Circulatory System

How many chambers does the heart have?

Right atria, left atria, right ventricle, left ventricle

What do the right atrium and ventricle do?

The right atrium collects blood from the body and passes it to the right ventricle, which pumps it to the lungs

What do the left atrium and ventricle do?

The left atrium collects reoxygenated blood from the lungs aad passes it to the left ventricle, which pumps it around the body

What are the 3 main layers of the heart?

Endocardium, myocardium, and pericardium

What is the endocardium?

The innermost layer of the heart lining the inside of the chambers

What is the myocardium?

The muscular middle layer of the heart

What is the pericardium?

The double layered membrane that encloses the heart

What is diastole?

Diastole is the relaxation phase where the heart refills with blood (low pressure)

What is systole?

The contraction phase where blood is pumped out to the body and lungs (high pressure)

What are steps 1 and 2 in the cycle?

Step 1 diastole is when the atria fill and all valves close, and step 2 diastole is where increased atrial pressure opens the AV valves and the ventricles fill

What are steps 3 and 4?

Step 3 systole begins is where the atria contract and empty leading to full ventricles, and step 4 systole is when the ventricles begin contraction, pressure closes the AV valves, and atria relax

What is step 5?

Step 5 systole is when the ventricles contract, there is increased pressure in the ventricles, the aortic and pulmonary valves open, and blood is ejected into the aorta and pulmonary artery

What is step 6?

Step 6 diastole is when the ventricles empty and relax, and the aortic and pulmonary valves close. After step 6 the cycle returns to step 1

What are valves?

Valves are flaps of tissue that permit one way blood flow

What are Atrioventricular Valves and which two are atrioventricular??

The AV valve allows only blood to flow from the atria to the ventricles. The two are the tricuspid and mitral (or bicuspid) valves.

What is the tricuspid valve?

The tricuspid valve (3 leaflets) is between the right atrium and right ventricle

What is the mitral valve?

The mitral valve (2 leaflets) is between the left atrium and left ventricle

What are semilunar valves and which two are semilunar??

Semilunar valves are the half moon valves that go out of a ventricle and into an artery. The two semilunar valves are the aortic valve and the pulmonary valve.

What is the aortic valve?

The valve from the left ventricle to the aorta

What is the pulmonary valve?

The valve from the right ventricle to the pulmonary artery

What is the sinoatrial node?

The sinoatrial node (SA node) is a conductive tissue that acts as the natural pacemaker of the heart, it initiates impulses for contraction that spreads over atria and passes to ventricles via the atrioventricular node (another conductive tissue)

What does the Vagus Nerve do?

The vagus nerve slows the heart rate using acetylcholine

What is acetylcholine?

ACh is a neurotransmitter that carries signals between nerve cells and target organs

What is the autonomic nervous system?

Something that increases heart rate using epinephrine and norepinephrine

What is epinephrine and norepinephrine?

Epinephrine is a neurotransmitter that increases heart rate and the force of heart contractions, and norepinephrine also increases heart rate but it constricts blood vessels, raising blood pressure

What is auscultation?

Listening through a stethoscope for abnormal sounds

What is an electrocardiogram (ECG)?

An electrocardiogram is an electrical recording of heart action

What is echocardiography?

A diagnostic procedure where high frequency sound waves are used to examine size, shape, and motion of the heart

What is doppler echocardiography?

A type of echocardiography that analyses blood flow patterns and changes in velocity of blood flow within the heart and great vessels

What is cardiac catheterization and what does it look for?

A catheter is passed into the heart through blood vessels to sample blood in each chamber. It looks for oxygen content and pressure

What is a coronary arteriography?

Contrast material is injected to visualize blood vessel function