CONTENTS:
RETURN HOME

 

Lab Objectives:

• Examine the orbit and its contents:
      - eyeball and optic nerve
      - muscles, vessels, and sensory & motor nerves
      - lacrimal gland, fat, and the deep part of the third eyelid

• Identify features of the eyeball:
      - fibrous layer (cornea & sclera)
      - vascular layer (iris, ciliary body, & choroid)
      - retina and optic disc
      also, aqueous humor chambers, lens, vitreous body

• Superficial veins of the head:
      - external jugular v. (from maxillary v. & linguofacial v.)
      - linguofacial v. (from lingual v. & facial v. )
      also, observe angularis oculi v.

CONTENTS

 

Anatomical Terms:

        The Eye & Related Structures
        orbit
                periorbita
        lacrimal gland
        superficial gland of the third eyelid

        Muscles:
        levator palpebrae superioris m.
        rectus muscles (dorsal, ventral, medial, & lateral)
        retractor bulbi m.
        ventral oblique m.
        dorsal oblique m.
                trochlea

        Eyeball:
        bulbus oculi (eyeball)
                external fibrous coat
                        cornea
                        sclera
                                limbus (corneoscleral junction)
                middle vascular coat (uvea)
                        iris
                                pupil
                        choroid
                                tapetum lucidum
                ciliary body
                        ciliary processes
                                zonule (zonular fibers)
                retina (internal coat)
                        ora serrata
                        optic disk
                        fundus
                lens
                anterior & posterior chambers
                        aqueous humor
                vitreous chamber
                vitreous body

        Superficial Veins of the Head:
        external jugular vein
                linguofacial vein
                        lingual vein
                        facial vein
                                dorsal nasal v.
                                angularis oculi v.
                maxillary vein

        Note:
             uvea [from Latin: uva = grape] = the vascular layer of the eyeball
             uvula [Latin = little grape] = small mass on the human soft palate
             vitreous [Latin: vitreus = glassy] e.g.. vitreous body
             hyaline [Greek:hyalos = glass] e.g., hyaline cartilage
             humor [Latin = a liquid] e.g., aqueous humor

CONTENTS

 

Instructor Commentary:

Seven muscles attach to the eyeball of domestic mammals (four recti, two obliques, and one retractor). The purpose of the retractor bulbi m. is to force the third eyelid across the surface of the cornea as a protective mechanism. Humans lack a third eyelid and a retractor bulbi m., and have only six muscles attaching to each eyeball.

The gland associated with the third eyelid is called "superficial" even though it is located deep because some species, such as the pig, have two glands, and the second is still deeper than the superficial gland of the third eyelid.

CONTENTS

 

Dissection Images:

Note: Click an image to see it enlarged, view its caption, and toggle its labels.

1 2
3 4
5 6
7 8
9 10

CONTENTS

 

Previous Lab  
  Next Lab
HOME             TOP