Chapter 5 - Cardiovascular System Flashcards
Pulmonary circuits
Exchange of gas.
Circulates blood through the lungs
Blood flow of heart
Superior vena cava > right atrium > atrioventricular valve > right ventricle > lungs > left atrium > atrioventricular valve > left ventricle > inferior vena cava > out to body
Systemic circuits
Serves the needs of body tissues. Include all veins and arteries.
High blood pressure - hypertension
When blood moves through the arteries at a higher pressure then normal.
Present when systolic blood pressure is 140 or greater, or the diastolic blood pressure is 90 or greater.
Arterioles
Are small arteries barely visible to the naked eye.
Capillary
An extremely narrow, microscopic tube with a wall composed only of endothelium.
Venules
Are small veins that drain blood from capillaries and then join to form a vein
Atrium
The two upper, thin walled - right and left atrium
Ventricles
The two lower thicker chambers - left and right ventricles.
Atrioventricular valves
Valves that lies between the atria and ventricles
Semilunar valves
Valves that are flaps shaped like half moons
Coronary circulation
Myocardium receives oxygen and nutrients from the coronary arteries - wastes are removed by the cardiac veins.
Systole
The working phase - contractions of the chambers
Diastole
Resting phase - relaxation of the chambers
Sinoatrial node (SA node)
Located in upper dorsal wall of right atrium
Initiates the heartbeat and automatically sends out an excitation signal every .85 second. - causes atria to contract
Atrioventricular node (AV node)
Base of right atrium near the septum
Slight delay when av node is reached - ventricles begin contraction after atria finishes.
Electrocardiogram (ECG)
A recording of the electrical changes that occur in the myocardium during a cardiac cycle.
