Introduction and Anatomy of Lungs, Airways and Blood Supply Flashcards
1
Q
Trachea: structure and function
A
- Composed of a series of 20 C shaped cartilage rings that protect and support it
- Higher resistance to airflow than bronchi etc
- Air from larynx reaches lungs using trachea
2
Q
Primary bronchi: Structure
A
- Two principle bronchi (left and right)
- Bronchi patency maintained by cartilage
- Left principal bronchus is more acute and splits into 2 secondary bronchi
- Right principal bronchus is more vertical and splits into 3 secondary bronchi
3
Q
Secondary bronchi: Structure
A
- Lined with cartilage
- Divide to form tertiary bronchi
4
Q
Tertiary bronchi: Function
A
- Each tertiary bronchus supplies a bronchopulmonary segment
5
Q
Pneumocytes
A
Cells which comprise alveolar surface
- Type 1
- Type 2
6
Q
Type 1 pneumocytes
A
- Thin cells (simple squamous epithelium) which allow gas exchange
- Alveolar capillaries are in direct contact with type 1 cells to allow sufficient gas exchange
7
Q
Type 2 pneumocytes
A
- Thick cells (cuboidal epithelium) which do not allow gas exchange
- Produce and secrete surfactant
8
Q
Surfactant
A
Substance which reduces surface tension between pulmonary fluids (and gases) and contributes to the elastic properties of the lungs
9
Q
Respiratory System functions (4)
A
- Gas exchange
- Acid-base balance
- Protection from infection
- Communication (via speech)
10
Q
Systemic vs pulmonary circulation
A
Systemic: artery delivers oxygenated blood to tissue
Pulmonary: artery delivers deoxygenated blood to lung tissue
11
Q
Points of gas exchange
A
- Alveoli in lungs
- Capillaries in tissues
12
Q
Volume of gas exchange per minute: oxygen and carbon dioxide
A
- Oxygen: 250ml
- Carbon dioxide: 200ml
- Volume exchanged in lungs = volume exchanged in tissues per unit time
13
Q
Normal respiratory rate
A
- 10-20 breaths/min at rest
- 40-45 maximum during exercise in adults
