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 spinal level is it at?
3) What is found here?
1) 2nd rib articulation and connection between manubrium and body of sternum
2) T5
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 types of 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 their 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? Why?
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.
In general, where are thoracic veins?
They follow arteries
How many thoracic veins are there?
1) 11 pairs intercostal veins
2) 1 pair subcostal veins
1) What do the posterior IC veins anastomose with?
2) What do most posterior IC veins drain into?
1) Anterior IC veins.
2) Azygos/hemi-azygos venous system to SVC
What 3 vessels are involved in CABG (coronary artery bypass grafting)?
1) Saphenous veins
2) Radial artery
3) Internal thoracic artery
1) What are mammary glands?
2) What normally creates breast contour and volume?
3) What creates contour and volume during pregnancy?
1) Modified sweat glands
2) SQ fat
3) New glandular tissue [and lobules growing]
1) Why do breasts grow during puberty?
2) What two things determine breast size?
3) Where is most of the breast?
4) What suspend the breasts?
1) Due to glandular tissue and SQ fat deposition
2) Genetics and nutrition
3) Most of the breast rests on the pectoral fascia
4) Suspensory ligaments suspend breast from skin and pectoral fascia
What is the superior lateral part of the breast called?
Axillary tail
1) What is the areola?
2) What are the lobules? How many? What are they made of?
1) Pigmented area
2) Breast contains 15-20 lobules; glandular tissue or parenchyma of breast
1) What are the lactiferous ducts?
2) What is the lactiferous sinus?
1) Drains each lobule, open independently on the nipple
2) Dilated portion of each lactiferous duct just deep to areola
Name two mammary gland structures not yet mentioned
Nipple and suspensory ligaments
List all 6 mammary gland structures
1) Nipple
2) Areola
3) Lobules
4) Lactiferous duct
5) Lactiferous sinus
6) Suspensory ligaments
With mastitis, what directions can infection spread?
Superiorly, laterally, or medial to the breast
What is the importance of the lymphatics of the breast?
Metastatic spread of cancers
1) How many routes are there to drain from the lymphatic plexus of the breast?
2) How does breast cancer spread?
1) Three
2) Spread via lymphatic, venous, direct extension
Where does most drainage from the lymphatic plexus of the breast go? What %?
75% to axillary nodes (pect., central, & apical nodes)
1) Where do the medial breast quadrants drain?
2) Where may the inferior quadrants pass?
1) Parasternal nodes or contralateral breast
2) Deeply to abdominal lymph nodes
Describe the route of breast cancer spreading; where does it usually start? List all 7 steps
1) Axillary LN (most common site of initial spread)
2) Pectoral *
3) Central *
4) Apical *
5) Supraclavicular
6) Subclavian
7) Right lymphatic duct
What are some visual symptoms of BC
1) Skin dimpling
2) Edema
3) Nipple retraction and deviation
4) Abnormal contours
When should mammograms start?
Age 40 (once every 2 years)
1) What do the right and left pulmonary cavities contain?
2) What is between the parietal and visceral pleura?
1) Lungs and pleura
2) Pleural cavity
What 6 things are found within the mediastinum?
1) Heart
2) Great vessels
3) Trachea
4) Esophagus
5) Thymus
6) Lymph nodes
What are the 4 parts of the parietal pleura?
1) Apical or cervical pleura
2) Costal pleura
3) Diaphragmatic pleura
4) Mediastinal pleura
What does the parietal pleura cover?
Endothoracic fascia/wall
What do the parietal and visceral pleura of the visceral cavity create?
Pleural “space” or sac
1) What do the visceral thoracic pleura cover?
2) What are the parietal thoracic pleura continuous with, and what do they cover?
1) Covers surface of lungs and extends into lobar and segmental fissures
2) Visceral pleura, covers wall
1) What is found within the pleural space or cavity (potential)?
2) What is found within there when there’s something wrong?
1) Normally small amount of serous fluid
2) Blood, effusion, or air
1) What is below the inferior lobes of the lungs?
2) What is at the medial aspect of the lung?
1) Costo diaphragmatic recesses [of pleura]
2) Hilum/root of the lung is the center
What are the lobes of the lungs?
1) Left: superior and inferior
2) Right: superior, middle, and inferior
List the lobes of the right lung and what separates each
1) Superior lobe
-Horizontal fissure
2) Middle lobe
-Oblique fissure
3) Inferior lobe
-Has costodiaphragmatic recess
List the lobes of the left side of the lung and what separates them
1) Superior lobe: lingula
-Oblique fissure
2) Inferior lobe
What muscles are normally involved with breathing?
1) Diaphragm
2) Intercostals (external and internal)
What muscles are recruited during times of increased respiratory effort?
Scalenes and SCM
What things are found around the sternal angle?
Bifurcation of trachea and base of the heart
Where is the sternal angle? (using surface anatomy)
About one inch below the jugular notch of the manubrium
What are the parts of the sternum?
1) Manubrium: superior part
-Jugular notch: middle notch
-Clavicular notches: lateral notches
2) Manubriosternal joint: aka sternal angle, attaches manubrium to sternal body
3) Sternum body: main part
-Has transverse ridges
4) Xiphisternal joint: attaches xiphoid process
5) Xiphoid process
What separate the breast from the underlying pectoral muscles?
1) SQ tissue
2) Retromammary space (bursa)
3) Pectoral fascia
1) What ribs articulate directly with the sternum?
2) What about via the costal arch?
3) What ribs are floating?
1) First 7 ribs (“true ribs”)
2) 8-10
3) Ribs 11 & 12
Where does most blood supply to the breasts come from? Know where the branches come from.
1) Medial mammary branches of perforating branches and anterior intercostal branches of the internal thoracic artery: originate from the subclavian artery
2) Mammary branches of lateral thoracic and thoraco- acromial arteries: branches of the axillary artery
3) Posterior intercostal arteries: branches of the thoracic aorta that run in the intercostal spaces
Where does most blood from the breasts drain?
1) Lateral mammary veins off axillary vein (most)
2) Perforating branches of the internal thoracic vein (some)
Describe the dermatomes of the neck and trunk
1) C1: inferior neck
2) C3: clavicle
3) C4: includes top of shoulder
4) T2: below C4 on thorax
5) T3-12 until L1
>T5 is where the male nipple is
What quadrant of the breast has the highest rate of cancer? What are the 4 quadrants?
Upper outer
(4 quadrants are: upper outer, upper inner, lower outer, lower inner)
Describe the basic process of lactation
1) Lobules of mammary gland grow and fill up
2) Lactiferous ducts confer milk to the nipple, passing through the lactiferous sinus just before reaching it
