Introduction and Anatomy of Lungs, Airways and Blood Supply Flashcards
What are the four main functions of the respiratory system?
- Gas exchange
- Acid/base balance
- Protection from infection
- Communication
What other system is needed for gas exchange to occur?
Cardiovascular system
How does the cardiovascular system aid in gas exchange?
- Transports CO2 to the lungs
- Transports oxygen to the tissues
What are the 4 main blood vessels that enter and exit the heart?
- Vena cava
- Pulmonary artery
- Pulmonary vein
- Aorta
What relationship does the pulmonary and cardiovascular system have during exercise?
- As rate of breathing speeds up heart rate and force of contraction increases
What two places does gas exchange occur?
- Lung alveoli
- Capillary beds
What is the average volume of oxygen exchanged (consumed) per breath
250ml
What is the average volume of CO2 exchanged (produced) per breath
200ml
What is average breathing rate at rest in an adult?
10 - 20
What is maximum breathing rate during exercise in adults?
40-45
What are the 7 main parts of the respiratory system starting at the mouth?
- Nose
- Pharynx
- Epiglottis
- Trachea
- Larynx
- Bronchus
- Lung
Functions of the nose
- Allow air to enter
- Trap dust and pathogens in cilia
Epiglottis?
A small flap of tissue that folds over the trachea and prevents food from entering the lungs during swallowing
Larynx?
Voice box - contains vocal chords that vibrate to make a sound
Bronchus?
Allows air to move into the right or left lung
Lung?
Where gas exchange occurs
What structures are in the upper respiratory tract?
- Nose
- Pharynx
- Epiglottis
- Larynx
What structures are in the lower respiratory tract?
- Trachea
- Bronchus
- Lung
- Diaphragm
How do the left and right bronchus differ?
- Right is a more obtuse angle (closer to vertical) and wider
- Left is an acute angle and thinner
What can come about from the differing shape of the R bronchus?
Foreign bodies can lodge there
How is the shape of the trachea maintained?
C shaped rings of cartilage
What structures does air pass through in order from the trachea?
- Trachea
- Primary bronchus
- Secondary bronchus
- Bronchiole
- Alveoli
In what lower respiratory tract structures does the most resistance occur?
- Trachea
- Primary bronchi
- Secondary bronchi
How many primary bronchi are there?
2
How can resistance to air be influenced?
Smooth muscle in the bronchus changing diameter
What does contraction do diameter and resistance?
- Decreases diameter
- Increases resistance
What does relaxation do diameter and resistance?
- Increases diameter
- Decreases resistance
Why are the alveoli suitable for gas exchange?
- Very thin walls
- High surface area
Why can’t the airways prior to the alveoli not allow gas exchange and what is their function instead?
- Walls too thick
- Conduction of the air
What is the air in the airways prior to the alveoli known as?
Anatomical dead space
What cells line the respiratory tract?
Epithelium
What type of epithelium lines the respiratory tract and how does it change as you move closer to the alveoli?
- Pseudostratified columnar ciliated cells in the higher up airways
- Progresses to become more SQUAMOUS as you move down
- Cilia are lost lower down
- Mucous cells are lost lower down
What other structures, besides epithelium and mucous, exist in the lining of the respiratory tract?
- Glands
- Lymph nodes
- Blood vessels
What are the functions of mucous in the respiratory tract
- Moistens air
- Traps particles
- Provides cilia with a large surface area
What cells produce the mucous
Goblet cells and sub epithelial glands
What are the cells in the alveoli called that are responsible for gas exchange?
Pneumocytes
What other cells are present in the alveoli
Macrophages
What percentage of alveoli are type 1 pneumocytes and what is their primary function?
- 97%
- Gas exchange
What type of epithelium are type 1 pneumocytes
Simple squamous
What are type 2 pneumocytes responsible for
Reducing surface tension
What does the reduction of surface tension allow?
Less work needed to breathe
What is correct body pH?
7.4
What do type 2 pneumocytes contain to allow surface tension to be reduced?
- Phospholipid
- Protein
What is pulmonary circulation?
- The movement of CO2 to the lungs
- Movement of O2 to the heart through the pulmonary great vessels
What is systemic circulation
- The movement of CO2 from tissues to heart
- Movement of O2 from heart to tissues
Where does gas exchange occur in the systemic circulation?
Between cells and capillary beds
Where does gas exchange occur in pulmonary respiration?
Between alveoli and capillaries
Why can gas exchange occur between alveoli and capillaries and cells and capillaries?
- Thin walls
- High surface area
- Gas moves down the conc gradients
