The Conjunctiva and The Eyelid

• What are the main learning goals of the lecture?

  Anatomy, microstructure, innervation, vascular supply
• What should students be able to describe and understand after the lecture?

  The conjunctiva's gross anatomy
• What are the two types of conjunctiva mentioned?

  • Bulbar conjunctiva
  • Palpebral conjunctiva
• What is the purpose of the fornix in the conjunctiva?

  It joins the bulbar and palpebral conjunctiva
• How is the palpebral conjunctiva divided?

  Into marginal, tarsal, and orbital parts
• What marks the inferior edge of the tarsal plate?

  The sulcus subtarsalis
• How far is the sulcus subtarsalis from the lid margin?

  2 mm
• What is the characteristic of the tarsal part of the palpebral conjunctiva?

  It is very vascular and adherent to tarsal plates
• What structures are visible through the tarsal conjunctiva?

  Meibomian glands

  
• What are Henle's mucus crypts?

  Structures in the nasal tarsal conjunctiva
• What are the two types of structures found in the tarsal part of the palpebral conjunctiva?

  Papillae and follicles
• What is the orbital part of the palpebral conjunctiva characterized by?

  It loosely covers between the tarsal plate and fornix
• What happens to the orbital conjunctiva during eye movements?

  It is thrown into horizontal folds
• What is the function of the conjunctival fornices?

  To allow free movement of the globe
• What is the bulbar conjunctiva's characteristic?

  It is the thinnest part of conjunctiva
• What does the limbal conjunctiva cover?

  The limbal region and fuses with corneal epithelium
• What are the layers of the conjunctival epithelium and their characteristics?

  • Marginal: 5 layers, non-keratinized, stratified, squamous
  • Tarsal & orbital: 2 layers, stratified, cuboidal
  • Fornix & sclera: 3 layers, stratified, squamous
  • Limbal: 10 layers, stratified, squamous
• What is the role of goblet cells in the conjunctiva?

  They produce the mucous component of the tear film

  
• Where are goblet cells absent in the conjunctiva?

  In marginal and limbal conjunctiva
• What happens to goblet cell density with age?

  It decreases, leading to dry eye

  
• What is the adenoid layer of the substantia propria composed of?

  Fine connective tissue reticulum with lymphocytes
• When does the adenoid layer develop?

  After 2-4 months of birth
• What does the fibrous layer of the substantia propria contain?

  Collagenous and elastic fibres
• What are the types of conjunctival glands?

  • Mucin glands
  • Goblet cells
  • Henle’s glands
  • Glands of Manz
  • Accessory lacrimal glands
  • Glands of Krause
  • Glands of Wolfring
• What is the function of the plica semilunaris conjunctivae?

  Allows full lateral movement without stretching
• What is the caruncle?

  A mound of tissue over the plica semilunaris
• What does the caruncle contain?

  Non-keratinized epithelium and accessory glands
• What are the three sources of blood supply to the conjunctiva?

  Marginal, peripheral, and anterior ciliary arcade

  
• How do conjunctival veins drain?

  Into the venous complex of the eyelids

  
• What are the two drainage systems for conjunctival veins?

  Veins from conjunctiva and eyelids

  
• Where do lymphatic vessels from the conjunctiva drain?

  Into preauricular and submandibular lymph nodes

  
• What nerves supply the conjunctiva?

  Supraorbital, infratrochlear, and lacrimal nerves

  
• What changes occur in conjunctival epithelial cells with age?

  They change from square to vertically elongated
• What happens to collagen in the conjunctival stroma with age?

  There is a decrease in collagen
• How does the attachment of conjunctiva to Tenon's fascia change with age?

  It becomes more tenuous, allowing easier movement
• What happens to blood vessels in the bulbar conjunctiva with age?

  They become more random with increased fragility
• What are the dimensions of the conjunctival fornices?

  • Superior fornix: 8-10 mm
  • Inferior fornix: 7 mm
  • Lateral fornix: 8-10 mm
  • Medial fornix: 14 mm
• What are the dimensions of the bulbar conjunctiva?

  • Thinnest part of conjunctiva
  • Loosely attached except for 3 mm near limbus
• What are the dimensions of the palpebral conjunctiva?

  • Marginal part: extends to sulcus subtarsalis
  • Tarsal part: adherent to tarsal plates
  • Orbital part: loosely covers tarsal plate