Lecture 1: Thoracic Wall and Cavities

Question 1

What is the thorax?

Answer 1

The area in between the neck and abdomen.

Question 2

What are the openings of the rib cage called?

Answer 2

Superior thoracic aperture–> allows the neck and thorax to communicate

Inferior thoracic aperture–> allows the thorax and abdomen to communicate

Question 3

What are the boundaries of the superior thoracic aperature?

Answer 3

1. T1 vertebra
2. Paired 1st ribs
3. Superior manubrium

Question 4

What are the boundaries of the inferior thoracic aperature?

Answer 4

1. T12 vertebral segment
2. 11th and 12 ribs
3. 7-12 costal cartilage
4. Xiphisternal joint

Question 5

Suprasternal notch is also called the

Answer 5

Jugular notch

Question 6

Sternal angle is also called

Answer 6

Angle of Louis

Question 7

Ribs 1-7 meet up with their own costal cartilage, and are called _______ ribs

Answer 7

Vertebrocostal

Question 8

Ribs 8-10 meet up with rib 7’s costal cartilage and are called ______ ribs

Answer 8

vertebrochondral

Question 9

Ribs 11-12 are called ______ ribs, are floating, and have no cartilage

Answer 9

Vertebral

Question 10

Only ribs _____ are considered typical ribs

Answer 10

3-9

Question 11

CN: Most commonly fractured ribs are the _________

Answer 11

middle ribs, at their weakest spot, anterior to the costal angle.

Question 12

CN: What can occur as a result of rib fracture?

Answer 12

Rib fracture can damage the internal organs and cause pain with respiration, coughing, laughing and sneezing.

Question 13

CN: Supernumeray ribs

Answer 13

Supernumerary ribs are extra ribs in the cerivical or lumbar region that are caused by costal elements becoming a rib.

Extra cervical ribs typically cause no symptoms, but can produce neural and circulatory problems based on how close they are to the brachial plexus and subclavian vessels.

Lumbar ribs are less common and also do not cause sx, but they can create confusing radiographic images.

Question 14

CN: Supernumerary ribs can cause ____

Answer 14

Thoracic outlet syndrome due to extra cervical ribs

Question 15

Divisions of the thoracic cavity

Answer 15

• 2 pulmonary cavities (contain lungs and plurae)
• Mediastimum (located in the middle and contains the heart, thoracic great vessel, trachea, thoracic esphogus and thymus)

Question 16

Primary cartilagenous joints are called what?

Answer 16

Synchondrosis

Question 17

Secondary cartilagenous joints are called what?

Answer 17

Symphysis- in between intervertebral disks.

They are slightly movable

Question 18

Manubriosternal joint

Joint classification:

What 2 bones articulate:

What ligmanents hold it together:

Answer 18

Joint classification: Symphysis (secondary cartilagenous joint)

What 2 bones articulate: Manubrium of the sternum and body of the sternum

What ligmanents hold it together:

Question 19

Xiphisternal joint

Joint classification:

What 2 bones articulate:

What ligmanents hold it together:

Answer 19

Joint classification: Synchondrosis

What 2 bones articulate: body of the sternum and xiphoid process of the sternum

What ligmanents hold it together:

Question 20

Sternocostal joints

Joint classification:

What 2 bones articulate:

What ligmanents hold it together:

Answer 20

Joint classification: Varies

Rib 1- Synchondrosis

Rib 2-7- Planar synovial

What 2 bones articulate: located where the costal cartilage meets the sternum.

What ligmanents hold it together: Anterior/posterior radiate sternocostal l.

Question 21

Costovertebral joints

Joint classification:

What 2 bones articulate:

What ligmanents hold it together:

Answer 21

Joint classification: Synovial planar

What 2 bones articulate: Located in between the head of the ribs and the vertebrae

What ligmanents hold it together: Radiate ligament and intraarticular ligalent (comes off the head of the ribs and meets on the vertebral disk

Question 22

How to the rib and vertebrae articulate?

Answer 22

The HEAD of rib 6 meets up with the superior costal facet of T6, transverse process of T6 and inferior costal facet of T5.

Question 23

Costotransverse joints

Joint classification:

What 2 bones articulate:

What ligmanents hold it together:

Answer 23

Joint classification: Planar synovial joint

What 2 bones articulate: between the tubercle of ribs and transverse process

What ligmanents hold it together:

lateral costotransverse ligament (connect the tubercle of the rib to the transverse process) &

Superior costotransverse ligament (connect the neck of the rib to the transverse process one vertebral segment superiorly

Question 24

lateral costotransverse ligament

Answer 24

connects the tubercle of the rib

–> transverse process

Question 25

Superior costotransverse ligament

Answer 25

Connects the neck of the rib –> transverse process one vertebrae up

Question 26

What is the movement at the costovetebral joint?

Answer 26

2 movements of the joint both function to increase thoracic volume, decreasing thoracic pressure, allowing you to breathe in (inspiration).

1. Bucket handle movement–> lateral most portion of the rib elevates, increasing the diameter of the thorax
2. Pump handle movement–> sternal end of the rib elevates, increasing the anterior –> posterior diameter of the thorax.

Question 27

Costochondral joints

Joint classification:

What 2 bones articulate:

What ligmanents hold it together:

Answer 27

Joint classification: Synchondrosis

What 2 bones articulate: in between the ribs and costal cartilage

What ligmanents hold it together:

Question 28

Dislocation of ribs

Answer 28

dislocation at the sternocostal joint

Question 29

Separation of the ribs

Answer 29

Seperation occurs at the costalchondral joint

Question 30

Intercostal muscles

Answer 30

There are 11 pairs, 3 layers deep

The internal intercostal muscle and innermost intercostal muscles are seperated by the intercostal neurovascular bundle.

1. External intercostal m.

2. Internal intercostal m.

3. Innermost intercostal m.

Question 31

External intercostal muscle

Action:

Innervation:

BS:

Answer 31

Action: Elevate the ribs (inspiration)

Innervation: Intercostal n.

BS: Intercostal a.

Muscle fibers go as if you are putting your hands in your pocket.

As we get closer to the sternum, the muscle is replaced by the external intercostal membrane, which covers the internal intercostal m.

Question 32

Internal intercostal m.

Action:

Innervation:

BS:

Answer 32

Action: Depress ribs (expiration)

Innervation: Intercostal n.

BS: Intercostal a.

Muscle fiber directions are perpendicular (opposite) to the external intercostal a.

Question 33

Innermost intercostal m.

Action:

Innervation:

BS:

Answer 33

Action: Probs same as internal intercostal m.

Innervation: Intercostal n.

BS: Intercostal a.

Intercostal bundle goes in between internal intercostal m and innermost intercostal m. If you cannot see the bundle–> Innermost intercostal m because it blocks the view.

Question 34

CN: Thoracentisis

Answer 34

Stick a hypodermic needle in the middle of the intercostal muscle to drain fliud from the pleural cavity.

The needle must be inserted between the ribs inferior to the intercostal neurovascular bundle, but above the collateral branches. SO RIGHT IN THE MIDDLE.

Question 35

CN: Insertion of chest tube

Answer 35

A tube is inserted in between the 5th or 6th intercostal space to remove air, fluid, blood or pus from the pleural cavity.

Question 36

CN: Thorascopy

Answer 36

Thorascopies are performed so that we can visualize/biopsy the space inside the pleural cavity.

Question 37

Transverse thoracic m.

Answer 37

Axn: Depress the ribs to help with inspiration

I: Intercostal N

BS:: _____

Go from sternum–>costal cartilage

Question 38

Subcostal M

Answer 38

Axn: Depress the ribs

I: Intercostal N

BS

Goes from the inferior border of one rib–> superior border of 1 rib.

Only found on the posterior thoracic wall.