AND CORRECT ANSWERS
Identify AND describe the THREE tunics (layers) of the eyeball - CORRECT
ANSWER Fibrous Tunic (outer layer) • Vascular Tunic (middle layer) • Retina (inner
layer)
Rods - rod shaped - CORRECT ANSWER specialized for black and white vision
shapes and movements
distributed around periphery of the retina
Cones - cone shaped - CORRECT ANSWER sharp, color vision
central fovea densely packed region
Cavities of the Interior of Eyeball Anterior cavity
•Has two chambers - CORRECT ANSWER Anterior chamber - between cornea and
iris
• Posterior chamber - between iris and lens
Cavities of the Interior of Eyeball
Posterior cavity - CORRECT ANSWER Lies between the lens & retina
• Contains the vitreous body, a jellylike substance that maintains the shape of the eye
Structures involved with Fibrous - CORRECT ANSWER Sclera and Cornea
Structures involved with Vascular - CORRECT ANSWER Choroid • Ciliary body •Iris
Sclera functions - CORRECT ANSWER Opaque, fibrous and tough providing
protection and form.
,Cornea functions - CORRECT ANSWER Refracts 75% of light for focus
Choroid functions - CORRECT ANSWER Accounts for 85% blood flow in eye •
Supplies O2, nutrients, removes waste
Ciliary body functions - CORRECT ANSWER Muscle that changes the shape of the
lens by changing tension on suspensory ligaments
Iris functions - CORRECT ANSWER Coloured part of the eye to control amount of
light entering by changing the diameter of the pupil
Structures involved with Neural/sensory - CORRECT ANSWER Retina Layer of
photoreceptors which change light into electrochemical signals that are transmitted to the
CNS.
describe the function for Eyelids - CORRECT ANSWER : Shield and protect the
eyeball from mechanical injury and drying out.
describe the function for Eyelashes - CORRECT ANSWER : Protect the eye from
airborne dirt, dust and irritants to the eye
describe the function for Eyebrows - CORRECT ANSWER : Protect the eye from
moisture to maintain sight.
describe the function for Lacrimal apparatus - CORRECT ANSWER Produce tears to
protect the eyeball and cornea through moisture and antibodies against infection. Contains
lysozyme to kill pathogens.
describe the function for Extrinsic eye muscles - CORRECT ANSWER Control
movement of the eyeball and superior palpabra
,Lacrimal fluid (tears)
+ what is lysozyme - CORRECT ANSWER Spread medially over eye by blinking.
Contains lysozyme
Lysozyme - A protective bactericidal enzyme; protects, cleans, and lubricates the eyeball
Refraction - CORRECT ANSWER Involves bending of light rays by cornea and lens to
focus an image on the retina (central fovea).
Accommodation - CORRECT ANSWER Involves changing the shape of the lens to
focus light rays on the retina.
Pupil constriction - CORRECT ANSWER Constriction of smooth muscle in the iris
changes the pupil diameter to control light entering the eye and prevent light scattering
around the retina.
Convergence - CORRECT ANSWER Medial movement of the eyeballs to allow focus
of image on the retina
Visual pathway Visual information in optic nerve travels to Hypothalamus - CORRECT
ANSWER to establish sleep patterns based upon circadian rhythms of light and
darkness
Visual pathway Visual information in optic nerve travels to Midbrain - CORRECT
ANSWER which has some visual reflex centers that control: • Movement of the head,
eyes and trunk in response to visual images
Visual pathway Visual information in optic nerve travels to occipital lobe - CORRECT
ANSWER Primary visual area and visual association area
, Visual Fields and Visual/Neural Pathway neuronal pathway - CORRECT
ANSWER Retina → 2. Optic Nerve → 3. Optic Chiasm → 4. Optic Tracts → 5.
Lateral Geniculate Nucleus (Thalamus) → 6. Optic Radiations → 7. Primary Visual Cortex
(Occipital Lobe)
Age related changes in the eye Lens - CORRECT ANSWER • Loses some of its
elasticity • Loses transparency resulting in cataracts
Age related changes in the eye Sclera - CORRECT ANSWER • thickens & changes
colour
Age related changes in the eye Iris - CORRECT ANSWER • fades or develops
irregular pigments • muscles weaken causing slower pupillary reactions resulting in slower
adaptation to darkened areas SO increased risk of falls
Identify the THREE anatomical regions of the ear - CORRECT ANSWER The external
(outer) ear collects sound waves.
The middle ear
The internal (inner) ear
external (outer) ear structures - CORRECT ANSWER 1. Auricle or Pinna • elastic
cartilage covered with skin
2. External auditory canal • curved 2.5cm tube of cartilage & bone leading into temporal bone
3.Tympanic membrane (eardrum) • thin, semi-transparent membrane that separates the
external & middle ear • - should be pearly grey and flat
External ear - functions - CORRECT ANSWER 1. Auricle or Pinna • Directs sound
waves toward the tympanic membrane (eardrum).