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
where does parietal pleura extend to at mid-inspiration?
attachments of parietal pleura will not change with inspiration and are usually 2 ribs below the level of the lungs
- mid clavicular line = rib 8
- mix-axillary line = rib 10
- scapular line = rib 12
parietal pleura extensions create?
extensions of parietal pleura create costodiaphragmatic recesses
- costomediastinal recesses are found posterior to the sternum (larger on left due to cardiac impression)
…
Features of lungs?
surfaces?
borders?
lobes?
lobes of left lung?
right lung?
left lung = superior + inferior lobe (divided by oblique fissure)
right lung = oblique fissure separates superior and inferior lobe (+ inferior and middle lobe), horizontal fissure separates superior lobe from middle lobe
…
impressions on right lung?
largest impression created by right atrium of the heart (still small compared to cardiac impression on left lung)
SVC leaves impression as it runs towards right atrium of the heart - upper part of this impression is created by right brachiocephalic vein
(the 2 brachiocephalic veins unite to form the SVC)
other impressions by azygos vein + oesophagus
arrangement of structures in hilum of right lung?
largest of these structures?
largest = pulmonary veins (anteriorly and inferiorly)
pulmonary arteries = more superiorly
right main bronchus = posteriorly
…
where is lingula located?
what is it?
inferior anterior border of left upper lung lobe
it is analogous to the middle lobe of the right lung
where is lingula located?
what is it?
inferior anterior border of left upper lung lobe
it is analogous to the middle lobe of the right lung
impressions of left lung on mediastinal surface?
very pronounced cardaic impression on left lung (left ventricle of heart)
arch of aorta above lung hilum and descending aorta posterior to the hilum
impression extending off arch of aorta = left subclavian artery
arrangement of structures in hilum of left lung?
pulmonary veins = anteriorly and inferiorly
pulmonary artery = superiorly
left main bronchus = posteriorly
arrangement of structures in hilum of left lung?
pulmonary veins = anteriorly and inferiorly
pulmonary artery = superiorly
left main bronchus = posteriorly
how to orient yourself at lung hilum?
pulmonary veins = always most anterior and inferior structures (always at least 2 pulmonary veins present)
pulmonary arteries = located superiorly in the hilum
bronchus = located posteriorly in the hilum (very easy to identify because can feel for cartilage in its wall)
relations of the right lung hilum?
azygos vein posteriorly and arching over top of the hilum to empty into SVC (anteriorly)
oesophagus posteriorly
2 important nerves
- vagus nerve will always travel posteriorly to hilum
- phrenic nerve will always travel anteriorly to hilum
relations of right lung hilum?
azygos vein posteriorly and arching over top of the hilum to empty into SVC (anteriorly)
oesophagus posteriorly
2 important nerves
- vagus nerve will always travel posteriorly to hilum
- phrenic nerve will always travel anteriorly to hilum
relations of left lung hilum?
arch of aorta above left lung hilum, and descending thoracic aorta posteriorly
vagus (posterior) + phrenic nerves (anterior)
on left side, vagus nerve will also give recurrent laryngeal nerve which loops underneath arch of the aorta
bronchial tree?
trachea will bifurcate at level of sternal angle into right and left main bronchus
- RMB will further subdivide into 3 lobar bronchi (superior, middle, inferior)
- LMB will subdivide into 2 (superior + inferior)
lobar bronchi will then further subdivide into many segmental bronchi (multicoloured branches) = supply segments of lung lobes
bronchopulmonary segmentation?
what is contained in each segment?
lobes of lungs divided into number of segments
- on left = 5 segments associated with superior lobe + 5 with inferior lobe
- on right = 3 segments with superior, 2 with middle, 5 with lower lobe
each segment will have: single segmental bronchus + single branch of pulmonary artery + single pulmonary vein
does respiratory tree end with segmental bronchi?
no - segmental bronchi will subdivide into bronchioles
types of bronchioles?
conducting
terminal
respiratory → connect to alveolar sac via alevolar duct
what is an alveolar sac?
function?
an air sac that has a profuse capillary network associated with it
gas exchange
lymphatic drainage of lungs?
within tissue of lungs, there are pulmonary nodes
as move towards the lung hilum, there are bronchopulmonary (hilar) nodes
surrounding point of bifurcation of trachea = superior + inferior tracheobrachial (carinal) nodes
either side of trachea = paratracheal nodes
…
Photograph C = blue paper has been used to highlight position of pulmonary artery and purple markers have been used to show positions of pulmonary veins
note at the hilum the bronchus is posterior and the pulmonary veins are anterior and inferior in position
on the left lung the pulmonary artery lies above the bronchus
Pic B = blue paper indicates position of pulmonary artery and purple markers indicate position of pulmonary veins
the bronchus is the most posterior structure at the hilum
the pulmonary veins are anterior and inferior
the pulmonary artery usually lies next to the bronchus in the right lung
mediastinum divided into?
separated at what point?
superior mediastinum
inferior mediastinum:
- anterior, middle + posterior mediastinum
separated at transverse thoracic plane - from sternal angle to IV disc between T4 + T5
middle mediastinum bounded by?
anterior and posterior?
fibrous pericardium of the heart
everything anterior to fibrous pericardium = anterior mediastinum
posterior is the same
anterior mediastinum boundaries?
contents?
boundaries
- body of sternum (anteriorly)
- fibrous pericardium (posteriorly)
- transverse thoracic plane (superiorly)
- diaphragm (inferiorly)
contents
- loose connective tissue
- fat
- lymphatics
- in children = thymus
- usually in superior mediastinum but as it is larger in children, it often extends below transverse thoracic plane into anterior mediastinum
middle mediastinum contents?
boundaries?
adjacent structures?
contents
- heart + pericardium
- roots of great vessels
bounded on all sides by pericardial sac
adjacent structures
- great vessels (pulm. a + v, aorta + SVC)
- phrenic nerves
- lung root structures
…
heart located?
relations?
heart is a midline structure located posteriorly to the body of the sternum (located slightly more to the left than to the right)
(⅓ right of the midline, ⅔ left of the midline)
right and left phrenic nerves
- right phrenic nerve associated with pericardium overlying RA
- left phrenic nerve associated with pericardium overlying LA and LV
fibrous pericardium continuous with?
superiorly = blends with tunica adventitia of great vessels
inferiorly = continuous with central tendon of diaphragm
what will you see if you open up fibrous pericardial sac?
sac itself is lined with parietal serous pericardium
this will be reflected onto surface of heart to form visceral serous pericardium
(from images you can see that there is a significant amount of fat deep to the serous pericardium on the surface of the heart)
arrangement of pericardium?
most superficially = tough fibrous pericardium (forming pericardial sac)
just deep to this = parietal serous pericardium
reflected over roots of great vessels onto surface of heart to become = visceral serous pericardium (also called epicardium)
between the 2 layers of serous pericardium = pericardial cavity (serous pericardium produces fluid that lubricates movements of the heart)
deep to epicardium = myocardium
lining chambers of the heart = endocardium
arrangement of serous pericardium creates?
how does T arise?
dissection?
arrangement of serous pericardium creates 2 pericardial sinuses = transverse pericardial sinus + oblique pericardial sinus
transverse pericardial sinus arises due to development of heart from simple heart tube with an inflow end + outflow end
- as heart develops it will close on itself, bringing 2 ends closer together + creating narrow channel between inflow and outflow vessels of heart
during dissection slide finger posterior to pulm. trunk and ascending aorta - ur finger is now in transverse pericardial sinus with outflow vessels in front of your finger and inflow vessels behind
what is the oblique pericardial sinus?
dissection?
space posterior to the heart
if you slide hand underneath and behind heart (fingers posterior to left atrium), fingers now within oblique pericardial sinus with pulmonary veins on either side
shape of heart?
borders?
base?
heart is trapezoidal shape
base of the heart is posterior aspect of the heart + made up of left atrium
anterior view of heart?
most of what we see is right side of heart
what separates right atrium from right ventricle?
what is found here?
what separates left and right ventricles anteriorly?
what is found here?
atrioventricular/coronary groove
groove contains the right coronary artery
anterior interventriclar groove
groove contains anterior interventricular artery (left anterior descending artery)
what enters right atrium?
what leaves left ventricle?
SVC + IVC enter right atrium
(IVC pierces through diaphragm and immediately enters inferior part of RA)
ascending aorta leaves left ventricle and then continues as aortic arch (arching over pulm. trunk as it divides into left + right pulmonary arteries)
what leaves right ventricle?
what enters left atrium?
pulmonary trunk leaves RV
right and left pulmonary veins enter LA
branches of the aortic arch?
what unite to form the SVC?
brachiocephalic trunk, left common carotid and left subclavian
SVC = brachiocephalic veins
posteroinferior view of the heart?
most of what we see is left side of heart
base of heart can be seen (mainly LA)
left pulmonary surface of heart?
diaphragmatic surface of heart?
seen posteroinferiorly
mainly composed of left ventricle
diaphragmatic surface = left + right ventricles
what separates left and right ventricles posteriorly?
where is it found?
posterior interventricular groove
runs along position of interventricular septum between left and right ventricles
shiny surface caused by serous visceral pericardium
deep to this layer is significant amount of epicardial fat
serous pericardium + epicardial fat cleared away
…
serous pericardium + epicardial fat cleared away
…
right coronary artery found?
left coronary artery divides into?
atrioventricular/coronary groove (between RA and RV)
left anterior descending artery (between right and left ventricle) + left circumflex artery (posteriorly)
ligamentum arteriosum?
function?
significance?
fibrous remnant of ductus arteriosus
DA allows communication between aorta and pulmonary trunk during foetal life (i.e. allows blood to bypass the lungs)
useful landmark - left recurrent laryngeal nerve runs posterior to it in the adult
(ligamentum arteriosum shown by blue arrow)
where is ligamentum arteriosum found?
between pulmonary trunk and arch of aorta (remnant of ductus arteriosus)
arteries that supply the heart arise from?
names?
arteries that supply the heart arise from ascending aorta
right and left coronary artery
right coronary artery branches?
first branch is small SA nodal branch = supplies SA node in wall of right atrium
right coronary will then continue in atrioventricular/coronary groove (will give off numerous branches to supply walls of RA and RV)
before turning into inferioposterior surface of heart, will give off right marginal branch (runs along inferior border of RV)
will then continue to inferoposterior surface of heart in AV groove and will give off AV nodal branch (located in wall of RA)
right coronary artery will then terminate by giving posterior interventricular artery which runs in posterior interventricular groove (between RV and LV)
left coronary artery branches?
by comparison to RCA, LCA is very short vessel quickly terminating as circumflex artery and anterior interventricular artery
anterior interventricular artery/LAD in anterior interventricular groove (between RV + LV)
anterior interventricular artery will give diagonal artery
circumflex artery will continue to posterior aspect of the heart (runs in left atrioventricular groove between LA + LV)
- before it passes to posterior surface it will give left marginal branch that runs along left border of heart
- it will then continue in AV groove ultimately anastomosing with RCA
variation in arterial supply of heart?
SA nodal branch + posterior interventricular artery can sometimes arise form circumflex artery
diagonal artery not always present in all individuals
areas of heart supplied by RCA?
basically right side of heart:
right atrium + most of right ventricle
SA (usually) and AV nodes
posterior ⅓rd of interventricular septum (via posterior interventricular artery)
part of left ventricle (again via posterior interventricular artery)
areas of heart supplied by left coronary artery?
left side of heart:
- left atrium + most of left ventricle
- anterior ⅔rd of interventricular septum (anterior interventriclar artery)
- AV bundle (part of the electrical component of the heart found within IV septum - so supplied by anterior interventricular artery)
- part of right ventricle via anterior interventricular artery
…
last pic can also see diagonal artery coming off of anterior interventicular artery
venous drainage of heart?
via cardiac veins
all veins drain to coronary sinus except anterior cardiac veins which drain directly to right atrium
what is coronary sinus?
coronary sinus = swollen venous structure on posterior surface of heart between LA + LV
all cardiac veins drain here except anterior cardiac veins (drain wall of RA and drain directly into RA)
cardiac veins?
found?
anterior cadiac veins (drain into RA)
great cardiac vein
- found in anterior IV groove alongside anterior interventricular artery
- will then curve around left border of heart to reach posterior surface where it empties into coronary sinus
middle cardiac vein
- posterior interventricular groove alongside posterior interventricular artery
small cardiac vein
- wall of RV alongside right marginal artery
- will curve around inferior border of heart to reach posterior surface where it empties into coronary sinus
main tributary to coronary sinus?
great cardiac vein
…
other venous structures on the heart?
(posterior surface of heart)
left marginal vein runs alongside left marginal artery
left posterior ventricular vein drains posterior wall of left ventricle
oblique vein of left atrium drains wall of left atrium
coronary sinus drains into?
coronary sinus opens directly into right atrium
…
internal wall of right atrium?
smooth area?
internal wall of RA can be divided into 2 distinct areas
- area with muscular ridges = musculi pectinati
- smooth area = sinus venarum
sinus venarum will connect entrance of SVC with entrance of IVC below
what separates sinus venarum and muscular wall of RA?
ridge called crista terminalis
interatrial wall (between RA and LA)?
what is this?
what can also be seen within right atrium?
there is a small thumb-shaped impression = fossa ovalis
fossa obvalis is a remnant of foramen ovale (allowed commonuication between RA and LA during development)
opening of coronary sinus can also be seen within right atrium
blood flow from RA to RV? found?
what is found along its margins?
function?
what else is found in right ventricle?
blood flows from RA to RV through tricuspid valve (can be found at right atrioventricular canal)
along margins of tricuspid valve there are string-like structures called chordae tendineae (found in right ventricle)
anchor valve at muscular projections of right ventricular wall called papillary muscles
a structure unique to right ventricle = moderator band
- extends from IV septum to anterior papillary muscle
- will carry part of conducting system of heart
muscular ridges in atrial wall?
muscular ridges in ventricular wall?
muscular ridges in atrial wall = musculi pectinati
muscular ridges in ventricular wall = trabeculae carneae
wall of right ventricle?
blood flow?
muscular ridges called trabeculae carneae
RA → RV → lungs via pulmonary trunk
…
internal wall left atrium?
however…
blood flow?
smooth and featureless
however, left atrium has left auricle as an expansion - auricle has muscular ridges called musculi pectinati
blood flows from LA to LV via bicuspid (mitral) valve
cusps of mitral valve connected to?
the 2 cusps of mitral valve connected at their edges by papillary muscles by chorda tendineae in left ventricle (anchors them to left ventricular wall)
features of left ventricular wall?
blood from LV?
much thicker than wall of right ventricle
will have numerous muscular ridges = trabeculae carneae
LV → aorta via aortic valve
blood flow through heart
- deoxygenated venous blood returned to RA via SVC + IVC
- pass through tricuspid valve to RV
- pumped into pulmonary trunk → lungs via pulmonary arteries
- pulmonary arteries only arteries in body that carry deoxygenated blood
- blood oxygenated in lungs + returned to heart via pulm. veins
- pulmonary veins only veins that carry oxygenated blood (4 total, 2 form either side)
- pulmonary veins enter LA
- LA → LV via mitral (bicuspid valve) → aorta via aortic valve
- rest of body
purpose of heart valves?
types of heart valve?
mechanisms of action?
ensures unidirectional flow of blood
2 types
- semilunar valves = aortic + pulmonary valves
- cuspid valves = mitral (bicuspid) + tricuspid
different mechanisms of action
-
semilunar valves open in response to high pressure (ventricles contract)
- valves closed in low pressure
-
cuspid valves open during low pressure
- close in response to ventricular contraction
how to semilunar valves close?
what does this allow?
when heart relaxes, blood will flow back towards ventricles
this blood will trickle in between cusp of valve and vessel wall (red dot) filling that space and forcing cusps of valve to close
this backflow also allows heart to receive blood supply through coronary vessels (remember coroanry arteries arise from acending aorta at level of aortic valve)
coronary arteries filled during low pressure via backflow of blood
what helps prevent prolapse of cuspid leaflets?
prolapse would allow regurgitation of blood back into atria
to prevent this happening chordae tendineae are anchored at papillary muscles and help to hold valve in place
papillary muscles will contract at same time as ventricles holding cusps in place :))
which valves are open during ventricular diastole?
systole?
diastole = cuspid valves open + semilunar valves closed
systole = cuspid valves closed + semilunar valves open
…
pulmonary valve cusps?
aortic valve cusps?
pulmonary = anterior, left + right
aortic = right, left + posterior
(can see opening of right coronary artery within the valve)
what are heart valves supported by?
other function?
fibrous skeleton of the heart
supports valves + electrical insulation between atria and ventricles (allows delay of contraction of ventricles until after atrial contraction)
pic = can see rings that support cuspid valves + coronets that support semilunar valves
SA node function? located?
signals?
located?
SA node (located in upper part of crista terminalis adjacent to entrance of SVC - in wall of RA) allows heart to regulate its own heart rate
signals from SA node pass through wall of right atrium + into wall of LA causing atria to contract at the same time
signals from SA node will also be picked up by AV node (located in lower part of interatrial septum)
AV node function?
how does it do this?
RV?
transmits signal from SA node into ventricles
does this via AV bundle which divides into right and left bundle branches
these bundle branches will give off many branches into walls of right and left ventricles
within RV - some fibres from RBB will travel via septomarginal trabecula (moderator band)
why do some fibres from right bundle branch travel via septomarginal trabecula (moderator band)?
ensures anterior papillary muscle + anterior part of wall of right ventricle contract at same time as rest of ventricular walls
SA node innervation?
effect?
can function without any external input from CNS - however, does receive autonomic supply via cardiac plexus
- parasympathetic - vagus (X) - intrinsic ganglia
- sympathetic - T1-T5/6 spinal levels - cervical and superior thoracic paravertebral ganglia (sympathetic chain)
parasympathetic = decrease HR + constrict coronary vessels
sympathetic = increase HR + dilate coronary vessels
what does cardiac plexus supply?
SA node
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pic A = fibrous pericardium, note fat on outer surface. Pericardial sac blends with fascia of diaphragm + great vessels
pic B = right and left phrenic nerves pass over fibrous pericardium on their way to supply innervation to diaphragm
pic C = surface of heart itself is only visible if pericardium is sectioned - parietal serous layer adheres to fibrous pericardium + visceral serous layer covers surface of the heart (visceral serous layer sometimes called epicardium)
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pic A = anterior surface of heart - RA, RV, LV can be seen. Aorta + pulm/trunk can also be seen (SVC seen lying behind aorta in this image but usually lies to the right of aorta)
pic B = roots of coronary arteries (fat usually surround surface of coronary arteries so have to remove this)
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coronary arteries
pic A - largest part of arteries as they leave ascending aorta
pic B - branches of right coronary artery on anterior surface of heart
pic C = anterolateral view of the heart, some branches of left coronary artery can be seen
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pic A + B = posterior surface of heart. LA + LV can be seen
there is fat associated with posterior surface of heart
pic C = shows middle + great cardiac veins
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pic A = external surface of RA, shows SVC as drains into RA, muscle of wall is deep red/brown colour
pic B = ridged patter of wall of atrium (musculi pectinati i.e. the pectinate muscles) - end/originate at crista terminalis
pic C = can see fossa ovalis
no photo of internal wall of LA as this is a mainly smooth wall except opening of pulm.veins and ridges inside left auricle
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when wall of RV is opened you can see trcuspid valve
3 valve flaps each attached to chordae tendineae and papillary muscles
moderator band (septomarginal trabecula)
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inner surface of both ventricles forms muscular network - trabeculae carneae
2 valve flaps in mitral valve - anterior an dposterior papillary muscles associated with them (pic B)
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pic A = semilunar valves + origins of left and right coronary arteries from ascending aorta
pic B = aortic valve - right, left cusps (associated with right and left coronary arteries) and posterior cusp
pic C = pulmonary trunk, right, left + anterior cusps
pic D = fatty plaque formation on flaps of aortic valve
