Chapter 9: Gas Exchange Flashcards
What are the main adaptations and functions of the gas exchange system?
- Clean and warm the air that enters
- Maximise the surface area
- Maintain the diffusion distance
- Maintain the diffusion gradient
Why do multicellular organisms need gas exchange surfaces?
The MCO’s have a large diffusion distance, so they need efficient gas exchange surfaces
What is the significance of alveoli?
The small alveoli in humans collectively make up a very large surface area.
Why in the human body are the lungs?
In the thorax
What is the membrane surrounding the lungs?
Pleural membranes
What is the function of pleural membranes?
Reduce friction between the the lungs and the diaphragm and ribs
What is the pleural membrane?
It is a membrane which surrounds a fluid region around the lungs
What is the trachea?
It is a cartilaginous tube that connects the larynx to the bronchi, allowing the passage of air
What is the intercostal muscle?
They are a group of muscles that run between the ribs and help form and move the chest walls.
What is the function of the intercostal muscles?
They are involved in the mechanical aspect of breathing by helping expand and shrink the chest cavity.
What is the diaphragm?
It is a thin skeletal muscle that sits at the bas of the chest and separates the abdomen from the chest.
What is the function of the cartilage of the trachea and the bronchi?
They help keep them open and prevent the collapse of the trachea and the bronchi.
What is the function of the terminal bronchiole?
It is the most distal segment of the conducting zone.
It branches off the lesser bronchioles. This branches off into the respiratory bronchioles.
What is respiratory bronchioles?
They are the final division of the bronchiole.
Describe the passage of air from the trachea to the alveoli.
Trachea -> Bronchi -> Bronchioles -> Terminal Bronchioles -> Alveoli
Where do we find cartilage in the respiratory system?
Trachea and Bronchus
Where do we find Goblet cells in the respiratory system?
In the trachea and Bronchus
Where do we find smooth muscle in the respiratory system?
In the Trachea, Bronchus, and Terminal Bronchioles
Where dow e find Cilia in the in the respiratory system?
In the Trachea, Bronchus, Terminal Bronchiole and a few in the respiratory bronchiole.
What are the gas exchange surface of the respiratory system?
The alveolar duct and the alveoli
Why do bronchioles have smooth muscle?
So that they can contract and relax based on the demand of oxygen.
How is the air entering the airway moistened?
From the evaporation of the mucus
Why is the air entering the air way moistened?
To prevent the lungs from drying out
What do mucous hairs do?
They trap larger particles
What is Mucin?
It is the highly glycosylated protein made by the epithelial cells
What is the function of the Goblet Cell?
To secrete Mucus
What is the function of the cilia?
They sweep the mucus upto the larynx where it can get digested
What are macrophages?
They are Phagocytic cells found in tissues throughout the body; they act as antigen presenting cells (APCs)
Why makes alveoli elastic in nature?
They have elastic fibres in them
Why do alveoli have to be elastic in nature?
So that they can stretch and recoil and have an adaptive expansion
What is the function of the alveoli?
To increase the surface area of the lungs - this is seen when they are fully expanded
Why can O2 and CO2 diffuse easily in and out of the alveoli?
Alveoli have thin squamous cell wall and tightly coiled blood vessels.
What are the 3 main threatening chemicals in smoke?
- Tar
- Nicotine
- Carbon Monoxide
What is tar? Why are they dangerous?
It is a mixture of compounds that settle on the lungs and cause lung disease and lung cancer.
Why are carcinogens dangerous?
They can cause cancer by mutations
Why does smoking cause lung diseases?
Harmful gases and particles settle and they are not swept away due to their small size. Tend to settle because of the slow movement of air through the lungs.
What is Chronic Obstructive Pulmonary disease?
COPD is a disease of the lungs characterised by bronchitis and emphysema.
What is bronchitis?
It is a disease in which the airways in the lungs become inflamed and congested with mucus; chronic bronchitis is often associated with smoking.
How does tar affect the respiratory system?
it stimulates the release of excess mucus which clogs the air way and also kills off the ciliated epithelial cells.
Name an infection likely to occur due to chronic bronchitis.
Pneumonia
What is emphysema?
It is caused when the alveoli burst as they have lost the ability to stretch and recoil
How do alveoli lose the ability to stretch and recoil in emphysema?
The elastin of the alveoli is broken down as phagocytes release elactase to reach the site of inflammation
Why do patients with emphysema have higher breathing rates?
Due to the decreased ventilation and build up of gases
Why doe emphysema patients have a lower quality of life?
Due to the wheezing and breathlessness.
Why does smoking cause lung cancer?
Tumours can form due to the mutations that occur due to carcinogens that is contained in tobacco smoke.
Why might lung cancer be dangerous and difficult to treat?
The tumour can spread through the bronchial epithelium and then through the lymphatic tissue, causing secondary tumors
Where do cancers start in lung cancer patients?
In the trachea because this is where the tar will deposit. However it will eventually spread into the bronchus.
What are the 3 main ways of identifying lung cancers?
- Bronchoscopy
- Chest X - Ray
- CT - scan
What are the methods taken to help patient whose lung cancers are going under Metastasis?
Chemotherapy and Anticancer drugs
How can cancers be treated?
- Chemotherapy
- Surgery
- Radiotherapy
What the components of cigarettes smoke that damage the cardiovascular system?
- Nicotine
2. Carbon Monoxide
What are the effects of consuming nicotine
- Stimulates the nervous system to constrict arteries
- Heart rate and the blood pressure increases
- Increases the risk of blood clots
Why is nicotine addictive?
It is a pleasurable compound that stimulates the release of Dopamine.
What is the effect of carbon monoxide to the circulatory system?
It moves into haemoglobin and forms the stable compound of carboxyhemoglobin
This means that the oxygen saturation decreases
It may damage the lining of the arteries
What are the long term effects of CO on the cardiovascular system?
Long term deterioration can lead to CHD or stroke due to fat build up.
