DIAPHRAGM THORACIC DIAPHRAGM - PowerPoint Presentation

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DIAPHRAGM

THORACIC DIAPHRAGM

Dome shaped

Musculoaponeurotic structureSeparates thorax from abdomen Forms roof of abdominal cavity & floor of thoracic cavity

Parts of thoracic diaphragm

Thoracic surface

: convex on right & left side but depressed in centre Summits of the convexities are c/as Cupolae

Right cupola is higher than left due to presence of liver

Abdominal surface :

concavePeripheral part :muscularCentral part : tendinous

THORACIC DIAPHRAGM(

contd

…..)Sternal heads: 2 fleshy slips from back of xiphoid process

Costal heads :

From inner surface of lower 6 ribs & their costal cartilages

Vertebral heads: A pair of crura A pair of medial arcuate ligament

A pair of lateral arcuate ligament

THORACIC DIAPHRAGM(

contd

…..)Right Crus of diaphragm: Right

crus

is longer & more muscular than left one .

Origin is from front of the bodies of L₁ - L₃ & interveining

intervertebral

discs .

THORACIC DIAPHRAGM(

contd

…..)Left crus of diaphragm:

shorter than right

crus

origin is from bodies & discs of L₁- L₂

left

crus

is attached to bare area of stomach by

Gastro

phrenic

ligament

both

crura

are connected to each other by a Median arcuate ligament

THORACIC DIAPHRAGM(

contd

…..)Medial Arcuate Ligament/ Medial Lumbocostal Arch

Bridges in front of

psoas

major Formed by thickening of psoas fascia Attached med to body of L

₁

- L

₂

Attached lat to transverse process of

L

₁

Lateral Arcuate Ligament/ Lateral

Lumbocostal

ArchBridges in front of

Quadratus lumborum

Formed by thickening of ant. Layer of

thoracolumbar

fascia Attachments : med… transverse process of L₁ lat….. Tip of 12th rib

THORACIC DIAPHRAGM(

contd

…..)Central TendonPresent in central depressed part

Trefoil leaf shaped with median, right & left leaflets

IVC opening present at junction of median & right leaflet

Left to IVC opening is central point of decussationSternal fibers are shortest Fibers from 9th

costal cartilage are longest

Openings in diaphragm

Venecaval

opening(T₈)Quadrilateral in shape

IVC

Branches of

Phrenic nerve Lymphatics from liver Oesophageal Opening (T

₁₀

)

Elliptical in shape

Oesophagus

Ant. & post.

Vagal

trunks Oesophageal branches of left gastric artery

Lymphatics

from liver

Phrenoesophageal ligament

Openings in diaphragm

Aortic Opening(T

₁₂)Rounded in shapeosseoaponeuroticBoundaries :median arcuate ligament (ant),

body of T

₁₂, both

crura on sides Abdominal aorta Thoracic duct

Azygos

vein (when its lumbar

azygos

vein )

Openings in diaphragm

Other Openings

Space of Larrey : Sup. Epigastric vessels & lymphaticsBetween costal origin & T.

abdominis

: lower 5 intercostal nerves & vessels

Between costal origin from 7th & 8th costal cartilage : musculophrenic vessels

Behind Lat . Arcuate ligament :

subcostal

nerve & vessels

Behind medial arcuate ligament : sympathetic trunk & least

splanchnic

nerve

Openings in diaphragm

Other Openings

Each crus is pierced by greater & lesser splanchnic nerves Left crus is also pierced by hemiazygos

vein

Left

phrenic nerve pierces left cupola in front of central tendon

Relations of diaphragm

Superior :

Pleurae Lungs Pericardium Heart

Inferior :

Peritoneum

Liver Fundus of stomachSpleen

Kidneys

Suprarenal glands

Nerve Supply

of Diaphragm

Motor supply:

Phrenic

nerve (C

₃‚₄‚₅)Anteromedial Anterolateral

Posteromedial

Posterolateral

Sensory supply:

Central –

phrenic nervePeripheral – lower 6 intercostal nerves

Sympathetic supply:

Coeliac

plexus via inferior phrenic plexus

Blood supply of diaphragm

Musculophrenic

arteryPericardiophrenic artery Lower 5-6 post. Intercostal arteries

Sup.

Phrenic

artery Inf. Phrenic artery

Actions of diaphragm

Principal muscle of inspiration

Contraction  descent  vertical diameter of thorax increasesUpper abdominal viscera displaced below ant. Abdominal wall bulges

Central tendon then becomes fixed  lower ribs are elevated  increase in AP diameter

Actions of diaphragm

Muscle of Abdominal Straining:

Supports expulsive acts like sneezing , coughing , vomiting , crying, defecation , micturation, etc.Sphincteric action at lower end of esophagus

Thoracoabdominal

pump for blood & lymph

Effect of contraction of diaphragm on 3 major openings in diaphragmVenacaval opening ---- dilates

Oesophageal

opening -------constricts

Aortic opening -------- no change

Development of diaphragm

Develops at level of neck & derives its muscular components from cervical myotomes

Septum transversum central tendonPleuroperitoneal membrane dorsal paired portion

Lateral thoracic wall circumferential portion of diaphragm

Dorsal mesentery of esophagus  dorsal unpaired portion (Crura )

Applied

Hiccups /hiccough

occurs due to spamodic contraction of diaphragm Central hiccups  due to hiccup centre in medulla (MC cause is uremia )

Peripheral

 local irritation of diaphragm or its nerve Shoulder tip pain

 irritation of diaphragm leads to pain in shoulder because of the common root value of

supraclavicular

nerve &

phrenic

nerve.

Unilateral paralysis of diaphragm

 due to lesion of

phrenic

nerve . Paralyzed side shows paradoxical movement .

Eventration

 is congenital defect in the musculature of diaphragm (fibrous membrane present )

Diaphragmatic hernias

Congenital diaphragmatic hernias

Morgagni hernia /Retrosternal hernia

(anterior right)

Bochdalek

hernia /posterolateral hernia (posterior left) Occurs through

pleuroperitoneal

hiatus

Fatal condition(lung

hypoplasia

)

S/S:

scaphoid abdomen

respiratory distress

3

. Central hernia 4. Posterior hernia (posterior defect

in diaphragm)

Hiatus hernia

Congenital / rolling / paraesophageal hiatus hernia :

stomach rolls upwards & lies in post. Mediastinum GE junction is normalS/S : nausea, dysphagia, pain Acquired / sliding hiatus hernia : weakness of phrenicoesophageal membrane .

S/S: GERD, heart burn