Thoracic Wall Flashcards
(128 cards)
1
Q
what forms the sternal angle?
A
intersection of manibrium and sternum
2
Q
where is the sternal angle?
A
rib 2, T4/5 vertebrae
3
Q
where is the most common site for a rib fracture
A
angle of middle ribs
4
Q
where is the most common site for a sternal fracture
A
sternal angle
5
Q
how many ribs are articulated to 1 thoracic vertebra?
A
1.5
6
Q
how many costal facets are on a thoracic vertebra?
A
3
7
Q
where in the intercostal space is a needle inserted for a nerve block
A
superior to the rib edge to avoid the structures in the costal groove (VAN complex) while avoiding the collateral branches that run superior to rib
between the paravertebral line and the location anesthetic is needed
do multiple levels because of overlap
8
Q
what portion of the mesoderm contributes to the parietal and visceral layers of a cavity
A
lateral mesoderm- forms the body cavities
9
Q
name 3 parts of a somite differentiates and segregates into during development of the body wall
A
sclerotome
myotome
dermatome
10
Q
what are true ribs
A
ribs 1-7, attach directly to the sternum via costal cartilage
11
Q
what are false ribs
A
ribs 8-10, attach indirectly to the sternum via costal cartilage of the rib superior
12
Q
what are floating ribs
A
ribs 11-12, end in abdominal musculature, no sternal attachment
13
Q
what is the rib head
A
where it interacts with thoracic vertebra, has 2 costal facets
14
Q
what is the rib neck
A
between the head and the tuberacle
15
Q
where is the rib tubercle
A
on the inferior aspect, down from the head and neck
has a costal facet
16
Q
where are costal facets located on a rib
A
2 on head
1 on tubercle
17
Q
where is the rib angle
A
where rib turns anterolaterally (curved part
18
Q
where is the costal groove
A
inferior edge of the rib
19
Q
what is in the costal groove
A
neurovascular bundle
20
Q
which ribs are typical
A
3-9
21
Q
which ribs are atypical
A
1, 2, 10-12
22
Q
describe rib 1
A
short and broad
1 articular facet- articulates with T1
scalene tubercle for attachment of scalene muscles
grooves for subclavian vessels
23
Q
how are intercostal spaces numbered
A
rib superior to it
24
Q
where is the subcostal space?
A
below rib 12
25
which rib is rarely fractured and why
rib 1- protected by clavical
26
what are supernumerary ribs and where are they found
extra ribs
can be in cervical area (rare)
more commonly in lumbar region
27
which articular facet is larger on the rib?
infeiror
28
what joint is formed between the rib and sternum
sternal costal interchondral joint
29
what joint is formed between the rib and thoracic vertebra?
costovertebral joint
30
what might bifid ribs be mistaken for
supernumerary ribs
31
what is thoracic outlet syndrome
compression of subclavian artery or brachial plexus (or any structure in the superior thoracic outlet)
32
what happens to costal cartilage with age?
cartilage becomes calcified and loses its elasticity, making it more likely to be fractured
33
what is the effect of an extra cervical rib?
thoracic outlet syndrome- extra rib compresses subclavian artery
34
what are the 3 parts of the sternum?
manibrium
body
xiphoid process
35
what does the location of the sternum make it good for?
getting bone marrow samples to detect blood diseases (leukemia)
36
what is the sternal cleft
fusion of bilateral pre-cartilage tissue at the midline during development
37
what are the 3 defects are related to sternal cleft
complete sternal cleft
partial cleft
sternal foramen
38
describe complete sternal cleft
the pre-cartilagenous tissue fails to fuse at all- rare
| the heart may stick be on the outside of the body
39
describe partial cleft
manibrium/upper aspect of the sternum do not fuse
40
describe sternal foramen
small hole in the sternum that is not clinically significant
41
what happens if the sternal angle is fractured?
dislocation of the manibriosternal joint that may cause damage to underlying organs
42
how common are sternal fractures
rare
43
what anatomical structures are at the sternal angle
```
bifurcation of the trachea
start of aortic arch
superior limit of pericardium
superior/inferior mediastinal boarder
arch of azygous vein
```
44
what is the joint between the manibrium and sternum?
manibriosternal joint
45
how many joints are in the costovertebral joint? what are they
2- thoracic vertebra with head of rib and thoracic vertebra with tubercle of rib
46
what is the joint between the thoracic vertebra and the tubercle of the rib
costotransverse joint
47
what does the superior rib facet articulate with
the inferior facet of the superior vertebra
48
what does the inferior rib facet articulate with
the superior articular facet of the vertebra at the same level
49
what does the tubercle rib facet articulate with
transverse articular facet of the vertebra at the same level
50
which ribs only have 1 articular facet
1, 10-12
51
what is the function of the thoracic wall and diaphragm
change the volume of the thorax to move air in and out
52
what changes the vertical height of the thorax
contraction/relaxation of the diaphragm (contract = increase volume)
53
what changes the lateral width of the thorax
elevation/depression of rib angle
54
what changes the anterioposterior width of the thorax
anterior rib and sternum moving out/up
55
what is the bucket handle movement
lateral ribs moving up while they are attached in the front and back
56
what is the pump handle movement
front of chest moving up
57
what is the most important inspiration muscle
diaphragm
58
what muscles are used in inspiration
diaphragm
| intercostal muscles
59
what do the intercostal muscles do
inspiration- raise the sternum and anterior ribs
| expiration- nothing, only used during forced expiration
60
what is the infrasternal angle
angle formed by costal margins
61
what is the costal margin
bilateral lines formed by ending of rib cage
62
what is the anterior median line
midline of sternum
63
what parts of the scapula are used to count ribs?
superior angle- rib 2
spine- rib 4
inferior angle- rib 8
64
what is the scapular line?
line down midline of scapula
65
what is the posterior median line
line down back of spine
66
what passes through the superior thoracic aperture
trachea
esophagus
subclavian artery
brachial plexus
67
what are the boundaries of the superior thoracic aperture
T1
rib pair 1 and the associated cartilage
manibrium
68
what are the two types of thoracic outlet syndrome?
costoclavicular syndrome
| cervical rib syndrome
69
what are the symptoms of costoclavicular syndrome?
compression of the subclavian artery between rib 1 and clavicle
pallor
cold upper limb skin
decreased radial pulse
70
what are the symptoms of cervical rib syndrome?
compression oc C8-T1 nerve roots and inferior trunk of brachial plexus
71
what structures are in the inferior thoracic aperture
esophagus
inferior vena cava
aorta
72
what covers the inferior thoracic aperture
diaphragm
73
how do the inferior thoracic aperture structures get through the diaphragm?
esophagus and inferior vena cava go through it
| aorta is behind it
74
what are the boundaries of the inferior thoracic apeture
T12
ribs 11 and 12
costal cartilage 7-10
xiphisternal joint
75
what is the joint between the xiphoid and sternum
xiphisternal joint
76
accessory muscles of inspiration
pectoralis major/minor
seratus anterior
serratus posterior inferior/superior
77
what might be the function of the serratus posterior inferior/superior?
proprioception
78
what are the intercostal muscles?
```
external intercostals
internal intercostals
innermost intercostals
subcostals
transverse thoracic
```
79
what direction do the external intercostal fibers run
"hands in the pocket"
| inferiorly, lateral to medial
80
where is the external intercostal membrane
anterior- begins at midclavicular line
81
when are external intercostals most active
inspiration- elevate ribs
82
what direction do internal intercostal fibers run
superiorly, medial to lateral (perpindicular to external obliques)
83
where is the internal intercostal membrane?
posteiror- begins at mid scapular line
84
when are the internal intercostals most active?
expiration- depress ribs (middle layer)
85
what are the 2 parts of the internal intercostals and what do they do
interosseous- depress ribs with expiration
| interchondral- elevate ribs during inspiration with the external intercostals
86
where are the innermost intercostal muscles located
lateral rib cage- approx mid clavicular to mid scapular
87
where are the subcostal muscles
posterior internal thoracic wal, spans 1 or 2 intercostal spaces
88
where are the transverse thoracic muscles
anterior internal thoracic wall connecting posterior sternum to costal cartilage 1 or 2 ribs superior
89
what is the function of the subcostal muscles
elevate ribs
90
what is the function of transverse thoracic muscle
unimportant respiratory function
91
where does the neuromuscular bundle travel
intercostal groove
92
what order are the structures of the neuromuscular bundle
superior- vein
artery
inferior- nerve
*all intercostal
93
what layer of the intercostal space is the van located in
between the internal intercostal and the innermost intercostal
94
where do the anterior intercostal arteries come from?
1-6 internal thoracic artery
| 7-9- musculophrenic artery
95
what and where does the internal thoracic artery split?
at ICS 6, it splits into the musculophrenic and superior epigastric arteries
96
what is the path of the musculophrenic arter
follows the subcostal angle down and gives off branches to ribs 7-9
97
what anterior intercostal artery supplies ICS 10 and 11?
none
98
where does the superior epigastric artery go?
runs inferiorly into the anterior abdominal wall
99
what supplies blood to each ICS?
two anterior intercostal arteries and 1 posterior intercostal artery (except 10 and 11- only posterior)
100
what do posterior intercostal arteries come from?
1-2- supreme intercostal artery
| 3-12- thoracic aorta
101
where does the supreme intercostal artery come from?
the costocervical trunk off of the subclavian artery
102
which side of the 3-12 intercostals is longer and why?
right side longer because the thoracic aorta travels to the left of the vertebra
103
what supplies the collateral branches that run superior to the rib?
posterior intercostal arteries
104
how do anterior and posterior intercostal arteries end
anastamose together
105
describe venous drainage of thorax
veins follow the arteries
anterior- intercostal veins drain into internal thoracic
- internal thoracic splits into musculophrenic and superior epigastric veins too
posterior- posterior- drain into azygous (right) or hemiazygous (lower left) or accessory hemiazygous (upper left) which all drain into azygous whig goes back to superior vena cava
106
where does the intercostal nerve come from
ventral rami T1-T11
107
where does the subcostal nerve come from
ventral rami T12
108
what are atypical thoracic nerves
T1- brachial plexus
T2- brachial plexus and intercostobrachial cutaneous branch
T7-T12- supply anterolateral abdominal wall
109
what are T7-T12 nerves called
thoracoabdominal nerves
110
significant thoracic dermatomes
T4- nipple
| T10- umbilicus
111
what are the 3 types of mesoderm and what do they differentiate into
paraxial- somites and body wall (muscle, bone, skin)
intermediate- urogenital system
lateral- body cavities (visceral and parietal pleura)
112
what are the 2 layers of lateral mesoderm and what do they become
somatic mesoderm- parietal layer lining body cavities
splanchnic mesoderm- visceral layer adherant to organs
intraembryonic cavity- space between the layers that forms the cavities
113
what is splanchopleurae
organ wall- splanchnic mesoderm + endoderm
114
what is somatopleurae
body wall- somatic mesoderm + ectoderm
115
what causes cleft sternum
incomplete lateral folding of the embryo
116
what is ectopic cordis
heart on outside of body due to incomplete lateral folding resulting in complete sternal cleft
117
how are somites formed
segmentally arranged groupings of paraxial mesoderm that run cranial to caudal
118
what are somitomeres
somites in head region that form pharyngeal arches
119
what is from sclerotome
ribs, vertebra, cartilage
120
myotome
segmented skeletal muscle
epimere- dorsal
hypomere- ventral
121
what does the ventral group of the hypomere of the myotome differentiate into
cervical- infrahyoid muscles
thorax- disappears
abdominal- rectus abdominins
122
what does dermatome segment of somites do
skin
123
what innervates the diaphragm
phrenic nerve- C3, C4, C5
124
what does the lateral group of the hypomere of the myotome differentiate into
thorax- intercostal muscles and transversus thoracis
| abdominal- abdominal oblique and transversus abdomins
125
what are the 4 components of the diaphragm
septum transversum
pleuroparietal membranes
lateral body musculature
esophageal mesentary
126
what is a parasternal hernia of the diaphragm
part of muscular fibers do not develop
127
what is an esophageal hernia of the diaphragm
congenital shortness of the esophagus
128
what is congenital diaphragmatic hernia?
failure of the pleuroperiotoneal membrane to close off the periocardio-peritoneal canals
results in intestines and stomach moving into the thorax and pushing the heart and mediastinum right and compression of the left lung
