Lecture 1: Thoracic Wall and Cavities Flashcards
What is the thorax?
The area in between the neck and abdomen.
What are the openings of the rib cage called?
Superior thoracic aperture–> allows the neck and thorax to communicate
Inferior thoracic aperture–> allows the thorax and abdomen to communicate
What are the boundaries of the superior thoracic aperature?
- T1 vertebra
- Paired 1st ribs
- Superior manubrium
What are the boundaries of the inferior thoracic aperature?
- T12 vertebral segment
- 11th and 12 ribs
- 7-12 costal cartilage
- Xiphisternal joint
Suprasternal notch is also called the
Jugular notch
Sternal angle is also called
Angle of Louis
Ribs 1-7 meet up with their own costal cartilage, and are called _______ ribs
Vertebrocostal
Ribs 8-10 meet up with rib 7’s costal cartilage and are called ______ ribs
vertebrochondral
Ribs 11-12 are called ______ ribs, are floating, and have no cartilage
Vertebral
Only ribs _____ are considered typical ribs
3-9
CN: Most commonly fractured ribs are the _________
middle ribs, at their weakest spot, anterior to the costal angle.
CN: What can occur as a result of rib fracture?
Rib fracture can damage the internal organs and cause pain with respiration, coughing, laughing and sneezing.
CN: Supernumeray ribs
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.
CN: Supernumerary ribs can cause ____
Thoracic outlet syndrome due to extra cervical ribs
Divisions of the thoracic cavity
- 2 pulmonary cavities (contain lungs and plurae)
- Mediastimum (located in the middle and contains the heart, thoracic great vessel, trachea, thoracic esphogus and thymus)
Primary cartilagenous joints are called what?
Synchondrosis
Secondary cartilagenous joints are called what?
Symphysis- in between intervertebral disks.
They are slightly movable
Manubriosternal joint
Joint classification:
What 2 bones articulate:
What ligmanents hold it together:
Joint classification: Symphysis (secondary cartilagenous joint)
What 2 bones articulate: Manubrium of the sternum and body of the sternum
What ligmanents hold it together:
Xiphisternal joint
Joint classification:
What 2 bones articulate:
What ligmanents hold it together:
Joint classification: Synchondrosis
What 2 bones articulate: body of the sternum and xiphoid process of the sternum
What ligmanents hold it together:
Sternocostal joints
Joint classification:
What 2 bones articulate:
What ligmanents hold it together:
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.
Costovertebral joints
Joint classification:
What 2 bones articulate:
What ligmanents hold it together:
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
How to the rib and vertebrae articulate?
The HEAD of rib 6 meets up with the superior costal facet of T6, transverse process of T6 and inferior costal facet of T5.
Costotransverse joints
Joint classification:
What 2 bones articulate:
What ligmanents hold it together:
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
lateral costotransverse ligament
connects the tubercle of the rib
–> transverse process
Superior costotransverse ligament
Connects the neck of the rib –> transverse process one vertebrae up
What is the movement at the costovetebral joint?
2 movements of the joint both function to increase thoracic volume, decreasing thoracic pressure, allowing you to breathe in (inspiration).
- Bucket handle movement–> lateral most portion of the rib elevates, increasing the diameter of the thorax
- Pump handle movement–> sternal end of the rib elevates, increasing the anterior –> posterior diameter of the thorax.
Costochondral joints
Joint classification:
What 2 bones articulate:
What ligmanents hold it together:
Joint classification: Synchondrosis
What 2 bones articulate: in between the ribs and costal cartilage
What ligmanents hold it together:
Dislocation of ribs
dislocation at the sternocostal joint
Separation of the ribs
Seperation occurs at the costalchondral joint
Intercostal muscles
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.
External intercostal muscle
Action:
Innervation:
BS:
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.
Internal intercostal m.
Action:
Innervation:
BS:
Action: Depress ribs (expiration)
Innervation: Intercostal n.
BS: Intercostal a.
Muscle fiber directions are perpendicular (opposite) to the external intercostal a.
Innermost intercostal m.
Action:
Innervation:
BS:
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.
CN: Thoracentisis
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.
CN: Insertion of chest tube
A tube is inserted in between the 5th or 6th intercostal space to remove air, fluid, blood or pus from the pleural cavity.
CN: Thorascopy
Thorascopies are performed so that we can visualize/biopsy the space inside the pleural cavity.
Transverse thoracic m.
Axn: Depress the ribs to help with inspiration
I: Intercostal N
BS:: _____
Go from sternum–>costal cartilage
Subcostal M
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.
