What cranial nerves are involved in pupillary light reflex?
The pupillary light reflex pathway involves the optic nerve and the oculomotor nerve and nuclei.
What does pupillary light reflex test assess?
Pupillary light reflex, or PLR, is a reflex that controls the diameter of the pupil. Based on the amount of light that falls on the eyes, the pupils will either contract or dilate. In situations in which light intensity is high, the pupils will constrict (or become smaller) so that less light enters the eye.
What part of the nervous system controls the pupillary reflex?
The parasympathetic nervous system is the main system responsible for pupil constriction in response to light. The integrated afferent input is transmitted along the axons of the retinal ganglion cells (RGC), which contribute to the optic nerve.
Which cranial nerve is tested for pupillary reflex and eye convergence?
Optic Nerve
Cranial Nerve II (Optic Nerve). The assessment of the optic nerve assessment includes fundoscopy, visual acuity testing, visual field examination, and testing for pupillary responses.
What is the function of cranial nerve 4?
The fourth cranial nerve controls the actions of one of the external eye muscles, the superior oblique muscle. This muscle runs from the back of the eye socket to the top of the eye. It passes through a loop of tissue near the nose known as the trochlea. It turns the eye inward and downward.
What is the function of cranial nerve 3?
The oculomotor nerve (the third cranial nerve; CN III) has three main motor functions: Innervation to the pupil and lens (autonomic, parasympathetic) Innervation to the upper eyelid (somatic) Innervation of the eye muscles that allow for visual tracking and gaze fixation (somatic)
What cranial nerve dilates the pupil?
Oculomotor Nerve
Motor nerve- Oculomotor Nerve-Controls most eye muscles. Works closely with Cranial Nerves 4 & 6. Controls eye movement, pupil dilation, and pupillary constriction. It also controls the muscles that elevate the upper eyelids.
What cranial nerves are involved in eye function?
Cranial nerves III (CNIII) (oculomotor), IV (trochlear), and VI (abducens) control the position of the eyeballs; CNIII influences the position of the eyelids and the size of the pupils.
What is the function of cranial nerve 5?
What is the trigeminal nerve? The trigeminal nerve is the part of the nervous system responsible for sending pain, touch and temperature sensations from your face to your brain. It’s a large, three-part nerve in your head that provides sensation.
What is the function of the 7th cranial nerve?
A nerve that runs from the brainstem, through openings in the skull, to the face and tongue. The seventh cranial nerve sends information between the brain and the muscles used in facial expression (such as smiling and frowning), some muscles in the jaw, and the muscles of a small bone in the middle ear.
What are the functions of the oculomotor nerve CN III )?
The oculomotor nerve (the third cranial nerve; CN III) has three main motor functions:
- Innervation to the pupil and lens (autonomic, parasympathetic)
- Innervation to the upper eyelid (somatic)
- Innervation of the eye muscles that allow for visual tracking and gaze fixation (somatic)
What does the 11th cranial nerve do?
This nerve supplies the sternocleidomastoid and trapezius muscles, which have the following functions: Rotation of head away from the side of the contracting sternocleidomastoid muscle. Tilting of the head toward the contracting sternocleidomastoid muscle. Flexion of the neck by both sternocleidomastoid muscles.
What is a function of cranial nerve Five?
The trigeminal nerve is the fifth cranial nerve (CN V). Its primary function is to provide sensory and motor innervation to the face. The trigeminal nerve consists of three branches on either side that extend to different territories of the face.
What type of reflex is pupillary light reflex?
The pupillary light reflex or Haab reflex is the reduction of pupil size in response to light. The pupillary accommodation reflex is the reduction of pupil size in response to an object coming close to the eye. Both these reflexes affect both eyes, even if only one eye is stimulated.
What is the protective aspect of the pupillary light reflex?
parasympathetic describe the protective aspect of the pupillary light reflex protects the retina from excessive illumination, which is damaging to the photoreceptors describe the protective aspect of the corneal reflex protects the eye from trauma describe the protective aspect of the crossed-extensor reflex
What is the indirect pupillary light reflex?
The pupillary light reflex is a reflex that controls the diameter of the pupil when it is exposed to varying intensities of light. This allows the eyes to adjust in response to bright or dim lights. Walk into any room and switch on the light; everything seems perfectly in its place.
Is pupillary light reflex somatic reflex or autonomic reflex?
Subsequently, question is, what type of reflex is the pupillary light reflex? The pupillary light reflex (PLR) or photopupillary reflex is a reflex that controls the diameter of the pupil, in response to the intensity (luminance) of light that falls on the retinal ganglion cells of the retina in the back of the eye, thereby assisting in adaptation of vision to various levels of lightness/ Similarly, you may ask, are reflexes autonomic or somatic? There are two types: autonomic reflex arc