Anatomy study note · Head and neck

Lens

A transparent biconvex structure in an elastic capsule, behind the iris and in front of the vitreous body, encircled by the ciliary processes.

Key points

• Biconvex, elastic capsule.
• Suspensory ligament → ciliary processes.
• Accommodation: ciliary muscle contracts → lens rounder.
• Presbyopia = loss of elasticity with age.
• Lens: surface ectoderm placode → vesicle.
• Posterior cells → lens fibres.
• Lens fibres: no nuclei, full of crystallins.
• Cataract = opacity; presbyopia = lost elasticity.

The full note in the atlas also covers

Features · Action · Histology · Development · Clinical notes

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Written from

• Snell’s Clinical Anatomy by Regions, 10th ed., ch. 12, PDF pp. 1600–1601
• Inderbir Singh’s Human Embryology, ch. 19, PDF pp. 352, 354–355, 357, 360
• BRS Cell Biology & Histology, 7th ed., ch. 21, PDF pp. 382–383

More from the head and neck

• Levator palpebrae superioris
• Levator veli palatini
• Lips and oral cavity
• Longus colli and longus capitis
• Mandible
• Mandibular nerve
• Masseter
• Maxilla
• Maxillary artery
• Maxillary nerve
• Medial pterygoid
• Medial rectus

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