Thoracic Wall- Dr. A Flashcards
The thoracic wall bounds the thoracic cavity and is formed by what types of tissues?
skin, bones, fascia, and muscle
What is the superior boundary of the thoracic wall?
vertebra T1, rib 1, manubrium
What is the inferior boundary of the thoracic wall?
vertebra T12, rib 12, costal margin, xiphoid process
What covers the thoracic wall transversely? What is it made up of?
thoracic cage which is the BONY portion of the thoracic wall
A stab wound below what rib level can pierce the abdominal cavity?
rib 5
T/F. Stab wound to the neck can pierce the lungs.
True!
The apex of the lung is in the superior thoracic aperture
What is the thoracic inlet of the thoracic cavity?
superior thoracic aperture
What is the thoracic outlet of the thoracic cavity?
inferior thoracic aperture
What is found in the superior thoracic aperture?
- apex of the lungs
- subclavian artery and vein
- internal jugular vein
- common carotid artery
- esophagus
- trachea
What two organs are found below the thoracic wall?
heart and lungs
What are the functions of the thoracic wall?
- protect internal air- and fluid-filled organs
- provide rigid exterior wall to prevent collapse of elastic lungs
- provide for lung expansion
- provide attachment and support to upper limbs
Where does the second rib attach?
sternal angle
What intercostal space is the nipple located at?
4th intercostal space
What important surface landmarks for clinical procedures (ECG, pericardial puncture, thoracoscope) are found on the anterior median (midsternal line)?
- jugular (suprasternal) notch
- sternal angle
- manubrium
- manubriosternal joint
- body of sternum
- xiphisternal joint
What marks the plane through T4-5 intervertebral disc separating the superior from the inferior mediastinum?
sternal angle
The sternal angle is used to ascertain the position of many landmarks in the body. What are they?
- rib 2, for counting
- marks the superior edge of the heart
- marks the bifurcation of the trachea
- marks the level of azygos arch
- marks the plane through T4-5 intervertebral disc
What is the directional orientation of the ribs? Why is this orientation critical?
downward slope of the ribs is critical to its function as it needs to be pulled upward to increase in diameter anteriorly and posteriorly to allow for a greater volume for air to come in during breathing (inhalation)
The head of the ribs attaches where on the vertebrae?
demifacets
The costal tubercle of the rib attaches where?
transverse process
What part of the rib shields the intercostal neurovascular bundle from impact?
costal facet
What are the atypical ribs?
ribs 1, 2, 11, and 12
What are the true ribs?
ribs 1-7
they all connect DIRECTLY to the sternum
What are the false ribs?
ribs 8-12
they connect to the sternum INDIRECTLY
What are ribs with costal cartilages?
ribs 8-10 as they connect to the sternum indirectly through costal cartilages
Which ribs are floating?
ribs 11-12
What is the importance of floating ribs?
to anchor the the rib cage by abdominal muscles
How is the first rib similar and different from the other ribs?
same: neck, head, tubercle
different: scalene tubercle, groove for subclavian vein anteriorly, groove for subclavian artery posteriorly
Which rib is the attachment of serratus anterior?
rib 1-8
have rib 2 in my notes for some reason
What do vertebrae, sternum, and ribs all contain that is a source of blood cells?
red marrow
Which facet on the thoracic vertebrae assists with elevation of the ribs?
costal facets on the transverse processes of the thoracic vertebrae that articulates with the costal tubercle of the rib
The costal demifacets are located where on the thoracic vertebrae and what do they articulate with?
body of the thoracic vertebrae
articulate with the head of the rib
The costovertebral joint refers to which facets? The costotransverse joints?
costovertebral joint: demifacets
costotransverse joint: costal facets
Rib has the same number as the ________vertebrae and its transverse process.
inferior
Rib articulates with the demifacet above (rib 4) and below (rib 5) which has the transverse process (costal facet) where the costal tubercle of rib will attach.
Which symphyses of the sternum ossify with age?
manubriosternal and xiphisternal symphyses
The sternocostal joints are what type of joint?
rib 1: fibrocartilaginous
ribs 2-7: synovial
The interchondral joints are what type of joint?
synovial
interchondral joints (in between the costal cartilages)
Rib dislocation occur at what joint? Rib separation? Rib fracture?
Rib dislocation: sternochondral joint
Rib separation: costochondral joint
Rib fracture: usually just anterior to angle
What occurs with flail chest due to multiple rib fractures?
- paradoxical movement produces pain and impairs breathing
- lose control of the intercostal muscles which stiffen and protect the integrity
- cannot expand the age to full capacity and so lose sufficient oxygenation of blood
What are the muscles of the upper limb that are considered accessory muscles of respiration?
- pectoralis major
- pectoralis minor
- serratus anterior
they help with elevation of ribs especially in forced elevation (pectoralis m.) and during inspiration (serratus anterior m.)
Which superficial muscles of the thoracic wall runs superomedially thus depressing the rib during exhalation?
internal intercostal muscles
Which superficial muscles of the thoracic wall runs inferomedially thus elevating the rib during inhalation?
external intercostal muscles
Where do the intercostal vein, artery, and nerve run?
in the subcostal groove between the internal intercostal and the innermost intercostal muscle
Which deep muscle of the thoracic wall assists in depressing the ribs during exhalation?
subcostalis m.
Where does the transversus thoracis m. originate?
originates from the lower 1/3 cartilage of the sternum
specifically the costal cartilages of last 3-4 true ribs, body of sternum and xiphoid process
What is the primary muscle of inspiration?
diaphragm
What is the major muscle of active forced expiration?
abdominal wall
The diaphragm is innervated by what?
phrenic nerve (derived from C3, C4, C5)
