Respiratory - Bones of the Thorax

Question 1

What are the bones of the thorax?

Answer 1

Thoracic vertebrae
Twelve pairs of ribs
The Sternum

Question 2

How many thoracic vertebrae are there?

Answer 2

12

Question 3

What is the role of the thoracic vertebrae?

Answer 3

Protect the internal viscera – such as the heart, lungs and oesophagus.

Question 4

What are the joints of the thoracic vertebrae divided up into?

Answer 4

Joints present throughout the vertebral column
Joints unique to the thoracic vertebrae

Question 5

What are the two types of joints present throughout the vertebral column?

Answer 5

Between vertebral bodies
Between vertebral arches

Question 6

Describe the joint found between vertebral bodies

Answer 6

Adjacent vertebral bodies are joined by intervertebral discs, made of fibrocartilage.

This is a type of cartilaginous joint, known as a symphysis.

Question 7

Describe the joint found between vertebral arches

Answer 7

Formed by the articulation of superior and inferior articular processes from adjacent vertebrae.

It is a synovial plane type joint.

Also called a facet joint.

Question 8

What joint is unique to the thoracic spine?

Answer 8

The articulations between the vertebrae and the ribs are unique to the thoracic spine.

For each rib, there are two separate articulations – costovertebral and costotransverse.

Question 9

What is a costovertebral joint?

Answer 9

Each costovertebral joint consists of the head of the rib articulating with:

Superior costal facet of the corresponding vertebra

Inferior costal facet of the superior vertebra

Intervertebral disc separating the two vertebrae

Question 10

What is a costotransverse joint?

Answer 10

The articulation of transverse processes of a thoracic vertebra and the tubercle of the adjacent rib.

They are present in all vertebrae except T11 and T12.

Question 11

What are the charactaristic features of the thoracic vertebrae?

Answer 11

Vertebral body is heart shaped.

Presence of demi-facets on the sides of each vertebral body – these articulate with the heads of the ribs.

The spinous processes are long and slant inferiorly. This offers increased protection to the spinal cord, preventing an object such as a knife entering the spinal canal.

Question 12

What are the atypical vertebrae of the thoracic vertebral column?

Answer 12

T1
T10
T11 & T12

Question 13

Why is T1 atypical?

Answer 13

Superior facet is not a demifacet, as this is the only vertebrae to articulate with the 1st rib.

Question 14

Why is T10 atypical?

Answer 14

A single pair of whole facets is present which articulate with the 10th rib. These facets are located across both the vertebral body and the pedicle.

Question 15

Why are T11 and T12 atypical?

Answer 15

Each have a single pair of entire costal facets, which are located on the pedicles.

Question 16

Discuss the movement of the thoracic spine

Answer 16

Thoracic spine is considered to have a restricted range of motion (ROM) during flexion and extension compared with that of cervical and lumbar spine.

ROM of thoracic spine is restricted by the rib cage.

Question 17

How many pairs of ribs are there?

Answer 17

12

Question 18

What are true ribs?

Answer 18

Ribs that attach directly to the sternum

Question 19

What are false ribs?

Answer 19

Ribs attached to the costal cartilage superior than them

Question 20

What are floating ribs?

Answer 20

Ribs that do not attach to the sternum

Question 21

What are the true, false and floating ribs?

Answer 21

True: 1 - 7
False: 8 - 10
Floating: 11 - 12

Question 22

What are the functions of the ribs?

Answer 22

The rib cage protects the organs in the thoracic cavity, assists in respiration, and provides support for the upper extremities.

Question 23

What do the ribs do during inspiration and expiration?

Answer 23

During inspiration the ribs are elevated, and during expiration the ribs are depressed.

Question 24

Which ribs are atypical?

Answer 24

Ribs 1, 2, 10, 11 and 12

Question 25

Why is rib 1 atypical?

Answer 25

Is shorter and wider than the other ribs. It only has one facet on its head for articulation with its corresponding vertebra (there isn’t a thoracic vertebra above it). The superior surface is marked by two grooves, which make way for the subclavian vessels.

Question 26

Why is rib 10 atypical?

Answer 26

It only has one facet – for articulation with its numerically corresponding vertebra.

Question 27

Why are ribs 11 and 12 atypical?

Answer 27

Ribs 11 and 12 have no neck, and only contain one facet, which is for articulation with their corresponding vertebra.

Question 28

What type of cartilage can be found between the anterior ends of the ribs and the sternum?

Answer 28

Costal cartilage - bars of hyaline cartilage

Question 29

What provides innervation to the costovertebral joints?

Answer 29

Lateral branches of the posterior rami of C8-T11 spinal nerves

Question 30

What provides blood supply to costovertebral joints?

Answer 30

Supreme intercostal, posterior intercostal arteries 1-10

Question 31

Discuss single rib articulation

Answer 31

A single rib articulates with two vertebral bodies and one vertebral transverse process. VB - same number as rib and above VTP - same number as rib EG - Rib 5 articulates with the body of T5 vertebra as well as the body of T4 vertebra.

Question 32

What bones form the boundaries for the thoracic inlet?

Answer 32

- T1 Vertebra - 1st pair of ribs laterally - Costal cartilage of 1st rib - Superior border of manubrium

Question 33

What bones form the boundaries for the thoracic outlet?

Answer 33

- 12th thoracic vertebra - 11 and 12th pair of ribs laterally - Costal cartilage of ribs 7-10 - Xiphisternal joint

Question 34

What ribs/costal cartilages form the costal margin and the subcostal angle?

Answer 34

Ribs 7-10

Question 35

What is the role of the sternum?

Answer 35

Protect organs of torso such as heart and lungs.

Question 36

What are the three main parts of a sternum?

Answer 36

- Manubrium - Body - Xiphoid process

Question 37

What are the main joints of the sternum?

Answer 37

- Sternomanubrial joint - Sternoclavicular joint - Sternocostal joint

Question 38

What type of joint is the sternomanubrial joint?

Answer 38

Secondary cartilaginous joint (symphysis)

Question 39

What is the vertebral level of the sternomanubrial joint?

Answer 39

T4

Question 40

What is the sternal angle an important landmark for?

Answer 40

Bifurcation of trachea at T4

Question 41

What type of joint is the sternoclavicular joint?

Answer 41

Synovial saddle joint

Question 42

What is unique about the sternoclavicular joint?

Answer 42

The only joint that directly connects the upper trunk of the appendicular skeleton to the axial skeleton of the trunk

Question 43

What innervates the the sternoclavicular joint?

Answer 43

Medial supraclavicular nerve, nerve to subclavius

Question 44

What provides blood supply to the sternoclavicular joint?

Answer 44

Suprascapular artery, internal thoracic artery

Question 45

What are the movements of the sternum?

Answer 45

Elevation - depression Protraction - retraction Axial rotation

Question 46

What type of joint is the sternocostal joint?

Answer 46

Synovial plane joint

Question 47

What type of joint is the sternocostal joint?

Answer 47

Synovial plane joint

Question 48

The first sternocostal joint is an exception, what type of joint is it?

Answer 48

Primary cartilaginous joint

Question 49

What provides innervation to the sternocostal joint?

Answer 49

Intercostal nerve

Question 50

What provides blood supply to the sternocostal joint?

Answer 50

Internal thoracic artery

Question 51

What is the movement of the sternocostal joint?

Answer 51

Sternochondral joint 1: almost no movement Sternochondral joints 2-7: translation, mainly superinferiorly

Question 52

What are the articular surfaces of all sternocostal joints lined by?

Answer 52

Fibrocartilage

Question 53

What can be found in the costal groove of a rib?

Answer 53

The posterior intercostal artery and the intercostal nerves

Question 54

What is the intercostal space?

Answer 54

Space located between the ribs

Question 55

What are the layers of muscles in the intercostal space?

Answer 55

External intercostal - inferoanterior muscle fibre direction - towards pocket Internal intercostal - inferoposterior muscle fibre Innermost intercostal -

Question 56

Where do the neurovascular bundle of the intercostal muscles lie?

Answer 56

Between the internal intercostal and innermost intercostal muscles

Question 57

How is the neurovascular bundle of the intercostal muscles organised?

Answer 57

VAN Veins Arteries Nerves

Question 58

What replaces the exterior and interior intercostal muscles?

Answer 58

Exterior intercostal membranes and interior intercostal membranes

Question 59

What is the arterial supply of the thoracic wall?

Answer 59

Posterior intercostal arteries (branch mainly off of descending thoracic aorta) Anterior intercostal arteries (branch off of internal thoracic artery) Branches of axillary arteries

Question 60

What is the venous drainage of the thoracic wall?

Answer 60

Azygos Hemiazygous accessory hemiazygous venous system and internal thoracic veins

Question 61

What does the azygos vein drain into?

Answer 61

The superior vena cava

Question 62

What drains into the azygos vein?

Answer 62

Accessory hemiazygos vein Hemizygos vein

Question 63

Where does the left side of the chest wall drain into?

Answer 63

Thoracic duct -> left subclavian vein

Question 64

Where does the right side of the chest wall drain into?

Answer 64

Right lymphatic duct -> right subclavian vein

Question 65

Where does the breast drain into?

Answer 65

Axillary lymph node Parasternal lymph node Abdominal lymph node

Question 66

What does the sternal angle separate?

Answer 66

Superior and inferior mediastinum

Question 67

How can the inferior mediastinum be divided up further?

Answer 67

Anterior Middle Posterior

Question 68

What are the three peripheral attachments of the diaphragm?

Answer 68

Lumbar vertebrae and arcuate ligaments Costal cartilages of ribs 7-12 Xiphoid process of the sternum

Question 69

What is the one central attachment of the diaphragm?

Answer 69

Central tendon

Question 70

What are the left and right crura?

Answer 70

The parts of the diaphragm that arise from the vertebrae and are tendionious in structure

Question 71

Where does the right crus arise from?

Answer 71

L1-L3

Question 72

Where does the left crus arise from?

Answer 72

L1-L2 and their IV discs

Question 73

What is the primary muscle of inspiration?

Answer 73

Diaphragm

Question 74

What does the diaphragm do during inspiration?

Answer 74

Contracts and descends (domes flatten) increasing the vertical diameter of the thoracic cavity

Question 75

What does the diaphragm do during expiration?

Answer 75

Relaxes, thoracic volume decreases

Question 76

What are the three openings of the diaphragm?

Answer 76

Caval opening - T8 Oesophageal hiatus - T10 Aortic hiatus - T12

Question 77

What passes through the caval opening?

Answer 77

Inferior vena cava Right phrenic nerve

Question 78

What passes through the oesophageal opening?

Answer 78

Oesophagus Both vagus nerves

Question 79

What passes through the aortic hiatus?

Answer 79

Aorta Azygos vein Hemiazygos vein Thoracic duct

Question 80

What are the nerve roots of the phrenic nerve?

Answer 80

Anterior rami of C3-5 Mainly C5

Question 81

What are motor functions of the phrenic nerve?

Answer 81

Pierces and innervates the diaphragm from its inferior surface

Question 82

What are the sensory functions?

Answer 82

Supplies the central part of the diaphragm