CHAPTER 24

Question 1

function
the function of the thoracic wall is to form a protective cavity for the \_\_\_\_\_ and \_\_\_\_\_ and for the organs of the \_\_\_\_\_ aspect of the \_\_\_\_\_

Answer 1

heart
lungs
superior
abdomen

Question 2

bones of the thoracic wall

• _____ (breast bone)
• -it is a _____ bone located at the _____ aspect of the thorax in the _____
• -from greek sternon = the breast of men
• -the sternum is divided into _____ parts
  1. _____
• the manubrium is the _____ portion of the sternum
• from latin manus = hand
• -the sternum is fancied to resemble a _____ with the manubrium being the part of the sword held in the _____
• a _____ is found on the _____ border of the manubrium
• the manubrium articulates with the _____ and the first two pairs of _____ (_____ between the _____ and the _____)

2. _____
   - the body is the _____ portion of the sternum
   - it is _____, _____, and _____ than the manubrium
   - it articulates with the _____ of ribs _____ to _____
   - the _____ is at the junction of the manubrium and body. it is an important, palpable landmark for counting _____
3. _____
   - it is the smallest, most _____, and _____ portion of the sternum
   - from greek xiphon and oeides = sword shaped
   - the _____ (pit of the stomach) is a _____ on the _____ aspect of the ixphoid process; it is _____ and often is _____
   - the _____ is found between the xiphoid process and the body at the _____ end of the _____

Answer 2

sternum
flat
anterior 
midline
3
manubrium
superior
sword
hand
jugular notch 
superior 
clavicles 
costal cartilages 
hyaline cartilage
ribs
sternum
body
middle
long
narrow
thinner
costal cartilages 
2 7
sternal angle 
ribs
xiphoid process
variable 
inferior 
epigastric fossa
depression 
anterior
palpable 
visible
xiphisternal joint 
superior
epigastric fossa

Question 3

bones of the thoracic wall
_____ (costae)
-the _____ pairs of _____ bones form the most of the thoracic wall
-humans have 12 ribs on each side of the body (variations include _____ at _____ or _____ at _____
–the elongated flattened bones course _____ and _____ from the _____
-the _____ portion of each rib articulates with the _____ of the thoracic vertebrae
-the _____ is the constricted portion _____ to the _____
-the _____, which is the posterior projection _____ to the _____, articulates with the _____ of its respective thoracic vertebrae
-the _____ is the shaft of the rib
-the _____ is the point where the curve (or angle) of the rib is the _____
-the anterior end of the rib articulates with the _____
-the _____ is the ridge that lies on the _____ surface of the shaft of the rib; the _____, _____, and _____ lie in this groove (from superior to inferior)
-the length of the ribs increases the _____ to the _____ rib, and the decreases to the _____ rib
-the first 7 ribs are _____; they are directly connected to the sternum via their _____
-the last 5 ribs are _____
–each costal cartilage of ribs _____, _____, and _____ joints its respective _____ costal cartilage (_____, _____, _____)
–the costal cartilages of ribs 11 and 12 end blindly in _____ with no _____ articulation; these ribs are also classified as _____
-the _____ is formed by the costal cartilages of ribs 7, 8, 9, and 10, which course _____ and _____
-the _____ is formed by the intersection of the costal margins at the _____ joint
-the _____ is bounded by the upper border of the sternum and by the _____ ribs. it is an opening through which the _____ and _____ ascend or descend between the _____ and the _____
-the _____ is normally closed by the _____. _____ major openings are found in the diaphragm which allow for the passage of the _____, _____ and _____

Answer 3

ribs
12
flat
cervical ribs CV7
lumbar LV1
anteriorly 
inferiorly
thoracic vertebrae
head
bodies
neck
lateral
head
tubercle
lateral
neck
tranaverse processes
body
angle
sharpest
costal cartilage
costal groove
inferior
intercostal vein, artery, & nerve
1st
7th
12th
true ribs
costal cartilages
false ribs
8, 9, 10
suprajacent
10 to 9
9 to 8
8 to 7
muscle
anterior 
floating ribs 
costal margin
medially
superiorly 
infrasternal angle 
xiphisternal joint 
superior thoracic aperture 
first
great vessels
visceral tubes
thorax
neck
inferior thoracic aperture
diaphragm
three
inferior vena cava 
esophagus
aorta

Question 4

muscles of the thoracic wall
the muscles of the thorax are arranged into three layers:
1. \_\_\_\_\_ layer: \_\_\_\_\_ muscles 
2. \_\_\_\_\_ layer: \_\_\_\_\_ muscles 
3. \_\_\_\_\_ layer: \_\_\_\_\_ muscles

Answer 4

external
external intercostal
middle
internal intercostal
internal
innermost intercostal

Question 5

external intercostal muscles

• there are _____ external intercostal muscles (from latin inter = between and costa = rib)
• from their origin, the fibers of these muscles pass _____ and _____ to their point of insertion
• in the intercostal spaces, the muscles extend from the _____ of the _____ posteriorly to the region of the _____ anteriorly
• -at or near the costochonral junction, the muscles _____ out and become _____ where they are then referred to as the _____

Answer 5

11
medially
inferiorly 
tubercle
rib
costochondral junction 
thin
membranous 
external intercostal membrane

Question 6

internal intercostal muscles

• there are _____ internal intercostal muscles
• from their origin, the fibers of these muscles pass _____ and _____ to their point of insertion
• in the intercostal spaces, the muscles extend from the _____ anteriorly to the _____ of the _____ posteriorly where they thin out and form the _____

Answer 6

11
medially
superiorly
sternum
angles 
ribs
internal intercostal membrane

Question 7

innermost intercostal muscles

• there are _____ innermost intercostal muscles
• they have the same origin, insertion, action and innervation as the _____
• they are separated from the _____ by the _____ and _____. this area between the internal and innermost intercostal muscles is termed the _____

-other muscles including the _____ and _____ are also associated with the thoracic wall

Answer 7

11
internal intercostal muscles 
internal intercostals
intercostal vessels and nerve
neurovascular plane 
transversus thoracis 
subcostales

Question 8

thoracic nerves

• there are _____ thoracic _____ all of which transverse an _____ and divide into a _____ and a _____
• the _____ course posteriorly and divide into _____ and _____ branches
• the _____ are the larger branches of the spinal nerves that course forward into the _____
• the ventral rami have regional names:
  1. T1-T6: _____ (proper)
  2. T7-T11: _____
  3. T12: _____
• a typical intercostal nerve has the following course and distribution:
• -it passes _____ the _____ of the rib numerically corresponding to it; e.g., T4 courses inferior to the fourth thoracic rib
• -it courses between the _____ and the _____ in the _____ plane
• -it passes _____ in the _____ on the _____ surface of the rib, where it courses _____ to the _____ and _____
• -it gives off a _____ that pierces the internal intercostal, external intercostal, and _____ muscles; it then divides into _____ and _____ branches that supply the _____ of the chest wall
• at the anterior end of the intercostal space, it turns _____ through the _____ muscle, the _____ membrane, and the _____ muscle and then is distributes as the _____ to the skin of the front of the chest

Answer 8

12
spinal nerves 
intervertebral foramen 
dorsal ramus 
ventral ramus 
dorsal rami
medial
lateral 
ventral rami
intercostal branches 
intercostal nerves 
throacoabdominal nerves 
subcostal nerves 
below 
neck 
innermost intercostal 
internal intercostal muscles 
neurovascular 
forward 
costal groove 
lower
inferior
intercostal vein 
artery 
lateral cutaneous branch 
serrates anterior
anterior 
posterior
skin
forward
internal intercostal
external intercostal
pectoralis major 
anterior cutaneous branch