EMT CHAPTER 6 Cardiovascular System

Heart

Muscular organ pumping blood through the body

Right atrium

Receives deoxygenated blood from body

Right ventricle

Pumps blood to lungs

Left atrium

Receives oxygenated blood from lungs

Left ventricle

Pumps oxygenated blood to body

Arteries

Carry blood away from heart

Veins

Carry blood to the heart

Capillaries

Tiny vessels for gas and nutrient exchange

Aorta

Main artery leaving the heart

Pulmonary artery

Carries deoxygenated blood to lungs

Superior vena cava

Returns blood from upper body to heart

Inferior vena cava

Returns blood from lower body to heart

Systole

Contraction of ventricles

Diastole

Relaxation and filling of ventricles

Perfusion

Blood flow meeting tissue needs

Hypoperfusion

Inadequate blood flow (shock)

Cardiac output

HR × Stroke Volume; blood pumped per minute

Stroke volume

Blood ejected in one heartbeat

Baroreceptors

Sense blood pressure changes

Sympathetic nervous system

Triggers fight-or-flight response

Parasympathetic nervous system

Slows body to rest-and-digest state