Respiratory system Flashcards
Name 2 products of Oxidation
- Water
- Carbon Dioxide
What are the 4 principle functions of the respiratory system?
- Extract o2 from atmosphere and transfer it to the bloodstream and the lungs
- Excrete water vapour and co2
- Maintain the normal acid base status of the blood
- Ventilate lungs
What are the 5 components of Inspired air?
- 79% Nitrogen
- 20% o2
- 0.04% co2
- 1% inert Gases
- Water vapour (variable)
What are the 5 components of expired air?
- 79% Nitrogen
- 16% o2
- 4% co2
- 1% Inert gases
- Water vapour increased amount to saturation
Is expired air resuscitation effective? If so why?
-Yes, because expired air still contains 16% o2
What are the 8 components of the respiratory tract?
- Nose
- Pharynx
- Larynx
- Trachea
- Bronchi
- Bronchioles
- Alveolar ducts
- Alveoli
What is the top of the larynx protected by?
-The epiglottis
What is the function of the epiglottis?
2
- Opens for breathing
- Shuts when food/fluid being swallowed by upward movement of the larynx
When does the protective mechanism of the epiglottis not operate?
-When PTs are unconscious
Which part of the respiratory tract divides into the Bronchi?
-The trachea
Which Bronchus is shorter?
The right is shorter than the left
What do the bronchi branch into?
-Bronchioles (smaller tubes)
What do the Bronchioles lead to?
-Alveolar ducts which end in air sacs (Alveoli)
What surrounds the Alveoli?
A fine network of capillaries
What happens in the network of capillaries that surround the alveoli?
An exchange of gases takes place across the endothelium (capillary wall)
What are the lungs comprised of?
2
Alveoli
Connective tissue
How many lobes does each lung have?
Left has 2
Right has 3
What is the outer surface of the lung called?
The pleura
What is the pleura continuous with?
The membrane lining of the inner surfaces of chest wall
What moves over each other as the lung expands and relaxes?
The pleura and inner membrane lining of chest wall
Where does external respiration take place?
In the lungs
Where does internal respiration take place?
In the tissues
Where does diffusion take place?
Internal and external respiration
What is the process of diffusion?
Dissolved substances cross a semi permeable membrane from high to low concentration.
If two gases of different composition come into contact intermingling of gases takes place until composition is both the same.
What are the 2 things that happen in external respiration?
- o2 from inhaled air is absorbed into the blood via capillaries of the lung
- co2 is released from the blood into lungs & exhaled
What 2 things happen on internal respiration?
- blood and circulatory system carries o2 to body cells
- O2 is given off for use by cells. Co2 is absorbed by the blood which is carried to lungs
How would you describe the process of normal quiet breathing?
Active, process involving muscle activity
How would you describe expiration?
Passive, relies on elastic recoil of lungs
What happens to the chest cavity when inspiration takes place?
It is enlarged
What happens when the chest cavity is enlarged by process of inspiration?
The pressure within it causes air to enter lungs via airways.
What change causes air to be drawn in?
The change of pressure in the chest cavity
What are the 2 main factors that enlarge the chest cavity?
- flattening downward movement of the diaphragm
- upward and outward movement of ribs, caused by action of intercostal muscles
Where is voluntary control of respiration controlled?
Cerebral cortex
When would an example of voluntary respiration control take place?
(2)
Speaking and singing
What is voluntary control of respiration overriden by?
2
Chemical and nervous activity
What is involuntary respiration controlled by?
3
- Nerve cells in brain stem
- Respiratory centre in the Medulla oblongata
- Pneumotaxic centre in pons varolii
The cells in the respiratory centre are covered with what?
Inspiration
What is concerned with the inhibition of inspiration?
The cells of the pneumotaxic centre
With regards to nerves how does inspiration take place?
Nerve impulses originating In respiratory centre pass via phrenic nerves to diaphragm via intercostal nerves to intercostal muscles resulting in contraction
How does expiration happen?
Nerve endings in the lungs sensitive to stretch are stimulated when lungs are inflated, impulses are passed to pneumotaxic centre
Where are chemoreceptors situated?
Walls of aorta
Carotid bodies
What are chemoreceptors sensitive to?
Partial pressure of co2 in blood
Partial pressure of o2 in blood
Chemoreceptors and respiratory centre are stimulated by what?
An increase in partial pressure of co2 in blood
In chemoreceptors, what does an increase in partial pressure of co2 in blood result in
Increased ventilation