Anatomy of Respiration Flashcards
What are the 4 main functions of the respiration system?
Gas exchange
Acid base balance
Protection from infection
Communication via speech
What is the most basic explanation of gas exchange?
Oxygen is added to the blood from air
CO2 is removed from the blood into the air
What is the term that describes the following?
“The transport of oxygen to tissues and CO2 away from tissues”
External respiration
What is significant about the pulmonary circulation?
It delivers CO2 to the alveoli and picks up O2
What type of blood does the pulmonary artery carry?
Deoxygenated blood
What type of blood does the pulmonary vein carry?
Oxygenated blood
Where are the 2 places in the body gas exchange can occur?
Capillaries
Alveoli
What is the normal breathing rate at rest?
10-20 breaths/min
Why is it significant that air typically is inhaled through the nose as opposed to the mouth?
The nose is much better at moistening the air
What 5 structures make up the upper respiratory system (above sternum)?
Pharynx Larynx Oesophagus Nasal cavity Tongue
What 4 structures make up the lower respiratory system (below sternum)?
Lungs
Trachea
Bronchi
Diaphragm
How many lobes are there in the right lung and what are there names (in order from top to bottom)?
3 (Superior, Middle, Inferior)
How many lobes are there in the left lung and what are there names (in order from top to bottom)?
2 (Superior, Inferior)
Which fissure separates the superior and middle lobe of the right lung?
Horizontal fissure
Which fissure separates the middle and inferior lobe of the right lung?
Oblique fissure
Which fissure separates the superior and inferior lobe of the left lung?
Oblique fissure
Which lung to aspirated foreign bodies tend to be found in and why?
The right lung due to the more vertical trajectory
How many times does each primary bronchi branch?
22 times
What structures maintains the patency of an airway in the trachea and bronchi?
C-shaped rings of cartilage
What is significant about bronchioles in comparison to bronchi?
They contain no cartilage
What is the function of type I pneumocytes?
Gas exchange
What is the function of type II pneumocytes?
To synthesise surfactant
What is surfactant?
A substance which reduces surface tension
What is the air in airways that cannot undergo gas exchange known as?
Anatomical dead space
What constitutes the lining of the respiratory tract? (6)
Epithelium Glands Lymph nodes Blood vessels (for nutrition) Cilia Mucous
What 3 changes occur in the lining of the respiratory tract as it progresses from the nose to the alveoli?
Epithelium becomes more squamous
Mucous cells lost
Cilia lost
What is mucous produced by?
Goblet cells
Sub-epithelial glands
What are the 3 functions of mucous?
Moisten air
Trap particles
Provide large surface are for cilia action
What covers the lungs and interior of the thorax?
The pleural sac
What are the structures of the 2 lung pleura (from the inside out)? (3)
Visceral pleura > Pleural cavity > Parietal pleura
What is pleurisy?
Inflammation of the pleura
What 2 forces keep the pleura and lung stretched?
Elastic recoil of the chest - outward pull
Elastic recoil of the lung - inward pull
What happens to the lung and visceral pleura after a pneumothorax?
They collapse to their un-stretched size
What 4 muscles are used for inspiration?
External intercostals
Diaphragm
Scalenes
External intercostals
What is significant about expiration in terms of muscle use?
Expiration is passive at rest
What 2 muscles are used during large expiratory loads?
Abdominal muscles
Internal intercostals
What happens to the diaphragm and thoracic volume during inspiration?
Diaphragm contracts
Thoracic volume increases
What happens to the diaphragm and thoracic volume during expiration?
Diaphragm relaxes
Thoracic volume decreases
What is the physiological change that occurs due to asthma?
Over-reactive constriction of bronchial smooth muscle
What effect does asthma have on expiration and inspiration?
Increases resistance of bronchus making expiration difficult
Has no effect on inspiration
What are the 3 relevant pressures for inspiration and expiration?
Alveolar pressure - Pa (intra-thoracic pressure)
Intra-pleural pressure - Pip
Transpulmonary pressure - Pt
What is alveolar pressure?
The pressure inside the thoracic cavity
What is intra-pleural pressure?
The pressure inside the pleural cavity
What is transpulmonary pressure?
The difference between alveolar pressure and intra-pleural pressure
Is alveolar pressure negative or positive compared to atmospheric pressure?
It can be either
Is intra-pleural pressure negative or positive compared to atmospheric pressure?
Always negative
Is transpulmonary pressure negative or positive compared to atmospheric pressure?
Always positive because intra-pleural pressure is always negative
