Lecture 8 (thorax) pt 1 Flashcards
& some stuff from 10.22 lab
What are the 3 components of the thoracic wall?
1) Skeletal
2) Muscular
3) Neurovascular
What are the two main parts of the thoracic cavity?
Pulmonary cavity and mediastinum
What are the two main parts of the pulmonary cavity?
1) Viscera: primarily lungs, vessels, airways
2) Pleura: Pleural cavity
What are the two main types of pleura found in the thoracic cavity?
Parietal and visceral
1) What is the sternal angle (manubriosternal joint)?
2) What level is it at?
3) What is found here?
1) 2nd rib articulation and connection between menubrium and body of sternum
2) T-5
3) Bifurcation of the trachea; base of the heart/root of the ascending aorta
Describe the thoracic inlet and thoracic outlet
1) Thoracic inlet: trachea, esophagus, vessels and nerves
2) Thoracic outlet: closed by diaphragm; IVC, esophagus pass through diaphragm, aorta passes posterior to diaphragm
Where do rib fractures usually occur? (i.e. where is the weakest point)?
Weakest point is just anterior to their angle
List the 8 parts of the sternum
1) Manubrium: upper section of sternum
2) Clavicular notch: superior lateral notches of manubrium
3) Jugular notch: superior medial notch of manubrium
4) Costal cartilage: lateral part of manubrium
5) Costal notches: lateral notches of body
6) Sternal angle: The manubriosternal joint
7) Body: general longer part
8) Xiphoid process: inferior small piece attached to body
What property is conveyed by the costochondral cartilages? Why?
Flexibility, prevent traumatic fx,
1) Describe flail chest
2) Is it painful? What does this cause?
1) Multiple rib fractures cause paradoxical wall movement
2) Painful to breathe in, which causes poor ventilation & leads to atelectasis
What causes thoracic outlet syndrome?
Compression of structures between 1st rib and clavicle
1) What line is at the midline of the chest?
2) What two lines are parallel and on opposite sides of this line?
3) What line is at the midline of the back?
4) What two lines are parallel and on opposite sides of this line?
1) Anterior median (midsternal) line
2) Midclavicular lines
3) Posterior median line
4) Scapular lines
1) What line runs through the middle of the armpit?
2) What line runs parallel and anterior to this?
3) What line runs parallel and posterior to this?
1) Midaxillary line
2) Anterior axillary line
3) Posterior axillary line
What are the two types of inhalation and exhalation?
Active and passive
What 3 muscles can be involved with inhalation?
1) Intercostals
2) Diaphragm
3) Accessory
1) How many pairs of thoracic spinal nerves are there?
2) What do the posterior rami innervate?
1) 12
2) Bones, joints, intrinsic back mm., and over lying skin (dermatomes)
What are the two things formed by the thoracic spinal nerve anterior rami?
1) Anterior rami T1-11: forms intercostal nerves
2) Anterior rami T12: forms subcostal nerve
What is the order of the vessels and nerve in each rib from superior to inferior?
V.A.N (vein, artery, nerve)
1) Where should thoracentesis be performed?
2) What is done during this procedure?
3) Why?
1) To avoid injury to intercostals, go over top of rib, high enough to avoid collaterals.
2) Collect pleural fluid sample for analysis
3) Therapeutic
1) When are intercostal nerve blocks used?
2) What should be done during this procedure?
3) What needs to be considered?
1) Pain relief for rib fracture or post op
2) Infiltrate around intercostal n and collateral to administer block
3) Collateral innervation and overlap; needs to be numbed in 4 different locations to get entire rib (unless you do it at the root before the rami split)
What space is the chest tube once
appropriately placed?
4th intercostal space, at the mid clavicular line
What are the 4 main arteries that supply the thoracic wall?
1) Posterior intercostal arteries
2) Internal thoracic artery
3) Anterior intercostal arteries (2)
4) Subcostal arteries
1) Where do the posterior intercostal arteries sometimes come from? What do they supply?
2) What does the part of the PIAs that supplies the rest of the ICSs (intercostal spaces) come from?
1) From supreme intercostals; ICS 1-2
2) Thoracic aorta
1) Where does the internal thoracic artery come from?
2) What two things does it divide into
1) Subclavian artery
2) Musculophrenic and superior epigastric arteries
What are the 2 supplies to the anterior intercostal arteries? What do they supply?
1) Internal thoracic artery branches, ICS (intercostal spaces) 1-6
2) Musculophrenic artery, ICS 7-9.
Where does the subcostal artery come from?
Aorta
What provide blood to the intercostal space?
1) Posterior intercostal arteries + collateral br.
2) Anterior intercostal arteries + collateral br.