Updated'Spring'2009'
Summary & Objectives Chapter 12 – The Circulatory System
Summary
A. The cardiovascular (CV) system is made of the heart that pumps blood and the vessels that carry blood
to all parts of your body.
B. The CV system maintains blood flow to all cells in the body.
C. The vessels include arteries, arterioles, capillaries, venules, and veins.
D. Arteries are thick and elastic and carry blood away from the heart. Veins are thinner than arteries,
larger in diameter than arteries, contain valves, and carry blood toward the heart. Capillaries are very
thin and are the location of material exchange.
E. Blood flow & pressure is controlled by changing the diameter of vessels (usually arterioles and venules)
through the action of smooth muscle.
F. Vessel walls can weaken leading to an aneurism or varicose veins.
G. The heart is made of three main layers and four chambers. Each chamber is separated from the next
region by a valve.
H. The noises the heart makes (lub-dub) are caused by the opening and closing of valves.
I. The systemic circuit moves blood through the body. The pulmonary circuit moves blood through the
lungs. Blood can only flow in one direction through these circuits.
J. The coronary circulation serves the heart. If it is blocked part of the heart does not receive blood flow
and may die. This is called a heart attack or myocardial infarction.
K. Signs of a heart attack include (but are not limited to) pain in the chest or stomach, shortness of breath,
and a cold sweat.
L. Treatment or prevention of a heart attack includes lifestyle, diet, angioplasty, and coronary bypass
surgery.
M. The electrical system of the heart is called the cardiac conduction system and maintains the beating of
your heart without nerves. Heart rate is controlled by nervous input. Artificial pacemakers send
electrical signals for the heart to contract and defibrillators “reset” this electrical system.
N. An electrocardiogram measures the electrical output of your heart.
O. The lymphatic system carries excess fluid from the tissues, through lymphatic vessels, and back into
the blood circulation.
Objectives
1. Describe (in order) the structures that blood moves through as it flows through circuits.
2. Compare and contrast the structure and function of arteries, veins, arterioles, venules, and capillaries.
3. Describe the membrane transport and filtration that occurs across capillary walls.
4. Define blood pressure, how to measure it, what is normal, how it changes based on position and
activity, what is hypertension, and why hypertension needs to be treated.
5. Identify the major structures of the heart, their functions, and the order that blood flows through them.
6. Compare and contrast the systemic, pulmonary, and coronary circuits.
7. Describe how the electrical system of the heart causes the heart to contract and controls the rate of
contraction.
8. Link HDL, LDL, and cholesterol with arthrosclerosis and heart and vessel health.
9. Describe the symptoms of a heart attack (myocardial infraction) and ways to prevent and/or treat a
heart attack.
10. Link the blood vessels and circulation with the lymphatic system.
Key Terms:
artery, vein, arteriole, venule, capillary, atria, ventricle, AV valve, semilunar valve, coronary circulation,
systemic circulation, pulmonary circulation, angioplasty, coronary bypass, myocardial infarction, diastole,
systole, fibrillation, electrocardiogram, bradychardia, tachycardia, hypertension, HDL, LDL,
hypercholesterolemia, sphygmomanometer, stethoscope, fibrillation, AED