Introduction to the Circulatory System Flashcards
Circulatory system:
made up of the cardiovascular system and the lymphatic system
Cardiovascular system:
made up of the arterial system, the heart, and the venous system
Pulmonary circulation:
right side of heart → lungs → left side of heart
Systemic circulation:
left side of heart → capillary beds of organs and tissues → right side of heart
Epicardium
(external): visceral serous pericardium
Myocardium(middle):
cardiac muscle layer
Endocardium(internal):
continuous with endothelium of blood vessels connecting with the heart
Conduction system of the heart
- Electrical impulse starts at SA node - atria contract
- Impulse travels to AV node at AV septum
- Impulse travels down left and right bundles in the IV septum
- Impulse spreads out to myocardium through conducting fibers - ventricles contract
the arterial system
Each artery (and its branches) carries oxygenated blood to a territory
Tunica intima(internal):
endothelium
Tunica media(middle):
smooth muscles and elastic fibres
Tunica adventitia(external):
connective tissue
Sympathetic tone:
background, low level contraction of smooth muscle in arterioles
- Due to tonic production of action potentials to arterioles by sympathetic nerves
Anastomoses
where arteries connect to each other without an intervening capillary network
End artery:
the only arterial blood supply to a given area of the body