Lecture 1 Flashcards
What are the functions of the respiratory system?
Gas exchange
Acid base balance
Protection from infection
Communication via speech
Why is gas exchange so important?
It is vital in energy production. Providing oxygen and removing carbon dioxide.
Integration of which two systems are required for the movement of gases between the air and cells?
Respiratory system - acquiring oxygen and removing carbon dioxide.
Cardiovascular system - transport oxygen to tissues and transporting carbon dioxide away from tissues
What is pulmonary circulation?
Blood circulating from the heart to the lungs and from the lungs to the heart.
What is systemic circulation?
Everything but pulmonary circulation
What are the two main blood vessels of the pulmonary circulation?
Pulmonary artery - deoxygenated blood travelling away from the heart.
Pulmonary vein - oxygenated blood travelling towards the heart.
Where does gas exchange occur?
At the lungs and at the systemic capillaries
What are the average volumes of gas exchanged per minute?
250ml of oxygen consumed
200ml of carbon dioxide produced
Breathing rates
10-20 breaths/min at rest
40-45 breaths/min at max exercise in adults
Name the 7 parts of the respiratory system in order
Nose Pharynx Epiglottis Larynx Trachea Lung Bronchus
How many lobes are there in the lungs?
3 in the right - 3 secondary bronchi
2 in the left - 2 secondary bronchi
What is the plural cavity?
The small gap between the lungs and the rib cage that is created by the action of two membranes and is filled with 3ml of fluid
Which branch of the lung is more likely to have foreign bodies in it?
Right
What is patency?
Patency is when an airway is open and unobstructed.
In the trachea what maintains patency?
C-shaped rings of cartilage
What maintains patency in the bronchioles?
Physical forces in the thorax
Describe resistance to air flow in the airways
There is more resistance in the upper airways and less in the lower airways because there are less particles in the smaller airways and more in the larger airways
In the alveoli what are capillaries always in contact with?
Type 1 alveoli cells
What is the purpose of the elastic fibres that surround the alveoli?
They force air out of the lungs by using the energy that is used to stretch them. This means that expiration is normally passive.
What is anatomical dead space?
The air in the airways above the alveoli as it cannot participate in gas exchange.
What is mucous for?
Moistens air
Traps particles
Provides large surface area for cilia to act on
Secreted by goblet cells subepithelial glands
What do type 2 pneumocytes do?
They reduce surface tension at the alveolar surface and so reduce the work of breathing .
