Unit 2 Lesson 3

Respiration: is a term used to describe the process of getting oxygen into our bodies and to our cells and the removal of carbon dioxide .  

The function of the respiratory systems are as follows: 

• To provide oxygen for the body

• To remove carbon dioxide from the body

The main components of the respiratory system:

• Mouth / Nose

• Trachea

• Bronchi/Bronchioles

• Alveoli

• Lungs

There are 4 main stages of  respiration:  

Important Structures of the Respiratory system: 

Mouth / Nose: Air moves in and pass through throat (pharynx) into the trachea 

Pharynx: The area behind the throat where the nasal and _oral cavity meet before entering the trachea.

Larynx: where two cords are located here which vibrate  as air passes through them producing a sound. 

Glottis: The opening of the trachea is called the glottis. 

Epiglottis: The epiglottis helps to prevent food from entering the trachea. 

Trachea: air passes through here. cartiliaginous rings keep it open at all times and prevent it from collapsing. 

Bronchi (singular = bronchus): Trachea separates into two pipes called the left and right bronchi. 

Bronchi are lined with cilia and have cartilage rings 

Bronchioles: Bronchi further split into smaller bronchioles. 

Bronchioles do not have cartilage rings and only larger bronchioles have cilia. 

Alveoli: clusters of tiny sacs with thin membranes at the end of bronchioles. Alveoli are surrounded by capilliares to support gas exchange. 

Alveoli have a large surface area to maximize diffusion of carbon dioxide and oxygen. 

Ventilation (Breathing)

Gases move from an area of high pressure to an area of low pressure. 

Pressure can be changed by changes in volume

• Volume increases, pressure decreases

• Volume decreases, pressure increases

Diaphragm: dome shaped muscle responsible for changing the volume of the lungs

Work with a partner to review the following mechanisms of ventilation. 

Two stages of breathing: 

External Respiration  

Examine the image to the right and answer the questions: 

1. As blood approaches you alveoli what gas is in high concentration in your blood vessels? 

carbon dioxide 

2. What gas is in high concentration in your alveoli? 

oxygen 

3. Where does the oxygen gas travel? 

from the alveoli to the bloodstream 

4. Where does the carbon dioxide gas travel? 

from bloodstream to the alveoli 

5. Why do both of these gases move the way they do? 

diffusion ( where solutes move from high concentration to low concentration)

6. Where is the oxygenated blood moving towards? 

the heart 

Internal Respiration 

Hemoglobin is an iron containing protein in red blood cells that bind to oxygen or carbon dioxide to assist in the delivery of gases throughout the body 

Homeostasis: maintaining balance (body monitors itself and brings things back to normal. 

Once the body detects that blood pH drops, this triggers the brain to increase the breathing rate, heart rate and volume of inhalation to remove excess carbon dioxide.

Aerobic cellular respiration 

This is a series of chemical reactions that occur in the cell that provide energy and require oxygen (from breathing) and glucose C₆H₁₂O₆ (from eating). 

ATP (Adenosine triphosphate): is the 

energy-carrying molecule found in cells

The breakdown of glucose frees up the energy to attach a phosphate onto adenosine diphosphate. 

When the phosphate group is removed ATP the energy stored within the bond is released and is freed for cellular work. 

LET’S PRACTICE / Homework

1. Double click on the image below and label the respiratory system 

2. Describe the features of alveoli in human lungs that make them efficient for gas exchange

Their expansion when inhaling takes in oxygen while shrinking when you exhale allowing the carbon dioxide to leave the lungs. Their thin lining makes their process efficient for gasses to quickly diffuse. 

3. A student begins hyperventilating before an exam (CO2 levels fall in the body). The teacher makes the student breathe into a paper bag for a few minutes. Explain the purpose of breathing into a paper bag from a biological perspective.  

The purpose of breathing into a paper bag is that when you lose a large amount of CO2 the tissues in your body start to malfunction. The idea of the paper bag is that rebreathing your air helps put CO2  back into your blood. 

4. As you travel to high altitudes, the concentration of gases in the air, including oxygen decreases.

1. What effect does this environment have on your breathing? 

This can cause us to have shorter breaths as the lungs have to work harder to deliver oxygen to its bloodstream 

2. How might a runner who trained at sea level perform in a race taking place at 2000m above sea level? Explain. 

The body will increase the pace of breathing to compensate for the change and will try to meet the requirement or what's needed. The runner who is trained to perform at sea level will perform badly.

5. Explain what might happen if a person has low goblet cell productions and how it might impact their health

It can cause a chronic infection leading to the depletion of goblet cells and causing immunologic implications. The size and number of goblet cells will rapidly decrease