RA week 2 Flashcards
thoracic cage made up of?
articulations?
seperated by?
girdle of upper limb? part of throacic cage?
12 pairs of ribs that form lateral walls
anteriorly = articulates with midline sternum
posteriorly = articulate with 12 throacic vertebrae
seperated by intercostal spaces
girdle of upper limb = scapula and clavicle, not part of thoracic cage
space enclosed by thoracic cage?
thoracic apertures?
thoracic cavity
boundaries of superior thoracic aperture (inlet)?
inferior throacic aperture (outlet)?
superior
- posteriorly = body of T1
- laterally = 1st pair of ribs + costal cartilages
- anteriorly = superior border of manubrium
inferior
- posteriorly = body T12
- anterolaterally (going from lateral to anterior) = 11th + 12th ribs, costal cartilages of ribs 7-10 (costal margin)
- anteriorly = xiphisternal joint
anterior body attached to posterior vertebral arch via pedicle
transverse process function?
what forms spinous process?
note long an sliding arrangement of spinous processes
attachments for muscles
+ articular surfaces for ribs
lamina extend posteriorly and unite to form spinous processes
describe articular surfaces for ribs on T6 and T7
on body of T7 (close to pedicle) - can see superior and inferior demi-facets
- will articulate with head of rib 7 but also rib 8 inferiorly
- head of rib 7 will also articulate with vertebrae above (T6)
articular surface of transverse process
- articulates with tubercle of the 7th rib
types of ribs
classification of ribs
atypical ribs?
ribs 1, 2, 10, 11 + 12
head articulates with body of own vertebrae but also with vertebra above (and with intervertebral disc via the crest)
tubercle - non articular part provides attachment for costotransverse ligament
most curved part of rib body?
costal angle
where is cosal groove?
purpose?
it is an indentation on the internal surface of the inferior border of the body of the rib
provides protection for intercostal vessels and nerves
what makes rib 1 atypical?
what is significant about the bony feature that seperates these grooves?
(pic is superior view)
single facet on head - articulates with T1 only
grooves for subclavian vessels on superior surface (seperated by scalene tubercle)
- scalene tubercle is attachment for anterior scalene muscle of the neck
what makes rib 2 atypical?
(pic is superior view)
has many typical features but is called atypical because it has a rough area on upper surface called = tubersoity for serratus anterior
- attachment site for serratus anterior muscle
what makes ribs 10, 11 and 12 atypical?
(image superior view)
10, 11 + 12 = single articular facet on head, articulates with single vertebra
11 + 12 = very short with no neck or tubercle
divisions of the sternum?
connected by?
manubrium, body and xiohoid process
- manubrium + body connect at sternal angle (manubriosternal joint)
- body and xiphoid process connect at xiphisternal joint
bony features of manubrium?
jugular notch superiorly
clavicular notche son either side of JN = articular surfaces for the clavicles
lateral border of sternum?
articulations?
lateral border has a number of indentations called the costal notches
- 7 costal notches for articulations of costal cartilages of the ribs
1st rib articulates with manubrium adjacent to the clavicular notch
2nd rib articulates at the sternal angle
ribs 3-6 articulate along the side of the body of the sternum
7th rib articulates at xiphisternal joint
level of sternal angle?
rib 2
intervertebral joints?
orientation of articular facets in thoracic region of vertebral coloumn?
intervertebral discs between bodies of vertebrae = secondary cartilagenous joints
synovial plane joints between superior and inferior articular facets (NOT costal facets) - zygapophyseal joint
orientation of articular facets in thoracic region allows rotational movement to occur between the vertebrae
zygapophyseal joint?
synovial plane joints between the articular processes of two adjacent vertebrae
also called facet joints
sternocostal joints?
explain
interchondral joints?
joints between costal cartilages of the ribs and the sternum
rib 1 = primary cartilagenous joint (synchondrosis)
rib 2-7 = synovial plane joints
interchondral joints (joints between costal cartilages) between 6+7, 7+8, 8+9, 9+10
- 6+7, 7+8, 8+9 = synovial plane joints
- 9+10 = fibrous joint
costovertebral joints?
type?
movement?
found between ribs and vertebrae
in image can see 7th rib with head of 7th rib articulating with body of T6+T7
- can also see tubercle of 7th rib articulate with transverse process of T7
-
all of these joints are plane synovial joints
- NOTE: movements will occur at joints formed by head and tubercle (rib moves around an axis that runs between both of these joints)
movement of ribs during respiration?
determined by axis of rotation
- upper ribs = more lateral xis - greatest degree of movement at anterior aspect of rib “pump handle movement”
- ribs 1-6
- lower ribs = more posterior axis - greatest degree of movement at lateral border of rib “bucket handle movement”
- ribs 7-12
rib cage changes in dimension during respiration?
on inspiration rib cage expands along 3 different axis
- sternum + upper ribs move anteriorly and superiorly = increases anterior-posterior dimension
- lower ribs flare out laterally = increases lateral dimension
- diaphragm descends = increases vertical dimension
primary muscle of inpiration at rest?
diaphragm
movements of rib cage are minimal (become more pronounced during forced inspiration and expiration)
thoracic wall muscles?
secondary muscles of respiration?
superficial muscles associated with upper limb and anterior abdominal wall?
upper limb and anterior abdominal wall muscles?
innervation?
pectoralis minor deep to pectoralis major
serratus anterior = muscular bands wrap around latral thoracic wall and attach on lower ribs (gets name from serrated appearance)
rectsu abdominus - run vertically on either side of the midline
fibres of external oblique = hands in pockets
…
secondary muscles of respiration?
attachments?
innervation?
2 serratus posterior muscles - superior and inferior
- superior = medially attached to spinous processes of C7-T3 then extends inferolaterally towards upper borders of ribs 2-4
- inferior = medially attached to spinous processes T11-L2 then extends superolaterally towards lower borders of ribs 8-12
there are 3 scalene muscles on either side of the neck - anterior, middle and posterior
- proximal attachments on transverse processes of cervical vertebrae
- distal attachments - 1st rib for anterior + middle scalene, 2nd rib for posterior scalene
scalene muscle function?
innervation?
movement of the neck
when neck is fixed, can also act as accessory respiratory muscles
(raise 1st + 2nd ribs)
serratus posterior muscle function?
innervation?
main function thought to be proprioception
superior muscle may assist with raising upper ribs
+ inferior muscle may assist with lowering the lower ribs
which muscles are found in the intercostal spaces?
from superficial to deep = external intercostal, internal intercostal, innermost intercostal
external intercostal muscle fibres?
found where?
function?
pass downwards and forwards (hands in pockets) from lower border of one rib to upper border of the rib below it
they extend from the tubercles of the ribs to the costochondral juction (most obvious posteriorly and laterally on the thoracic wall)
- beyond this point they are replaced anteriorly by the external intercostal membrane (extends between costal cartilages towards sternum)
raise the ribs in inspiration
internal intercostal muscles
found where?
function?
fibres pass dowards and backwards from lower border of one rib to upper border of rib below (hands on chest) - at a 90* angle to external intercostal muscles
- internal intercostal muscle most obvious anteriorly on the thoracic wall
- extends from sternum to angle of ribs - after which it is replaced posteriorly by internal intercostal membrane
1 - interosseus part (i.e. between ribs) depresses ribs on expiration
2 - interchondral (between costal cartilages) part raises ribs on inspiration
innermost intercostal muscles found?
direction?
features
deep to lateral part of internal intercostal muscles
fibres pass dowards and backwards (same direction as internal intercostals)
very thin, often incomplete layer (difficult to distinguish from internal intercostal)
deepest muscles of thoracic wall?
attachments?
what lies superficial to transversus thoracis?
subcostal muscle + transversus thoracis muscle
internal thoracic vessels lie superficial to transversus thoracis (run on either side of the sternum)
what is intercostal space?
contains? (2)
space between adjacent ribs
contains intercostal muscles
neurovascular plane is found between internal and innermost intercostal muscles:
- contains intercostal Vein, Artery and Nerve (superior to inferior)
- run in costal groove at inferior border of rib
- (also give off branches that can be found near upper border of rib)
…
intercostal nerve function?
within each intercostal space, there is intercostal nerve
this nerve will supply intercostal muscles
- will also give lateral and anterior branches that pierce through muscle layer into skin where they supply sensory innveration
arterial supply to intercostal space?
branches?
majority by posterior intercostal arteries (most branch directly from the aorta)
- posterior intercostal artery will also give cutaneous branch whcih passes through muscle walls to supply the skin
anterior part of intercostal space supplied by anterior intercostal artery (branch directly from internal thoracic artery)
- will give anterior perforating branch to supply the anterior skin
posterior intercostal arteries branch from?
1 + 2 from supreme intercostal artery (branch of costocervical trunk from subclavian artery)
3-11 and subcostal artery branch directly from thoracic aorta
(will see in posterior mediastinum dissection)
which intercostal spaces also have an anterior intercostal artery?
branch from?
what does internal thoracic artery branch from?
where is it found?
what does it become?
intercostal spaces 1-9 have anterior intercostal artery (in addition to posterior)
- 1-6 direct from internal thoracic artery
- 7-9 from musculophrenic artery
Internal throacic artery branches from the subclavian artery
internal throacic artery bifurcates to give superior epigastric artery and musculophrenic artery
venous drainage of thoracic wall?
follows similar pattern to arterial supply
- anterior intercostal veins drain to –> internal thoracic vein
- runs alongside internal thoracic artery
- posterior intercostal veins drain to –> azygos/hemiazygos veins
- azygos vein on right
- hemiazygous and accessory hemiazygous on the left
can see posterior intercostal veins draining into (hemi?)-azygos vein
can also see posterior intercostal arteries coming from the aorta
…
where is breast located?
anterior surface of pectoralis major muscle (also has axillary tail which extends laterally towards axilla)
glandular tissue of breast oragnised into?
what happens during lactation?
where do lobules open into?
glandular tissue of breast oragnised into lobules
in resting state these lobules are small - during lactation they enlarge and produce milk
lobules of mammary gland open into nipple via lactiferous ducts
how is glandular tissue of breast supported?
organised into? - function?
supported by fibrous tissue
organised into thick fibrous bands called suspensory ligaments
- provide support
- anchors breast at dermis of the skin
…
blood supply to breast?
venous drainage?
medial and lateral mammary arteries
- lateral mammary arteries branch from lateral thoracic artery (whcih branches from axillary artery)
- medial mammary artery branches from internal throacic artery
venous drainage follows similar pattern
- lateral mammary vein
- medial mammary vein
lymphatic drainage of breast?
within breast there is subareolar lymphatic plexus
- from here, most (>75%) lymph drains to axillary nodes
- remainder will drain to parasternal lymph nodes and some to abdominal nodes
layers of thoracic wall dissection
1st layer = skin
2nd layer = superficial fascia (carries superficial blood vessels and nerves that supply the skin and fascia), will probabably see subcutaneous fat in this layer
3rd layer = muscles
- pectoralis major, serratus anterior, external oblique muscles
- in image you can see the nerve that supplies serratus anterior (long thoracic nerve) on the scissors
note muscular bands that give serratus anterior its serrated appearance
The intercostal nerves form branches that supply motor innervation to the intercostal muscles but also carry sensory fibresfrom the skin. Photograph A shows some of these nerves as they pierce through the muscle of the thoracic wall and enter the superficial fascia
Pectoralis minor lies inferior to pectoralis major on the anterior thoracic wall. Photograph B shows pectoralis major reflected away from the ribs and pectoralis minor passing to ribs 3-5
The pectoral muscles are innervated by the medial and lateral pectoral nerves. The nerves are named for the cords of the brachial plexus from which they originate, not for their position on the thoracic wall
Photograph A shows the lateral pectoral nerve (raised by the forceps) piercing through the posterior surface of pectoralis major. This muscle is also innervated by the medial pectoral nerve
Photograph B show part of the medial pectoral nerve piercing the posterior surface of pectoralis minor and pectoralis major (raised by the forceps in the photograph)
Photograph B shows serratus anterior reflected away from the thoracic wall to reveal one of the external intercostal muscles lying between the ribs. External intercostal is more muscular posteriorly and laterally
It becomes membranous anteriorly, as shown by the blue arrows on the photograph
Pic A shows some of the muscle fibres of internal intercostal visible through the membranous part of external intercostal (indicated by the arrows). Internal intercostal is more muscular anteriorly and laterally and becomes membranous posteriorly
Pic B shows the initial stages of removal of the anterior thoracic wall. The ribs have been sectioned and the left lung is just visible. You can also see the internal thoracic vessels that lie either side of the sternum
Once the ribs have been sectioned the thoracic shield can be lifted away from the heart and lungs, this is shown in photograph A. Note the presence of transversus thoracis muscles radiating from the sternum to the ribs.
Photograph B shows the innermost intercostal muscles visible through the costal parietal pleura (shown by arrows on the photograph)
function of non-articular part of tubercle?
non articular part provides attachment for costotransverse ligament
Divisions of the thoracic cavity? (3)
What do they contain?
pulmonary cavities contain lungs
between pulmonary cavities there is the mediastinum (all other organs of throax including heart contained here)
lining of pulmonary cavities?
purpose?
lined by serous membrane called pleura
produces fluid to lubricate movement of organ in the cavity
pleura divided into?
are they completely separate layers?
parietal = lines pulmonary cavity, has cervical, costal, diaphragmatic and mediastinal parts
visceral = covers surface of lung
no - continuous at lung root/hilum
sleeve of pleura hanging down below lung root? purpose?
layer of connective tissue that attaches… to …?
sleeve of pleura hanging down below lung root = pulmonary ligament
- allows expansion of vessels in the hilum e.g. during exercise
layer of connective tissue that attaches costal parietal pleura to thoracic wall = endothoracic fascia
endothroacic fascia?
continuous with?
attachments?
endothoracic fascia = layer of connective tissue that attaches costal parietal pleura to thoracic wall
superiorly (yellow part of image) - it is continuous with fibrous suprapleural membrane
suprapleural membrane has attachments on 1st rib and transverse process of C7
what is purpose of suprapleural membrane?
prevents expansion of lungs up into the neck
surface markings of pleura and lungs described when?
where do lungs/pleura extend to at mid-isnpiration?
usually described at mid-inspiration
at mid inspiration lungs/visceral pleura:
- extend in mid-clavicular line to level of 6th rib
- mid-axillary line to 8th rib
- scapular line to 10th rib