Biology 8 Lesson 17: Heart and blood vessels
1. Summary of theory
1.1. Heart structure
a. External structure
– The heart is pyramidal, the top is below, the bottom is up and slightly deviated to the left.
b. Internal structure
– Heart has 4 chambers
– Ventricles are thicker than atria.
– Between the ventricles and the atria and the ventricles with the arteries have valves to ensure blood flow in one direction.
1.2. Blood vessel structure
1.3. The contraction cycle of the heart
– Heart contraction cycle, each cycle consists of 3 phases:
+ Atrial fibrillation
+ Phase loss
+ General expansion phase
⇒ Blood is pumped in one direction from the atria to the ventricles and from the ventricles to the arteries.
2. Illustrated exercise
Please fill in the description of the structural components of the heart in Figure 17-4?
Figure 17-4. Diagram of the internal structure of the heart
3.1. Essay exercises
Question 1: Fill in table 17-2.
Verse 2: What are the structural differences between the types of blood vessels?
Question 3: How are the functions of arteries, veins and capillaries different?
3.2. Multiple choice exercises
Question 1: Between the ventricle and the atrium and the ventricle with the valved artery, what is its role?
A. Ensure blood circulation in one direction.
B. Prevent the mixing of blood
C. Pushing blood
D. There is no correct answer.
Verse 2: The circuit system consists of several types
Question 3: Which type of vessel has the narrowest lumen?
D. Pulmonary artery
Verse 4: Which type of vessel has the function of carrying blood from all the cells to the heart, with low velocity and pressure.
D. Lymphatic vessels
Question 5: Which type of vessel has 3 layers: connective tissue, smooth muscle tissue, thick epidermal tissue?
D. Lymphatic vessels
Question 6: The direction of blood flow in the body.
A. Atrium => ventricle => artery
B. Atria => ventricles => veins
C. Ventricles => atria => arteries
D. Ventricles => atria => veins
After completing this lesson, you should:
- Indicate the outer and inner chambers of the heart, the heart valves, distinguish the types of blood vessels.
- Describe the phases of the cardiac contraction cycle.