Lesson 9: Respiratory system Flashcards
Where does air enter our lungs from?
Air enters from nose/ mouth.
What does it mean if an object has a large surface area to volume ratio?
- This means a large surface area is folded into a small volume.
How does a bacterial cell get oxygen into it?
By diffusion, it is small and so has a large surface area to do so.
What is the function of cartliage rings in the trachea?
- To keep the trachea open.
- Allow it to move during breathing.
What does the trachea have that stops dirt from entering the lungs?
- Mucus catches dirt and bacteria
- Cilia (on ciliated epithelial cells) waft mucus up to swallow.
What is diffusion?
Diffusion is the movement of particles from an area of high to low concentration down a concentration gradient.
passive process that doesn’t require energy
Where does oxygen diffuse into the blood?
- Oxygen diffuses into the blood at the alveoli.
* This is where gas exchange occurs.*
What is gas exchange?
- Gas exchange is the delivery of oxygen from alveoli to blood and removal of carbon dioxide from blood to alveoli.
What are alveoli?
Alveoli are tiny air sacs in the lungs, where gas exchange occurs.
What are the adaptations of the alveoli?
- ) Thin lining -> short diffusion pathway-> increased rate of diffusion.
- ) Large surface area (folded membranes/many alveoli) -> more contact with carbon dioxide and blood -> increased rate of diffusion.
- ) Good blood supply -> mantains steep concentration gradient between alveoli and blood -> increased rate of diffusion (more efficient.)
What is the function of the red blood cell?
- Carry oxygen from lungs to tissues and cells around the body.
What is aerobic respiration?
- Aerobic respiration is a chemical reaction that releases energy using oxygen and glucose.
What do we need energy for?
- Growth
- Building larger molecules
- Matain internal body temperature
- Cell division
- Muscle contraction
What is the symbol equation for aerobic respiration?
60₂+C₆H₁₂0₆ —>6C0₂ +6H₂0
Where does aerobic respiration take place?
- Aerobic respiration takes place in the mitochondria.
How can a low red blood cell count lead to tiredness?
- Red blood cells transport oxygen around the body to release energy.
- If less oxygen is transported, less enegy is released.
- This is why a low red blood cell count can lead to tiredness.
What happens to diaphragm when you inhale and exhale?
Inhale: contracts, flattens.
Exhale: relaxes, returns to dome- like shape.
What happens to the intercostal muscles when you inhale and exhale?
Inhale: Contracts
Exhale: Relax
What happens to the ribcage when you inhale and exhale?
Inhale: Upwards and outwards
Exhale: Downwards and inwards
What happens to the volume in the thorax when you inhale and exhale?
Inhale: Increase
Exhale: Decrease
What happens to the pressure in the lungs when you inhale and exhale?
Inhale: Decrease (air rushes in)
Exhale: Increase (air rushes out)
Where does air move in terms of pressure?
Air moves from an area of high to low pressure.
What is lung volume?
Lung volume: Volume of air that can be held in lungs
What affects lung volume?
- Age
- Fitness levels
- Smoking
- Biological sex
- Diseases eg. asthma.
What is the issue for people with asthma?
- Airways are narrowed and inflamed.
- Makes breathing difficult.
What happens in an asthma attack?
- Contraction occur –> make airways more narrow
What do inhalers do?
- Inhalers will relax muscle -> widen airways -> more air can be inhaled.
Does the percentage of nitrogen change when exhaled?
- No. The percentage of nitrogen stays the same as it is not used in respiration.
Does the percentage of argon change when exhaled?
- No. The percentage of argon stays the same as it is not used in respiration.
Does the percentage of carbon dioxide change when exhaled?
- Yes. The percentage increases as it is released by respiration.
Does the percentage of oxygen change when exhaled?
- Yes. The percentage of oxygen decreases as it is used up in respiration.
How are the lungs adapted for gas exchange?
- Alveoli have good blood supply: mantains concentration gradient.
- Alveoli are thin: short diffusion pathway.
- Alveoli = large surface area. Increases rate of diffusion. (more diffusion spots.)
- Lungs are ventilated to mantain concentration gradient.
Why does the trachea have cartliage rings on it?
- These prevent the trachea from collapsing in inhalation.
