Question

name______
respiratory system
follow the
air flow
directions: number the steps of respiration in the correct order.
____ air flows into the bronchi
____ air flows into the alveoli
____ air flows through the pharynx
____ air flows into tiny tubes called bronchioles
____ air flows into the trachea
____ oxygen is transferred to the blood stream
____ air is inhaled through the nose and mouth
____ air is exhaled from the lungs
____ air flows passes through the epiglottis and larynx
question: describe what happens to the gases oxygen and carbon dioxide
in the alveoli of the lungs.

Explanation:

Part 1: Ordering the steps of respiration

To determine the correct order of air flow in the respiratory system, we follow the anatomical pathway of inhaled air:

1. Air is inhaled through the nose and mouth (first step of inhalation).
2. Air flows through the pharynx (air moves from nose/mouth to pharynx).
3. Air flows passes through the epiglottis and larynx (air moves from pharynx to larynx, then to trachea).
4. Air flows into the trachea (air moves from larynx to trachea).
5. Air flows into the bronchi (trachea splits into bronchi).
6. Air flows into tiny tubes called bronchioles (bronchi branch into bronchioles).
7. Air flows into the alveoli (bronchioles end in alveoli).
8. Oxygen is transferred to the blood stream (gas exchange in alveoli).
9. Air is exhaled from the lungs (final step of respiration, after gas exchange).

So the correct numbering is:

• Air is inhaled through the nose and mouth: \( 1 \)
• Air flows through the pharynx: \( 2 \)
• Air flows passes through the epiglottis and larynx: \( 3 \)
• Air flows into the trachea: \( 4 \)
• Air flows into the bronchi: \( 5 \)
• Air flows into tiny tubes called bronchioles: \( 6 \)
• Air flows into the alveoli: \( 7 \)
• Oxygen is transferred to the blood stream: \( 8 \)
• Air is exhaled from the lungs: \( 9 \)

Part 2: Gas exchange in alveoli

In the alveoli of the lungs, gas exchange occurs via diffusion (movement of gases from high to low concentration):

• Oxygen (\( \text{O}_2 \)): Moves from the alveoli (high \( \text{O}_2 \) concentration, as inhaled air has more \( \text{O}_2 \)) into the surrounding capillaries (low \( \text{O}_2 \) concentration, as blood has used \( \text{O}_2 \) for cellular respiration). It binds to hemoglobin in red blood cells for transport to body tissues.
• Carbon dioxide (\( \text{CO}_2 \)): Moves from the capillaries (high \( \text{CO}_2 \) concentration, as tissues produce \( \text{CO}_2 \) during respiration) into the alveoli (low \( \text{CO}_2 \) concentration, as exhaled air has more \( \text{CO}_2 \)). It is then exhaled from the lungs.

Final Answers

• Respiration Step Order: \( 1 \): Air is inhaled through the nose and mouth; \( 2 \): Air flows through the pharynx; \( 3 \): Air flows passes through the epiglottis and larynx; \( 4 \): Air flows into the trachea; \( 5 \): Air flows into the bronchi; \( 6 \): Air flows into tiny tubes called bronchioles; \( 7 \): Air flows into the alveoli; \( 8 \): Oxygen is transferred to the blood stream; \( 9 \): Air is exhaled from the lungs.
• Gas Exchange in Alveoli: Oxygen diffuses from alveoli to blood; carbon dioxide diffuses from blood to alveoli.

Answer:

Part 1: Ordering the steps of respiration

To determine the correct order of air flow in the respiratory system, we follow the anatomical pathway of inhaled air:

1. Air is inhaled through the nose and mouth (first step of inhalation).
2. Air flows through the pharynx (air moves from nose/mouth to pharynx).
3. Air flows passes through the epiglottis and larynx (air moves from pharynx to larynx, then to trachea).
4. Air flows into the trachea (air moves from larynx to trachea).
5. Air flows into the bronchi (trachea splits into bronchi).
6. Air flows into tiny tubes called bronchioles (bronchi branch into bronchioles).
7. Air flows into the alveoli (bronchioles end in alveoli).
8. Oxygen is transferred to the blood stream (gas exchange in alveoli).
9. Air is exhaled from the lungs (final step of respiration, after gas exchange).

So the correct numbering is:

• Air is inhaled through the nose and mouth: \( 1 \)
• Air flows through the pharynx: \( 2 \)
• Air flows passes through the epiglottis and larynx: \( 3 \)
• Air flows into the trachea: \( 4 \)
• Air flows into the bronchi: \( 5 \)
• Air flows into tiny tubes called bronchioles: \( 6 \)
• Air flows into the alveoli: \( 7 \)
• Oxygen is transferred to the blood stream: \( 8 \)
• Air is exhaled from the lungs: \( 9 \)

Part 2: Gas exchange in alveoli

In the alveoli of the lungs, gas exchange occurs via diffusion (movement of gases from high to low concentration):

• Oxygen (\( \text{O}_2 \)): Moves from the alveoli (high \( \text{O}_2 \) concentration, as inhaled air has more \( \text{O}_2 \)) into the surrounding capillaries (low \( \text{O}_2 \) concentration, as blood has used \( \text{O}_2 \) for cellular respiration). It binds to hemoglobin in red blood cells for transport to body tissues.
• Carbon dioxide (\( \text{CO}_2 \)): Moves from the capillaries (high \( \text{CO}_2 \) concentration, as tissues produce \( \text{CO}_2 \) during respiration) into the alveoli (low \( \text{CO}_2 \) concentration, as exhaled air has more \( \text{CO}_2 \)). It is then exhaled from the lungs.

Final Answers

• Respiration Step Order: \( 1 \): Air is inhaled through the nose and mouth; \( 2 \): Air flows through the pharynx; \( 3 \): Air flows passes through the epiglottis and larynx; \( 4 \): Air flows into the trachea; \( 5 \): Air flows into the bronchi; \( 6 \): Air flows into tiny tubes called bronchioles; \( 7 \): Air flows into the alveoli; \( 8 \): Oxygen is transferred to the blood stream; \( 9 \): Air is exhaled from the lungs.
• Gas Exchange in Alveoli: Oxygen diffuses from alveoli to blood; carbon dioxide diffuses from blood to alveoli.