Lecture 6: Anatomy and Physiology of the Eye

Introduction

• Lecturer: Professor Long
• Course: Anatomy and Physiology, Del Mar College, Corpus Christi, Texas
• Context: Transition to online lectures due to COVID-19
• Focus: Sensory Nervous System, specifically the eye (anatomy and physiology)

General Overview

• Sequence: Previous lectures covered general senses, olfaction, and gustation.
• Current Focus: Anatomy of the eye, with future discussions on physiology, hearing, and vision.

Anatomy of the Eye

External Features

• Eyelids (Palpebrae):

  • Superior and Inferior Palpebrae
  • Meet at Canthus (Medial and Lateral)

• Sclera:

  • White part of the eye
  • Dense connective tissue with collagen fibers
  • Provides shape, support, and attachment point for extraocular muscles

• Cornea:

  • Transparent portion of the sclera
  • Allows light entry into the eye

Internal Structures

• Eye Tunics (Layers):

  • Fibrous Tunic: Composed of sclera and cornea
  • Vascular Tunic:
    • Contains blood vessels
    • Choroid Coat: Supplies nutrients and removes waste
    • Ciliary Body: Contains ciliary muscle and suspensory ligaments
    • Iris: Controls pupil size to regulate light entry

• Lens and Ciliary Muscle:

  • Lens suspended by suspensory ligaments
  • Adjusts shape to focus light onto the retina

Tear Production and Flow

• Lacrimal Gland: Produces tears

• Lacrimal Ducts: Channel tears to the eye surface

• Functions of Tears:

  • Keep eye moist
  • Wash away debris
  • Contain lysozyme, an antimicrobial enzyme

• Tear Drainage Path:

  1. Lacrimal Gland
  2. Lacrimal Ducts
  3. Lacrimal Punctum
  4. Lacrimal Canals
  5. Lacrimal Sac
  6. Nasolacrimal Duct

Conjunctiva

• Ocular Conjunctiva: Covers the visible part of the sclera and cornea
• Palpebral Conjunctiva: Lines the inside of the eyelids
• Conjunctivitis (Pink Eye): Inflammation of the conjunctiva, can be contagious if caused by pathogens

Additional Points

• Sclera and Cornea Junction: Known as the limbus or corneal limbus

• Iris and Pupil:

  • Iris gives eye color
  • Pupil is the central opening for light entry

• Tear Functions:

  • Moisturize eye
  • Protect against infections
  • Flush debris

Concluding Remarks

• Upcoming Topics: More on the eye's physiology, hearing, and sensory processing
• Technical Note: Apologies for video interruptions; effort to edit and improve video quality

These notes cover the anatomy and basic functions of the eye as discussed in Prof. Long's lecture. Future lectures will build on this by exploring the physiology and sensory functions in greater detail.