The Respiratory System Flashcards
Where is the parietal pleura?
It lines the ribcage.
Where is the visceral pleura?
It adheres to the lung surface.
During inspiration which direction does the diaphragm move?
It moves downwards increasing thoracic volume.
Factors that lead to increased ventilation
- Increased CO2 in the blood
- Decreased 02 in the blood
- Lowered pH level in the blood.
How much anatomical dead space is there in the lungs?
About 150ml.
How is minute volume calculated?
Respiratory rate x tidal volume
The volume of air that can be exhaled after normal exhalation is….
Expiratory reserve volume
Contraction of the diaphragm causes….
Inspiration of air.
Lung compliance
Determines how easy it is for inspiration to occur. Low compliance makes is more difficult while high compliance makes it easier.
Tidal Volume
The volume of air that passes in and out of the lungs with each breath at rest.
Chemoreceptors
Important in regulating breathing.
Name the three parts of the pharynx
Nasopharynx - posterior to the nasal cavity
Oropharynx - posterior to the mouth
Laryngopharynx - above the layrnx
Functions of the larynx
- Produces sound
- Protects the airway
- Passageway for air during breathing
Main Functions of the Respiratory System
- Enable oxygen to move from the air into the blood
- Enable carbon dioxide to move from the blood to the air
- Metabolism of some compounds
- Filtration of toxic materials from the circulation.
- To act as a reservoir for blood.
Function of the Epiglottis
Blocks the trachea during swallowing to prevent food from entering the lungs.
Function of the nasal, pharyngeal and laryngeal cavities
To filter, heat and moisten air that passes through it. They also produce mucous secretions to trap impurities.
Pleura
Made up of the visceral pleura (covers the lungs) and the parietal pleura (lines the ribs). Pleural spaces between these two layers is filled with serous lubricating fluid allowing the lungs to expand and deflate with little frictional resistance.
What lines the trachea?
Ciliated epithelium which transport mucus and trapped particles upwards toward the epiglottis for swallowing.
Name the divisions of the bronchi
- Trachea
- Right & Left Primary Bronchi
- Secondary Bronchi
- Tertiary Bronchi
- Terminal Bronchioles (no alveoli)
- Respiratory Bronchioles (occasional alveoli)
- Alveolar ducts (completely lined with alveoli)
Bronchioles
Smallest airways without alveoli. Take no part in gas exchange and are referred to as anatomical dead space. Encapsulate about 150ml of air.
What does the diaphragm do at rest?
It contracts and pulls downward to increase the thoracic space so air can flow in.
Function of the external intercostal muscles
Aid expansion of the chest when increased respiratory effort is required. Pull the ribs upwards and outwards increasing thoracic space.
Accessory Muscles
Include:
- External intercostal muscles (lift ribs up and out)
- Scalene Muscles (lift the first 2 ribs)
- Sternomastoids (raise the sternum)
All work to increase the thoracic cavity.
What do the lungs do during expiration?
They passively recoil as they are very elastic. Inspiratory muscles rest.
Compression of air in the lungs occurs making higher pressure inside the lungs than out causing expiration.