Chest Wall and Diaphragm Flashcards
1
Q
What are the functions of the chest wall?
A
- Respiration
- Protection
- Muscle Attachments
2
Q
Describe the thoracic cavity
A
- Divided into 3 major spaces
- Heart with coverings (pericardium- pericardial cavity) + the major vessels
- Lungs with coverings (pleura-pleural cavities)
3
Q
What is the superior thoracic aperture?
A
Apex of thorax to 2nd rib
-Trachea, clavicle, oesophagus, sternum etc
4
Q
What is the inferior thoracic aperture?
A
Rib cage from 2nd rib down
-Diaphragm, oesophageal hiatus, aortic hiatus etc
5
Q
What does the chest wall consist of?
A
- Thoracic vertebrae
- Ribs
- Sternum- manubrium, body, xiphoid process
- Intercostal spaces- intercostal muscles
6
Q
Describe a typical thoracic vertebra
A
- Body
- Facets for articulation with ribs
- Facet for articulation with adjacent vertebra
- Spinous process
- Inferior articular process
- Transverse process
- Superior articular process with facet for articulation with adjacent vertebra
- Vertebral foreamen
- Pedicle
- Lamina
7
Q
What are the features of the rib cage?
A
- Jugular notch
- Clavicle
- Sternoclavicular joint
- Manubrium of sternum
- Coracoid process
- Sternal angle
- Body of sternum
- Ribs 1-10
- Xiphoid process
- Costal cartilage and margin
8
Q
What are the features of a typical rib?
A
- Costal cartilage
- External surface
- Costal groove
- Internal surface
- Angle
- Neck
- Tubercle
- Neck
- Head
- Crest
- Articular facets
9
Q
How do ribs articulate with vertebrae?
A
- Joint capsule and cavities
- Intra-articular ligament
- Superior, lateral and normal costotransverse ligament
- Costotransverse joint
10
Q
What are the features of the sternum?
A
Articular site for clavicle
- Jugular notch
- Manubrium of sternum
- Attachment site for Ribs
- Articular demi facets for rib 2
- Sternal angle (manubriosternal joint)
- Transverse ridges
- Body of sternum
- Xiphoid process
11
Q
What are the different types of ribs?
A
- True (1-7)= articulate with sternum via own costal cartilage
- False (8-10)= articulate with sternum via costal cartilage of rib above
- Floating (11-12)= do not articulate with sternum
12
Q
What are the muscles of the chest wall?
A
- Pectoralis major and minor
- Serratus anterior
- External, inner and innermost intercostal
13
Q
What are the movements of the rib cage?
A
Inspiration:
- Sternum moves forward because of rib elevation- pump handle superior and anterior movements
- Elevation of lateral aspect of ribs- bucket handle movement
- Diaphragm descends to increase thoracic cavity
14
Q
What are the openings of the diaphragm?
A
Inferior Vena Cava= T8
Oesophagus= T10
Aorta= 12
15
Q
What are the features of the diaphragm?
A
- Central tendon
- Left and Right Crus (musculo-tendinous)
- Inferior VC, hemi-azygos vein
- Inferior phrenic artery, superior epigastric artery, aorta
- Right and Left phrenic nerve, greater+ lesser and least splanchnic nerve
- Oesophagus with anterior and posterior trunks, sympathetic trunk, thoracic duct
16
Q
Describe the thoracic diaphragm
A
- Sheet of skeletal muscle that is critical for respiration
- Anatomical boundary separating thorax from abdomen
- Structures pass through or behind to move into a different cavity
17
Q
What structures pass through or behind the diaphragm and at what vertebral level?
A
- Inferior Vena Cava= T8 (anterior)
- Phrenic nerve (R)= T8 (anterior)
- Oesophagus= T10 (middle)
- Thoracic aorta= T12 (posterior)
18
Q
Where are the diaphragmatic muscles fibres attached to on the skeleton?
A
- Anterior fibres attached to Xiphoid process
- Lateral fibres (including domes) attach to internal aspect of lower 6 ribs and costal cartilages
- Posterior fibres (particularly crura)= upper 2/3 lumbar vertebrae
19
Q
When standing in the anatomical position, in which direction does the central tendon of the diaphragm move during inhalation/ inspiration?
A
Inferiorly
20
Q
What nerve provides motor function to the diaphragm?
A
Phrenic
21
Q
At which levels do the spinal nerves that give rise to the phrenic nerves arise?
A
C3, 4, 5 (keep the diaphragm alive)
22
Q
How might a severe neck injury at upper/lower levels of cervical spinal cord affect the diaphragm?
A
Upper cervical lesion (C1/2) would lead to paralysis of the diaphragm while a lower cervical lesion (C6,7,8) would spare the phrenic nerve
23
Q
What are hiccups?
A
Involuntary spasmodic contractions of the diaphragm can be caused by irritation to the phrenic nerve and/or the diaphragm
24
Q
What is referred pain?
A
- Sensory information from the central region of the diaphragm is transmitted back to the spinal cord in the phrenic nerves
- Referred pain= signals emanating from the diaphragm may be perceived by the patient in their neck/ shoulder region
25
Which nerves carry sensory information from the lateral regions of the diaphragm?
Intercostal nerves
26
How does each layer of intercostal muscle not fully cover the length of each intercostal space?
- External layer= incomplete anteriorly, where it is replaced with anterior intercostal membrane
- Internal layer= incomplete posteriorly, where it is replaced with the posterior intercostal membrane
- Innermost layer= only present on the lateral aspects of the thoracic wall. Anteriorly, layer completed by transversus thoracis muscle (sternocostalis), posteriorly completed by subcostal muscles
27
What is the fibre orientation and action of each intercostal muscle layer?
- External= I/A, elevate ribs in inhalation
- Internal= I/P, depress ribs in exhalation
- Innermost= variable, depress ribs in exhalation
28
Between which two layers of the intercostal muscles will you find the intercostal neurovascular bundle?
Internal and innermost
29
Is the neurovascular bundle located in the superior or inferior portion of each intercostal space?
Superiorly at the inferior aspect of upper rib bordering space
30
What is the name of the groove on the corresponding rib where the neurovascular bundle runs?
Subcostal groove
31
Where would you insert a needle or chest drain when attempting to access the thoracic cavity?
Just above the superior border of the rib
32
Which arteries can be found in the intercostal neurovascular bundles?
Anterior and posterior intercostal arteries
33
From where do the anterior and posterior intercostal arteries arrive?
```
Anterior= internal thoracic artery or branch (musculophrenic artery)
Posterior= thoracic descending aorta
```
34
Which veins can be found in the intercostal neurovascular bundles and where do they drain?
```
Anterior= internal thoracic vein/ musculophrenic vein
Posterior= azygous system
```
35
Which nerves are responsible for innervating the intercostal muscles?
Intercostal nerves= from anterior rami of thoracic spinal nerves
36
What are the accessory muscles of respiration?
```
-Additional muscle groups recruited to aid movement during physical exertion
=Pectoralis major
=Seratus anterior
=Scalenus
-Sternocleido mastoid
```
37
Describe the rib cage
- 12 pairs of ribs which articulate with 12 thoracic vertebrae posteriorly
- Anteriorly, rib cage completed by sternum
- Ribs 1-7 (true ribs) articulate directly with sternum via costal cartilage
- 8-10 (false)= articulate with sternum via costal cartilage of superior ribs
- 11-12= suspended within muscles and fascia of back (floating ribs)
38
What are typical and atypical ribs?
```
Typical= ribs 3-9 all share common features
Atypical= 1,2,10,11,12= own distinctive features
```
39
What muscle attaches to the scalene tubercle?
Anterior scalene muscle (scalenus)
40
Which major blood vessels pass across the superior surface of the first rib immediately anterior and posterior to this muscle attachment? (scalene)
Anterior subclavian vein, posterior subclavian artery
41
Describe the costovertebral joint
Rib 8: head of rib articulates with superior costal demi facet of T8 (vertebra at same level as rib), inferior costal demi facet of T7 (vertebrae above rib)
42
Describe the costotransverse joint
Rib 8: tubercle of rib articulates with transverse facet of T8 (vertebra at same level as rib)
43
What is the angle of Louis?
- Sternal angle/ manubriosternal angle
- Junction between manubrium and body of sternum meet, with the two parts of the sternum running at different angle to one another
- Secondary cartilaginous joint, symphysis
- Landmark for transverse thoracic plane
44
Which pair of costal cartilages articulate with the sternum at the sternal angle?
2nd pair of costal cartilages linked with ribs 2
45
What vertebral level is indicated by the sternal angle?
T4/5
46
What major thoracic structures lie on the transverse thoracic plane?
- Boundary line between superior and inferior parts of the mediastinum
- Bifurcation of the trachea into left and right primary bronchi
- Start and end of aortic arch
- Entry of the azygous vein in superior vena cava
47
How might scoliosis affect normal respiratory movements?
Alter position and joint attachment of ribs
Alter position and attachment of diaphragm
Restricts space in thoracic cavity
