Thorax

Question 1

Clinical significance of superficial fascia of abdomen and thorax?

Answer 1

• continuity of fascia
• superficial veins anastomose with larger vessels
• if blockage of vena cava, veins will hypertrophy and serve as alternate path back to heart

Question 2

Thorax functions?

Answer 2

1. Protection of important cardiac and respiratory structures
2. Respiration framework offers stabilization during inhalation and exhalation
3. Attachment and support for muscles of upper limbs, neck, abdomen

Question 3

3 major spaces of thorax?

Answer 3

1. Central compartment (mediastinum)
   - thoracic organs except lungs
2. Right and left pulmonary cavities
   - lungs

Question 4

Specific features of thoracic vertebrae?

Answer 4

• long spinous processes
• facets on body for head of ribs
• facets on transverse processes for tubercle of rib

Question 5

Which thoracic vertebrae are closely related to the Aorta?

Answer 5

T5-T8

Question 6

Lower rib fracture clinical significance?

Answer 6

• could puncture liver or spleen

- huge cardiac output going here

Question 7

Location of bone marrow biopsies?

Answer 7

• Ilium used most often

- Sternum can also be used, but risk of puncturing heart

Question 8

Manubrium?

Answer 8

• widest
• thickest
• Jugular notch: level of T3 posterior
• clavicular notches
• Sternal angle: level of T4 posterior (junction of 2nd rib)

Question 9

Body of sternum? clinical significance?

Answer 9

• joined to manubrium by Fibrocartilage
• transverse lines
• bone marrow found here

Question 10

Xiphoid process? clinical significance?

Answer 10

• smallest
• variable in size and shape
• hyaline cartilage surrounding bone, ossified
• Epigastric mass from xiphoid

Question 11

True ribs?

Answer 11

• 1st 7 ribs
• articulate with sternum through their own costal cartilage
• vertebrosternal

Question 12

False ribs?

Answer 12

• ribs 8, 9, 10
• articulate to sternum via costal cartilage #7
• vertebrochondral

Question 13

Floating ribs?

Answer 13

• ribs 11 and 12
• do not articulate with sternum
• muscles of posterior abdomen attach here

Question 14

Supernumerary ribs?

Answer 14

• common
• more common in cervical than lumbar
• extra ribs

Question 15

Typical ribs?

Answer 15

• Ribs 3-9

- head, neck, and shaft

Question 16

Angle of rib? Clinical significance?

Answer 16

• where ribs extends anterolaterally at same level of spinous process
• shaft turns medially and down
• most common fracture is anterior to angle

Question 17

Costal groove? clinical significance?

Answer 17

• inferior groove of rib
• protects intercostal artery, vein, and nerve
• Pleural effusion: fluid accumulation in chest (CHF, pneumonia, cancer), compresses lungs
• require pleurocentesis (stick needle to remove fluid), needle must be stuck superior to rib to not puncture neurovascular bundle

Question 18

First rib? Clinical significance?

Answer 18

• highest, broadest, strongest, flattest, most curved, shortest
• closely associated with brachial plexus, Axillary artery and vein (subclavian vessels pass over 1st rib)
• Anterior scalene muscles attach to scalene tubercle
• Phrenic nerve lies on anterior surface of scalene
• axillary artery/vein is anterior
• brachial plexus is posterior
• closely related to apex of lung, if broken may cause pneumothorax
• tumor on lung could grow and disrupt neurovascular structures
• Horner’s syndrome: tumor grows posterior into sympathetic trunk to affect autonomic NS

Question 19

Importance of 2nd rib?

Answer 19

• twice as long as first

- tuberosity for Serratus Anterior muscle

Question 20

Costal cartilages? Clinical significance?

Answer 20

• bars of hyaline cartilage
• progressively ossify
• costal margin: costal cartilage of ribs 8, 9, 10
• Clinical: ossification and osteoporosis with age, ribs fracture easier, hurts to cough, greater risk of pneumonia, can be fatal
• Clinical: joints are synovial, can become fibrous over time becoming irritated or inflamed (costochondritis), pain can be mistaken for heart issue

Question 21

External intercostal muscles attachments?

Answer 21

• lower margin of 1st 11 ribs
• from tubercles of ribs behind to cartilages of ribs in front
• give way to external intercostal membrane

Question 22

External intercostal muscles function?

Answer 22

elevate ribs and muscle of inspiration

Question 23

Anterior vs posterior arteries and veins in intercostal grooves?

Answer 23

• anterior: from internal thoracic vessels

- posterior: from Aorta

Question 24

Levator Costarum attachments?

Answer 24

• transverse process of 7th cervical to 11th thoracic vertebrae
• insert into lower adjacent rib between tubercle and angel

Question 25

Levator costarum function and innervation?

Answer 25

- function: elevate ribs for inspiration | - innervation: dorsal rami

Question 26

Internal intercostal attachments?

Answer 26

- lower margin of rib and costal cartilage - fibers pass down and back to upper margin of lower ribs and cartilage - from medial ends of intercostal spaces to angle of ribs - give way to intercostal membrane

Question 27

Internal intercostal function?

Answer 27

expiration

Question 28

Innermost intercostals?

Answer 28

- part of internal intercostals separated by intercostal vessels and nerves - not well developed - subcostal: variable in number, arise form ribs near angles and insert 2-3 ribs below - sternocostalis: sternum to costal cartilage

Question 29

Transversus thoracis?

Answer 29

- attaches on posterior side of sternum and goes up and lateral to ribs - innervated by anterior rami - function in expiration

Question 30

Diaphragm attachments?

Answer 30

- most important muscle of respiration (increases volume of thorax) - no bony attachments - inserts on central tendon (attaches to pericardium) - divided into halves and has three parts (sternal, costal, lumbar)

Question 31

Sternal part of diaphragm?

Answer 31

- fibers arise from back of diploid and descend to central tendon - sternocostal triangle: transmits the superior epigastric vessels (branch of internal thoracic artery)

Question 32

Costal part of diaphragm?

Answer 32

arise from inner surfaces of lower 6 costal cartilages and lower 4 ribs

Question 33

Lumbar part of diaphragm?

Answer 33

- arise from two fibrous arches and bodies of L1 and L2 - medial and lateral arcuate ligament - part of diaphragm arises from lumbar vertebrae - forms two muscular crura that ascend to central tendon - forms aortic opening

Question 34

Medial arcuate ligament location?

Answer 34

over Psoas major muscle

Question 35

Lateral arcuate ligament location?

Answer 35

over Quadratus lumborum

Question 36

Action of diaphragm?

Answer 36

- central tendon descends when it contracts, increase volume of thorax and air rushes in - facilitates return of blood to heart through vena cava - each half separates nerve supply - hiccups are spasmodic contraction of diaphragm - no one can voluntarily hold breath to point of asphyxiation

Question 37

Innervation and blood supply of diaphragm?

Answer 37

- Phrenic nerve (C3, 4, 5) - supplies from underneath blood vessels - rich sensory response (peritoneum, pericardium, pleura) - each half has separate nerve supply

Question 38

Shoulder pain related to diaphragm?

Answer 38

- shoulder pain over trapezius - epigastric pain, xray shows free air under diaphragm - perforated abdominal organ, ruptured posterior gastric ulcer - continuous with inferior aspect of diaphragm - referred pain to neck

Question 39

Internal thoracic artery and branches?

Answer 39

- first branch of Subclavian Artery - passes down through thorax behind costal cartilages - ends at 6th intercostal space by dividing into terminal branches: - Superior Epigastric (pierces diaphragm) - Musculophrenic

Question 40

Sternocostal triangle?

Answer 40

space for passage of Superior epigastric vessels (branch of internal thoracic artery)

Question 41

Thoracic nerves?

Answer 41

- meningeal branches - dorsal rami - ventral rami - first, second, third intercostal nerves supply the arm and thorax

Question 42

Joints of thorax?

Answer 42

- Costovertebral - Costotransverse (synovial- motion) - Costochondral (hyaline-no motion) - Sternocostal (starts as synovial but fibrous over time, 2-7)

Question 43

Movements of thoracic cage?

Answer 43

- movements change volume of rib cage, creates vacuum for air to rush in - inhalation (ribs rise and move laterally) - intercostal muscles especially external