In order to understand how animals make use of sensory processing and motor control, one must first know what it is. Simple definition is this: The brain does not use only one set of sensory reception and motor control tools at once; rather it combines these tools. Most animals make use of at least two sets of sensory reception tools to perform their behavior. There are some animals that even make use of all three sets of tools at once.
When an animal uses sensory organs such as eyes, ears, and skin, they receive information from the sensory organ. They then send that information through a neural tube to a spinal cord, where a series of commands to various parts of the body are made. Humans also use this same process of sensory reception and motor control to coordinate actions and movements. In order to do this though, the brains of humans must first receive instructions from the spinal cord.
The nerves provide the primary inputs to the spinal cord by traveling along the nerve pathways. From there, the impulses travel to various areas of the body depending on the direction of the pulse. When the pulse stops, so does the signal. As a result, the spinal cord continues to provide inputs to the various neuron and nerve receptor organs. The reflex action programs receive impulses from the sensory neurons, which in turn send them to the appropriate muscle groups.
In the case of humans, this entire process happens inside the brain through the central nervous system (CNS). In animals, however, the nerves deliver the messages from sensory neuron to the various effector organs through the effector organ system. Humans have twenty different affected organs, including the eyes, ears, nose, mouth, hand, feet, abdomen, penis, whiskers, and even the scalp. The effector organ that receives messages from the sensory neuron is the central nervous system, or CNS for short.
The CNS consists of a number of major and minor cell types. It also contains about twenty different sensory neurons and afferent neurons, which are responsible for receiving inputs from the sensory neurons and sending them to the CNS. When an irritation or a disease prevents the afferent neurons from sending the information directly to the CNS, the result is that the effector organ fails to perform its proper function. If the spinal cord is injured in any way, or the muscles are paralyzed, the CNS is unable to perform its normal processing and this is what leads to muscular weakness and atrophy.
The parts of the body affected by the loss of the effector organ include the muscles and the spinal cord itself. This is why the loss of the CNS is commonly referred to as a motor disorder. In addition to affecting the central nervous system, it can also affect the sensory organs. It is important to note that the loss of the sensory organs is not caused by the nervous system; it is caused by injury or disease that affects the nerves.
The loss of an effector organ is referred to as neuropathy. Commonly used terms for this condition are Loss of Muscle Control (LOMC), Spinal Cord Injury (SCI), Neuromuscular Disease (DMN), and Motor Neuron Disease (MTVD). A person with LOMC will lose strength and control over certain muscles; conversely, SCI affects the strength of a person’s muscles. Neuromuscular disease refers to conditions such as Multiple Sclerosis, a disease that damages the nerves. Motor Neuron Disease affects the nerve cells and can be inherited by an individual from his/her parents.
When a nerve impulse is released, it travels from the spine up the spinal cord to the local area and terminal parts of the body where it activates muscle contractions. When the muscle contractions produce a movement, neurons fire along the pathways. The location of the neurons is called a target site; once the signal arrives at the target site, other neurons fire along the target pathway to carry out the reflex action.