“Topography of the Thorax: The Thoracic Wall” Excerpt From: Imperial College London. “MBBS Year 1 Anatomy of the Thorax Spring Term Course Guide 2017/18”. Apple Books. Flashcards
What is the vertebral level of the sternal notch
T2
Vertebral level off the manubrium
T2-T4
Vertebral level of the sternal angle
T4/T5
Vertebral level of the sternal body
T5-T8
Vertebral level of the diploid process
T9
What is the vertebrae prominens
The spinous process of C7 (which overlies the vertebral body of T1)- most prominent in the lower neck
When the patient bends you can see this
What guidance is used for aspiration and injection into the sternoclavicular joint
Although the sternoclavicular joint is easily palpable and accessible, CT guidance is used during aspiration and injection to prevent entry into the superior mediastinum and damage to pleura and great vessels
How can we facilitate radiographic identification of ribs
Knowledge of rib angulation aids radiographic identification, for example the posterior part of the rib appears to curve inferolaterally and is the most visible part.
The angle of the rib is palpated posteriorly, a few centimetres lateral to the vertebral spinous processes.
What is the angle of the rib a useful marker for
The angle is a useful marker for the lateral cutaneous nerves and vessels, which emerge just lateral to it and can be anaesthised in this region.
How can ribs be palpated
Ribs 4-10 can be palpated in the midaxillary line starting with rib 4 at the skin of the axillary floor. Rib 10 is continuous with the costal margin.
The free lateral ends of ribs 11 and 12, can be palpated posteriorly in lean individuals and can be traced medially to help identify the T11 and T12 vertebrae.
What is meant by the costal margin
This refers to the free inferior border of the anterior and lateral thoracic cage formed by the distal ends of the costal cartillages 7-10. It can be palpated inferolaterally from the xiphisternum to rib 10 and is a useful landmark.
Describe the costal cartillages
These connect the distal parts of ribs 1-10 to the sternum or adjacent costal cartilage. In lean individuals the cartillage of ribs 1-7 vertebrosternal can be identified at the sternum and serve as useful markers of underlying structures.
The cartillages pass medially, or superomedially, to the sternum and can be identified on radiographs by their direction of travel and relative radiolucency
Structure of a typical ribs
see diagram!
Structure of atypical ribs
see diagrams!
Structure of thoracic vertebrae
see diagram!
What structures pass through the intervertebral foramen
Spinal nerve and blood vessels
Each spinal nerve exits the vertebral canal laterally through an intervertebral foramen. The foramen is formed between adjacent vertebral arches and is closely related to intervertebral joints.
Describe the structure of the intervertebral foramen
The superior and inferior margins are formed by notices in adjacent pedicles.
The posterior margin is formed by the articular processes of the vertebral arches and the associated joint (zygapophysial joint).
The anterior border is formed by the intervertebral disc between the vertebral bodies of adjacent vertebrae.
Summarise the types of joints that exist between vertebrae
symphyses between vertebral bodies
synovial joints between articular processes
A typical vertebrae has a total of six joints with adjacent vertebrae: four synovial joints (two above and two below) and two symphyses (one above and one below). Each symphyses includes an intervertebral disc.
Describe the symphyses joints
The symphysis joints between adjacent vertebral bodies is formed by a layer of hyaline cartilage on each vertebral body and an intervertebral disc, which lies between the layers.
Describe the movement that these symphyses joints allow for
An amphiarthrosis is a joint that has limited mobility. An example of this type of joint is the cartilaginous joint that unites the bodies of adjacent vertebrae. Filling the gap between the vertebrae is a thick pad of fibrocartilage called an intervertebral disc (Figure 2). Each intervertebral disc strongly unites the vertebrae but still allows for a limited amount of movement between them. However, the small movements available between adjacent vertebrae can sum together along the length of the vertebral column to provide for large ranges of body movements.
The annulus fibrosis limits rotation between vertebrae.
Describe the joints between vertebral arches (zygapophysial joints)
the synovial joints between superior and inferior articular processes on adjacent vertebrae are the zygapophysial joints. A thin articular capsule attached to the margins of the articular facets encloses the joints.
What type of movements do the zygapophysial joints allow
In cervical regions, the zygapophysial joints slope inferiorly from anterior to posterior. This orientation facilitates flexion and extension.
In thoracic regions, the joints are orientated vertically and limit flexion and extension, but facilitate rotation.
In lumbar regions, the joint surfaces are curved and adjacent processes are interlocked, thereby limiting range of movement, though flexion and extension are still. major movements in the lumbar region
Describe the joints between spinous processes
Interspinous and supraspinous – join the spinous processes of adjacent vertebrae. The interspinous ligaments attach between processes, and the supraspinous ligaments attach to the tips.
These are ligaments
What types of movement do the joints between spinous processes allow for
Allow for gliding movements between vertebrae These serve to resist excess forward or backward bending movements of the vertebral column, respectively.
Compare the sizes of cervical, thoracic and lumbar vertebrae
cervical- small
thoracic- larger
lumbar- largest
Describe the foramina of each vertebrae
cervical- one vertebral, two transverse
thoracic and lumbar- one vertebral
Describe the spinous processes of each vertebrae
cervical- slender and often bifid
thoracic- long, thick and project inferiorly
lumbar- short and blunt
Describe the transverse processes of each vertebrae
cervical- trough shaped and perforated by a round foramen transversarium and are small
thoracic- large and has a facet for articulation for the tubercle of its own rib
lumbar- thin and long with the exception of LV- which are massive and somewhat cone shaped for attachment of iliolumbar ligaments
Articular facets for ribs?
only thoracic
Direction of superior articular facets
cervical- postero superior
thoracic- postero lateral
lumbar- medial
Direction of inferior articular facets
cervical- anteroinferior
thoracic- anteromedial
lumbar- lateral
Size of intervertebral disc
cervical- thick (relative)
thoracic- thin (relative)
lumbar- very thick
describe the joints formed by the heads of ribs
First rib and the last three ribs have a single synovial joint with the corresponding vertebrae while the remaining ribs have two synovial joints: one with the corresponding vertebra and one with the immediate above. These joints are formed by the heads of the ribs with the body of vertebrae
describe the joints formed by the tubercles of ribs
The tubercle of each rib articulates with the transverse process of the corresponding vertebra through a synovial joint. The tubercles are absent on the eleventh and twelfth ribs and therefore no such joints occur for these ribs.
Describe costochondral joints
Costochondral joint means the joint between the rib and its costal cartilage. These are cartilaginous joints and no movements are possible here
describe the joints of the costal cartillages with the sternum
The first costal cartilage of both sides attach to the manubrium sterni. At this joint, no movement is possible. The second costal cartilage articulates with the body of sternum and the manubrium sterni by a synovial joint where movement is possible. The third to seventh costal cartilages articulate with lateral border of the body of sternum at mobile synovial joints. The mobility of these joints allows the movements of respiration to take place in the rib cage. The sixth, seventh, eighth, ninth and tenth costal cartilages are jointed with each other along the borders by synovial joints. The eleventh and twelfth ribs are floating, which means that they do not articulate in front with the sternum and are embedded in the musculature of abdominal wall.
summarise the joints of costal cartillages with the sternum
sternocostal joints:
1st rib- primary cartilaginous
2nd- 7th – synovial
What type of joints are costochondral joints
primary cartilaginous
Describe the joints of the sternum
Manubriosternal joint: It is a fibrocartilaginous joint between the manubrium sterni and the body of sternum. A small amount of angular movement is possible at this joint. This movement occurs during respiration.
Xiphisternal joint: It is also a fibrocartilaginous joint and occurs between the xiphoid process and body of sternum. The capability of occurring movements may be present but there is no significance of movements at this joint. The xiphoid process fuses with the body of sternum during middle ages.
joints with costal cartillages- already explained
what type of joint is the manubriosternal joint
secondary cartilaginous
What type of joint is the xiphisternal joint
primary cartilaginous
Label the parts of the upper limb girdle
see diagram!
label the parts of the humerus
see diagram!
What happens at the sternal angle
a) trachea bifurcates
b) aortic arch begins and ends
c) 2nd costal cartilage attaches
d) plane separates superior mediastinum from inferior and it also marks the superior border of the pericardium
How do we locate the sternal angle
use index finger
manubrium normally angles posteriorly on the body of the sternum, forming a raised feature referred to as the sternal angle (felt as a blunt ridge)
this site marks the site of articulation of rib 2 with the sternum
rib 1 is not palpable because it lies inferior to the clavicle and is embedded in the tissues at the base of the neck
therefore rib 2 is used as reference for counting ribs and is immediately lateral to the sternal angle
Summarise the location of the nipple
lateral to the MCL overlying the 4th ICS
Describe the base of the breast
extends vertically between the 2nd and 6th ribs
What can happen to the xiphisternum as we age
It can ossify
Describe the borders of the costal margin
Laterally, the lowest border of the costal margin is the 10th costal cartilage (L2). The lateral border of the rectus abdominis meets the costal margin at the tip of the 9th costal cartilage (L1).
How can we see the outline of the rectus abdominis
Ask the supine patient to raise their fully extended lower limb, by flexing the hip joint
How can we see the costal margin in the patient
ask the subject to lie supine, and relax the abdomen by flexing the thigh and knee
How do we palpate the spinous process of C7
ask the patient to flex their neck- C7 is the first palpable spine at the root of the neck
What bony landmark can we use to locate the T2 spine
superior angle of the scapula
What bony landmark can we use to locate the T3 spine
spine of scapula- medial end at the level of the T3 spine
Laterally, the spine ends at the acromion
What bony landmark can we use to locate the T7 spine
Inferior angle of scapula
What can deviation in the position of the trachea indicate
pathology in the lung or mediastinum
How do we palpate the trachea
a) examiner should stand facing the subject
b) palpate with index finger (of right hand) from the jugular notch
c) is the trachea palpable in the midline?
What do the deviations of the trachea suggest
deviation to same side of lesion- upper lobe collapse or fibrosis
deviation to other side of lesion- large pleural effusion or tension pneumothorax
Common causes of unilateral decrease in expansion of chest
pneumothorax
pleural effusion
collapsed lung
What is bilateral decrease in expansion of chest seen in
asthma
How do we observe chest movements in the patient
The examiner stands facing the patient (who is sat on the edge of the bed) and firmly places their hands on the patient’s anterior chest wall (just below the 5th or 6th ribs) with fingers extended around their chest.
The thumbs just meet in the anterior midline (mid-sternal line), resting lightly only the chest wall, to allow its movement during respiration.
Ask the patient to take a deep breath and observe how far the tips of the examiner’s thumbs move apart (at least 5cm)
Repeat this examination on the posterior chest wall, with the thumbs meeting in the posterior midline T10 (T7 is the inferior angle of the scapula)
Differences in the analysis of the anterior and posterior chest wall during breathing
movement in anterior - gives some idea about expansion in the upper and middle lobes
movement in posterior- expansion in lower lobes
look for asymmetry
