Special Senses

Biology 2121 Lab

The Eye - Structure

• Layers of the Wall of the Eyeball – 1. Fibrous – 2. Vascular – 3. Inner Layer (Retina)

Layers of the Eyball

• 1. Fibrous Layer – Sclera ------ Cornea

• 2. Vascular Layer – “Uvea”

• Posterior: Choroid • Ciliary Body• Anterior: Iris

Layers of the Eyeball

• 3. Retina– Outer: Pigmented

Layer– Inner: Neural Layer

• 4. Inner Layer– Photoreceptor Cells

• Rods and Cones

Retinal Layer

• Macula Lutea and Fovea Centralis – Cones – Sharp Vision

Internal Chambers – Fluids

• Aqueous Humor – Anterior Eye – Clear Fluid; Ciliary

process produces – Constantly drained

• Vitreous Humor – Embryonic

Development

Lens

• Biconvex

• Transparent

• Avascular

Outer Structure

• Superior Rectus Muscle – Attaches to Frontal

bone – Indicates medial

• Extrinsic Eye Muscles – Insert into the

Sclera

Sheep’s Eyeball

The Ear

• Sections of the Ear– 1. Outer Ear– 2. Middle Ear– 3. Inner Ear

• Cranial Nerve VIII– Vestibulocochlear Nerve

Parts of the Ear

Outer Ear

Helix

1.Pinna (Auricle) 2. Helix and

Lobule 3. Ends where the

tympanic membrane begins

Middle Ear – Ossicles

1. Malleus – hammer

2. Incus – anvil

3. Stapes - stirrup

Inner Ear

• Semi-circular canals

• Vestibule – Saccule – Utricle

• Cochlea – Cochlear Duct

• Organ of Corti