Explain the significance of the thickness of the left ventricular wall.

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The Heart

Utilizing knowledge from your learning and assigned readings, respond to the following questions:

1. Explain the significance of the thickness of the left ventricular wall.

2. The major coronary vessels are on the surface of the heart. What is the advantage of that location?

3. Since the SA node is at the top of the atrial mass, the atria contract from the top down. How does this increase the efficiency of atrial contraction? Do the ventricles have a similar arrangement? If so, how does it work?

4. What is the purpose of prolonged contraction of the myocardium?

1. Identify or trace the path of a red blood cell through all anatomical/structural areas of the heart.

2. Identify and briefly describe the components of the intrinsic conduction system in the transmission of the impulse in the heart.

3. View the anatomical models Figure 30.2 (a), (b), (c), and Figure 31.1 from your Laboratory Manual and identify the structures that are described by the following statements. Post your brief responses in the threaded Discussion Area below.

a) Superior heart chambers

b) Pumps the heart

c) Provides nutrient blood to the L ventricle heart muscle

d) Drains blood into the R atrium

e) Delivers oxygenated blood from lungs to L atrium

f) AV valve between R atrium and R ventricle

g) Divides the heart longitudinally into R and L sides

h) Carries oxygenated blood to all arteries

i) Pacemaker

j) Dense network of conductive cells throughout the ventricles

4. View the histology slides Figure 30.7 in your Laboratory Manual and identify the microscopic structures indicated by a leader line, number, or bracket. In the threaded Discussion Area below, briefly describe the function of:

a) Figure 30.7 intercalated discs

b) Figure 30.7 cardiac muscle cells

c) Figure 30.7 nucleus

image1.png Below is Figure 30.2(a)

image2.png

image3.png Below is Figure 30.2(b)

Below is Figure 30.2(c)image4.png

Below is Figure 30. 7