Ach: Anterior Thoracic Wall

Question 1

When looking at the sternal angle, you know it is a clinical landmark for….

Answer 1

second rib and second intercostal space

T4/T5 plane
mediastinum
aortic arch
tracheal bifurcation
SVC entering the pericardium 
superior limit of the pulmonary trunk

Question 2

How many ribs/vertebra make up hte bony thorax?

Answer 2

12 ribs
12 vertebra
sternum

Question 3

What are the “true ribs”?

Answer 3

1-7

articulate with sternum by costal cartilages

Question 4

What are the “false ribs”? Which connect to costal cartilage of rib above?

Answer 4

8-12

8-10

Question 5

What are the floating or free ribs?

Answer 5

11, 12

Question 6

What are the main components of a rib?

Answer 6

Facets- articulate with the vertebral bodies
Head
Neck
Tubercle- articulates with the transverse process
angle
costal groove

Question 7

Where is the weakest part of a rib?

Answer 7

anterior to it’s angle

middle ribs break most often

Question 8

The facets on the head of the rib articulate with?

Answer 8

body of the corresponding vertebra and the vertebra above

superior and inferior facet

Question 9

Facet on the tubercle articulates with what?

Answer 9

Tip of corresponding transverse process

Question 10

What do the costal cartilages articulate with?

Answer 10

1-7 sternum

8-10 adjacent costal cartilages

Question 11

Facets on the head of rib 7 and the facet of the tubercle articulate with what vertebra?

Answer 11

Vertebra 7 and 6

Transverse process of rib 7

Question 12

How many vertebra and intervertebral disks are there?

Answer 12

12

Question 13

What is the thoracic inlet?

Answer 13

Border between the neck and thorax

manubrium
1st ribs
T1 vertebra

Question 14

What is the thoracic outlet and what marks this location?

Answer 14

border between thorax and abdomen

costal margins of 12th ribs and the costal cartilages of ribs 7-11

Question 15

The thoracic outlet is the origin for the…

Answer 15

respiratory diaphragm

Question 16

How does the chest increase in vertical diameter?

Answer 16

Contract the diaphragm

Question 17

How does the chest increase the transverse diameter?

Answer 17

BUCKET HANDLE

movement of ribs up and out

Question 18

How does the chest increase the anterioposterior diameter?

Answer 18

PUMP HANDLE

raise sternum and anterior ends of ribs

Question 19

How do you breathe?

Answer 19

Thoracic cage moves>
increases/decreases the intrathoracic volume>
pressure change>
air follows decrease in pressure

Question 20

What is the superior thoracic aperture (thoracic inlet)? Boundaries?

Answer 20

Communicates with the root of the neck

T1
1st ribs and costal cartilage
Manubrium

Question 21

What is the inferior thoracic aperture (thoracic outlet)? Boundaries?

Answer 21

Diaphragm closes the aperture
Openings in the diaphragm allow communication with the abodomen

T12
12th pair of ribs and costal margins
xiphesternal joint

Question 22

How many layers of muscle fill the intercostal space?

Answer 22

3

Question 23

Where does VAN (intercostal vein, artery, nerve) lie?

Answer 23

subcostal groove under the lower border of the upper rib

Question 24

How many pairs of external intercostal muscles are there? How do they lie? Do the reach the sternum?

Answer 24

11 pair

Fibers slant DOWNWARD and FORWARD from rib above to rib below

NO

Question 25

How many pairs of internal intercostal muscles are there? How do they run?

Answer 25

11 pair Fibers run DEEP to and at RIGHT ANGLES to the external intercostals

Question 26

How do external and internal intercostals differ in what they're replaced by?

Answer 26

external- replaced by EXTERNAL intercostal membrane ANTERIORLY internal- replaced by INTERNAL intercostal membrane POSTERIORLY

Question 27

What do the innermost intercostal muscles cover?

Answer 27

The middle half of intercostal spaces

Question 28

What are the actions of intercostal muscles?

Answer 28

WIDEN intercostal spaces keep intercostal spaces RIGID during respiration ELEVATE or DEPRESS ribs

Question 29

What forms the intercostal nerves?

Answer 29

Ventral rami of the first 11 thoracic nerves as they enter the intercostal spaces

Question 30

What forms the subcostal nerve?

Answer 30

Ventral ramus of the 12th nerve | lies INFERIOR to the 12th rib

Question 31

A ganglion of the sympathetic trunk is associated with each ventral ramus. It connects to the nerve via rami communicantes. What is the difference between white ramus and gray ramus?

Answer 31

white- conveys preganglionic sympathetic fibers to the ganglion (myelinated) gray- conveys postganglionic sympathetic fibers from the ganglion into the intercostal nerve (unmyelinated)

Question 32

What are the typical branches of an intercostal nerve?

Answer 32

``` rami communicantes collateral branches lateral cutaneous branches anterior cutaneous branches muscular branches to the intercostal muscles ```

Question 33

What nerves supply the abdominal musculature, pleura, periotoneum and skin?

Answer 33

Nerves from T7-12 Motor innervation: intercostal muscles Sensory innervation: skin and pleura

Question 34

What nerves supply the nipple and the umbilicus respectively?

Answer 34

T4 | T10

Question 35

How many arterial sources are there for each intercostal space? What are they?

Answer 35

2 that form an anastomoses Posterior intercostal artery (branches of the thoracic aorta) Anterior intercostal arteries in spaces 1-6 (branches of internal thoracic artery which branches from the subclavian)

Question 36

Where does the internal thoracic artery run?

Answer 36

posterior to costal cartilage and lateral to sternum

Question 37

What are the branches off the internal thoracic artery?

Answer 37

Pericardiacophrenic- accompanies phrenic nerve musculophrenic- supplies spaces 7-9 superior epigastric- diaphgram and superior abdominal wall anterior intercostal arteries

Question 38

Where do they anterior intercostal veins drain?

Answer 38

into the itnernal thoracic veins

Question 39

What systems do the posterior intercostal veins drain into?

Answer 39

azygos and hemiazygos system of veins

Question 40

What is thoracic outlet syndrome?

Answer 40

Clinical syndromes caused by congenital or acquired compression of brachial plexus/subclavian veins passing through thoracic outlet to the upper limb

Question 41

What are sxs of brachial plexus compression?

Answer 41

Pain paresthesia numbness of upper limbs

Question 42

What are sxs of subclavian artery compression?

Answer 42

ischemia pallor coolness decrease in limb pulses

Question 43

What are sxs of subclavian vein compression?

Answer 43

swelling pain venous thrombosis

Question 44

From how many ossification centers does the bony thorax develop? When does it fuse?

Answer 44

6 ossification centers fuse around age 25 xiphoid process fuses 30-40

Question 45

What is a symphysis and what are examples of it?

Answer 45

secondary cartolaginous joint bones are joined by fibrocartilage sternal angle pubic symphpysis joints between intervertebral discs

Question 46

What is a synchondrosis?

Answer 46

primary cartilaginous joint bones united by hyaline cartilage temporarily then converted to bone xiphesternal joint

Question 47

What do the external intercostal muscles do?

Answer 47

Elevates ribs | forced INSPIRATION

Question 48

What do the internal intercostal muscles do?

Answer 48

Depresses ribs | forced EXPIERATION