Respiratory System Flashcards
What does the respiratory system do?
Provides the route of O2 into the body and CO2 out of the body
What does blood do in terms of the respiratory system?
Carries oxygen from lungs to cells and returns carbon dioxide from cells to lungs
What does the respiratory system consist of?
- nasal cavity
- pharynx
- larynx
- trachea
- 2 bronchi
- bronchioles
- alveoli
- lungs
What is the function of the nasal cavity
- warms, moistens and filters air
- protection of underlying epithelium via mucous membrane
- smell, conveyed by olfactory nerves to the brain
What is the nasal lining?
Ciliated columnar epithelium
What is the pharynx? (Throat)
A tube like structure about 12-14cm long from base of skull to oesophagus
Where is the pharynx situated?
Posterior to the nasal and oral cavities
What is the pharynx made of?
Muscle and lined with mucous membrane
What are the 3 sections of the phaynx?
Nasopharynx, oropharynx and laryngopharynx
What are the 3 layers of tissue present in the pharynx?
- mucous membrane lining
- fibrous tissue- intermediate layer
- smooth muscle tissue- play an important part in deglutition
What are the functions of the pharynx?
- passageway for air and food
- warming and humidifying
- taste
- hearing
where is the larynx (voice box) situated?
Lies at the root of the tongue and extends to trachea
What is the larynx lined with?
Ciliated mucous membrane
What are the functions of the larynx?
- sound
- protection of respiratory tract
- passageway for air between pharynx & trachea
- humidify, warming filter for air
What are the 3 layers of the trachea?
- Outer layer- fibrous and elastic tissue encloses the cartilage
- middle layer- cartilage & bands of smooth muscle
- inner layer- lined with ciliated columnar epithelium
Functions of the trachea?
- support
- regular beating of cillia
- cough reflex
Describe the right bronchi
- 2.5cm long, wider and shorter, divides into 3, one to each lobe of the lung
Describe left bronchi?
- 5cm long, narrower, divides into 2, one to each lobe
What is the structure and function of the 2 bronchi?
The same as the trachea
What do bronchi divide into?
Bronchioles, alveolar ducts and finally alveoli (tiny air sacs)
Describe a bronchiole?
- minute branch of bronchi
- at bronchioles cartilage deminishes and muscle takes over
What is the function of the bronchioles?
- warming and humidifying
- defence against microbes
Describe the structure of alveoli?
- tiny air sacs
- the alveoli are surrounded by a network of capillaries
What is the function of alevoli
the site of gas exchange during respiration via diffusion
Describe the gas exchange process that happens in the alveoli
CO2 diffuses from venous blood into the alveoli, by the same process O2 diffuses from the alveoli into the blood
Where are the lungs located?
Each side of midline of thoracic cavity
What does the right lung divide into?
3 lobes
What does the left lung divide into?
2 lobes to accommodate the heart
What is the inner visceral pleura?
A serous membrane which is adherent to each lung
What is the outer parietal pleura?
A serous membrane which adheres to the chest wall (diaphragm)
What is the intercostal muscle?
Thin sheets of muscle running across gaps between the ribs
What is the function of the intercostal muscle?
Contraction of these muscles causes the ribcage to expand upwards & outwards
