Anatomy of breathing Flashcards
What is the location of the lungs?
- located in the thorax
- separated by mediastinum and heart
- extend from neck to diaphragm
What are features of the lungs and where do the different surfaces lie?
- Conical shaped with a soft, spongy texture
- There are black speckles of carbon on the lungs
- The apex of the lung lies above the clavicle (in the neck)
- Diaphragmatic surface (base) sits on the diaphragm
- Costal surface – lies adjacent to the ribs (basically the entire middle section except the mediastinal surface)
- Mediastinal surface – faces the mediastinum
Describe the structure of the right lung
- Shorter and wider than the left lung (liver impedes up into it)
- Three lobes:
Superior (upper)
Middle
Inferior (lower) - Two fissures (separate lobes):
Oblique: separates middle and superior lobes from inferior lobe
Horizontal fissure: separates superior and middle lobes
Describe the structure of the left lung
- Narrower and longer than the right lung (heart projects to the left taking up some of the place in the thorax)
- Two lobes:
Superior
Inferior - One fissure:
Oblique
Where is the Hilum of the lung located and what is it?
- Located on the mediastinal surface
- Area where the pulmonary vessels, bronchi, bronchial vessels, lymphatics and nerves enter/ leave the lung (parasympathetic and sympathetic that go to the vessels to cause constriction and dilation)
- Usually lots of lymph nodes around the entrance to the lung
What are the two physical properties of the lungs?
- Compliance (distensibility)
- Elasticity
what is compliance and what is it affected by?
Th- e ability of the lungs to expand
Affected by:
- Connective tissue structure of the lungs
- Level of surfactant
- Mobility of the thoracic cage (if it can’t expand then the lungs can’t expand)
What is elasticity in the lungs
The fact that elastic tissue allows lung expansion during inspiration and recoil during expiration
Give features of the Pleura
- Double layered serous membrane
- Visceral pleura adheres to the lung
- Parietal pleura attaches to the thoracic wall and diaphragm
- The pleural cavity is a potential space between the parietal and visceral layers that contain a thin layer of serous fluid
- When lungs expand and visceral and parietal pleura don’t go with it, it creates a big pleural cavity which leads to a collapsed lung
What are the functions of the pleura?
- Reduces friction during breathing
- Creates a pressure gradient which assists in ventilation
- Compartmentalises each lung therefore reduces spread of infection
What is the Thoracic wall and what is it made up of?
The chest wall Made up of: - Bony thorax - sternum - Ribs - Thoracic vertebrae - intercostal muscles - intercostal nerves and vessels?
What does the bony thorax do and what does it consist of?
- Forms a skeleton of the chest wall
- Consists of
Sternum
Ribs (12 pair)
Thoracic vertebrae (12)
What is another name for the sternum and what does it consist of?
- Also called Breast bone
- Consists of
Manubrium – superior portion of sternum
Body
Xiphisternum (xiphoid process) – inferior portion of breast bone
Give features of the ribs
- Attached by the head and tubercule to the thoracic vertebrae
- Slope downwards and forwards
- Ribs 1-10 attached by costal cartilage to the sternum:
7 p airs true (costal cartilage directly attached to sternum)
3 pairs false (Cartilage attached to the cartilage above)
2 floating (Cartilage doesn’t attach at all at the front – just goes into the abdominal wall)
Give features of the thoracic vertebrae
- Part of the vertebrae column
- Have the ribs attach into them
- Have a body, transverse process and spinal process behind
- Head of rib articulates (attaches) to the body of the thoracic vertebrae
- Tubercule of rib articulates (attaches) with the transverse process of the thoracic vertebrae
- These attachments form small synovial joints allowing the movement of the ribs
What do the intercostal muscles do and what are the different types?
- Span the spaces between the ribs (intercostal spaces)
- External intercostal muscles – superficial layer
- Internal intercostal muscles – middle layer
- Innermost intercostal muscles – deep layer
- External intercostals: fibres run downwards and forwards
- Internal intercostals: fibres run downwards and backwards (start right from edge of sternum)
- Intercostal muscles running in different directions give strength
Where do the intercostal vessels and nerves run and what do they do?
- Run in intercostal spaces and are protected by the ribs
- Run in the intercostal spaces between the internal intercostal and innermost intercostal muscles
- Supply the muscles, adjacent skin and pleura
What does the diaphragm separate?
The thorax from the abdomen