Thoracic Wall Flashcards
Boundaries of the thoracic wall:
- Anterior:
- Posterior:
- Lateral:
- Sternum, costal cartilages, ribs
- Thoracic vertebrae, ribs
- Ribs
Thoracic inlet (or outlet) boundaries
Anterior:
Posterior:
On each side:
Manubrium
T1
1st rib and 1st costal cartilage
Name 6 important lines for clinical procedures
Anterior median (midsternal) line, midclavicular lines (2), mid axillary line, anterior and posterior axillary line (anterior is closer to the nipple)
Which thoracic vertebrae articulate with the ribs?
2-9 (and form the posterior border of the cage)
Typical vs atypical thoracic vertebrae?
Typical = 2-9, facets on body and transverse process
Atypical = 1 and 10-12, only have facet on the body, shorter and broader spinous processes
Location on vertebrae of the following parts of the sternum:
- Manubrium
- Body
- Xiphoid
- T3 and T4
- T5-T8
- T9
Sternum has costal notches for ribs ____
Other ribs attach?
1-7
Ribs 8-10 attach to the costal cartilage of the 7th costal notch, 11 and 12 are floating
Which ribs are typical?
Atypical?
Typical= 3-9 Atypical= 1, 2, 10-12
Where does the neurovascular bundle of the rib go through?
What does this space hold on the first rib?
What attaches to the upper inner border of the first rib?
The costal groove
Grooves located at the first rib are for your subclavian artery and vein
Scalenus anterior muscle (in between subclavian artery and vein)
Are costal tubercle and costal angle of the rib more anterior or posterior?
Posterior
Costal tubercle attaches to vertebrae
The rib attaches to which vertebraes transverse process?
The rib articulates with the numerically corresponding vertebrae (rib 5 articulates with the transverse process of T5)
___ + ___ = thoracic cage
Ribs + their cartilage
Name a joint between the ribs and spine that DOES permit movement
The joint the connects the transverse process and tubercle of rib
Function of the joints between the ribs and their costal cartilages?
Mobility?
Raising and lowering the ribs during respiration
All are mobile except for the 1st rib; other ribs have movement in their joints of their head and tubercle which allows the neck to rotate around its axis
Function of thoracic outlet (superior thoracic aperature)?
Vessels and nerves from thorax enter the neck and upper limbs through thoracic outlet; thats how the chest communicates with the root of the neck
Boundaries of thoracic inlet:
- Anterior
- Posterior
- Lateral
- Manubrium
- T1
- First pair of ribs and costal cartilage
Posterior dislocation of the sternoclavicular joint could injure?
The subclavian artery and/or vein
- 4 structures that pass through the thoracic inlet?
- 4 nerves?
- 2 arteries?
- 3 veins?
- Trachea, esophagus, apices of lungs, and thoracic duct
- Phrenic, vagus, recurrent laryngeal and sympathetic trunks
- Left and right common carotid arteries and left subclavian arteries
- Subclavian, brachiocephalic, and internal jugular
- Stab wound where will pierce the abdominal cavity?
2. Fracture of lower ribs can cause what?
- Below rib 5
2. Diaphragmatic hernia
Thoracic outlet is formed by?
T12, rib 12, xiphoid process and dome of diaphragm
If you need to place a needle in between ribs, where would you put needle?
Closer to the inferior border of the muscle because there are bigger vessels on the superior border
External intercostal muscles:
Origin
Insertion
Innervation
Action
How do fibers run?
Origin: Lower border of superior rib
Insertion: outer lip of upper border of inferior rib
Innervation: intercostal nerves
Action: elevates ribs during inspiration
Like you’re putting your hands in your pockets
Internal intercostal muscle
Origin
Insertion
Innervation
Action
Origin: floor of costal groove
Insertion: inner lip of upper border of inferior rib
Innervation: intercostal nerves
Action: depresses the rib during expiration
Name the 3 deeper muscle of the intercostal space
One is formed from 3 different muscles, which one and what are they?
Innermost intercostals, subcostalis, and transversus thoracis
Transversus thoracis = innermost intercostal, sternocostalis and subcostalis
Origin and insertion of two parts of transversus thoracicus muscle:
- Sternocostalis
- Subcostalis
- Origin: lower part of body of sternum and costal cartilages
Insertion: inner surface of costal cartilages 2-6 - Origin: inner surface and lower border of rib above
Insertion: upper border of 2nd or 3rd rib below
All innervated by intercostal nerves
Extent of muscle layers; where is each of the following deficient?
- EIM
- IIM
- Innermost IM
If you were stabbed posteriorly at the 10th intercostal space, what muscle would you injure?
- Deficient anteriorly
- Deficient posteriorly
- Deficient posteriorly
External intercostal muscle
Each intercostal space contains three arteries:
A large single posterior intercostal artery and two small anterior intercostal arteries
~in each space the posterior intercostal artery and its collateral branch anastomose with the 2 anterior intercostal arteries
Anterior intercostal arteries arise from?
Drains into?
The upper 6 arise from internal mammary artery; the lower 3 from musculo-phrenic artery
Internal mammary artery drains into brachiocephalic vein
Posterior intercostal arteries arise from ?
1 and 2 arise from superior intercostal artery of costocervical trunk of 2nd part of subclavian artery
Lower 9 arise descending thoracic aorta (subcostal artery arises from there too)
Intercostal nerves come from T1-T12
- Which are typical?
- Atypical?
- Neither?
- T3-T6
- T1, T2, T7-T11
- T12 is called subcostal
Where does each intercostal nerve run?
Lab: When you cant see the nerve anymore what does that mean?
In the intercostal space inferior to the intercostal vessels
Lab: when you can no longer see the nerve running, that means you have reached the innermost intercostal muscle
When does the ventral ramus change its name?
What does its name change to at this location?
When it runs in between the internal and innermost intercostal muscles
Intercostal nerve
Intercostal nerve has branches for __ function of the intercostal muscles
Intercostal nerves have branches:
1. Lateral cutaneous nerve innervates?
- Anterior cutaneous nerve innervates?
Motor
- All the sensory information of the skin in the lateral portion of the body wall
- Sensory information of the skin in the anterior and lateral portion of the segment
- What is unique about the first intercostal nerve?
2. What is unique about the second intercostal nerve?
- Divides into 2 branches: larger exits to join the brachial plexus; smaller (first intercostal nerve) ends on the front of the chest as the first anterior cutaneous branch
- Joined by to the brachial plexus (medial cutaneous nerve of the arm) by a branch called intercostobrachial nerve
What do the first 6 intercostal nerves innervate?
Skin, parietal pleura and intercostal muscles in each space
Clinical significance of second intercostal nerve?
Referred pain to medial side of arm along this nerve in angina and MI
Where is the incision for tube thoracostomy kept close to in order to avoid damaging the neurovascularature
Close to the upper border of the rib below the intercostal space. So if piercing 8th intercostal space, you would put needle above the margin of rib 9
Where do the internal thoracic arteries/veins run?
Internal thoracic artery is a branch from?
Internal thoracic artery ends where? By dividing into ___ and ___ arteries
On each side of the sternum (posterior to the costal cartilages)
Subclavian artery
In the 6th intercostal space; by dividing into superior epigastric and musculophrenic arteries
Pleural cavity is intermediate to?`
Pleural cavity is in between visceral pleura and parietal pleura
Internal thoracic artery is blood supply for?
The anterior wall of the body from the clavicle to umbilicus
Branches of the internal thoracic artery (6) (hint: includes what it divides into)
Two anterior intercostal arteries, perforating arteries, pericardiacophrenic artery, mediastina arteries, superior epigastric and musculophrenic artery
What do the following branches of the internal thoracic artery supply:
- Anterior intercostal arteries
- Pericardiacophrenic
- Mediastinal
- Superior epigastric
- Musculophrenic
- Upper six intercostal spaces (each of the six spaces has their own 2 arteries
- Accompanies phrenic nerve and supplies the pericardium
- Supplies contents of the anterior mediastinum (thymus)
- Rectus muscle as far as the umbilicus
- Lower intercostal spaces and the diaphragm
Internal thoracic vein drains into?
Brachiocephalic vein on each side
Superior intercostal artery supplies ?
First and second intercostal spaces
Where does the radicular artery run?
What does it supply?
Runs along the posterior and anterior roots of the spinal nerves
Supplies spinal nerves
Name three arteries that contribute to superficial arterial supply (hint: think block one)
Superior thoracic artery
Thoracoacromial artery
Lateral thoracic artery (especially important for females)
- What does the azygos vein connect?
2. Where does azygos vein start?
- Connects IVC with SVC
2. In abdomen from back of IVC at level of L2
Describe how the azygos vein runs from IVC to SVC
Enters thorax through aortic opening of diaphragm on right side of thoracic duct and aorta, passes behind right border of esophagus and behind root of right lung, enters the middle of the back of the SVC
What is the significance of the thoracoepigastric vein?
Provides alternate circulation when there is liver disease
Function of axillary lymph nodes?
Drain ~75% of lymph from breast
Diaphragm is dome shaped:
Left dome reaches?
Right dome reaches?
Left dome reaches the lower border of 5th rib
Right dome reaches upper border of 5th rib
What are the crus of the diaphragm?
Lateral to the crura, the diaphragm arises from what ligaments?
Tendinous structures that extend below to the diaphragm to the vertebral column
The medial and lateral arcuate ligaments
Location of the following diaphragm ligaments:
- Medial arcuate
- Lateral arcuate
- Median arcuate
- Body (side) of L2 to transverse process of L1
- Transverse process of L1 to lower border of rib 12
- Connects the medial borders of the two crura
Diaphragm
Origin (3 parts)
Insertion
Innervation
Action
Origin - 3 parts: Sternal part (xiphoid process) Costal part (lower 6 ribs and their costal cartilages) Vertebral part (arising by crura and from the arcuate ligament)
Insertion- central tendon which lies at the xiphsternal junction
Innervation - phrenic nerves (all motor function and supplies sensory for the parietal pleura and peritoneum covering the central surfaces of the diaphragm) and lower six intercostal nerves (sensory for the periphery of the diaphragm)
Action- pulls down its central tendon and increases the vertical diameter of the thorax
Name what the following 3 openings of the diaphragm transmit and their location:
- Caval opening
- Esophageal opening
- Aortic opening
Name 3 other openings of the diaphragm
- T8; transmits IVC and right phrenic nerve
- T10; transmits esophagus, vagi, esophageal branches of left gastric vessels and lymph vessels
- T12; transmits aorta, thoracic duct, and azygos vein
Splanchnic nerves, superior epigastric vessels, left phrenic nerve
Clinical significance:
- What is a hiccup?
- Any penetrating would below ___ should be suspected in causing damage to the diaphragm
- Weak musculature could lead to?
- Involuntary spasmodic contraction of the diaphragm
- Below the level of nipples
- Diaphragmatic hernia
Superior mediastinum is at what vertebral level?
T4
What vertebral levels are the following structures at:
- Suprasternal notch?
- Sternal angle?
- Xiphisternal joint?
- Between T2 and T3
- Between T4 and T5 (aortic arch)
- Between T8 and T9 (diaphragm)
Head of the rib has __ facets that articulate with what?
2 facets; articulates with numerically corresponding vertebral body and body of vertebra immediately above it
The neck of the rib is located where?
In between the head and tubercle
Tubercle has a facet that articulates with ?
Transverse process of numerically corresponding vertebra
What makes the second rib atypical?
It has a rough area on the upper surface (tuberosity for the serratus anterior)
What is thoracic outlet syndrome and what does it cause?
Obstruction of thoracic outlet that compresses brachial plexus/ subclavian artery and vein; pain down medial side of forearm and hand and wasting of the small muscles of the hand
Innermost intercostal muscle is divided into what 3 parts?
Subcostal muscles (most posterior), innermost intercostals (lateral portion) and transversus thoracis (anterior)
- Posterior intercostal veins drain backward into?
2. Anterior intercostal veins drain forward into?
- Azygos or hemiazygos vein
2. Internal thoracic and musculophrenic veins
