Introduction and Anatomy of lungs, airways and blood supply Flashcards
What are the main functions of the respiratory system?
Gas exchange
Acid base regulation - pH 7.4 +/- 0.1
Protection from infection
Communication
What is cellular respiration?
Cells uptake of oxygen and metabolism to release energy, producing CO2 as a waste product
What is internal respiration?
Transport of O2 in the blood to tissues, as well as removing CO2 from these tissues
What system is responsible for internal respiration?
Cardiovascular
What is external respiration?
Acquiring O2 from the environment, while removing CO2 from the body by releasing it. Movement of gases between air and the cells of the body
What system is responsible for external respiration?
Respiratory system, which must integrate with the cardiovascular system
What is unusual about the pulmonary circulation?
Deliver CO2 to the lungs and picks up O2 (instead of systemic circulation delivering O2 rich blood and bringing back CO2 rich blood)
What is the average breathing rate at rest?
10-20 breaths/min
What is the average breathing rate during maximum exercise?
40-45 breaths/min
What makes up the upper respiratory system?
Nose
Pharynx
Larynx
What makes up the lower respiratory tract?
Trachea Lungs Bronchi Bronchioles Alveoli
What is responsible for maintaining patency of the airways?
Cricoid cartilage
Surfactant?
Elastic fibres surrounding alveoli
What affect does contraction of the airways have on resistance to air flow?
Increases resistance
What affect does relaxation of the airways have on resistance to air flow?
Decreases resistance
What are alveolar type I cells responsible for?
Gas exchange
What are alveolar type II cells responsible for?
Produce surfactant
Describe the epithelium of the respiratory tract
Pseudo stratified ciliated columnar cells
Presence of glands secreting mucus
Lymph nodes
Nutritive blood vessels
What happens to the epithelium as you move down the respiratory tract?
Epithelium becomes more squamous
Cilia lost
Mucus producing goblet cells are lost
Which are lost first as you move down the respiratory tract - mucus cells or cilia?
Mucus cells
What is the function of mucous?
Moistens air
Traps particles/pathogens
Provides large surface area for cilia to act on
Where do macrophages migrate to following gathering of pathogens in the respiratory tract?
Migrate to pharynx/larynx lymph nodes to prime immune responses
What % of the alveolar surface is made up of type I pneumocytes?
97%
What % of the alveolar surface is made up of type II pneumocytes?
3%?
Describe the epithelium of type I pneumocytes
Simple squamous