Sense organs (eye and ear)
Sclera
Sclera
- Origin
- White, tough connective tissue coat of the posterior five sixths of the globe, from the limbus to the exit of the optic nerve
- Insertion
- Attachment site of the four recti and two oblique muscles and of the fascial sheath of the eyeball (Tenon capsule)
- Function
- Maintains the shape and intraocular pressure of the eye and protects the inner layers; the lamina cribrosa transmits the optic nerve
- Innervation
- Long and short ciliary nerves from the ophthalmic nerve (V1)
- Movement & chain
- Transmits the pull of the extraocular muscles; the attachment plane shifts with every direction of gaze
- Palpation
- Directly visible as the white of the eye; look for yellow (jaundice), blue (osteogenesis imperfecta) or sectoral redness
- Clinical
- Scleritis (deep boring pain, often in rheumatoid disease), episcleritis, blue sclerae in collagen disorders, globe perforation after trauma
- Segmental innervation
- Sensory V1 (trigeminal nerve)
- In clinical practice
- Scleral discolouration is one of the fastest bedside clues to jaundice and anaemia
- Region in the model
- Sense organs (eye and ear)