Midterms PO

Visual Integrity

involves the different ocular structures and its adnexa, visual pathway and brain that must be properly functioning.

Visual Efficiency

 includes the refractive condition of the eye, eye teaming, focusing and tracking.

Visual Processing

composed of visual memory, form constancy, spatial relations, sequential memory, figure ground, closure and visualization.

Adnexa

Accessory structures which are involve in protecting and/or supporting the function of an organ

Receptors

receiver of environmental stimulus

Receptors

Lacks Axons

Receptors

forms synapses with dendrites of other sensory neurons

1. Receptors

2. Effectors

3. Physiological Connectors

This is where the Adaptive Mechanism of Humans depend on

Effectors

End Receiver of this phenomenon

Effectors

refers to the responding organ

Physiological Connectors

the nerve fibers where the nerve impulse travel

1. Visual/Sight

2. Auditory/Sound

3. Olfactory/Smell

4. Gustatory/Taste

5. Touch

What are the Five Senses

Sensation

refers to physical stimulation of the sensory receptors

Perceptions

involves interpreting sensory information (decoded)

Sensation and Perception

These are the sensory information from the environment

True

Stimulus Response Phenomenon creates homeostasis to the body

Central and Peripheral Nervous System

It dictates the response of our body

Stimulus

Any change in an environment that causes a reaction

External and Internal Stimulus

Types of Stimulus

Response

Reaction to stimulus and a change in behavior

Instinctual/Reflex and Learned Response

Types of Response

Homeostasis

process that living things use to actively maintain fairly stable conditions necessary for survival. leading to dynamic equilibrium in the body

True

Successful self regulating process leads to continuity of life, if unsuccessful it can lead to disaster or death

Nervous System (brain)

Responsible for all stimulus response phenomenon

Nervous System (brain)

Responsible for body’s response whether it is learned or taught

Sensory Receptors

It causes reaction of the body by receiving stimulus. It is also known to be biological transducers that collect stimulus(energy) and convert them to impulses (electrical)

Dendrites of Sensory Neurons

Specialized for receiving specific kind of stimuli

Afferent Nerve

A sensory neuron that sends signals from sensory receptors to the brain

Efferent Nerve

A motor neuron that sends signal from the brain to the muscles

1. Reception

2. Transduction

3. Perception

What are the sensory processes

Reception

it is the receiving stimulus in the sensory perception

Transduction

it is the conversion of stimulus into impulse (energy → electrical)

Perception

It is how brain interacts or intercepts (process) the stimulus

1. Exteroceptors

2. Visceroceptors/Interoceptors

3. Proprioceptors

Types of Receptors in terms of location

Exteroceptors

Located on the body surface or specialized to detect external stimuli

Its Specific Response are pressure, pain, touch, temperature.

It Functions in reporting the external environment.

It is Found in Sense organs

Visceroceptors/Interoceptors

Located within internal organs detects internal stimuli

It is Found in internal organs

Its Specific Response are blood pressure, pain, fullness.

It Functions in sampling the internal environment.

Proprioceptors

It is found in the joints and muscles, also in vestibular structures and the semicircular canals of the ear and limbs.

Its Specific Response are body position, and movement.

It Functions in sensing the posture, movement of body, & position in space.

1. Mechanoceptive

2. Thermoceptive

3. Nociceptive

4. Photoreceptors

5. Chemoreceptive

Types of Receptor in terms of modality or sensitivity

Mechanoceptive

it detects stimuli which mechanically deform the receptor

Its Stimulus are pressure, vibration, touch, sound.

It can be found in the skin and cornea

Thermoceptive

It detects changes in temperature

Its Stimulus are hot or cold.

It can be found in the Skin

Nociceptive

It detects damage to the structure

Its Stimulus is pain.

It can be found in the Skin and viscera

Photoreceptors

It detects light

Its Stimulus is vision

It can be found in the Eye specifically in retina

Chemoreceptive

It detects chemical stimuli

Its Stimulus are carbon dioxide and oxygen in blood, glucose, smell, taste.

It can be found in the Olfactory and Gustatory Also known as Tongue and Nose

1. Simple

2. Complex

Types of Receptor in terms of complexity

Simple

It is usually a single modified dendrite

and used for General sense

Its Stimulus are touch in skin, pressure, pain, vibration, and temperature.

It has No physical specialization.

Complex

It is usually highly modified dendrites.

It is used for Specialized sensory senses

Its Stimulus are vision, hearing, smell and taste.

It has physical specialization.

400-700nm

range of energy level received by the eye

20-20000Hz

range of energy level received by the ear

True

Taste buds only accept specific chemicals

Johannes Muller

He wrote the Law of Specific Energies

Law of Specific Energies

It states that:
Sensory messages are carried on separate channels to different areas of the brain.

Nerve impulses have only one pathway going to the brain (converted to image or SAMPLING)

Mind has no access to objects in the world but only to our nerves

Contents of the mind have no qualities in command with environmental objects
Each type of sensory nerve has its own specific sensation

Sensory messages are carries on specific channels to specific areas i n the brain

Photoreceptors

special cells in the retinal responsible for converting light into signals that are sent to the brain

Rods and Cones

Reflex Action

An automatic neural activity wherein a stimulus leads to an immediate action

Reflex Action

An inborn central nervous system activity not involving consciousness

1. Pupillary Light Reflex

2. Lacrimal Reflex

3. Eyelash Reflex

Types of Reflex Action

Pupillary Light Reflex

When light is flashed near one eye, both pupils of the eye will constrict

Its Stimulus is  Light stimulus creates impulses that reach the brain via the optic nerve

Its Response is that it is conveyed to the pupillary musculature by autonomic nerves.

Direct Pupillary Light Reflex

Dilation / constriction when light is dim/directed in one eye (same stimulated w/ light)

Indirect Pupillary Reflex

Dilation/constriction in the other eye when light is dim/directed in the other eye (eye not stimulated by light)

Lacrimal Reflex

Its stimulus is irritation on the conjunctiva or cornea of the eye

Its response in afferent is nerve impulses pass along the fifth cranial nerve or the trigeminal nerve and reach the midbrain then the efferent is autonomic and parasympathetic nerves causing the outpouring of tears by the lacrimal gland

1. Basal

2. Reflexive

3. Psychic

Types of Tears

Basal

normal tears for lubrication

Reflexive

tears caused by wind or foreign objects

Psychic

tears produced due to emotion

Eyelash Reflex

Its stimulus is peripheral stimulus in the mechanoreceptors in the epithelium of the cornea and its response in afferent is nerve impulse sent to the trigeminal and facial nerve and the efferent is impulse sent to cranial nerve 7 or facial nerve and will cause a contraction of the orbicularis oculi or eyelids

Dioptrics of the Eye

Includes curvature, thickness, refractive index, and axial length 

Optical System of the Eye or Optical Function of the Eye

Other term for Dioptrics of the eye

Refraction

the bending of light a s it travels from one medium to another

Medium

any substance through which light can propagate and transfer energy.

Interface

the line or boundary between two mediums of difference indices

60D

total refractive power of the eye

Refraction of Light

where do the measurement of the refractive power of the eye base on

True

Refraction is dependent on the index of refraction

1. Cornea

2. Aqueous Humor/Anterior Chamber

3. Crystalline Lens

4. Vitreous Humor

5. Retina

These are the Dioptric Apparatus

Gauss Cardinal Points

It calculates the image position without concern for optical details

Gauss Cardinal Points

It is the simplification of refraction in the eye through compound homocentric system of six points

Optical Axis

where do the cardinal points based on

False

In Gauss Cardinal points, the refractive surfaces are not considered to have one refractive index and points are independent on the refractive index

True

In Gauss Cardinal points, all the refraction or bending o light in the eye are ignored

1. Anterior Focal Point

2. Posterior Focal Point

3. Anterior Principal Point

4. Posterior Principal Point

5. Anterior Nodal Point

6. Posterior Nodal Point

What are the Cardinal Points

Anterior Focal Point

It is the nearest or the most anterior point to the object and it is composed of Diverging Light Rays

Posterior Focal Point

It is the farthest and most posterior point to the object and it is composed of converging light rays

Focal Point

it is the focus of parallel rays on the retinal plane after refraction or reflection by a curved mirror or lens

Principal Point

point of intersection of the principal plane with the optical axis

Pupillary Plane

posterior cornea to the pupil

Nodal Point

points in the lens on the principal/optical axis from which objects and images appear under the same angle

Anterior Nodal Point

point in the anterior lens capsule

Posterior Nodal Point

point in the posterior lens capsule

False

Anterior and Posterior nodal points are not equal

True

Nodal points don’t intersect

Optical Center

point that intersects the visual axis with the optical axis

Optical Center

point where the undeviated ray crosses the optical axis

Optical Axis

the line joining the centers of all the refractive surfaces of the eye

False

points entering the posterior lens capsule and the light exiting the posterior lens capsule is unequal

7.7mm

Curvature of Cornea

0.5mm

Thickness of cornea

1.37

RI of Cornea

40D

Estimated Dioptric Power of Cornea

1.33

RI of Aqueous Humor

10-5.3mm

Curvature of Anterior Lens