Respiration Flashcards
Aerobic respiration
- Involves the breakdown of glucose in the presence of oxygen
- Generates a large amount of energy
Equation:
C6H12O6 + 6 O2 –> 6 CO2 + 6 H2O + Energy
Anaerobic respiration
- Involves the breakdown of glucose in the absence of oxygen
- Generates a small amount of energy
- Produces lactic acid
Lactic acid
When resting, lactic acid is converted back to glucose
Importance of anaerobic respiration
During vigorous activities:
- aerobic respiration alone is not fast enough to supply the increased energy demand
- Anaerobic respiration takes place to meet the increased energy demand
- However, this causes oxygen debt
Oxygen debt
The build up of lactic acid in muscles that needs to be removed
This causes:
- Continued fast heart rate to transport lactic acid to the liver via blood for removal and oxygen
- Continued deeper and faster breathing to obtain oxygen for liver
Path of air in the human gas exchange system
Nasal passage –> Larynx –> Trachea –> Bronchus
–> Bronchioles –> Alveoli
Nose
Function:
- The fringe of hair and the mucus layer on the walls of the nasal cavity trap dust and foregin particles
Nasal cavity
Function:
- Warm and moisten the air passing through
Trachea
Function:
- C-shaped rings of cartilage support the trachea and keep the lumen of the trachea open
- Gland cells secrete mucus that traps dust particles and foreign particles
- Cilia sweeps trapped particles in the bronchi and trachea up to the pharynx
Adaptation of alveoli for exchange of gases
- Numerous alveoli in the lungs
- Increases the SATV for faster rate of diffusion of gases during gaseous exchange - Has many capillaries
- To maintain a steep diffusion gradient of gases for faster rate of diffusion of gases - Thin film of moisture on alveolar wall
- Allow oxygen to dissolve and enter the bloodstream - Alveolar wall and capillary wall are one cell thick
- To keep a shorter diffusion distance for faster rate of diffusion of gases
Breathing
It is the muscular contraction and movement of the ribs which result in air moving in and out of the lungs
Process of Inhalation
- The diaphragm contracts and flattens
- Internal intercostal muscles relax, external intercostal muscle contracts
- RIbs move upwards and outwards
- Thoracic cavity volume increases, causing the lungs expands and pressure decreases in the lungs
- Causing atmospheric air to enter the lung
Process of Exhalation
- The diaphragm relaxes and arches upwards
- The internal intercostal muscles contracts, the external intercostal muscles relaxes (ERIC)
- Ribs move downwards and inwards
- Thoracic cavity volume decreases, causing the lungs to compress and pressure to increase in the lungs
- Air exits the lungs to the atmosphere
Components of Tobacco smoke
- Nicotine
- Carbon monoxide
- Tar
- Irritants
Nicotine
- Nicotine is an addictive substance
- Increases risk of blood clot in blood vessels and heart diseases
Carbon monoxide
- Combines irreversibly with haemoblobin to form carboxyhaemoblobin, reducing the efficiency of blood to transport oxygen
- Increases the rate at which fats are deposited on the inner arterial wall, increasing the risk of atherosclerosis
Tar
- Carcinogenic
- Paralyses the cilia lining in air passages, hence dust and irritants in the mucus lining cannot be removed
- Increases the risk of chronic bronchitis and emphysema
- Reduces the efficiency of gaseous exchange
Irritants
- Paralyses the cilia lining in air passages (excess mucus secretion)
- Increases the risk of chronic bronchitis and emphysema
Chronic bronchitis
Symptoms:
- Breathing difficulties due to blocked airways
- Persistent cough
Emphysema
Symptoms:
- Breathing diffuculties dues to decrease in SATV for gaseous exchange
- Wheezing due to obstruction of air passage
