Introduction and anatomy of lungs, airways and blood supply Flashcards
(23 cards)
What is the breathing rate of an adult?
10-20/min at rest
40-45/min during exercise
Function of the nose
Air enters, cilia and mucus trap particles and warm/moisten the air
Function of the Pharnyx
Air moves down into pharynx or throat, which is shared with digestive system
Function of Epiglottis
Small flap of tissue folds over the trachea and prevents food from entering when you swallow
Function of Larynx
Larynx or voice box, contains vocal chords which vibrate to produce sound
Function of Trachea
From the pharynx, air moves down towards lungs through the trachea. Made up of stiff rings of cartilage that support and protect it
Describe the structure of the Lungs?
Soft, spongy texture is due to thousands of tiny hollow sacs that compose them
Function of Bronchus
Air moves from trachea to right and left bronchi
What composes the URT?
Nasal cavity, tongue, pharynx, vocal cords, larynx & oesophagus
What composes the LRT?
Trachea, lungs, diaphram & bronchi
Describe differences between the right & left bronchi
Right bronchi: wider, shorter, more vertical, more commonly associated with foreign bodies, enters lungs at T5.
Describe the branching of the trachea
Branches into 2 bronchi, one to each lung. Then branches 22 more times, finally terminating in a cluster of alveoli
What is patency?
The condition of being open
How is patency maintained in the airways?
Larynx, trachea & bronchi = rings of cartilage
Bronchiole = physical forces in the thorax
Describe the resistance to air flow
It is proportional to diameter of the airways. Most resistance to air flow occurs in the trachea and bronchi. It is increased by contraction of bronchial smooth muscle.
Describe the structure of the lung lobule
Each cluster of alveolis is surrounded by elastic fibres and a network of capillaries
Describe the structure of the alveoli
Thin walls, site of gas exchange, contain elastic fibres
Composed of :
type I cells = gas exchange type II cells = synthesise surfactant
alveolar macrophages = ingest foreign material that reaches the alveoli (escape to pharynx/lymph nodes
Describe gas exchange in the lungs
Only possible in alveoli because of the very thin walls - huge surfaces area enhances function. The air in upper airways is known as anatomical dead space.
Describe the lining of the respiratory tract & progression from nose to alveoli
- epithelium (pseudo-stratified, ciliated, columnar)
- glands
- lymph nodes
- blood vessles
- ciliated
- mucous
Epithelium becomes more squamous, mucous cells lost first then cilia
What is the function of mucous?
Moistens air, traps particles, provides large surface area, goblet cells, subepithelial glands
Describe type I Pneumocytes
97% of alveolar surface
Simple squamous epithelium
Gas exchange
Describe type II Pneumocytes
Surfactant
Phospholipids and protein
Reduces surface tension at alveolar surface
Reduces work of breathing
What are the functions of respiratory system?
1) Gas exchange
2) Acid base balance - (ECF) around 7.4 (renal system)
3) Protection from infection
4) Communication via speech
