Thorax 1 Flashcards
What shape is the vertebral body of thoracic vertebra?
Heart shaped
Is the spinous process of thoracic vertebra short or long?
Long
What is the shape of the thoracic vertebral foramen?
Circular
Describe the articular processes of the thoracic vertebrae?
Superior - Points directly upwards and articular facets face directly posteriorly
Inferior - points directly downwards and articular facets directly anteriorly
What is number 1 on this diagram?
Vertebral body
What is number 2 on this diagram?
Vertebral foramen
What is number 3 on this diagram?
Facet for articulation with tubercle of rib
What is number 4 on this diagram?
Spinous process
What is number 5 on this diagram?
Lamina
What is number 6 on this diagram?
Transverse process
What is number 7 on this diagram?
Pedicle
What is number 8 on this diagram?
Facet for articulation with tubercle of rib
What is number 9 on this diagram?
Superior articular process
What is number 10 on this diagram?
Demifacets for articulation with head of ribs
What is number 11 on this diagram?
Inferior articular process
What do the superior and inferior costal facets articulate with
Superior - part of Head of its own rib
Inferior - part of Head of the rib below
Which thoracic vertebrae are atypical?
10, 11, 12
How is T10 atypical?
Lacks inferior demifacets
How are T11 and T12 atypical?
Lack inferior demifacets and transverse costal facets
Which ribs articulate with the vertebral column?
All of them
Which ribs are ‘true ribs’?
Upper seven ribs
Why are ribs 8 to 10 false ribs?
Their costal cartilages articulate anteriorly only with the costal cartilages of the ribs above and not with the sternum
Why are ribs 11 and 12 false ribs?
They have no anterior connection with other ribs or w the sternum.
They are floating ribs
What is number 1 on this diagram?
Head
What is number 2 on this diagram?
Tubercle
What is number 3 on this diagram?
Neck
What is number 4 on this diagram?
Angle
What is number 5 on this diagram?
Internal surface
What is number 6 on this diagram?
Costal groove
What is number 7 on this diagram?
External surface
What is number 8 on this diagram?
Costal cartilage
What is number 9 on this diagram?
Crest
Label this diagram
1) Jugular notch
2) Manubrium
3) sternal angle
4) body of sternum
5) Xiphoid process
What is the significance of the sternal angle
Clinically important as it acts as a surface landmark of the sternum
What are costovertebral joints
The point at which the head of the ribs articulate with costal facets
What are the boundaries of the superior thoracic aperture?
The body of vertebra T1 posteriorly
The medial margin of rib 1 on each side
The manubrium anteriorly.
What are the boundaries of the inferior thoracic aperture?
- The body of T12 posteriorly
- rib 12 and the distal end of rib 11 posterolaterally
- the distal cartilaginous ends of ribs 7 to 10 anterolaterally
- the xiphoid process anteriorly
- It is closed by the diaphragm
Describe the external intercostal muscles
- 11 pairs
- Run inferomedially
- Attach to inferior margin of rib above and superior margin of rib below
-Innervated by intercostal nerves
Describe the internal intercostal muscles
- 11 pairs
- Run superomedially
- Attach to lateral edge of costal groove of rib above and to superior margin of rib below (under external)
- Innervated by intercostal nerves
Describe the innermost intercostal muscles
- 11 pairs
- Run superomedially
- Attach to medial eve of costal groove of rib above and superior margin of rib below
- Innervated by intercostal nerves
How are external intercostal muscles involved in respiration?
Contract to lift ribs upwards and outwards and increase intrathoracic volume so lungs can expand during FORCED inspiration
How are internal and innermost intercostal muscles involved in breathing.
Contract to pull ribs inwards and downwards to decrease intrathoracic volume in FORCED expiration
Label the diagram
1) Intercostal nerve
2) Intercostal artery
3) Intercostal vein
4) Collateral branches
What is the function of the transverse thoracic muscle?
Assists with forced expiration as it depresses ribs.
Proprioceptive function - feeds back info about position of rib cage to CNS
What is the function of the serratus posterior superior muscle
Elevation of the rib cage
Proprioception - transmits info to CNS about rib position
What is the function of the serratus posterior inferior muscle
Depression of ribs
Proprioception
Describe the internal thoracic arteries
- Branch from subclavian arteries
- Run parallel to sternum on internal wall of anterior thoracic cage
- Past rib cage, continue as superior epigastric arteries to supply anterior abdominal wall
What are the significant branches of the internal thoracic artery?
Pericardiacophrenic artery: pericardium and diaphragm
Musculophrenic artery: intercostal muscles, diaphragm and abdominal muscles
Perforating branches: pec. major, breast and overlying skin
Label the diagram
1) Subclavian artery
2) Internal thoracic artery
3) Pericardiacophrenic artery
4) Perforating branches of the internal thoracic artery
5) Musculophrenic artery
6) Superior epigastric artery
What are the 2 parts the pectoral region is split into?
- Superficial part - skin, fascia and breast tissue
- Deep part - 4 muscles of anterior thorax
What are the 4 pairs of muscles in the pectoral region
- Pectoralis major
- Subclavius muscle
- Pectoralis minor
- Serratus anterior muscle
What is the origin of the Pectoralis major muscle?
Medial half of clavicle and anterior surface of sternum, first seven costal cartilages, aponeurosis of external oblique
What is the insertion of the Pectoralis major muscle
Lateral lip of intertubercular sulcus of humerus
What is the action of the pectoral region?
Adduction, medial rotation and flexion of the humerus at the shoulder joint
How are the Pectoralis major muscles Innervated?
Medial and lateral pectoral nerves
What is the origin of the subclavius muscle?
Rib 1 at junction between rib and costal cartilage
What is the insertion of the subclavius muscle?
Groove on inferior surface of the middle third of clavicle
What is the action of the subclavius muscle?
Pulls clavicle medially to stabilize sternoclavicular joint; depresses tip of shoul
How is the subclavius muscle innervated?
Nerve to subclavius
What is the origin of the Pectoralis minor?
Anterior surfaces of the third, fourth, and fifth ribs, and deep fascia overlying the related intercostal spaces
What is the insertion of the Pectoralis minor muscle?
Coracoid process of scapula
What is the action of the Pectoralis minor muscle?
Depresses tip of shoulder; protracts scapula
How is the Pectoralis minor muscle Innervated?
Medial pectoral nerves
What is the origin of the serratus anterior muscle
Anterior portions of first 8 ribs
What is the insertion of the serratus anterior muscle?
Internal surface of medial border of scapula
What is the action of the serratus anterior muscle?
Holds scapula against ribcage to prevent ‘winging’ of the inferior angle of the scapula
How is the serratus anterior muscle Innervated?
Long thoracic nerve
What are the main components of the breasts?
- Mammary glands
- skin
- Connective tissues
What are the main components of the mammary glands?
- Lactiferous ducts which open independently onto the nipple
- Associated secretory lobules
- suspensory ligaments of the breast
Where does the breast lie?
- Deep fascia related to the pec major and other surrounding muscles
- The base extends vertically from ribs 2 to 6 and transversely from the sternum to midaxillary line
What separates the breast from the deep fascia?
Retromammary space
Function of retromammary glands?
- separates breast from deep fascia
- provides some degree of movement
What blood vessels supply the breast?
- laterally, vessels from the axillary artery—superior thoracic, thoraco-acromial, lateral thoracic, and subscapular arteries;
- medially, branches from the internal thoracic artery;
- the second to fourth intercostal arteries via branches
Describe the venous drainage of the breast
Veins draining breast drain into the axillary, internal thoracic and intercostal veins
How is the breast Innervated?
Via anterior and lateral cutaneous branches of the 2nd to 6th intercostal nerves
How is the nipple innervated?
By the 4th intercostal nerve
Describe the lymphatic drainage of the breast
- 75% via lymphatic vessels that drain into axillary nodes
- Most of the rest is into parasternal nodes
- Some is via intercostal nodes
Why is lymph drainage of the breast important in malignant cancer?
Because it is so complex and the large number of drainage routes mean that metastases in can spread easily.
Describe the structure of the diaphragm
- It is a musculotendinous structure
- Balloons superiorly to form domes
- Right dome reaches rib 5 and left reaches lower.
- oesophagus and inferior vena cava penetrate it and aorta passes posterior to it.
How does the diaphragm act during breathing?
Expiration: Diaphragm contracts and height of domes decreases and volume of thorax increases.
What is the difference between extrinsic and intrinsic muscles?
Extrinsic - Muscles that originate in one region and insert into another
Intrinsic - muscles that originate and insert in the same region
What are the three groups of back muscles called?
Superficial - Extrinsic
Intermediate - Extrinsic
Deep - Intrinsic
How are the superficial and intermediate muscles Innervated?
By the branches of the anterior rami of the spinal nerves of the back
How are the deep muscles innervated?
By the posterior rami of the spinal nerves
What is the action of the superficial muscles of the back?
To move the shoulder muscles
What is the action of the intermediate muscles
Only consists of serrator posterior superior muscle therefore action is elevation of rib cage
What is the action of the deep back muscles ?
Movement of the vertebral column and posture.
Name labels 2, 4, 5, 6,7,8
2) Clavicle
4) Internal intercostal muscle
5) Transversus Thoracic muscle
6) Intercostal arteries and nerves
7) Musculophrenic artery
8) Superior epigastric artery and vein
Name labels 9-14
9) Diaphragm
10) Rectus abdominis
11) Subclavian artery and brachial plexus
12) First Rib
13) Internal thoracic artery and vein
14) Sternum
Name labels 16 and 17
16) Intercostal artery and vein
17) Xiphoid process
Name labels 6-10
6) Clavicle
7) Subclavius muscle
8) Second rib
9) Anterior cutaneous branches of intercostal nerves
10) External intercostal membrane
Name labels 14-17
14) Supraclavicular nerves
15) Pec. Major and lat3ral pectoral nerves
16) Thoraco-acromial artery and subclavian vein
17) Pectoralis minor muscle
Name labels 23
23) Latissimus Dorsi muscle
Name labels 25, 30, 31, 36
25) Axillary artery
30) Serratus anterior muscle
31) Thoraco-acromial artery
36) Anterior intercostal artery,vein and nerve
Name labels 17,19, 20, 21
17) Axillary lymph nodes
19) Lateral thoracic vein
20) Lymph vessels
21) Serratus anterior muscle
Name all labels in picture
4)Pectoralis major muscle
12) Pectoral fascia
13) Mammary gland
14) Serratus anterior muscle
9) Areola
10) Nipple (papilla)
15) Lactiferous sinus
Name labels 1-5
1) Internal thoracic artery
2) Secretory lobules
3) Suspensory ligaments
4) Lactiferous ducts
5) Lactiferous sinuses
Name labels 6-10
6) Retromammary space
7) Parasternal nodes
8)Areola
9) Axillary process
10) Pectoral axillary nodes
Name labels 11-14
11) Lateral Axillary nodes
12) Lateral thoracic artery
13) Central Axillary nodes
14) Apical Axillary nodes
