Science Form 3

Term 1: Chapter 1-3

What is the human respiratory system?

The human respiratory system is the system that facilitates breathing, allowing the exchange of oxygen and carbon dioxide between the body and the environment.

What are the main functions of the human respiratory system?

The primary functions are to supply oxygen to the body and remove carbon dioxide from the body cells.

List the major components of the human respiratory system.

The major components include the nasal cavity, nostrils, pharynx, larynx, trachea, bronchi, bronchioles, and alveoli.

What is the breathing mechanism?

The breathing mechanism involves inhaling and exhaling air, facilitated by the movement of the diaphragm and intercostal muscles, affecting lung volume and air pressure.

What is the pathway of air during inhalation?

During inhalation, air travels through the nostrils, nasal cavity, pharynx, larynx, trachea, bronchi, bronchioles, and finally reaches the alveoli for gas exchange.

Describe the role of alveoli in the respiratory system.

Alveoli are tiny air sacs in the lungs where the exchange of oxygen and carbon dioxide occurs between the air and the blood.

What importance does correct breathing technique have?

Correct breathing technique is vital for ensuring physical and mental health, improving performance during exercise or sports, and maintaining overall well-being.

How does the diaphragm contribute to respiration?

The diaphragm contracts and moves downwards during inhalation, increasing lung volume and drawing air in. It relaxes and moves upwards during exhalation, pushing air out.

What is the process of gas exchange in the alveoli?

The process involves oxygen moving from the alveoli, where its concentration is high, into the blood capillaries, while carbon dioxide moves from the blood, where its concentration is high, into the alveoli to be exhaled.

What is hemoglobin and its role in gas exchange?

Hemoglobin is a protein in red blood cells that binds with oxygen in the lungs to form oxyhemoglobin, facilitating the transport of oxygen to body cells.

Describe how oxygen is transported to body cells.

Oxygen is transported from the lungs through the blood as oxyhemoglobin in red blood cells to body cells, where it is released for cellular respiration.

What happens to oxyhemoglobin when it reaches body cells?

When oxyhemoglobin reaches body cells, it decomposes to release oxygen molecules, which are then used for cellular respiration.

What is the chemical equation summarizing cellular respiration?

The chemical equation is: ext{Glucose} + ext{oxygen}
ightarrow ext{carbon dioxide} + ext{water} + ext{energy}.

What occurs to carbon dioxide produced in body cells?

Carbon dioxide produced in body cells diffuses into the blood capillaries, where it is transported back to the lungs to be exhaled.

Explain the concept of diffusion in gas exchange.

Diffusion is the movement of gas molecules from an area of higher concentration to an area of lower concentration, facilitating the exchange of oxygen and carbon dioxide in the alveoli and blood.

What is the function of capillary walls during gas exchange?

Capillary walls allow for the diffusion of oxygen and carbon dioxide between the alveoli and the blood, as they are thin and permeable to gases.