Question

2. Some actions of the human body occur as reflexes, without an individual realizing they are taking place. For example, if a bright light is suddenly turned on in a darkened room, a person’s pupils quickly contract.

a. Construct an explanation about how the human nervous system detects a light signal, transmits and integrates the information, and produces the observed response of the pupils.

b. Construct a representation of a reflex.

Answer 1

A) Vision is the special sense of sight that is based on the transduction of light stimuli received through the eyes

The main sensory organ of the visual system is the eye, which takes in the physical stimuli of light rays and transduces them into electrical and chemical signals that can be interpreted by the brain to construct physical images.

In the eye, two types of photoreceptor cells are clustered on the retina, or back portion of the eye. These receptors, rods and cones, apparently evolved from hair cells. Rods detect differences in light intensity; cones detect color

Light reaching a photoreceptor causes the breakdown of the chemical rhodopsin, which in turn causes a membrane potential that is transmitted to an action potential. The action potential transfers to synapsed neurons that connect to the optic nerve.

The optic nerve connects to the occipital lobe of the brain. The visual cortex in the brain interprets the image to extract form, meaning, memory, and context.

B) The reflex arc describes the pathway in which the nerve impulse is carried and the response is generated and shown by the effector organ.

The reflex arc typically consists of five components:

a) The receptor is present in the receptor organ.

b)The sensory neuron conducts the nerve impulses towards the central nervous system (CNS). The CNS is comprised of the brain and the spinal cord.

c)The information is transferred from one neuron to other.

d) A motor neuron conducts the response nerve from the CNS to the effector organ.

e) The effector organ shows response by contracting or secreting a product.

Ps- An upvote would be highly appreciated