Medical Dictionary Search here

Extraocular Muscles : Function and Innervation

Eye Movement Control Systems

Extraocular Muscles : Function

Superior Oblique muscle : can depress and abduct the eye from the neutral position. From the adducted position, it is the only muscle that can depress the eye

Inferior Oblique muscle : can elevate and abduct the eye from the neutral position.From the adducted position, it is the only muscle that can elevate the eye

Superior rectus muscle : can elevate and adduct the eye from neutral position. it is the only muscle that can elevate the eye from the abducted position

Inferior rectus muscle : can depress and adduct the eye from the neutral position. From the abducted position , it is the only muscle that can depress the eye.

The Lateral rectus muscle can abduct the eye.


Innervation:

Cranial Nerve III :

  • Medial rectus : adducts eye
  • Superior rectus : elevate, intorts, adducts eye
  • Inferior rectus  : depresses, extorts, adducts eye
  • Inferior Oblique: elevates, extorts, abducts eye

Cranial Nerve IV : 

  • Superior Oblique : depresses, intorts , abducts eye
Cranial Nerve VI : 

  • Lateral rectus: Abducts eye.

Intraperitoneal and Retroperitoneal Organs

Major Intraperitoneal Organs: (suspended by a mesentery)


  • Stomach
  • Liver and Gallbladder
  • Spleen
  • Duodenum, 1st part
  • Tail of pancreas
  • Jejunum
  • Ileum
  • Appendix
  • Transverse colon
  • Sigmoid colon


Major Secondary Retroperitoneal Organs : (loss of mesentery during development)


  • Duodenum 2 & 3 parts
  • Head ,neck, & body of pancreas
  • Ascending colon
  • Descending colon
  • Upper rectum


Major Primary Retroperitoneal Organs : (never had a mesentery)


  • Kidneys
  • Adrenal glands
  • Ureters
  • Aorta
  • Inferior vena cava
  • Lower rectum 
  • Anal canal

Germ layer Derivatives Ectoderm (Neural crest)

Neural crest


  • Adrenal Medulla

  • Ganglia :

-Sensory-pseudounipolar neurons
-Autonomic-postganglionic neurons
  • Pigment cells

  • Schwann cells

  • Meninges- Pia and arachnoid mater

  • Pharyngeal arch cartilage

  • Odontoblasts

  • Parafollicular (C) cells

  • Aorticopulmonary septum


  • Endocardial cushions