cardiovascular system 🫀

What is the cardiovascular system?

A closed system of the heart and blood vessels

Where is the heart located?

thorax between the lungs

How much does the heart weigh?

less than 1lb

What membrane is the heart covered by?

pericardium

List the three layers of the heart wall:

epicardium (outer), myocardium (middle cardiac muscle), endocardium (inner endothelium)

List the four heart chambers:

right atrium & left atrium (receiving chambers), right ventricle & left ventricle (discharging chambers)

what are the four valves that ensure unidirectional blood flow?

atrioventricular (biscupid & tricuspid) and semilunar valves (pulmonary & aortic)

heart valves _____

prevent back flow of blood

What vessels are associated with the heart?

aorta, arteries, superior vena cava, inferior vena cava, and pulmonary veins

what circulation nourishes the heart muscle?

Coronary arteries & veins

Heart pathologies include ______

filtration, tachycardia, and bradycardia

What does the cardiac cycle consist of?

the contraction (systole) and relaxation (diastole) of the heart

Cardiac Output (CO)

Volume of blood pumped by heart per minute

What is considered normal blood pressure?

120/80 mm Hg

What are blood vessels classified into?

arteries, arterioles, capillaries, venules, & veins

name the three tunics:

tunica intima (endothelium), tunica media (smooth muscle), tunica externa (connective tissue)

How is blood pressure measured?

systolic/diastolic

What is blood pressure influenced by?

neural, renal, temperature, chemical, and dietary factors

Pericardium

Membrane surrounding the heart

Myocardium

muscular, middle layer of the heart

endocardium

inner lining of the heart

atria

Upper chambers that receive blood

Ventricles

Lower heart chambers that pump blood out

valves

prevent back flow of blood

chordae tendineae

tendinous cords anchoring valves

Coronary circulation

flow of blood to and from the tissues of the heart

sinoatrial node (SA node)

Heart natural pacemaker

atrioventricular node (AV node)

relay station between atria & ventricles

electrocardiogram (EKG/ECG)

A test that records the electrical heart activity

systole

Contraction phase of the heart

diastole

Relaxation phase of the heart

cardiac output (CO)

Volume of blood pumped by the heart per minute

stroke volume (SV)

Volume of blood pumped per heartbeat

Sympathetic nervous system

increase heart rate

parasympathetic nervous system

decreases heart rate

congestive heart failure (CHF)

heart is too weak/unable to pump its required amount of blood

tunics

layers of blood vessel walls

Capillaries

Microscopic vessels for exchange between blood and tissue

pulse

Pressure waves in arteries from heartbeat

blood pressure

Force of blood on artery walls

Hypertension

high blood pressure

hypostension

low blood pressure

hypotension is systolic below _____

110 mm Hg

hypertension is systolic above ____

140 mm Hg

heat causes what in the blood vessels?

vasodilation (widening vessels)

cold causes what in blood vessels?

vasoconstriction (narrowing vessels)

_______ and ______ affect blood pressure

neutral factors (sympathetic nervous system) & renal factors (blood volume regulation)

what valve conditions increase the heart workload?

incompetence and stenosis

blood pressure decreases with _______

distance from the heart

Pulse points are locations where _____

arterial pulses can be easily felt