Respiratory physiology Flashcards
What are the functions of the respiratory system?
Gas exchange - oxygen added to blood from air and carbon dioxide removed from blood into the air.
Acid-base balance - regulation of body pH.
Protection from infection.
Communication via speech.
Which of the functions is most important in the respiratory system.
Gas exchange
Why do we breathe?
Method of obtaining oxygen which can be burned to release energy required to fuel cells.
What is the respiratory system responsible for?
Acquiring oxygen and removing carbon dioxide.
How does the cardiovascular system help out the respiratory system?
Transports oxygen towards tissues and transports carbon dioxide away from tissues.
What is meant by external respiration?
Integration of respiratory and cardiovascular systems to allow movement of gases between the air and the body’s cells.
How does pulmonary circulation differ from systemic circulation?
The pulmonary circulation has opposite function to systemic. The pulmonary artery carries deoxygenated blood away from the heart and the pulmonary vein carries oxygenated blood towards heart.
Give an example of the intimate relationship between the CV and respiratory systems?
During exercise - Increase in energy demand by working muscle leads to:
Respiratory system increasing rate and depth of breathing and speeding up oxygen acquisition and waste disposal.
This causes the CV system to increase heart rate and force of contraction. Also speeds up substrate delivery to muscle via blood and the removal of waste via blood.
Where does gas exchange occur?
Occurs in the Alveolar of the lungs and at the Systemic capillaries.
What are the average volumes of gas that are exchanged per minute?
250 ml oxygen exchanged (consumed)
200 ml carbon dioxide exchanged (produced)
What are the average breathing rates of adults at rest and during exercise?
10-20 breaths/min at rest
40-50 breaths/min during max exercise
What is the epiglottis?
Small flap of tissue that folds over the trachea and prevents food entering when you swallow.
What structures make up the upper respiratory tract?
Pharynx, nasal cavity, Larynx, mouth
What structures make up the lower respiratory tract?
Trachea, bronchi and lungs.
How many lobes does each lung have?
Right has 3 lobes and left has 2 lobes.
What makes the right bronchi the one more likely to have aspirated foreign bodies commonly lodge here?
Tha right bronchi is more vertical and is wider than the left bronchi so it is easier for foreign particles to get lodged within it.
What is meant by latency?
Patency is the condition of being open or unobstructed. Therefore a patent airway is an open airway.
What maintains the patency of the trachea and bronchi?
C - shaped rings of cartilage.
Why does most resistance to airflow occur in the trachea and not the smaller alveoli?
We only have 1 trachea however we have thousands of alveoli. The surface of the thousands of alveoli is greater than the surface area of the trachea so in total they have less resistance.
How can bronchial smooth muscle activity alter the diameter and therefore resistance to airflow?
Contraction decreases diameter = increases resistance
Relaxation increases diameter = decreases resistance
What makes up the lining of the respiratory tract?
Epithelium (psuedo-stratified, ciliated, columnar) Glands Lymph nodes Blood vessels (nutritive) Ciliated Mucous
What happens to the lining as it progresses form the nose down towards the Alveoli?
Epithelium becomes more squamous
Cilia lost
Mucous cells lost (before cilia)
What is the role of mucous?
Moistens air Traps particles Provides large surface area for cilia to act on Goblet cells Subepithelial glands