The Cardiovascular System. Flashcards
What are the functions of the cardiovascular system?
Delivers gas, nutrients and hormones to cells and tissues and removes waste.
What does the circulatory system do?
Transport oxygen, carbon dioxide, nutrients, hormones and cells.
How do you measure heart rate?
Pushing superficial artery against bone.
What is pulmonary circulation?
Deoxygenated blood from the heart to the lung via the pulmonary artery and Oxygenated blood from the lung to the heart via the pulmonary vein.
The 3 layers of blood vessels…
Tunica Intimata (epithelial), Tunica Media (muscular) and Tunica Externa (connective tissue)
Types of Arteries…
Muscular (distribute blood to muscles) Elastic (withstand pressure, cont. blood flow) Arterioles (resistance)
Types of Capillaries…
Continuous, Fenestrated and Sinusoid.
Vein vs Artery…
Veins have valves, bigger lumen and thinner walls.
What is the role of the capillaries?
Site of gaseous/nutrient/waste exchange.
What connects arterioles and venues?
Metarterioles
What does the pre capillary sphincter do?
Controls blood flow at the opening of the capillary bed.
What do venules do?
Collect blood from the capillary bed and return it to the small veins. Holds 54% of blood volume.
Location of the heart…
2/3 left of midline, between the 2nd and 5th ribs.
Heart wall layers…
Endocardium, Myocardium and Epicardium.
What does the pericardium consist of and what does it do?
Fibrous = inelastic sac of dense connective tissue preventing overfilling. Serous = Parietal and Visceral layers full of serous fluid to prevent friction.
What are atrioventricular valves?
Opened when blood flows from atria to ventricle, anchored by chordae tendinae>papillary muscles to prevent blood back flow.
What are semilunar valves?
Valves opened when blood pushes out ventricle.
What does the P wave represent?
Atrial depolarisation.
What does the QRS wave represent?
Ventricular depolarisation.
What does the T wave represent?
Ventricular repolarisation.
What is cardiac output?
The volume expelled by the heart per minute = Stroke volume x Heart rate.
What is stroke volume?
The volume of blood ejected by the heart per beat = Cardiac output / Heart rate.
