Basic Respiratory Physiology Flashcards
What are the 4 main functions of the respiratory system?
Gas Exchange
Acid base balance
Protection from infection
Communication via speech
What is the waste product of oxygen being used to produce energy?
Carbon dioxide
What type of blood does the pulmonary artery transport?
Deoxygenated
Where is oxygen delivered to in the pulmonary circulation?
The heart
What are the two main points of gas exchange within the respiratory system?
The lungs
Systemic capillaries
What is the average volume of oxygen exchanged in the lungs per minute?
250 ml
In which part of the respiratory system is the air shared with the digestive system?
The pharynx
What is the name given to the small flap of tissue folding over the trachea to prevent food from entering the trachea?
Epiglottis
Which parts make up the upper respiratory tract?
Pharynx Nasal cavity Vocal cords Tongue Larynx Oesophagus
Which parts make up the lower respiratory tract?
Lungs
Trachea
Bronchi
Diaphragm
Which lung has 3 lobes?
The right lung
What are the names of the 3 lobes in the right lung?
Superior
Middle
Inferior
Where is the point of gas exhange in the airways?
Alveoli
Which type of alveolar cells permit gas exchange?
Type 1 cells
Which fluid produced by Type 2 alveolar cells reduces surface tension on the alveolar surface membrane
Surfactant
What does surfactant reduce the tendency for alveoli to do?
Collapse
Is surfactant more effective in smaller or larger alveoli?
Smaller alveoli
At roughly what time gestation period does surfactant production start?
25 weeks
What is the name given to the change in volume relative to change in pressure?
Compliance
What does compliance represent?
The stretchability of the lungs
Emphysema is the loss of what?
Elastic tissue
Where is alveolar ventilation highest?
The base of the lung
Give 2 examples of obstructive lung disorders
Chronic Bronchitis
Emphysema
Which lung volume cannot be measured directly by spirometry?
Residual volume
What does FEV1 stand for?
Forced expiratory volume in 1 second
Which type of circulation sends oxygenated blood to the airway’s smooth muscle?
Bronchial
Which type of circulation carries the entire cardiac output from the right ventricle?
Pulmonary
Where does the pulmonary circulation return oxygenated blood to?
Left Atrium
Is vascular resistance higher at the base or the apex of the lung?
The apex
Where in the lung is blood flow highest?
The base of the lung
What is the name given to when ventilation is greater than blood flow?
Alveolar dead space
What does the term anatomical dead space refer to?
Air in the conducting zone of the respiratory tract unable to participate in gas exchange
The partial pressure only refers to what?
Oxygen dissolved in solution
Where does most of the arterial oxygen content come from?
The haemoglobin in the RBCs
How many oxygen molecules can haemoglobin co-operatively bind?
4
What is the major determinant of teh degree to which haemoglobin is saturated with oxygen?
Partial pressure of oxygen in arterial blood
Why can a fetus extract oxygen from the mother’s blood>
Due to foetal haemoglobin having a higher affinity for oxygen than HbA
Why, in anaemic patients would arterial blood be normal?
Because ventilation is not affected, it is normal also
If pH decreases, what will happen to the haemoglobin saturation?
It will also decrease
DPG is produced as a result of what?
Red cell metabolism
Why is carbon monoxide so dangerous?
It has a greater affinity than oxygen for haemoglobin
In hypoventilation, what happens to the oxygen levels?
They decrease
What is the name given to when more carbon dioxide is given off by the body?
Hyperventilation
For the body to be able to breath, it requires a cycle of activation of what nerves?
Phrenic and Intercostal nerves
Which nerves innervates the diaphragm?
The phrenic nerve
What is the most important factor in changing the breathing rhythm?
The chemical composition of the blood
What are the names of the 2 types of chemoreceptor?
Central and peripheral
What is the central chemoreceptor controlled by?
The medulla
Which chemoreceptor is responsible for the primary ventilatory drive?
The central chemoreceptor
If arterial partial pressure of carbon dioxide decreases, what can also decrease?
Ventilation rate
What are peripheral chemoreceptors controlled by?
Carotid and aortic bodies
The peripheral chemoreceptors stimulate ventilation following what?
A large fall in arterial partial pressure of oxygen
True or False? any voluntary breathing pattern can be overriden by the cortex if need be
True
During swallowing, respiration is inhibited to avoid what?
Aspiration of food or fluids into the airways
What is the name given to the total air movement in and out of lungs?
Pulmonary ventilation
