Sem 1 - D - Thoracic Wall - Thoracic Skeleton, Ribs & Joints, Resp Movements & Muscles, Blood Supply/ Drainage & Breast

Question 1

Which structures make up the thoracic cage? (bony structures)

Answer 1

12 thoracic vertebrae each with a pair of ribs coming anteriorly from it (24 ribs in total then) Sternum Clavicles x2 Scapula x2 Calvicles articulate with the sternum anteriorly and scapula posteriorly

Question 2

In the thoracic cage, there is a superior and inferior thoracic aperture What makes up both superior and inferior thoracic apertures?

Answer 2

Superior thoracic aperture - T1 vertebral body, 1st pair of ribs and their costal cartilages and the superior border of the manubrium Inferior thoracic aperture - T12 vertebral body, 11th and 12th pairs of ribs, costal cartilages of ribs 7 to 10 and the xiphersternal joint (technically xiphoid process is in the inferior thoracic aperture)

Question 3

What do the superior and inferior thoracic apertures allow for? What is the costal cartilages of rib 7-10 collectively known as?

Answer 3

Superior thoracic aperture allows for passage of structures between thorax and neck/upper limb Inferior thoracic aperture allows for passage of structures between thorax and abdomen Costal cartilages of ribs 7-10 = costal margin

Question 4

Recap What forms the superior and inferior thoracic apertures? What do they allow for the passage of?

Answer 4

Superior - T1 body, 1st pair of ribs & costal cartilages, superior border of manubrium - passage of structures between thorax and neck/upper limb Inferior - T12 body, 11th &12th pairs of ribs, costal cartilages of ribs 7-10 and xiphersternal joint - passage of structures between thorax & abdomen

Question 5

WHat is the costal margin again?

Answer 5

This is the joining of the costal cartilages from ribs 7-10 Both costal margins join to form the infrasternal angle

Question 6

https://s3.amazonaws.com/classconnection/403/flashcards/11907403/jpg/ppngjpgpng-166019DC12F2DA7FD58.jpg

Answer 6

Black - superior articular process Maroon - lamina Orange - spinous process Yellow - transverse process Green - pedicle Blue - vertebral canal Red -transverse costal facet Purple - superior costal facet Pink- inferior costal facet

Question 7

What does the superior and inferior costal facets articulate with? What does the superior articular process articulate with? What does the transverse costal facet articulate with?

Answer 7

Superior costal facet - articulates with head of the rib of the same number Inferior costal facet - articulates with the head of the rib of the below Superior articular process - articulates with the inferior articular process of the vertebrae above Transverse costal facet - articulates with the tubercle of the rib

Question 8

Ribs can be split into two distinct groups: * Classification - which depends on the bony features of the rib * Type - which depends on the ribs connection with the sternum What are the three different types of ribs? Explain how they are different?

Answer 8

Three types of ribs True ribs - ribs 1-7 - attach directly to the sternum via their own costal cartilage False ribs - ribs 8-10 - attach indirectly to sternum with their costal cartilages uniting with the costal cartilages of the ribs above Floating ribs - ribs 11 and 12 -no connecting to sternum

Question 9

Now have discussed the different types of ribs (true, false and floating), lets talk about the classification of ribs which is based on their bony features Classification can be split into Typical and atypical Which ribs are typical and which are atyical?

Answer 9

Typical ribs - ribs 3 to 9 Atypical ribs - ribs 1,2 and 10,11,12

Question 10

What makes a rib a typical rib

Answer 10

Rib has a head, neck, tubercle and body

Question 11

Describe the head of a typical rib? What does the neck of a typical rib connect?

Answer 11

Head of a typical rib - wedge shaped with a superior articular facet and an inferior articular facet separated by the crest of the head * Superior articular facet articulates with the inferior costal facet of the vertebrae above * Crest of the head articulates with the IV disc * Inferior articular facet articulates with the superior costal facet of the vertebrae of the same number Neck of a typical rib - connects the head of the rib to the body of the rib at the tubercle

Question 12

Describe the tubercle of a typical rib?

Answer 12

Tubercle has an * Articular part for the transverse process of the rib of the same number * Non-articular part for the attachment of the costotransverse ligament

Question 13

What is the most curved part of the rib known as? What is the costal groove?

Answer 13

The costal angle is the most curved part of the rib The costal groove is a groove on the internal surface of the inferior border of the rib - the groove exists for the protection of intercostal vessels and nerves

Question 14

Describe how rib 1 is an atypical rib?

Answer 14

The head of the rib only has one articular facet as it only articulates with the transverse process of vertebra T1 - C7 vertebrae does not have a costal facet Rib 1 does not have a costal angle Also has groove for subclavian vessels on the superior surface (subclavian artery and vein) separated by the scalene tubercle

Question 15

What does the scalene tubercle serve for the attachment of? Is the subclavian artery or vein groove more posterior?

Answer 15

Serves for the attachment of the anterior scalene muscle Subclavian artery groove is more posterior Subclavian vein groove is more anterior

Question 16

What makes the second rib an atypical rib?

Answer 16

It has a tuberosity on the upper surface for the attachment of the serratus anterior muscle

Question 17

What makes ribs 10-12 atypical?

Answer 17

They all have a single facet on the head as they only articulate with the vertebrae of the same number Ribs 11 and 12 also short with no neck or tubercle

Question 18

Along the lateral border of the sternum are a number of costal grooves – this is where the ribs will articulate Sternum is split into the manubrium, body and xiphoid process What is another name for the sternal angle? Which part of the sternum do each of the ribs articulate?

Answer 18

Sternal angle aka manubriosternal joint

Rib 1 - articulates at superior manubrium

Rib 2 - articulates at sternal angle

Rib 3-6 - articulate along body of the sternum

Rib 7 - articulates at the xiphisternal joint

Question 19

The intervertebral joints consist of the facet joint and the intervertebral discs What makes each of these joints? What type of joint are each of these joints? What is another name for the facet joint?

Answer 19

Facet joints - * formed by superior articular process of vertebrae articulating with inferior articular process of vertebra above * It is a synovial plane joint * Also known as zygapophysial joint Intervertebral disc - * between two vertebral bodies * this is a secondary cartilagenous joint

Question 20

The sternocostal joints also have different types of joint What type of joint exists between rib 1 and the sternum? What type of joint exists between ribs 2-7 and the sternum?

Answer 20

Rib 1 and the sternum - primary cartilagenous joint Ribs 2-7 and the sternum - synovial plane joints

Question 21

Interchondral joints are between costal cartilages They exist between ribs 6-7,7-8 and 8-9 WHat type of joint are these? What type of joint exists between ribs 9 and 10?

Answer 21

INterchondral joints - synovial plane joints Joint between rib 9 and 10 - fibrous joint

Question 22

The two costovertebral joints are between * the head of the rib and the vertebrae * the tubercle of rib and the vertebrae What are the participants in the joint of the head of the rib? What are the participants in the joint at the tubercle of the rib? What is this joint also known as?

Answer 22

Head of the rib - superior articular facet with inferior costal facet of rib above Crest of head of rib - with IV disc Inferior articular facet with superior costal facet of rib of the same number Tubercle articulates with transverse costal facet - costotransverse joint

Question 23

If a line were drawn between the costovertebral joints (between head of rib and tubercle articulations with vertebrae) , the axis of the line is far more lateral in the upper ribs (ribs 1-6) and far more posterior in the lower ribs (ribs 7-12) This axis causes a difference in the movement of the ribs during inspiration * What direction do upper ribs move on inspiration? * What is the name for this movement? What direction do lower ribs move on inspiration? * What is the name for this movement?

Answer 23

Upper ribs move in an anterior direction on inspiration due to more lateral axis between costoverebtral joints- described as a PUMP HANDLE MOVEMENT Lower ribs move in a lateral direction on inspiration (due to more posterior axis between costovertebral joints) - described as a BUCKET HANDLE MOVEMENT

Question 24

What are the changes in dimensions of the thoracic cavity during inspiration? What is the primary muscle of inspiration at rest?

Answer 24

The sternum and upper ribs move anteriorly and superiorly

The lower ribs move laterally

The diaphragm (primary muscle of inspiration at rest) descends Thoracic cavity increases in size, vertically, horizontally and laterally

Question 25

The thoracic wall contains many muscles * intercostal muscles * subcostal and transversus thoracis As well as the secondary muscles of respiration * Scalene muscles * Serratus posterior (superior and inferior) 3 scalane muscles in the neck, they come down to attach on the upper ribs * What is the nerve supply? * Which scalene attaches to the tubercle on rib 1?

Answer 25

Scalene muscles - nerve supply C3-C7 anterior rami * (Anterior scalene muscle - C3-C7) * (Middle scalene muscle - C4-C7) * (Posterior scalene muscle - C5-C7) Anterior scalene muscles attahes to scalene tubercle on rib 1

Question 26

Serratus posterior superior and inferior have different nerve supplies due to originating at different levels What is the nerve supply?

Answer 26

Serratus posterior superior - 2nd - 5th intercostal nerves Serratus posterior inferio - anterior rami T9-12

Question 27

The intercostal, subcostal and transversus thoracis were the other muscles of the thoracic wall What are the three intercostal muscle layers? Which direction do they pass in? Which layer is often incomplete?

Answer 27

External intercostal muscle - passes in a downward and forward direction Internal intercostal muscle - passes in a downward and backward direction Innermost intercostal muscle - passes in the same direction as internal - this muscle layer is often incompete

Question 28

What effect does the external, internal and innermost intercostal muscles have on respiration?

Answer 28

Externl intercostal muscles raise the ribs on inspiration The interchondral part of the internal intercostals will raise the ribs on inspiration The interosseous part of the internal intercostals depresses the ribs on expiration

Question 29

Subcostal muscle: * Near angle of ribs * Spans 1 or 2 Intercostal spaces * Fibres may blend with Innermost Intercostal Where does the transversus thoracis attach?

Answer 29

Transversus thoracis radiates from the sides of the sternum to the costal cartilages of ribs 2-6 They exist on the posterior aspect of the anterior thoracic wall

Question 30

Superficial Muscles Associated with Pectoral Gridle/Upper Limb/Anterior Abdominal Wall * Pectoral muscles * External oblique * Serratus anterior * Rectus abdominus What are there nerve supplies?

Answer 30

Pec major - median (C8,T1) and lateral (C5,-7) pectoral nerves Pec minor - medial pectoral nerve External oblique - Anterior rami T7-T12 Serratus anterior - long thoracic nerve (C5,6,7) Rectus abdominus - Anterior rami T7-T12

Question 31

Where in the intercostal space does the neurovascular bundle lie? What order does it lie in?

Answer 31

The NVB lies in the plane between the inner and innermost intercostal muscles It lies immediately inferior to the rib Vein Artery Nerve

Question 32

Obviously posterior intercostal arteries supply the posterior intercostal spaces, the anterior intercostal arteries supply the anterior aspect of the intercostal spaces Where do the posterior intercostal artery branches come from? (Different origin for 1/2 vs 3-11)

Answer 32

Posterior intercostal arteries 1 and 2 - come from the supreme intercostal artery which is a branch of the costocervical trunk which is a branch from the subclavian artery Posterior intercostal arteries 3-11 and subcostal artery all come direct from the thoracic aorta

Question 33

State again the posterior intercostal arteries origin?

Answer 33

1and2 come from the the supreme intercostal artery which is branch of the costocervical trunk of the subclavian artery 3-11 and the subcostal artery all come direct from the thoracic aorta

Question 34

State the origin of the anterior intercostal arteries?

Answer 34

1-6 come direct from the internal thoracic artery Arteries 7-9 come from a branch of the internal thoracic artery

Question 35

What does the internal thoracic artery bifrucate into? This is where it gives off the branch that gives of the anterior intercostal arteries for ribs 7-9 Also what muscle does the interal thoracic (mammary) artery lie run superifical to?

Answer 35

Internal thoracic artery bifurcates to give the superior epigastric artery and the musculophrenic artery The musculophrenic artery gives anterior intercostal arteries 7-9 Internal thoracic artery runs superficial to the transversus thoracis

Question 36

Where do the anterior intercostal veins drain? Where do the posterior intercostal veins drain?

Answer 36

Anterior intercostal veins drain into the internal thoracic vein Posterior interocstal veins drain into the azygous vein on the right side and the hemiazygous/ accessory hemiazygous veins on the left (the hemiazygous vein will drain into the azygous vein)

Question 37

On the left side, the posterior intercostal veins drain into the hemiazygous system which eventually drains into the azygous vein Is the hemiazygous vein or the accesory hemiazygous veins superior to the other?

Answer 37

Accessory hemiazygous vein lies superior to the hemiazygous vein

Question 38

Where do both the internal thoracic vein and the azygous vein drain into?

Answer 38

Internal thoracic vein drains into the brachiocephalic vein (anterior intercostal drainage) The aygous vein drains into the superior vena cava (posterior intercostal drainage)

Question 39

What is the blood supply to the breast? What is the venous drainage of the breast?

Answer 39

Medially - medial mammary branches from the internal thoracic artery Laterally - lateral mammary branches from lateral thoracic artery (a branch of the axillary artery) Venous drainage by Medial and Lateral Mammary veins

Question 40

What is the lymphatic drainage of the breast?

Answer 40

75% of the breast drains lymphatics to the axillary lymph nodes Most of the remaining 25% goes to the parasternal lymph nodes (although some will drain down into the abdominal lymph nodes)