Thoracic Wall

Question 1

Describe the sagittal anatomical plane

Answer 1

Divides into left and right

Question 1

Describe the median sagittal/midsagittal anatomical plane

Answer 1

Sagittal plane divided at the midline

Question 2

Describe the parasagittal anatomical plane

Answer 2

Divides the body into uneven left and right, so NOT at the midline

Question 2

Describe the coronal/frontal anatomical plane

Answer 2

Divides the body into anterior and posterior portions

Question 2

Describe the transverse/axial anatomical plane

Answer 2

Divides the body into superior and inferior portions

Question 2

What point of view is utilized when looking at the transverse/axial plane?

Answer 2

From the patients feet, looking up towards their nose

Question 3

What does the axial skeleton consist of?

Answer 3

The skull, vertebral column, ribs, and sternum

Question 4

What does the appendicular skeleton consist of?

Answer 4

The bones of the limbs, including the shoulder girdle and hip bones

Question 5

Define fascia

Answer 5

A layer of fibrous connective tissue that wraps around and supports different structures of the body

Question 6

What does the superficial fascia consist of?

Answer 6

Found directly under the skin, consists of loose connective tissue, blood vessels, and nerves

Question 7

What is deep fascia?

Answer 7

Fascia that surrounds bones, muscles, some nerves, and some blood vessels

Question 8

What is the thorax?

Answer 8

The anatomical region inferior to the neck and superior to the abdomen

Question 9

What is the thoracic wall comprised of?

Answer 9

The skin, fascia, nerves, vessels, muscles, cartilage, and bones

Question 10

What is the function of the thoracic wall?

Answer 10

Protect underlying viscera and to provide attachments for muscles

Question 11

What does the thoracic skeleton consist of?

Answer 11

12 thoracic vertebrae and intervertebral discs, 12 pairs of ribs and costal cartilage, the sternum

Question 12

What are costal facets?

Answer 12

Points where the ribs articulate with the costal vertabrae and form synovial joints

Question 13

What do the articular facets of typical ribs articulate with? (Non-specifically)

Answer 13

With the costal facets of the thoracic vertebrae

Question 14

What does the tubercle facet of typical ribs articulate with?

Answer 14

With the costal facets of the transverse process of thoracic vertebrae

Question 15

Which ribs are deemed to be “atypical ribs”

Answer 15

Ribs 1, 11, and 12

Question 16

What is costal cartilage?

Answer 16

Cartilage comprised of hyaline cartilage that connects the ribs to the sternum. Contributes to the elasticity of the rib cage

Question 17

Where are the sternocostal joints located?

Answer 17

Between the sternum and the costal cartilage (these are synovial joints)

Question 18

What is the costal margin?

Answer 18

The medial margin formed by the cartilage of ribs 7-10

Question 19

Which ribs are deemed to be “True ribs”?

Answer 19

Ribs 1-7 (attached to the sternum directly via their own costal cartilage)

Question 20

Which ribs are deemed to be “False ribs”?

Answer 20

Ribs 8-10 (attached to the sternum indirectly via the costal cartilage of superior ribs)

Question 21

Which ribs are deemed to be "Floating ribs"?

Answer 21

Ribs 11 and 12 (do not attach to the sternum)

Question 22

Which ribs does the manubrium of the sternum articulate with?

Answer 22

Ribs 1 and 2

Question 23

Which ribs does the body of the sternum articulate with?

Answer 23

Ribs 2-7

Question 24

Which ribs does the xiphoid process of the sternum articulate with?

Answer 24

None (trick question!)

Question 25

What is the superior-most notch of the sternum called?

Answer 25

Jugular or suprasternal notch

Question 26

What is the sternal angle?

Answer 26

The point at which the manubrium and body of the sternum articulate. Found at the level of the T4/T5 intervertebral disc space

Question 27

What is the xiphisternal joint?

Answer 27

Where the body of the sternum and the xiphoid process articulate. Found at the level of the T10 vertebrae

Question 28

What marks the inferior limit of the thoracic cavity?

Answer 28

The xiphisternal joint

Question 29

Name the muscles of the thoracic wall

Answer 29

Pectoralis major, pectoralis minor, and serratus anterior

Question 30

Describe the intercostal muscles

Answer 30

3 layers of muscle found within the intercostal spaces that help stabilize the ribcage during respiration. Muscle fibers of each layer run in different directions for added strength (layers are thin)

Question 31

Name the 3 intercostal muscles from superficial to deep

Answer 31

External intercostal, internal intercostal, innermost intercostal

Question 32

What are intercostal neurovascular bundles?

Answer 32

A bundle consisting of an intercostal vein, intercostal artery, and intercostal nerve (listed from superior to inferior) that supplies the muscles and overlying skin

Question 33

Where are intercostal neurovascular bundles located?

Answer 33

In the costal grove in between the internal and innermost intercostal muscles

Question 34

Intercostal nerves are the ventral rami of what spinal nerves?

Answer 34

Intercostal nerves are ventral rami of the T1-T11 spinal nerves (T12 is the subcostal nerve)

Question 35

What is the subcostal nerve?

Answer 35

The ventral ramus from the T12 spinal nerve (there are only 11 intercostal spaces)

Question 36

What is meant by the collateral branch with respect to intercostal nerves?

Answer 36

Each intercostal nerve gives off a collateral branch that travels along the superior boarder of the rib below it (so each intercostal space has 2 neurovascular bundles)

Question 37

What types of fibers are found in the intercostal & subcostal nerves?

Answer 37

Somatic motor nerves (intercostal muscles), somatic sensory nerves (skin, joints, muscles), and sympathetic nerves (targets in skin)

Question 38

What dermatome landmark is located at the nipple line?

Answer 38

T4

Question 39

What dermatome landmark is located at the umbilicus?

Answer 39

T10

Question 40

What is the anatomical relationship between dermatomes and myotones?

Answer 40

Myotomes are found deep to dermatomes (the 2 do not perfectly align with one another!)

Question 41

If you were going to remove a mole from the skin between Ribs 5 & 6, where would you inject your patient with anesthesia, and why?

Answer 41

1) Inferior to Rib 5 to anesthetize the 5th intercostal nerve travelling in the costal groove 2) Superior to Rib 6 to anesthetize the collateral branch from the 5th intercostal nerve 3/4) Superior to Rib 5 & Inferior to Rib 6 to anesthetize adjacent areas in consideration of overlapping dermatomes

Question 42

Describe the thoracic aorta

Answer 42

a large, singular vessel located posteriorly that supplies blood to the posterior intercostal arteries and their collateral branches

Question 43

Describe the internal thoracic arteries

Answer 43

A pair of 2 vessels located anteriorly (just deep of the ribcage) that supplies blood to the anterior intercostal arteries

Question 44

Describe the flow of blood from the thoracic aorta to the thoracic wall

Answer 44

Thoracic aorta > posterior intercostal arteries > collateral branches

Question 45

Describe the flow of blood from the internal thoracic arteries

Answer 45

Internal thoracic arteries > anterior intercostal arteries (there are usually only 2 anterior intercostal arteries in each intercostal space)

Question 46

Describe the relationship between the anterior intercostal arteries and the posterior intercostal arteries

Answer 46

They anastomose (connect) with one another

Question 47

How is venous drainage achieved within the thoracic wall?

Answer 47

Via the anterior intercostal veins and the posterior intercostal veins (they too anastomose with one another)

Question 48

Describe the flow of venous drainage from the posterior intercostal veins

Answer 48

Posterior intercostal veins > azygos system > superior vena cava (SVC)

Question 49

Describe the flow of venous drainage from the anterior intercostal veins

Answer 49

Anterior intercostal veins > Internal thoracic veins > brachiocephalic veins > superior vena cava (SVC)

Question 50

If the left internal thoracic artery was removed for a coronary bypass, how would oxygen rich blood get to the affected intercostal spaces?

Answer 50

Via the anastomosis' between the internal thoracic artery and the thoracic aorta

Question 51

A patient suffered a stab wound that severed the proximal end of the T10 intercostal nerve. Which answer best describes how the patient would present? A) Anesthesia of the lateral & anterior aspects of the T10 dermatome B) Anesthesia of the lateral & anterior aspects of the T10 myotome C) Lack of sweating in the lateral & anterior aspects of the T10 dermatome D) A&B E) A, B, & C

Answer 51

E

Question 52

Each intercostal nerve gives off a _____________ that travels along the superior border of the rib below

Answer 52

Collateral branch

Question 53

What what level is the sternal angle?

Answer 53

T4/T5

Question 54

At what angle is the the xiphoid process at?

Answer 54

T10

Question 55

Define ipsilateral

Answer 55

Meaning on the same side

Question 56

Define contralateral

Answer 56

On opposite sides

Question 57

What is known as the weakest part of the rib?

Answer 57

The angle (most common location of rib fractures)

Question 58

What are the visible and/or palpable features of the thoracic wall?

Answer 58

Jugular notch, clavicles, sternal angle, costal margin, xiphoid process, etc.

Question 59

From superior to inferior, list the structures found in an intercostal neurovascular bundle

Answer 59

Intercostal vein, intercostal artery, intercostal nerve

Question 59

In the costal grove, the intercostal neurovascular bundles travel between what 2 layers of intercostal musculature?

Answer 59

The internal and innermost intercostal muscles

Question 59

All 3 layers of the intercostal muscles are supplied by what (nerve and vasculature)

Answer 59

Intercostal neurovascular bundles

Question 60

The intercostal neurovascular bundles are responsible for supplying what structures?

Answer 60

The muscles and overlying skin

Question 61

What type of nerve fibers are found in the intercostal and subcostal nerves?

Answer 61

Somatic motor (intercostal muscles), somatic sensory (skin, joints, and muscles), and sympathetic (targets in the skin such as sweat glands, arrector pili muscles, and blood vessels)

Question 62

Posterior intercostal veins drain into what?

Answer 62

The azygous system

Question 63

The azygous system drains into what structure?

Answer 63

The superior vena cava (SVC)

Question 64

The anterior intercostal veins drain into what?

Answer 64

Internal thoracic veins

Question 65

Internal thoracic veins drain into what?

Answer 65

Brachiocephalic veins

Question 66

Brachiocephalic veins drain into what?

Answer 66

The superior vena cava (SVC)