What is the line passing between center or cornea and lens to the retina?
Bulbar Axis
What is the coordination of both eyes and focusing on the same object?
Binocular Vision
What is called when one eye focuses on an object?
Monocular Vision
What eye position is on a long narrow head?
Lateral Placement
- Visual Feild is large
- Binocular vision is less than formal
Lateral Placement
What eye position is on a broad head?
Frontal Placement
- Visual Feild is less than lateral
- Binocular vision is greater
Frontal Placement
What eye shape has these characteristics Diurnal Birds, Narrow Head, and low visual acuity?
Flat Eye Shape
What eye shape has these characteristics Diurnal Birds, Broad Head, and greater visual acuity?
Globular Eye Shape
What eye shape is for nocturnal birds?
Tubular Eye Shape
What are the three eye tunics?
- Outer fibrous tunic
- Middle vascular tunic
- Inner nervous tunic
The Shape of the eye is maintained by what?
Fibrous Tunic
What is the transparent region of the eye and that refracts light?
Cornea
What is the fibrous tunic of the eye?
Scleral ossicles
What is the junction between the cornea and the sclera?
Limbus
What suspends the eye lens and has zonular fibers?
Ciliary body
What is the Vascular Tunic?
It is choroid thick vascular dark pigmented area that covers the retina continued by ciliary body and iris.
Where is the Iris attached?
It is attached to the ciliary body.
What is ciliary process?
It is a small fold.
What controls the Iris?
Controlled by sphincter and dilator muscles.
What is the Iris?
It forms the Pupil.
What makes up the Iris?
- Lipochromes
- Guanine Pigment
- Iridocytes
What influences the color of the Iris?
- season
- maturity
- gender
What are Iridocytes?
They are reflective cells located in the cell.
What is the Tapetum Lucidum?
It is the reflective body
What is the function of Nervous Tunic?
Image Analysis
What is the size of the Avian Retina?
It is thick and avascular
What type of birds have cone shaped and what is the purpose?
Diurnal birds and they serve for color acuity.
What type of bird has rod shapes and what is the purpose?
Nocturnal Birds and they serve for better Light intensity.
The function of the Fovea centralis?
- high cone concentration
- Two fovea in some species
- No rods
Where is the eye blind spot?
where the optic nerve enters the eye
What is the function of Pecten projection of retina and choroid into
vitreous body?
Nourishes the inner retinal layers
What are some characteristics of the chickens lens?
- Softer than mammals
- Rapid accommodation
- Optically clear in diurnal birds
- Transmits light to 350nm almost UV
What is the mechanism of the Compression of the entire lens?
Posterior sclerocorneal muscle in Diurnal birds
What is the mechanism of the Distortion of corneal center?
Anterior sclerocorneal muscle in Nocturnal birds and hawks
Compression of lens front via anterior muscle and
sphincter of iris
Found in Diving birds
What are the functions of hearing in birds?
- Predator and food id
- Social communication
- Echo location
What do ear coverts have?
Feathers with barbules and reduce noise from turbulence during flight.
The characteristics of the External acoustic meatus?
- circular opening on the side of the skull
- Operculum flap of skin to assist with hearing
- Diving birds have the ability to close it
What parts make up the middle ear?
- Includes air filled cavity between the inner ear
- tympanum
– Tympanum projects outward and is semi transparent
– Attaches to columellar muscle - Columella auris bone (stapes)
What parks make up the inner ear?
- Membranous and bony labyrinths
- Filled with endolymph and perilymph
- Cochlea short curved containing sound
receptors - Vestibular organ semi-circular canals filled
with fluid for balance
What nerve stimulates smelling in Avian?
The Olfactory cervical nerve
What are the Three parts to somatosensory receptors?
- Sensory nerve terminal
- Afferent fiber
- Non-nervous tissue
What type of somatosensory receptor has Herbst corpuscles Grandry corpuscles?
Mechanoreceptors
What type of somatosensory receptor senses temperature?
Thermoreceptors
What type of somatosensory receptor senses pain?
Nociceptors
What type of somatosensory receptor senses chemicals?
Chemoreceptors
What type of somatosensory receptor senses light?
Photoreceptors
What type of somatosensory receptor senses electric current?
Electroreceptors