DIAPHRAGM

MARYAM JAMILAH BINTI ABDUL HAMID082013100002IMS BANGALORE

LEARNING OUTCOME

Student should be able to

understand:-

Origin

Insertion

Nerve supply

Actions of the diaphragm

ANATOMY OF THE DIAPHRAGM

ORIGIN

Grouped into 3 parts Sternal part Costal part Lumbar part

Medial lumbocostal arch Lateral lumbocostal arch Right crus Left crus

Sternal part

Arises by 2 fleshy slips from the back

of the

xiphoid process.

Costal part

Arises from inner surfaces of the

cartilages

Adjacent parts of the lower 6th ribs

on each side

Interdigitating with transversus

abdominis

Lumbar part:-

a) Medial lumbocostal arch

Tendinous arch in fascia covering psoas

major

Medially, attach to the side of the body of

vertebra L1.

Laterally, attach to the front of transverse

process of vertebra L1

b) Lateral lumbocostal arch

Tendinous arch in fascia covering upper

part of quadratus lumborum.

Medially, attach to front of the

transverse process of vertebra L1

Laterally, attach to lower border of 12th

rib

c) Right crus

Arises from anterolateral surfaces of the bodies of the

upper three lumbar vertebrae and the intervening

intervertebral disc.

d) Left crus

Arises from the corresponding parts of the upper two

lumbar vertebrae.

Medial margin of two crura form tendinous arc across the

front of the aorta; median arcuate ligament.

INSERTION Insert into central

tendon of diaphragm Trilobar in shape; three

leaflets▪ Middle leaflet: ▪ Triangular in shape with its apex

directed towards xiphoid process

▪ Right and left leaflets▪ Tongue shaped, curve laterally

and backwards▪ Left is narrower than right

▪ Central point:▪ Four well-marked diagonal

bands comes out from central point of decussation (intersections); located in front of esophagus opening.

NERVE SUPPLY

Motor

Phrenic nerves

Sensory

Phrenic nerves; central part of diaphragm

Lower six thoracic nerves; peripheral part

of the diaphragm

ACTIONS OF DIAPHRAGM

Contraction of diaphragm

Flatten the diaphragm

Vertical diameter for thorax increase

Happens in inspiration

Quiet breathing: 1.5 cm

Deep breathing: 6 to 10 cm

Expulsive act: sneezing, coughing, laughing, crying,

vomiting, defecation, parturition, micturation, deep

inspiration (closure of glottis & powerful contraction

of trunk muscle)

Relaxation of diaphragm

Concave of the diaphragm

Vertical diameter for thorax decrease

Main factors affecting position of diaphragm

Elastic recoil of lung tissue

Lying down, abdominal viscera pushes

diaphragm upwards

Standing, muscle in abdominal wall contract

CLINICAL IMPORTANCE

Lumbocostal triangle or Bochdalek's

foramen

Diaphragmatic hernia

Diaphragmatic paralysis

Congenital eventration of diaphragm

Hiccup

CONCLUSION

Why diaphragm is important to

us?

Main muscle in respiration

(75% in normal inspiration); by contracting

Separating thorax and abdomen

REFERENCES

Chaurasia, B. (2013). Human anatomy regional and

applied dissection and clinical. (6 ed., Vol. 2, pp.

331-335). New Delhi, India: CBS Publishers &

Distributors.

digitallab3d. (n.d.). 3d model of human diaphragm.

Retrieved from http://www.exchange3d.com/3D-

Model-of-Human-Diaphragm/prod_28281.html

THANKYOU