Introduction: Anatomy of lungs, airways and blood supply (functions of respiratory system) Flashcards
What are the main functions of the respiratory system?
Gas exchange
Acid-Base Balance
Protection from infection
Communication via speech
What is the process of burning oxygen to release energy and produce CO2 as a waste product called?
Cellular respiration
What is the respiratory system responsible for?
Acquiring O2 and removing CO2
What is the cardiovascular system responsible for?
Transporting O2 to tissues and CO2 away from tissues
What does the integration of the respiratory and cardiovascular systems allow for?
The movement of gases between the air and the body’s cells known as external respiration
The pulmonary artery travels where and carries what?
Away from the heart towards the lungs carrying de-oxygenated blood and CO2 for expiration
The pulmonary vein travels where and carries what?
Towards the heart from the lungs carrying re-oxygenated blood ready to be pumped around the body
What is the opposite of the pulmonary circulation?
Systematic circulation
Gas exchange occurs at the lungs and the…
Systematic capillaries into cells
What does an increase in rate and depth of breathing during exercise speed up?
O2 acquisition and waste disposal of CO2
What does and increase in heart rate and force of contraction speed up during exercise?
O2 delivery to muscle via blood
Waste removal of CO2 via blood
In the steady state, the net volume of oxygen exchanged in the lungs per unit time is equal to what? Does the same apply to CO2?
The net volume exchanged in the tissues. The same also applied to CO2
What does this steady state “constant” ensure?
Ensures the supply always equals the demand and stops gas build up in circulation that would hamper gas exchange
Average volumes of oxygen and carbon dioxide exchanged per minute?
O2 - 250ml
CO2 - 200ml
What is the average breathing rate at rest in adults?
10-20 per min
Max breathing rate during exercise for adults?
40-45 per min
The point of gas exchange in the lungs is the…
Alveoli
Airway diameter and therefore resistance to airflow can be altered by…
Activity of bronchial smooth muscle
If contraction decreases the diameter of the airways, the resistance…
Increases
What is each cluster of alveoli surrounded by?
Elastic fibres
Capillary network
What are alveoli composed of?
Type 1 cells for gas exchange
Type 2 cells for production of surfactant
What do alveolar macrophages do?
Ingest foreign material that reaches the alveoli
Is there elastic fibres between the capillaries and the type 1 cells?
No, would hamper gas exchange
What is the function of the upper airways?
Conduction of air to and from the alveoli
What is the air in the upper airways that is left there known as?
Anatomical dead space
Alveoli’s large surface area means?
Better gas exchange
Is the respiratory tract cilliated?
Yes
What type of epithelium is in the tract?
Pseudo-stratified, ciliated, columnar
What else does the respiratory tract have?
Glands
Lymph nodes
Blood vessels (nutritive)
Mucous
In the progression from the nose to the alveoli, what changes occur in the epithelium?
Epithelium becomes more squamous
Mucous cells are lost
Cilia are lost
What does the mucous in the tract do?
Moistens and humidifies air
Traps particles
Provides large surface area for cilia to act on
What type of pneumocytes make up 97% of the alveolar surface?
Type 1
What are type 1 pneumocytes made from?
Simple squamous epithelium
What type of pneumocytes are responsible for surfactant production and secretion
Type 2
What are the main components of surfactant?
Phospholipids and protein
Function of surfactant?
Reduces surface tension at alveolar surface
Reduces work of breathing
