Cardiopulmonary Module: Thoracic Cage

CARDIOPULMONARY MODULE

• Cardiopulmonary module is on structures and functions of the respiratory and circulatory system

Thoracic Cage

• The thoracic cage is the osteocartilaginous framework forming the thoracic skeleton
• It has a conical shape, with the anterior wall being shorter than the posterior wall
• It is formed by the sternum, costal cartilages, thoracic vertebrae, intervertebral discs, and ribs, including 12 pairs of ribs, mainly shaft (on each side).
• It supports and protects thoracic and upper abdominal viscera and participates in respiratory movements

Thoracic Cage Parts

• Inlet: Narrow and continuous with the neck root
• Cavity: Encloses thoracic structures including the lungs and heart
• Outlet: Broad and closed by the diaphragm, separating it from the abdominal cavity

Thoracic Inlet

• The upper narrow opening connects the thoracic cavity with the neck root.
• Its plane is oblique, sloping downwards and forwards
• It is bound by the upper border of the manubrium sterni (in front), the body of the 1st thoracic vertebra (behind), and the inner border of the 1st rib (on each side)

Structures Passing Through the Thoracic Inlet

• In the middle: trachea and oesophagus, along with the left recurrent laryngeal nerve in between
• On each side: lung apex, the internal thoracic artery (anterior), three structures behind the lung (in front of the 1st rib neck), including the sympathetic chain (medial), the ventral ramus of T1 (lateral), and the superior intercostal artery (in between
• Between the lungs and midline structures: brachiocephalic artery (on the right), left common carotid and left subclavian arteries (on the left), and left and right brachiocephalic veins (on either side). Also: left and right phrenic and vagus nerves (on either side)

Suprapleural Membrane (Sibson's Fascia)

• Triangular in shape, with the apex posterior and the base anterolateral
• Apex attachments: C7 transverse process
• Base attachments: inner border of the 1st rib and its costal cartilage
• Functions: protects the lung apex and cervical pleura, prevents inward suction of structures at the neck root during inspiration, and prevents upward bulging of the lung apex during forcible expiration

Thoracic Outlet

• Defined as the lower broad opening, which is closed by the diaphragm
• Its plane is oblique, sloping downwards and backwards.
• Boundaries include the xiphoid process (in front), the body of the 12th thoracic vertebra, 11th and 12th rib pairs (behind), and the 7th, 8th, 9th and 10th costal cartilages (on each side)

Sternum

• The sternum consists of three parts: the manubrium sterni (upper part), body, and xiphoid process (lower part).

Features of the Manubrium Sterni

• Superior border: presents the suprasternal (jugular) notch (at the level of the T2 lower border)
• Superolateral angle: presents the clavicular notch, which articulates with the clavicle, medial end forming the sternoclavicular joint
• Lateral border: has a notch (articulates with the 1st costal cartilage) and a demifacet (for the upper half of the 2nd costal cartilage)
• Inferior border: articulates with the body, upper border forming the manubriosternal joint (junction)

Sternal Angle

• The sternal angle forms a forward projection called the sternal angle of Louis
• The Louis sternal angle is at the level of the T4 lower border or disc between T4/T5
• An important landmark demarcating the 2nd costal cartilages

Features of the Sternum Body

• Opposite T5, 6, 7, 8 & upper part of T9 vertebrae
• Lower border articulates with the xiphoid process at the xiphisternal junction (at the level of T9)
• Lateral border carries notches that articulate with the 2nd costal cartilage, lower half, 3rd, 4th, 5th & 6th costal cartilages as well as the 7th costal cartilage, upper half)

Features of the Xiphoid Process

• Usually remains as cartilage
• Its lateral border articulates with the 7th costal cartilage, lower half

Posterior Relations of the Sternum

• Anterior borders of lungs & pleurae (Laterally)
• Aortic arch (behind lower 1/2) & its branches (behind upper 1/2)
• The left Brachiocephalic Vein (behind the upper 1/2 crossing in front of arteries)
• Anterior borders of the Right lung & pleura (behind the whole Rt. side)
• Pericardium and the heart (behind the Lt side, cardiac notch)
• Liver and the falciform ligament (behind the Rt side lower half)

Clinical Points Regarding the Sternum

• Sternal Puncture: the bone marrow specimen (biopsy) can be taken from the sternum being subcutaneous and having a thin cortical layer
• Sternal Splitting: the whole sternum may be split longitudinally in modern cardiac surgery to gain heart access, with the manubrium can be split in middle to reach the superior mediastinum in retrosternal thyroid gland operations

Structures at the Sternal Angle Plane

• T4 lower border at the angle plane
• The ascending aorta end at the at the sternal angle plane
• The aortic arch (beginning and end) is at the sternal angle plane
• The descending aorta (beginning) is at the sternal angle plane
• The pulmonary trunk (bifurcation) is at the sternal angle plane
• The superficial cardiac plexus and ligamentum arteriosum are at the sternal angle plane
• The tracheal (bifurcation) & deep cardiac plexus
• The thoracic duct (reaches oesophagus Lt. side)

Thoracic Transverse Planes & Levels

• Thoracic inlet plane: Oblique, extending from the manubrium upper border (in front) to the upper border of the T1 vertebral body (behind)
• Manubrium upper border: (Suprasternal or jugular notch), opposite the lower border of T2 vertebral body or disc between T2/T3
• Sternal angle plane: Between the manubriosternal junction & T4 lower border or disc between T4/T5
• Xiphisternal junction & xiphoid process: Opposite the T9 body

Typical Thoracic Vertebrae

• Ant. vertebral part transmitting body weight, bodies articulate by intervertebral discs of fibrocartilage
• The vertebral (neural) arch is attached to vertebral body, consists of 2 pedicles, 2 lamina, & has 7 processes
  • Two short bars extending from the body, upper & lower borders
• Lamina: two broad flat plates extending backwards & med. to fuse forming spine
• Processes: Transverse, two horizontal, each projects lat. from the junction of the pedicle and its lamina
  • Spine: midline, projects backwards, serve as levers for vertebral column rotation & extension
• Articular processes: Each has 2 superior & 2 inferior, projecting from the lamina, upwards and downwards (has an articular facet)
• The vertebral foramen: Between vertebral body & arch, successive vertebral foramina form vertebral canal
• The spinal cord, meninges, arteries & veins, and roots & ganglia nerves lodge in the vertebral foramen

Thoracic vertebrae:

• The classification is T2-T8 vertebrae are typical
• Non-typical are T1, T9, T10, T11 & T12 vertebrae

Typical Thoracic Vertebra -Characteristics

• Heart-shaped & carries on each side 2 costal demifacets for ribs heads
• Each vertebra articulates with 2 ribs on each side, rib with the same number as the vertebra & rib below
• Vertebral foramen circular
• Transverse processes: Each carries costal facet for facet on rib tubercle with same number as vertebra
  • Long with pointed tip, directed downwards & backwards
• Articular processes, nearly vertical, on superior aspects face backwards while inferior aspects face forwards

Non-typical Thoracic Vertebrae

• T1: Body has complete circular facet for 1st rib head & inf. demifacet for upper facet of 2nd rib head, spine long & nearly horizontal
• T9: Body has 1 superior demifacet for the lower facet on the 9th rib head
• T10: Body has 1 complete oval facet for the 10th rib head
• T11: Body has 1 complete circular facet for 11th rib head
• T12: Body has 1 complete circular facet for 12th rib head, the inferior facets are directed laterally (as lumbar vertebrae)

Thoracic Vertebrae Joints

• Between vertebral bodies (intervertebral discs): 2 ry cartilaginous
• Between articular processes: Synovial plane joints
• Between laminae, between transverse processes and spines: fibrous joints (connected by ligaments)
• Allows for twisting of vertebrae

Ribs (costae)

• Twelve pairs articulating behind with thoracic vertebrae and separated by intercostal spaces
• Each intercostal space lies below its corresponding rib
• First and last ribs are difficult to palpate, count from the second rib as it articulates at the sternal angle

Ribs Types:

• According to articulation at sternum: True, false, vertebrochondral, floating
• According to vertebral articulation: Typical (3rd to 9th), non-typical (1st, 2nd, 10th, 11th & 12th)

According to Articulation

• True ribs: upper 7 pairs, costal cartilages directly articulate anteriorly with sternum (vertebrosternal)
• False ribs: lower 5 pairs, do not join sternum directly. Includes, the vertebrochondral (8th, 9th and 10th) (attach to costal margin), and the floating ribs (11th & 12th), where cartilage tips is free and ending in abdominal muscles

According to Features

• Typical ribs (3rd to 9th): their basic features & & each articulates with 2 successive vertebrae, it’s own and one above
• Non-typical ribs (1st, 2nd, 10th, 11th & 12th), a differ in one or more feature & articulate only with vertebra of same number (except 2nd which articulates with T2 & T1)

Features of Typical Ribs

• Anterior end (shows notch articulating with its costal cartilage)
• Shaft: Curved with angle dividing it into ant. 3/4 (flattened) & post. 1/4 (cylindrical) parts (Upper border is thick & rounded, while lower border is thin & sharp, outer surface is convex & rough, while inner surface is concave & smooth showing costal groove which lodges intercostal VAN)
• Posterior end (includes head, neck & tubercle): head bears 2 facets & crest in between, articulating with 2 vertebrae & the disc in between, the neck is flattened, the tubercle 2 parts (lat. rough & med. smooth)

Side Identification

• Posterior end indicates head, neck & tubercle, upper border is thick and rounded, outer surface is convex

Features of the 1st Rib

• Highest, shortest, most curved & most fixed rib
• Anterior end: thick
• Posterior end: head with one facet articulating with a circular facet on the T1 body, a rounded neck, and tubercle coincides with the angle
• Shaft: Flattened & has no angle, with a concave inner border attachment to the suprapleural membrane (marked at its middle by the scalene tubercle, an outer border is convex and shows at its middle serrate tubercle
• Lower surface: smooth
• Middle surface: has no costa groove , lies on pleura with a ridge extending from the scalene tubercle which separates into 2 shallow grooves. the In front of and behind the scalene tubercle

2nd Rib

• Outer surface is convex upwards & lat. and inner surface is concave downwards & med. and ribbed serrate tubercle at its middle

10th Rib:

• Head may carry 2 facets & articulate 2 vertebrae or one with the bodies of the T10 vertebrae only

11th and 12 Ribs:

• Head is large, bears one facet articulating with corresponding vertebra
• No neck & no tubercle, pointed anterior end. Both ribs in that, 12th rib is
• Shorter, has no angle & no costal groove

Rib Fractures

• Rare in children with elastic chest walls, common in adults from direct impact or indirect crushing
• In crushing, the ribs usually break at their angles, Broken ribs can pierce pleura & lungs causing pneumothorax, or injuries resulting in internal hemorrhage
• Upper 2 least likely to be broken

Respiratory paradoxical movements

• Several ribs are fractured at angles
• Loose flaps suck during inspiration & blown out due to normal respiratory movements

Thoracic Cage Joints:

• Sternal joints (manubriosternal & xiphisternal)
• Vertebral joints
• Costal joints

Vertebral Column

• Average adult: 70 / 65 cm
• Curvatures: Anterior-posterior, concavity directed Anterior
• Secondary- Cervial 3rd to 4th month when baby raises/supports head.
• Sacral remains concave anterior and is slightly convex, right-handed individuals

Ribs component

• vertebrae (3/4), separate vertebrae 7 cervical, 12 thoracic & lumbar
• Fused and vertebrae (1 /4) to vertebral column. 5 sacral, 3/4 Coocygeal)
• Intervertebral disc made up from annulus fibrosas material

Body

• Ant, noted above and below forming inter-vertebral forum
• Lemina has both anterior and posterior

Joint Between Vertebrae

• Secondary cartilage intervertebral. between 2 vertebral
• Between superior and inferior, articular ligaments between vetebrae (longitudinal, flavum, inters tranverse, inters pinous, and supraspinous)

Identification to Vertebrae

• Transverse in precess, and Cervical, thoracic or lumbar

INERCOSTAL SPACES

• Gaps that below ribs
• There are 11 intercostal spaces and the upper 9 spaces are complete while the two are incomplete.

INTERCOSTAL MUSCLES

• The External intercostal (External intercostal rib above and to tube above)
• The Direction of to downward/ upward rib
• Innermost intercostal nerve of branch

INTERCOSTAL BUNDLE

• Each bundle is lying between internal, intercostal and the vessels arranged as van rib lining
• There are twelve thoracic nerves but only eleven branches innervate
• The cordials thoracic make up inner vessels

Typical Intercostal Nerves

• Course, post, to medial and related and to the Costal Grove
• ganglonic to gangl on by 2 communication, collagen from angle supplies inter costa

Thoracic Veins

• Azgos stems are connecting back V.C in adbocmen to back, of SV.c and thorax
• It trains most direclty side from rt and indirect side from and inf

Intercostal Venis

• drains into upper to lower based on level

Vertical lies

• Midline vertical lines in the median plane
• Midclivicular line vertical midclavicular lines
• Scapular line: is on post thoracic wall through inf angle of scaplua

Lungs

• Organs of atmospheric air
• Apex, Base, medial 2 surfaces and have 3 borders upper and
• Apex are rounding. In neck, thoracic Inlet are above to Med clavicle is covered. By sura membrane and is good

base

• The base rest diaphragm and the surface base from Rt liver and Lt liver and to Spleen

Borders

• Media surface by hillum by several groups and impressions for medial surface border

Transverse/ longitudinal

• It's on one side only with a deep cut and is in costal medistinum surface and the level above 4 level

fissures

• Superior cut into media surface where media lower surface then the surface and to end and

Rt lung

• Lower one is equivalent above meddle lungs base has cardic knot
• Deeper than mediastrium and surface (aortic/esophage)

SURFACE ANATOMY

curvilinear convex upwards where the is point is on

the Junction

• surface landmark of oblique and horixonal

Relations of lung, medial surface impression in lung and pulmonary ligament

• medial surface and where diaphragm
• impression, the trachea

Relations for Grooves Above to hills

• The narrow continuous groove connected to arch
• Related arch and the vagus nerve

THE SUPERIOR SIDE

• The esophagus

Blood supply Lymphthatic

• P.A is oxygenated and as branches
• These segamtnel are ended and do not anasimotise

Lt brochinus is 2

• Rt has 3 bronchus but Lt has 2 bronciy and segment lung tissue

Constitents

• A segment is in respiration and has to be bronces and have alvei
• Segmented or and 2-3 Blood nerves

Blood Supply

• Most of lungs area bloods the upper supply

Pulmanary Vasculature:

• The pulm veins that each is drained has (I and 2)

Lymphatics;

• Has branchiles to 3 lumbs

Clinical Points

• 1st breath leads to becoming the first breath
• The 2rd if part disease is remove

Lung (Right-Left) Difference

• Lt Long has more projection to Large Rt
• Has 2 fissures to compare Rt has one fisure in it
• Has greater and large Capacity in heart protection

Pericardium

• Conial and tissue

Defintion

• That middle is it is the mediastrium side

THE SITE

• From sterna to angles and adjoing cartilages from

IN CLUDE THE PARTS

• Visceral Layer inner surfaces and great vessels

TRanverse Sinus

It has passage a great end and RT and IT to pericardial cavity

function

• is for the diaphragm

Definitons

• Heart is musculr. orgab to pump blood
• slightly large and to 12 cm

Heart Def (site)

It is lies the in thoracic is mediastrim and behind joining costing

• Size large from base to Apex

Chambers

• Anaotonmical is 4 chambers to artia, where they (recive blood. & 2 renticlule = pumping to blood
• the Heart pump and right has to pumps each has recives

The Surface Heart Features

The surface borders where and the diagrmatic with border from right

Interal Right side Atrium

• smooth walls is 3m thick

Venous Receivers

Venis smooth to blood and deoxygenates and

• Has some veins on to that level to the orifcle

interartrial

Is smooth to that side and obliqure

• and has to oval

Lt Atruim

• smaller that and post

Post Sptum

• This forms on both sides to right

Trancuspi

• Which has has and to trunckle

Internvicular Septum (IVS)

• is separate both to that

The Rt Ventricole

Innerior that its and lumen and

the in flow part

• has the to valve and wall which can the the wall is muscle
• the paplillary comes

Heart FIXation:

-Periclardum structures to support.

• C) Pleurate and side by side. and supports has support them

DEvelopment Arterial

• The arteries 1 appear, the parts heart tubes with followngs the
• The ventral and the dorsata

Sac

• The has tube singole sac from stem from horns and to upper

Arches

• As for develop
  1. has pairs which is conected
  2. the formed which in the 3rts

Arterol System

1. Heart are Arches in development 5 -4 week diureticulum

Cartilago

And structure forms cartilage