
What is a precapillary sphincter?
A band of smooth muscle that adjusts blood flow into capillaries.
Name the layers of blood vessels
Tunica intima (inner lining)
Tunic media (middle layer)
Tunica adventitia (outer covering)
Describe the tunica intima (inner lining)
Epithelial lining consisting of endothelial cells lining the lumen of the vessel, and a connective tissue.
Describe the tunica media (middle layer)
Smooth muscle and elastic connective tissue.
Primary role is to regulate the diameter of the lumen.
Middle layer helps to distinguish between the different types of vessels.
Describe the tunica adventitia (outer covering)
Connective tissue mainly collagen fibres.
Contains nerves and small blood vessels.