Thoracic Wall Flashcards
what forms lateral walls of thoracic cage
12 pairs of ribs
anteriorly the ribs articulate with what
midline sternum
are the scapula and clavicle part of the thoracic cage
no
posteriorly ribs articulate with what
12 thoracic vertebrae
what are the boundaries of the superior thoracic aperture (inlet)
body of T1 posteriorly
1st pair of ribs and costal cartilages (laterally)
superior border of manubrium (anteriorly)
what are the boundaries of the inferior thoracic aperture (outlet)
body of T12 posteriorly
ribs 11 and 12 and costal cartilages of ribs 7-10 (costal margin) laterally and anteriorly
xiphysternal joint anterior midline
transverse process of vertebrae allows what
allows muscle attachment and articulation with ribs
the head of the 7th rib will sit above/below T7
above - head of the 7th rib will sit between T6 and T7
what are the parts of the vertebrae called that articulate with the heads of the ribs
superior and inferior demifacets
what part of the rib articulates with the transverse process
tubercle
the tubercle of rib 7 will articulate with the transverse process of
T7
what are the true ribs
1-7
what are the false ribs
8-10
what are the floating ribs
11 and 12
how do true ribs connect with sternum
directly via own cartilage
how do false ribs connect with sternum
indirectly via cartilage of ribs above - costal cartilage fuses with costal cartilage of rib above
how do floating ribs connect with the sternum
no connection - end on musculature of posterior abdominal wall
what are the 2 classifications of ribs based on their bony features
typical - 3rd - 9th
atypical 1st 2nd and 10-12
describe the head of a typical rib
wedge shaped with 2 articular facets separated by a crest
the head of a typical rib articulates with what
articular facets articulate with own vertebra and vertebra above
crest articulates with IVD
typical rib : the tubercle articulates with what
transverse process of own vertebrae
typical rib : what are the non-articular parts of the tubercle for
costotransverse ligament
typical rib : what attaches the head and body at the tubercle
neck
what is the most curved part of a typical rib
costal angle
where is the costal groove of a typical rib
on the internal surface of inferior border of body
what does the costal groove protect
intercostal vessels and nerves
what is different about the head of the first rib
only has 1 facet on head
why does rib 1 only have one facet on its head
articulates with T1 only as C7 doesn’t have costal facets
the 1st rib has grooves on superior surface for what
subclavian vessels
what separates the subclavian grooves on the first rib
scalene tubercle for attachment of anterior scalene muscle
what else makes rib 1 atypical
highly curved
rib 2 has a tuberosity for the attachment of what
serratus anterior
rib 2 has a rough area where
upper surface
describe the heads of ribs 10-12
single facet on head as they only articulate with single vertebra
describe ribs 11 and 12
short with no neck or tubercle
what are the 3 parts of the sternum
manubrium
body
xiphoid process
what are the 2 joints of the sternum
sternal angle (manubriosternal joint)
xiphisternal joint
how many notches does the sternum have on lateral border
7 for articulation of costal cartilages of ribs
where does the 1st rib articulate with the sternum
with manubrium adjacent to clavicular notch
where does the 2nd rib articulate with the sternum
with sternal angle
where does the 7th rib articulate with the sternum
at xiphisternal joint
the joints between adjacent vertebrae are intervertebral joints and they are
secondary cartilaginous joints
what kind of joints are between articular facets of vertebrae
synovial plane joints
the synovial plane joints between articular facets in vertebra are called
zygopophysial joints
can rotational movement occur between vertebrae of the thoracic region of vertebral column
yes - due to the orientation of articular facets
what are sternocostal joints
joints between sternum and costal cartilages of ribs
the sternocostal joint between rib 1 and manubrium is what kind of joint
primary cartilaginous joint (synchondrosis)
the sternocostal joints between ribs 2-7 and body of sternum are what kind of joints
synovial plane joints
what are interchondral joints
joints between adjacent costal cartilages
interchondral joints are what kind of joints
synovial plane
- between 6-7-8-9
fibrous
- between 9 and 10
costovertebral joints are what kind of joints
synovial plane joints
describe the axis of movement of the costovertebral joints
movement will occur at joints formed by the head and tubercle at the same time so rib will move around an axis that runs through both of these joints
- elevation and depression of rib
what are the participants in the costovertebral joint of head of rib
body of vertebra superior to rib
IVD
head of rib - 2 facets and crest
body of vertebra of same number as rib
what are the participants in the costotransverse joint
transverse process of vertebra of same number as rib
tubercle of rib
upper ribs (1-6) have an axis which is angled more _____
laterally
lower ribs (7-12) have an axis that is angled more ____
posteriorly
upper ribs (1-6) have their greatest degree of movement at the _____ aspect
anterior
upper ribs (1-6) have a movement called
pump handle
lower ribs (7-12) have their greatest degree of motion at the _____ aspect
lateral
lower ribs (7-12) have a movement called
bucket handle
how is the rib cage expanded in the AP dimension
sternum and upper ribs move anteriorly and superiorly
how is the rib cage expanded laterally
lower ribs flare out laterally
how is the rib cage expanded vertically
diaphragm descends as it contracts and flattens
what is the primary muscle of inspiration at rest
diaphragm
what are the groups of muscles of the thoracic wall
respiratory - true muscles of thoracic wall
accessory respiratory
superficial - assoc. with upper limb or abdominal wall
what are the true muscles of the thoracic wall
intercostal muscles
subcostal and transversus thoracis
what are the secondary muscles of respiration
scalene muscles of the neck
serratus posterior (superior and inferior) of back
what are the superficial muscles assoc. with the upper limb and anterior abdominal wall
pectoral muscles
serratus anterior
external oblique
rectus abdominis
nerve supply of pec major
medial (C8,T1) and lateral (C5-7) pectoral nerves
nerve supply of pec minor
medial pectoral nerve (C8,T1)
nerve supply of serratus anterior
long thoracic nerve (C5-7)
nerve supply of external oblique
anterior rami T7-T12
nerve supply of rectus abdominis
anterior rami T7 - T12
nerve supply of serratus posterior superior
2nd - 5th intercostal nerves
nerve supply of serratus posterior inferior
anterior rami T9-12
nerve supply of anterior scalene
anterior rami C3-7
nerve supply of middle scalene
anterior rami C4-7
nerve supply of posterior scalene
anterior rami C5-7
where do scalene muscles attach proximally
transverse process of cervical vertebrae
where do anterior and middle scalene attach distally
first rib
where does posterior scalene attach distally
second rib
what is the function of the scalene muscles
primarily involved in neck movement but when neck is fixed can act as accessory respiratory muscles by raising 1st and 2nd ribs
serratus posterior superior extends downwards from what to what
spinous process of C7-T3
to upper borders of ribs 2-4
serratus posterior inferior extends upwards from what to what
spinous process of T11-L2 towards the lower borders of ribs 8-12
what is the main function of serratus posterior superior and inferior
proprioception but may assist in raising/lowering ribs respectively
what are the 3 layers of intercostal muscles
external
internal
innermost
fibres of external intercostal muscles run in what directoin
anteriorly and inferiorly from lower border of upper rib to upper border of lower rib
- inferomedial, hands in pockets
fibres of external intercostal muscles run from where to where
tubercles of ribs to costochondral junction
what are the external intercostals replaced with anteriorly
external intercostal membrane that extends between costal cartilages to lateral border of sternum
where are the external intercostals most obvious
posteriorly and laterally
what is the function of the external intercostal muscles
raise ribs in inspiration
what way do fibres of the internal intercostal muscles run
posteroinferiorly (down and back) - 90 degree angle to external intercostal
from where to where do fibres of internal intercostal muscles run
sternum to angle of ribs
what are internal intercostal muscles replaced with posteriorly
internal intercostal membrane
what is the function of the internal intercostal muscles
interosseous part - depresses ribs on expiration
interchondral part - raises ribs on inspiration
the fibres of the innermost intercostal muscles run in the same direction as what
internal intercostal muscle fibres
is the innermost intercostal muscle layer continuous
no, very thin often incomplete
what are the deepest muscles of the thoracic wall
subcostal and transversus thoracis
the internal thoracic vessels that run on either side of the sternum lie _____ to the transversus thoracis muscle
superficial
where are the subcostal muscles found
near angle of ribs
fibres of subcostal span ____ ribs and may blend with fibres of ____
span 1-2 ribs
may blend with innermost intercostal
where is the neurovascular plane of the intercostal space
between internal and innermost layers
describe the neurovascular bundle in the ICS from superior to inferior
VAN
vein
artery
nerve
the vein artery and nerve run where
costal groove
describe the nerve bundle of the ICS
intercostal nerve that will supply musculature of the ICS
- also give lateral and anterior branches that pierce through the muscle layers into skin to supply sensory innervation
describe the arterial supply of the ICS
most via posterior intercostal arteries, most of which will come directly from aorta
PIA will also give a cutaneous branch to pass through muscle walls and out to supply skin
anterior part of each ICS is supplied by what
anterior ICA - will branch out to supply skin
anterior ICA usually branch directly from
internal thoracic artery
the internal thoracic artery is a branch of what
subclavian artery
PICA supplying spaces 3-11 and subcostal (inferior to rib 12) originate as posterolateral branches of
thoracic aorta
PICA supplying 1st and 2nd ICS arise from
supreme intercostal artery
the supreme intercostal artery is a branch of
costocervical trunk from subclavian artery
AICAs for 1-6 come directly from
internal thoracic artery
internal thoracic artery runs
either side of sternum the bifurcates to form superior epigastric artery and musculophrenic artery
AICAs supplying ICS 7-9 come from
musculophrenic artery
the anterior intercostal veins drain to the
internal thoracic vein
the internal thoracic vein runs with the
internal thoracic artery
on the right, the 1st PICV drains to the
right brachiocephalic vein
on the right the 2-11 PICVs + subcostal drain to the
azygous vein
on the left, the 1-4 PICVs drain to the
left brachiocephalic vein
on the left, the 5-8 PICVs drain to the
accessory hemiazygous vein
on the left the 9-11 PICVs + subcostal drain to
hemiazygous vein
nipple dermatome
T4
belly button dermatome
T10
glandular tissue in the breast is organised into
lobules
lobules of the mammary gland will open at the nipple via
lactiferous ducts
how is support for the glandular tissue provided
fibrous tissue which is organised into a number of thick fibrous glands - suspensory ligaments
what is the function of the suspensory ligaments
support the breasts and anchor breasts at dermis of skin
what is the arterial supply of the breast
lateral and medial mammary branches
lateral mammary branches come from
lateral thoracic artery from axillary artery
medial mammary branches come from
internal thoracic artery
venous drainage of the breast goes to
medial and lateral mammary veins
what is the name of lymphatic plexus in the breast
subareolar lymphatic plexus
> 75% of lymph of breast goes where
axillary nodes
remainder of lymph from breast goes where
parasternal nodes and some may go to abdominal nodes
