Biology 8 Lesson 20: Respiration and respiratory organs
1. Summary of theory
1.1. Breathing concept
– Respiration is the process of constantly supplying O2 to the body’s cells and removing CO2 by the cells, out of the body.
Respiration has 3 stages:
- Breathing (ventilation in the lungs).
- Gas exchange in the lungs: CO2 from the blood into the lung cells, O2 from lung cells into the blood.
- Gas exchange in cells: O2 from blood into cells, CO2 from cells into the blood.
– Meaning of respiration: Through respiration, O . gas2 taken in to oxidize organic compounds to create energy needed for the body’s vital activities.
1.2. Organs of the respiratory system and their functions
The respiratory system consists of two parts: the airways and the lungs
– Air conduit:
Structure: includes the following organs: nose, pharynx, larynx, trachea, bronchi.
- Nose: has many nasal hairs, has a mucus-secreting mucosa, has a dense capillary layer.
- Laryngeal: Has a movable epiglottis that seals the airways.
- Trachea: Composed of 15-20 rings of cartilage, stacked on top of each other, with a mucous-secreting mucosa with many vibrating hairs.
- Bronchi: Composed of rings of cartilage, in the bronchi where it comes into contact with the alveoli, there is no cartilage ring but muscle fibers.
- Function: Leads air in and out of the lungs; clean, warm and humidify the air entering the lungs; protect the lungs from harmful agents.
+ This function is performed well thanks to the structure of the air duct with the following suitable characteristics:
- The entire airways are lightly lined with mucous membranes and are mostly mucoid (humidify and purify the air by binding small dust particles), have many capillaries (warm the air).
- The outer part of the nasal cavity has many hairs, which have the effect of blocking large dust particles (cleansing the air and protecting the lungs).
- The lining of the trachea has bristles that vibrate continuously to sweep the dust that is attached to the outside.
– Two lungs:
- Outside the two lungs are two layers of membranes, the outer layer is attached to the ribcage, the inner layer is attached to the lungs, between the two layers is a fluid that helps the lungs expand and spongy.
- The structural units of the lung are the alveoli gathered in clusters and surrounded by a dense network of capillaries. There are 700-800 million alveoli (alveoli) that make up the lungs, making the small surface area for gas exchange up to 70-80m2.
- Function: exchange gases between the body and the external environment.
2. Illustrated exercise
How important is respiration for living organisms?
Respiration is the process of continuously supplying O .2 for cells to maintain all vital activities of cells and bodies and remove CO2 out of the body.
3.1. Essay exercises
Question 1: Compare the respiratory system of humans with the respiratory system of rabbits?
Verse 2: Explain the saying “just stop breathing for 3-5 minutes, the blood through the lungs will not have O2 to receive”.
Question 3: Thanks to that, astronauts, firemen, and scuba divers can function normally in an O2-deficient environment (in space, in a fire, on the ocean floor).
3.2. Multiple choice exercises
Question 1: In the human airway, the trachea is the part that connects to the
A. Throat and bronchi.
B. Bronchi and nose.
C. Throat and larynx
D. The larynx and bronchi.
Verse 2: During respiration, what gases do humans use and what gases are eliminated?
A. Nitrogen use and carbon dioxide removal
B. Using carbon dioxide and eliminating oxygen
C. Use of oxygen and removal of carbon dioxide
D. Use of Oxygen and Elimination of Nitrogen
Question 3: How many alveoli are there in the human body?
A. 500-600 million alveoli
B. 600-700 million alveoli
C. 700-800 million alveoli
D. 800-900 million alveoli
Verse 4: The structural unit of the lung is:
C. 2 lungs
Question 5: What type of cartilage has the function of sealing the airways when swallowing food to prevent food from entering the airways?
A. Ring cartilage
B. Cartilage of the vocal cords
C. Thyroid cartilage
D. All of the above answers
After completing this lesson, you should:
- Explain the concept of respiration and its role in living organisms.
- Identify on the picture the respiratory organs in humans and state their functions.