Cardiovascular System Notes

Flashcards based on key concepts from the cardiovascular system lecture.

Function of the cardiovascular system

Deliver oxygen and nutrients and remove carbon dioxide and other waste products.

Epicardium

The outer layer of the heart wall, also known as the parietal pericardium; connective tissue layer.

Myocardium

The middle layer of the heart wall, made mostly of cardiac tissue.

Endocardium

The inner layer of the heart wall, consisting of endothelium.

Atria

The receiving chambers of the heart; left and right sides.

Ventricles

The discharging chambers of the heart.

Atrioventricular valves

Valves between atria and ventricles; includes the bicuspid (mitral) valve and tricuspid valve.

Semilunar valves

Valves located between ventricles and arteries; includes the pulmonary and aortic semilunar valves.

Coronary circulation

The system of blood vessels that nourish the myocardium.

Sinoatrial node

The pacemaker of the heart that initiates contraction.

Cardiac cycle

The sequence of events in one heartbeat, including systole (contraction) and diastole (relaxation).

Arteries

Blood vessels that carry blood away from the heart.

Capillaries

The smallest blood vessels where exchange of materials occurs.

Veins

Blood vessels that carry blood to the heart.

Tunica intima

The innermost layer of blood vessels.

Tunica media

The middle layer of blood vessels that contains smooth muscle and elastin.

Tunica externa

The outermost layer of blood vessels, composed primarily of collagen fibers.

Elastic arteries l

Thick-walled arteries near the heart that can expand and recoil to manage blood pressure.

Muscular arteries

Arteries that deliver blood to specific organs and have a thicker tunica media.

Capillary beds

Networks of capillaries that facilitate microcirculation.

Precapillary sphincter

Cuff of smooth muscle fibers that regulate blood flow into capillaries.

Venules

Small veins that carry blood from the capillaries to larger veins.

Cardiac output (CO)

The volume of blood flowing through a vessel or the entire circulation in a given period.

Stroke volume (SV)

The volume of blood pumped out by a ventricle with each heartbeat.

Blood pressure

The force exerted by circulating blood on the walls of blood vessels.

Resistance (R)

The opposition to blood flow, measured by the friction blood encounters as it moves through vessels.

Systolic pressure

The pressure in the arteries during the contraction of the heart.

Diastolic pressure

The pressure in the arteries during the relaxation of the heart.

Hypotension

Low blood pressure, identified by systolic pressure below 110 mm Hg.

Hypertension

High blood pressure, identified by systolic pressure above 140 mm Hg.

Pulse pressure

The difference between systolic and diastolic pressure.

Arterial blood pressure

Pressure based on the stretch in elastic arteries and blood volume.

Neural factors affecting blood pressure

Adjustments by the autonomic nervous system, which can cause vasoconstriction.

Renal factors affecting blood pressure

Regulation of blood volume by the kidneys, particularly through the actions of renin.

Development of the cardiovascular system

The simple tube heart develops in the embryo and becomes four-lchambered by the end of the seventh week.

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