Download UNIT 13 STUDY GUIDE KEY CARDIOVASCULAR SYSTEM: THE

UNIT 13 STUDY GUIDE KEY
CARDIOVASCULAR SYSTEM: THE HEART AND VESSELS
Part A: Heart Location
1. 1-base; 2-right lung; 3- left lung; 4- apex; 5- fibrous pericardium; 6- diaphragm
Part B: Heart Coverings and Layers
2. Why is it important to have fluid between layers of the pericardium?
The serous fluid reduces friction when the heart beats.
3. How are the myocardium muscle fibers arranged in the heart?
Arranged in bundles wrapped around the heart.
4. What gives the myocardium extra strength and support?
Fibrous skeleton throughout myocardium.
5. Which ventricle has much thicker walls than the other and why?
Left ventricle; must pump blood to entire body, not just lungs.
6. List and describe the heart coverings.
a. Fibrous Pericardium—fibrous layer on very outside; continuous with
other vessels and organs
b. Parietal Pericardium—outer part of serous pericardium; smooth thin
layer just under fibrous pericardium that wraps around on itself to
reduce friction
c. Visceral Pericardium—inner part of serous pericardium; reduces
friction; also called epicardium
7. List and describe the three heart layers:
a. Epicardium—outer layer; also known as visceral pericardium
b. Myocardium—middle layer; muscle
c. Endocardium—inner layer; glistening white sheet; very thin
8. Which heart covering is also the outermost heart layer? Give both names.
Epicardium. Also called visceral pericardium.
Diagram: 7- fibrous pericardium; 8- parietal layer of serous pericardium; 9- pericardial
cavity; 10- visceral layer of serous pericardium (epicardium); 11- endocardium; 12myocardium
PART C: HEART STRUCTURES AND FUNCTIONS
9. Follow an RBC on its trip through the heart and part of a lung. Begin with the 2
main blood vessels that it might pass through to empty into the heart and end with
the main vessel that will carry it from the heart, back out to the body (be sure to
name all these vessels). Include all the heart chambers, the heart valves, the main
vessels leading to and from the heart and the lungs.
Blood travels from the body through the Vena cava, which empties into
Right Atrium. Blood then goes through the tricuspid valve into the right
ventricle. It then goes through the pulmonary semilunar valve into the
pulmonary trunk, which branches into the pulmonary arteries and delivers
blood to the lungs for gas exchange. Blood is then brought back to the heart
through the pulmonary veins which empty into the left atrium. It goes
through the mitral valve and enters the left ventricle. Blood is then pumped
through the aortic semilunar valve to the aorta and then to the body.
10. Explain the differences between the functions of arteries, veins and capillaries.
Arteries take blood away from the heart (A for Away!)
The arteries then branch at tissues to form tiny capillaries that the nutrients
and oxygen can diffuse across.
The capillaries then come together again to form veins, which return blood to
the heart.
11. Explain the differences between the functions of atria and ventricles.
Atria collects the blood from other organs and ventricles pump it back out to
the body (including lungs).
12. What is the general purpose of heart valves?
To make sure blood flows in one direction.
13. What is the difference between systole and diastole?
Systole is when the atrium or ventricle is contracted.
Diastole is when the atrium or ventricle is relaxed.
Diagrams: 1- auricle of right atrium; 2- coronary sulcus (not on test); 3- right ventricle; 4auricle of left atrium; 5- anterior interventricular groove (sulcus); 6- left ventricle; 7- left
auricle; 8- coronary sulcus (not on test); 9- left ventricle; 10- adipose tissue; 11- posterior
interventricular groove (sulcus); 12- right auricle; 13- right ventricle
Great Vessels of the heart diagrams (next page): 1-superior vena cava; 2- right
pulmonary artery; 3- ascending aorta; 4- pulmonary trunk; 5- right pulmonary veins; 6inferior vena cava; 7- aortic arch; 8- ligamentum arteriosum; 9- left pulmonary arteries;
10- descending aorta; 11- left pulmonary veins 12- aortic arch; 13- ligamentum
arteriosum; 14- left pulmonary arteries; 15- left pulmonary veins; 16- coronary sinus (not
on test); 17- superior vena cava; 18- ascending aorta; 19- right pulmonary artery; 20right pulmonary veins; 21- inferior vena cava
Interior structures of the heart diagram (next page): 1- pulmonary semilunar valve; 2right atrium; 3- coronary sinus opening (not on test); 4- tricuspid valve; 5- right ventricle;
6- trabeculae carneae (not on test); 7- left atrium 8- aortic semilunar valve; 9- bicuspid
valve (mitral); 10- chordae tendonae; 11- interventricular septum; 12- papillary muscle;
13- left ventricle
PART D: A BEATING HEART
14. What causes each of the 2 characteristic heart beat sounds?
Lub is caused by a-v valves closing.
Dub is caused by semilunar valves closing.
15. Explain what causes the following conditions:
a. Murmur—swishing of blood through a defective valve; can be caused
by congenital deformation or from heart inflammation
b. Mitral valve stenosis—thickening of mitral valve flaps because of scar
tissue; restricts flow
c. Valvular insufficiency—one or more cusps are too short to close the
valve and blood can flow the wrong way
d. Mitral valve prolapse—one or more cusps just do not work correctly
and the valve does not close properly and blood can flow the wrong
way
16. How does hypertension cause more atherosclerosis which causes more
hypertension? When there is too much pressure on your vessel walls,
materials in the blood may get caught and build up more easily, leading to
atherosclerosis. This in turn can cause your arteries to harden and not
expand, even minimizing the room for blood to flow through, increasing
blood pressure, or creating hypertension.
17. Name the risk factors for atherosclerosis.
High cholesterol and LDL, Low HDL, High Blood Pressure, Tobacco Smoke,
diabetes mellitus, obesity, inactive lifestyle, age, and family history of heart
disease
18. Name and describe the 2 types of ischemic heart problems.
Angina Pectoris—chest pain due to lack of oxygen for heart tissue
Myocardial Infarction (aka heart attack)—coronary vessel is blocked so
blood cannot deliver oxygen and nutrients and tissue dies, leaving scar tissue
19. Explain how an action potential spreads throughout the heart, causing a
contraction. Be sure to name and describe the three main structures involved.
Sino-atrial node (SA node) in right atrium near vena cava self-excites,
triggering an action potential that spreads across the atria. The action
potential reaches the AV node, which delays the message so the atria can
finish contracting. The action potential then gets sent down the AV bundles
to the Purkinje fibers in the myocardium to signal the ventricles to contract.
20. What mechanical devices can help overcome heart conduction problems?
Artificial pacemakers
21. Explain what causes the following conditions:
a. Tachycardia—fast heart rate; caused by fever, hormones, drugs, or
sympathetic nervouse system
b. Atrial fibrillation—blood pools in the atrium and could lead to clotting
c. Ventricular fibrillation—caused by trauma, electrical shock, or lack of
oxygen; can cause death; defibrillation may depolarize the heart and
allow the SA node to take control again—may save life!
d. Arrhythmia—diseased valves cause flutter
e. Bradycardia—slow heart rate due to low temp, drugs, parasympathetic
nervous system, or athletic training
22. List and describe the series of three waves that occur on a normal EKG. Tell
what each represents.
P wave—atrial depolarization before atria can contract
QRS complex—ventricular depolarization
T wave—ventricular repolarization after ventricles contract
23. Why would a longer period between EKG waves be a cause for concern?
It may mean there is damaged or diseased tissue. The tissue cannot
depolarize or repolarize fast enough.
24. How do you find cardiac output?
Multiply stroke volume (mL/beat) x heart rate (beats/min).
25. When you condition your heart, it doesn’t beat as fast during exercise as it does if
you are out of shape. Why is this? HINT- it has to do with the critical factor in
looking for cardiac output.
If you condition your heart, you are increasing stroke volume. You are
allowing your heart to stretch more and therefore contract more, pumping
out more blood. Because it pumps more blood in each beat, it does not have
to beat as many times to get the same result.
PART E: BLOOD VESSELS
26. Follow the path of an RBC as it leaves the heart and travels to the body and back
to the heart.. Name the general vessels in order that an RBC encounters them.
Heart to aorta to arteries to aterioles to capillaries to venules to veins to vena
cava to heart.
27. What is the main vessel type to constrict or dilate according to where the body
needs blood?
Arteries
28. How can veins work against gravity to bring blood back to the heart?
Blood pressure keeps the blood moving; skeletal and respiratory muscles
help push and a system of one-way valves trap the blood from moving
backwards.
29. What materials do the capillaries allow to flow into the tissues?
Gases, nutrients, and hormones.
30. How does the structure of the capillary allow for such flow? What must stay
behind? Capillaries only have the thin tunica intima. Blood cells can go
through the vessel in single file and nutrients and gases can diffuse across the
membrane or through pores in the membrane.
31. Explain why plasma, lymph, and intersitital fluid all describe the same fluid.
Plasma can move freely into tissues carrying many solutes with it. Once in
the tissues, plasma is called intersitital fluid. It then gets picked up by vessels
in the lymphatic system. This is called lymph. The lymph eventually gets
dumped back into the blood stream.
32. Which type blood vessel takes care of the body’s tissues?
Capillaries. They flow through the tissues.
33. What tunic makes up the capillaries?
Tunica intima.
34. Which vessel has a thicker tunica media? Why is this important?
(Muscular) Arteries. They have more muscle to function in vasoconstriction.
35. Which vessel has a thicker tunica externa? Why is this important?
Veins. There are thick bundles of collagen and elastic to help the veins
stretch if needed and to support the large lumen.
36. Explain why we have 2 separate circulation systems and the heart is really a
double pump.
The right side functions to pump blood to the lungs for gas exchange. The
left side functions to pump blood from the lungs to the body.
37. Blood returning to the heart from the legs would have to pass through:
a. what major leg veins? Femoral and Iliac Veins
b. What large abdominal vein? Inferior Vena Cava
38. Blood going to the legs would go through
a. What abdominal blood vessel? Abdominal Aorta
b. What major leg arteries? Iliac Arteries
39. What is the artery that leaves the aortic arch on the left side and goes down the
left arm? Left Subclavian
40. What artery leaves the brachiocephalic artery (on the right side of the chest) and
goes down the right arm? Right subclavian
41. What are the 2 large arteries that go from the heart, directly along either side of
the neck to the brain? Left and right common carotid
42. What are the major veins that go directly along either side of the neck and bring
blood back to the chest cavity from the brain? Left and right jugular veins