Thoracic anatomy

Question 1

What are the joints between vertebrae and ribs and what is their function?

Answer 1

Costotransverse

Costverterbral

Elevation + depression

Question 2

What is the thoracic cage?

Answer 2

The thoracic cage is skeletal.

Question 3

What is the thoracic wall?

Answer 3

The thoracic wall is muscular.

Question 4

What is the thoracic cavity?

Answer 4

The thoracic cavity is internal.

Question 5

What is the function of the superior thoracic aperture?

Answer 5

The superior thoracic aperture allows communication between the thorax, head, neck, and upper limbs.

Question 6

What is the function of the inferior thoracic aperture?

Answer 6

The inferior thoracic aperture allows communication between the thorax, pelvis, and lower limbs.

Question 7

What are the boundaries of the superior thoracic aperture?

Answer 7

The boundaries are the manubrium, 1st pair of ribs, and T1.

Question 8

What are the boundaries of the inferior thoracic aperture?

Answer 8

The boundaries are the xiphoid process, false ribs, and T12 vertebrae.

Question 9

What are the functions of the thoracic cage?

Answer 9

The functions include protection of organs, support of the weight of upper limbs, and muscle attachment.

Question 10

What structures make up the thoracic cage?

Answer 10

The thoracic cage is made up of the sternum, ribs, costal cartilages, and thoracic vertebrae.

Question 11

What are the subclassifications of the ribs?

Answer 11

True ribs (1-7) articulate with the sternum, false ribs (8-10) form the costal margin, and floating ribs (11-12) do not articulate anteriorly.

Question 12

What type of cartilage is costal cartilage?

Answer 12

Costal cartilage is hyaline.

Question 13

What structures articulate via the sternocostal joints?

Answer 13

The upper 7 costal cartilages (true ribs) articulate with the sternum.

Question 14

What are the two joints that vertebrae use to articulate?

Answer 14

The two joints are costovertebral (head of rib) and costotransverse (with transverse process).

Question 15

What does the thoracic cage expand to in inspiration?

Answer 15

The thoracic cage expands vertically (diaphragm), transversely (ribs), and antero-posteriorly (sternum and true ribs).

Question 16

What is Boyle’s law?

Answer 16

Boyle’s law states that gas pressure is inversely proportional to volume at constant temperature.

Question 17

Describe the relationship between thoracic volume and pressure in inspiration and expiration.

Answer 17

Inspiration: increased thoracic volume (diaphragm contracts) leads to decreased pressure. Expiration: decreased thoracic volume (diaphragm relaxes superiorly) leads to increased pressure.

Question 18

What are the muscles of respiration?

Answer 18

The muscles of respiration are the diaphragm and intercostal muscles.

Question 19

What are the origins and insertions of the diaphragm?

Answer 19

The diaphragm originates from the xiphoid process and T12 and inserts into the central tendon.

Question 20

What is the function of the diaphragm?

Answer 20

Contraction of the diaphragm leads to inspiration (creates negative pressure, drawing air inwards), while relaxation leads to expiration.

Question 21

What innervates the diaphragm?

Answer 21

The diaphragm is innervated by the phrenic nerves.

Question 22

What are the origins and insertions of the intercostal muscles?

Answer 22

The intercostal muscles originate from the inferior border of one rib and insert into the superior border of the rib below.

Question 23

What is the function of the intercostal muscles?

Answer 23

The intercostal muscles maintain rigidity to maximize lung volume by preventing bulging or collapse.

Question 24

What is the innervation of the intercostal muscles?

Answer 24

The intercostal muscles are innervated by the intercostal neurovascular bundle.

Question 25

What nerves innervate the thoracic wall?

Answer 25

The thoracic wall is innervated by intercostal nerves, lateral cutaneous branch, and anterior cutaneous branch.

Question 26

What dermatomes make up the thorax and abdomen?

Answer 26

The thorax and abdomen are made up of cervical and thoracic spinal nerves.

Question 27

What nodes provide lymphatic drainage of the thoracic wall?

Answer 27

The lymphatic drainage is provided by parasternal nodes, intercostal nodes, and diaphragmatic nodes.

Question 28

Where is the thoracic cavity entered in a thoracostomy?

Answer 28

The thoracic cavity is entered above the rib, usually at the 5th intercostal space and mid-axillary line.

Question 29

Describe the anatomical position of the neuromuscular bundle.

Answer 29

The neuromuscular bundle is situated inferior to the ribs in the costal groove and lies between the internal intercostal and innermost intercostal muscles.

Question 30

Where do the posterior intercostal veins drain into?

Answer 30

The posterior intercostal veins drain into the azygous system of veins: right side into the azygous vein and left side into the hemiazygos and accessory hemiazygos veins.

Question 31

What structures provide arterial supply of the thoracic wall?

Answer 31

The arterial supply of the thoracic wall comes from anterior and posterior intercostal arteries.

Question 32

What is the course of the anterior intercostal arteries?

Answer 32

The anterior intercostal arteries course from the subclavian artery to the costocervical trunk, then to the supreme intercostal artery, and finally to the superior 2 posterior intercostal arteries.

Question 33

What structures provide venous drainage of the thoracic wall?

Answer 33

The venous drainage of the thoracic wall is provided by anterior and posterior intercostal veins.

Question 34

What do the 2nd-6th intercostal nerves supply?

Answer 34

The 2nd-6th intercostal nerves supply the thoracic wall.

Question 35

What do the 7th-11th intercostal nerves supply?

Answer 35

The 7th-11th intercostal nerves supply the abdominal skin and muscles.

Question 36

What does the subcostal nerve supply?

Answer 36

The subcostal nerve supplies the skin on the anterior inferior abdominal wall.

Question 37

What do the lymphatic nodes of the thoracic wall ultimately drain into?

Answer 37

The lymphatic nodes of the thoracic wall ultimately drain into the thoracic duct, which leads to the left brachiocephalic vein.

Question 38

What parts of the body does the thoracic duct drain?

Answer 38

The thoracic duct drains all of the left side, as well as the right abdomen, pelvis, perineum, and lower limb.

Question 39

What makes up the inferior thoracic aperture?

Answer 39

The inferior thoracic aperture is made up of the esophagus, aorta, inferior vena cava, thoracic duct, azygous vein, and phrenic nerve.

Question 40

What makes up the superior thoracic aperture?

Answer 40

The superior thoracic aperture is made up of the esophagus, trachea, brachiocephalic veins, brachiocephalic artery, left common carotid artery, left subclavian artery, phrenic and vagus nerves, and apex of lungs.

Question 41

What do external, internal, and innermost intercostal muscles allow for?

Answer 41

They keep the intercostal spaces rigid, preventing bulging or being drawn in.

Question 42

What other muscles are recruited for inspiration?

Answer 42

Other muscles recruited for inspiration include scalenes, sternocleidomastoid, pectoralis major and minor, serratus anterior and posterior, and the levator costarum.

Question 43

What other muscle is recruited for expiration?

Answer 43

The rectus abdominis is recruited for expiration.

Question 44

Where do posterior intercostal arteries arise from?

Answer 44

The posterior intercostal arteries arise from the aorta at each cervical level except superiorly.

Question 45

What are the two features of thoracic vertebrae that relate to the ribs?

Answer 45

The thoracic vertebrae have facets for articulation with the tubercle of the rib and demifacets for articulation with the head of the rib.

Question 46

What is the joint between ribs and costal cartilage and what is its function?

Answer 46

costochondral joint (synchondroses) flexible and expansion during inhalation

Question 47

What types of joint are found in the sternocostal joints?

Answer 47

1st = synchros (caliginous) 2nd-7th = synovial

Question 48

what are the 2 joints of the sternum and what are their classifications?

Answer 48

manubriosternal (symphysis) Xiphisternal (symphysis)