Biology 1220



Biology 1220

Quiz #13 with answers

Name:________________________________________________________

Total Marks: 31 Total Pages: 3

(1) 1. Through how many capillary beds must a human red blood cell travel if it takes the shortest possible route from the right ventricle to the right atrium?

A) one

B) two

C) three

D) four

E) five

(1) 2. What is the name of the mass of tissue located between the lungs, which is the location of the heart?

mediastinum

(2) 3. Which chambers of the heart carry oxygenated blood (after birth)?

left atrium, left ventricle

(2) 4. There are several major vessels which are directly associated with the heart: the superior vena cava, the inferior vena cava, the coronary sinus, the pulmonary trunk, and the aorta. Which of these vessels carries oxygenated blood?

aorta

(3) 5. The ___________empties into the right atrium.

1. superior vena cava

2. inferior vena cava

3. coronary sinus

(1) 6. Blood normally leaves the right ventricle through:

A. the pulmonary semilunar valve

B. the right atrioventricular valve

C. the left atrioventricular valve

D. the aortic semilunar valve

E. it doesn’t pass through a valve

(1) 7. How many pulmonary arteries empty into the left atrium of the heart?

A. none

B. one

C. two

D. four

E. six

(3) 8. Describe the basic structure and function of the pericardium.

fibrous pericardium: tough outer layer

serous pericardium: forms double layer around heart

parietal pericardium: fused with fibrous pericardium

visceral pericardium or epicardium: adheres to heart surface

pericardial cavity: between parietal and visceral pericardium, filled with pericardial fluid

(3) 9. Name the three layers of the heart wall, superficial to deep.

1. epicardium (which is the same as visceral pericardium)

2. myocardium

3. endocardium

(1) 10. The individual chambers of the heart are easily identified by dissecting the heart to reveal the interior. However, there are external landmarks that distinguish the chambers. What is the name of the grooves on the external surface of the heart that locate the divisions between the heart chambers?

sulci (plural)

(1) 11. What is the general term used to describe the tissue divisions between the heart chambers.

septa (plural)

(2) 12. In very basic terms, describe how the heart can establish its own pace of contraction.

no stable resting membrane potential in pacemaker cells of SA node

slow leak caused repeated depolarizations

(5) 13. Compare the structure and function of cardiac myocytes with skeletal muscle fibers.

Compared with skeletal muscle cells, cardiac myocytes:

1. are shorter

2. are less circular in diameter

3. are branched

4. have a single nucleus

5. have larger and more numerous mitochondria

6. have the same arrangements of myofibrils into sarcomeres

7. have intercalated discs with gap junctions.

(5) 14. Draw a labeled diagram of the heart describing the structures associated with the conduction system of the heart. Add a written description of the basic timing of the events associated with the conduction system: where does the signal originate, where does it go, what does it do?

i. SA node in right atrium establishes rhythm

ii. depolarization of SA node causes spread of signal through both atria

iii. signal reaches AV node, which is in the septum between the atria, the AV node slows the signal to delay contraction of ventricles compared with atria

iv. the AV bundle conducts the signal from the AV node to the apex of the heart via the intraventricular septum

v. the Purkinje fibers conduct the signal from the apex towards the atria, causing the ventricles to contract

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