Ch 7 Respiration in Humans Flashcards
What are the two types of respiration?
Aerobic and anaerobic.
What is respiration?
The breakdown of food molecules such as glucose to release energy.
What is aerobic respiration in terms of:
1. What does it break down
2. Does it require oxygen
3. What are the waste products
4. Amount of energy released
Aerobic respiration releases energy by
1. Breaking down glucose
2. In the presence of oxygen
3. Carbon dioxide and water are released in the process
4. A large amount of energy is released
Equation:
Glucose + Oxygen -> Carbon dioxide + Water
Factors affecting the rate of aerobic respiration?
- Heart rate
- Breathing rate
- Depth of breaths
By increasing these 3 factors, the rate of aerobic respiration is increases, increasing the amount of energy released for vigorous muscular contractions.
Where does aerobic respiration take place?
Mitochondria.
What is anaerobic respiration in terms of:
1. What does it break down
2. Does it require oxygen
3. What are the waste products
4. Amount of energy released
Anaerobic respiration releases energy by
1. Breaking down glucose
2. In the absence of oxygen
3. Lactic acid is produced in the process
4. A relatively small amount of energy is released
Equation:
Glucose -> Lactic acid + Relatively small amount of energy
When does the body use anaerobic respiration?
When muscle contractions are so vigorous that the maximum rate of aerobic respiration is unable to release energy fast enough to meet the demand.
Where does anaerobic respiration take place?
Muscles.
How is oxygen debt incurred?
There is an insufficient intake of oxygen to meet the energy demand for vigorous muscular contractions. Thus an oxygen debt is incurred.
How is oxygen debt removed?
- Continuation of fast heart rate
Results in the faster transportation of
- Lactic acid from the muscles to the liver
- Oxygen from the lungs to liver - Continuation of deeper and faster breathing
Results in
- Continued and fast intake of oxygen by the lungs
- Oxygen is needed for the removal of lactic acid
Once lactic acid is removed, oxygen debt is repaid.
Parts of the respiratory system? (In order of air flow)
- Nasal passages
- Pharynx
- Larynx
- Trachea
- Bronchi
- Bronchioles
- Alveoli
What is the role of cilia in the trachea?
Cilia sweeps dust-trapped mucus to the pharynx to be coughed out or swallowed.
How is the lung adapted for efficient gaseous exchange?
- Numerous alveoli: Large surface area
Alveoli:
2. One-cell thick wall: Short diffusion distance
3. Thin film of moisture on the walls: Allows oxygen to dissolve
4. Surrounded by numerous blood capillaries: Flow of blood maintains steep gas concentration gradient
How does gaseous exchange occur in the lungs?
OXYGEN:
1. Oxygen dissolves into the thin film of moisture on the alveolar walls.
2. Dissolved oxygen diffuses through the alveolar wall and the blood capillary wall, into the blood cells.
3. Oxygen combines with haemoglobin to form oxyhaemoglobin.
CARBON DIOXIDE:
1. Carbon dioxide diffuses from the blood capillaries to the alveolar cavity.
What happens when you inhale?
- Diaphragm muscle contracts, diaphragm flattens.
- Internal intercostal muscles relax and external intercostal muscles contract. (RICE)
- Ribs and sternum move upward and forward.
- Volume of the thoracic cavity increases.
- Air pressure in the lungs drop to become lower than that of the atmosphere.
- Air moves from the surroundings into the lungs.
What happens when you exhale?
- Diaphragm muscle relaxes, diaphragm arches upwards.
- External intercostal muscles relax, internal intercostal muscles contract.
- Ribs and sternum move downward and inward.
- Volume of thoracic cavity decreases.
- Air pressure in the lungs increase to become higher than that of the atmosphere
- Air moves out of the lungs.
Harmful chemicals in tobacco smoke?
- Tar
- Nicotine
- Carbon monoxide
What effect does nicotine have on the respiratory system?
- Increases heart rate and blood pressure.
- Increases the risk of blood clots in arteries, which increases the risk of coronary heart disease.
- Narrows arteries (In a pregnant mother, this can cause fetal development issues due to less oxygen and nutrients reaching the fetus from the mother. Potentially results in miscarriage.)
What effect does carbon monoxide have on the respiratory system?
- Reduces the ability of oxygen to bind with haemoglobin, as carbon monoxide binds irreversibly to the haemoglobin at a higher affinity (more likely to) than oxygen does -> less absorption of oxygen -> lower rate of aerobic respiration -> less energy released -> fatigue
- In a pregnant mother, less oxygen reaches the fetus, resulting in fetal development issues. - Increases the risk of coronary heart disease.
What effect does tar have on the respiratory system?
- Increases the risk of lung cancer, as tar can cause uncontrolled cell division.
- Increases the risk of chronic bronchitis and emphysema.
- Tar paralyses the cilia hairs, so dust-trapped mucus cannot be removed.
Diseases caused by tobacco smoke?
- Chronic bronchitis
Prolonged exposure to irritants -> Lung epithelium lining become inflamed -> Excessive mucus produced by the epithelium lining -> Cilia become paralysed by the excessive mucus -> Dust trapped in mucus -> Air passages become blocked, difficult to breathe -> Persistent coughing to clear the air passages
(Can lead to emphysema and increase the risk of lung infections) - Emphysema
Persistent and violent coughing due to bronchitis -> Partition walls between alveoli break down -> Decreased surface area for efficient gaseous exchange -> Lungs lose their elasticity and remain inflated with air -> Wheezing, breathlessness - Lung cancer
Tar in tobacco smoke can cause uncontrolled cell division.
