Thorax Flashcards
What are the differences between the ribs?
Ribs 1-2 are mostly flat and are irregularly bumpy.
Ribs 3-10 are more gently curved and their costal heads+tubercles project notably.
Ribs 11-12 are floating. NOT CONNECTED to sternum. Subtle tuberosity.
What part of the sternum starts out as cartilage?
All of it, but the xiphoid process takes much longer to ossify.
Which ribs have their own costal cartilage?
Ribs 1-7 attach to the sternum with their individual costal cartilages.
Ribs 8-10 attach to the costal cartilage of 7.
Ribs 11-12 have costal cartilage but it is NOT connected to the sternum.
What sits between the articulation of the clavicle and the manubrium?
An articular disc.
What ligament and muscle is attached to rib 1 near the sternum?
Subclavius muscle
Costoclavicular ligament
What ligaments do I find on the rib near the vertebrae?
Radiate ligament between the rib and the vertebrae.
Costotransverse, lateral costotransverse ligaments, and superior costotransverse ligaments between the neck of a rib to the transverse process at the same level and above.
How do the ribs move during inspiration?
Ribs 1-2 anteriorly
Ribs 3-10 open laterally (like a bucket handle)
Ribs 11-12 open laterally like pincers
Sternum moves superiorly
What muscle covers the rectus abdominis and serratus anterior?
External Abdominal Obliques
What groove would I find my cephalic vein in?
Deltopectoral
What nerve innervates my serratus anterior?
Long thoracic nerve
What artery supplies my serratus anterior?
Lateral thoracic artery
What artery supplies my external intercostal muscles?
Superior thoracic artery for ribs 1-2
ascending aorta for the rest
Where do my external intercostals originate from, insert at, and what direction are they going?
Originating at the vertebrae, they go INFEROMEDIALLY (like hands in a pocket) to the sternum.
What do the external intercostals become at the sternum?
External intercostal membrane
Where do my internal intercostals originate from, insert at, and what direction are they going?
Originating at the sternum, they go SUPEROMEDIALLY to the vertebrae.
What do the internal intercostals become at the vertebrae?
Internal intercostal membrane
Where do I find innermost intercostal muscles specifically?
Parallel to my internal intercostals, but only in the lateral portion of my ribs.
What muscles extend from my sternum directly to my ribs and cartilage?
Transversus thoracis
What three vessels/tubes travel through my diaphragm?
Aorta, Inferior vena cava, esophagus.
What does the diaphragm originate and insert at?
Originates from the xiphoid process, attaching to the T12 and upper lumbar vertebrae
What nerve innervates the diaphragm and what is the nerve a combination of?
Phrenic nerve
C3,4,5 keep the diaphragm alive
What muscles are used in inspiration?
Diaphragm
External intercostals
Internal intercostals (parasternal)
Scalene
What muscles are used in normal expiration?
Just the diaphragm
What muscles are used in heavy/forced expiration?
Diaphragm
Internal intercostals (lateral portion)
Innermost intercostals
Abdominal obliques
Rectus abdominis
Transversus thoracis
What is the purpose of the extrinsic back muscles in relation to breathing?
Stabilizing/fixing the scapula in place so our other muscles can move just our ribcage.
What muscles elevate ribs 1-2?
Scalenes (mainly anterior?)
What muscles elevate our anterior ribcage? What condition must be met?
Pectoralis major and minor.
The scapula must be fixed/stabilized by the back muscles.
What muscles elevate our lateral ribcage? What condition must be met?
Serratus anterior.
The scapula must be fixed/stabilized by the back muscles.
What muscles tend to hypertrophy in patients with COPD?
Inspiratory muscles
What supplies the thoracic wall with blood?
Intercostal arteries, which originate from the internal thoracic artery and aorta
What kind of branches do intercostal nerves and arteries have?
anterior and lateral cutaneous branches.
What are the 3 major branches off the arch of the aorta?
Brachiocephalic trunk
Left common carotid artery
Left subclavian
Where do intercostal veins drain to?
Internal thoracic veins anteriorly
Azygos system posteriorly
Note: azygos means unpaired
Explain the difference between the left and right venous drainage of the ribs?
The right side uses a single azygos vein which drains to the superior vena cava.
The left side has a hemiazygos vein (lower left intercostal veins and left ascending lumbar veins). The hemiazygos goes to the azygos & accessory hemiazygos veins.
It also has a accessory hemiazygos vein (upper left intercostal veins & left brachiocephalic vein)
Note: *Only pattern used for the exam per his email.
Superiorly to inferiorly, describe the order of the artery, vein and nerves.
Vein
Artery
Nerve
However, they give a small branch that runs within the same intercostal space, which goes nerve, artery, vein.
Clinical: If I wanted to perform a thoracocentesis (inserting a needle into the thorax for drainage), where should I poke?
In the center of an intercostal space. Veins, Nerves, and Arteries run along the superior and inferior grooves of a rib.
Confirmed per Dr. Ward email
Note: This is for MIDAXILLARY and example showed 9th intercostal specifically.
*Emailed Dr. Ward regarding this
Clinical: If I wanted to perform a intercostal nerve block where should I poke?
Slighty superior or inferior from the center of an intercostal space. Nerves are closest to the center of the intercostal space.
Note: The example in class was in the 9th intercostal space.
What is the center of the thoracic cavity known as?
Mediastinum
What makes up the inferior borders of my superior mediastinum?
Sternal angle anteriorly
T4-T5 posteriorly
What is in my superior mediastinum?
The great vessels (superior vena cava, brachiocephalic veins, aortic arch)
Nerves (Vagus, Phrenic, Left recurrent laryngeal)
Thoracic duct
Trachea
Esophagus
Thymus
Great Sushi Bar Ay? No, Very Poor Lemonade. Think That Every Time -Billie
What is in my anterior inferior mediastinum?
Thymus, Lymph nodes, and fat/connective tissue.
What is in my middle inferior mediastinum?
Pericardium and heart
Roots of great vessels
Arch of azygos vein
Primary Bronchi
What is in my posterior inferior mediastinum?
Esophagus
Aorta
Azygos & hemiazygos veins
Thoracic duct
Vagus nerves
Sympathetic trunk
Splanchnic nerves
Where is the thymus found primarly?
Superior mediastinum.
What does the superior vena cava branch into?
The left & right brachiocephalic veins.
What ligament connects the aortic arch and the pulmonary trunk?
Ligamentum Arteriosum
What is more superior, the aortic arch or the primary bronchi?
Aortic arch
What lobules do I find more superiorly in the breast?
Fat lobules
What lobules do I find more inferiorly in the breast?
Lactating mammary gland lobules.
Describe the path of milk in the breast.
Milk is made in the lactating mammary gland lobules, going to the lactiferous ducts, then to the lactiferous sinuses, which eventually drain at the nipple.
What ligaments attach the lobules to the chest wall?
Suspensory ligaments (of cooper)
What is the space called between the breast and the pectoralis major?
Retromammary space.
What are some signs of breast cancer?
Orange peel sign
Breasts adhering to the chest wall
What vessels supply the breast with blood?
Internal thoracic and lateral thoracic, with small contributions of the lateral cutaneous branches of the intercostal artery and vein.
What is the predominant path of lymph flow in the breast?
Lateral and central -> interpectoral -> axillary (pectoral nodes)
This accounts for ~75% of lymph flow
What is the minor path of lymph flow in the breast?
Medial -> parasternal nodes to the opposite breast
What makes up the right border of the heart?
Superior vena cava
Right atrium
Inferior vena cava
Right auricle
What makes up the inferior border of the heart?
Primarily the right ventricle
What makes up the left border of the heart?
Left ventricle
Left auricle
What makes up the superior border of the heart?
Left atrium
Right atrium
Where is the fossa ovalis?
Found in each atrium.
Note: important in embryological development
What is the crista terminalis and where is it found?
Found in the right atrium near the right auricle, a common location for pacemakers.
Where are pectinate muscles found?
Along the walls of the atrium.
Where do I find papillary muscles? What is attached to them?
Found only in the ventricles, they have chordae tendineae coming off them, connecting to the AV valves.