Test 2 - Cardiovascular System Flashcards
Cardiovascular System
consists of heart and blood vessels
rapidly transports blood to every cell in the body
controls the pressure of blood, allowing system to move blood where it wants it to go
Heart
muscular pump that generates pressure for pumping blood
consists of mostly cardiac muscle tissue
Blood Vessels
blood transport tubes of varying diameter
Pericardium
tough, fibrous sac that surrounds and protects the heart
Endocardium
smooth lining inside the heart chambers
Heart Structure and Function - Cardiac Cycle
cardiac cycle: sequence of contraction and relaxation of the heart chambers
contraction phase: systole
relaxation phase: diastole
makes up a heartbeat
occurs almost simultaneously in both sides of the heart
Muscle Contraction and Relaxation
electrical changes happen when a muscle fiber contracts and relaxes
the level of electrical charges that happen when a muscle contracts or relaxes at the same time can tell us how much a muscle is active
How Cardiac Muscles Contract
electrical signals from cells drive the heart’s contractions
sinoatrial node generates signals
nervous system adjusts rate and strength of cardiac contractions
Factors that Control Blood Pressure
cardiac output (blood volume leaving the heart)
vasoconstriction (how “small” the blood vessel is)
viscosity (how “thick” the blood is)
volume of the blood
Blood Pressure
fluid pressure exerted by blood against vessel walls, generated by heart contractions
Baroreceptor Reflex
pressure sensors called baroreceptors monitor changes in aterial pressure
Cardiovascular System and Blood in Hemostasis
blood pressure keeps blood flowing
blood relievers cargo to body cells and carries away wastes
blood flow adjustments to different body areas made by vessel contraction/enlargement
blood distributes body heat
blood clotting allows body to sustain minor wounds
