Coordination

You do a lot of things every day. You clean your teeth. Tie your shoes and comb your hair. Most of the time, you don't even think about it when you do these things. It's almost as though your body is performing these duties without your conscious awareness. What governs your body's automatic movements?

Reflexes

Reflexes are quick, reflexive responses to the environment that take place without brain activity. Reflexes came with you from birth. Despite the fact that you may sometimes override them, reflexes are involuntary. Most reactions guard you against injury. For instance, reflex actions like coughing and sneezing can assist clear debris from your airways and throat. A reaction that helps to safeguard your eyes is blinking.

Your reflexes may have been evaluated during a physical examination. A simple test to see if your nerves are functioning correctly is the knee jerk. When your knee is touched, your leg jerks up in response. Reflex actions refer to this uncontrollable jerking. When you tap your knee, nerve endings communicate with the spinal cord via a sensory neuron. Here, an interneuron connects the impulse to a motor neuron. The motor neuron then transmits the impulse to the leg's muscles by its axon, causing the muscles to contract and cause the leg to move. Less than 1/50 of a second is required to complete this reflex action.

Reflex arc refers to the path taken by impulses during a reflex action. Figure 13-8 demonstrates this reflex arc. The body's re-flex arc is its most basic reaction pattern. The brain is not involved in this sort of reaction. Only the coordination of sensory and motor neurons is involved. Reflexes can happen fast since the brain does not initiate them.

Your arm is swiftly dragged away from the heat when you unintentionally touch a hot pan by your muscles. Your hand moves as a reflex, which first goes to your spinal cord and then returns to your muscles. As a result, the hand doesn't burn as intensely as it could have if the impulses had instead gone to the brain before returning to the arm muscles. Your hand is simultaneously communicating pain to your brain. You have already released the hot pan by the time the pain signal reaches the brain and you experience agony.

Key Points:

• Reflexes are involuntary, quick, and reflexive responses to the environment.
• Reflex actions help to protect you against injury, such as coughing and sneezing, which assist in clearing debris from your airways and throat, and blinking, which helps to safeguard your eyes.
• The knee jerk is a simple test to evaluate if nerves are functioning correctly.
• During a reflex action, nerve endings communicate with the spinal cord via a sensory neuron.
• An interneuron connects the impulse to a motor neuron, which then transmits the impulse to the muscles causing them to contract and move the body part.
• The reflex arc is the path taken by impulses during a reflex action.
• The brain is not involved in a reflex action, only the coordination of sensory and motor neurons.
• Reflexes are fast because the brain does not initiate them.
• During a reflex action, the impulse first goes to the spinal cord and then returns to the muscles, which can prevent injury.
• Pain signals still reach the brain during a reflex action, but they may arrive after the body has already taken action to protect itself.

Voluntary Body Movements

Voluntary bodily motions are made up of a series of little muscle contractions that work together to produce a desired reaction. These motions are coordinated in various ways by your neurological system. each as straightforward or intricate as the action itself. Your cerebellum, brainstem, spinal cord, and cerebrum all contribute to that control.

Your body is always moving. Your body moves in many different ways while you sleep or sit still. Your nervous system is responsible for more than just directing each of your individual motions. They are able to collaborate easily because of it. Coordination is the capacity to make many movements flow seamlessly into one another. Your nervous system controls how your eyes move while you read this so that they both concentrate and form a single image on the page. Consider all the numerous tasks you perform with your fingertips every day. Different types of coordination are needed for tasks like buttoning a shirt, using a fork to eat, twisting a doorknob, and tossing a ball. Your physical motions must also adapt to changing demands. For example, eating with a fork or spoon requires a more delicate control than throwing a ball as far as you can.

Key Points:

• Voluntary bodily motions consist of a series of muscle contractions that work together to produce a desired reaction.
• The neurological system coordinates voluntary movements, which can be simple or complex.
• The cerebellum, brainstem, spinal cord, and cerebrum all contribute to the control of voluntary movements.
• Coordination is the ability to make multiple movements flow seamlessly into one another, which is facilitated by the nervous system.
• The nervous system controls eye movements to focus on a single image while reading.
• Different types of coordination are required for various tasks, such as buttoning a shirt, using a fork to eat, twisting a doorknob, and throwing a ball.
• Physical movements must adapt to changing demands, such as using delicate control while eating with a fork or spoon, versus using more forceful movements while throwing a ball.

Balance and Smooth Movement

A large portion of your muscular control happens subconsciously. You don't consider which muscles to tighten as you down the stairs in order to maintain balance. Your balance and the fluidity of your motions are controlled by two areas of the brain. The brainstem and cerebellum are those. Your brainstem receives signals from your inner ear all the time. Your muscles contract just enough to maintain equilibrium thanks to impulses sent to them by the brainstem. Signals are sent to your legs, stomach, and back muscles depending on whether you are sitting or standing. You remain upright due to the continual, tiny contractions of these muscles.

Your cerebellum perfects all of your movements. Your muscles, tendons, and joints have specialised sensory neurons. Your brain receives messages from these neurons that describe the angle of each joint and the strength of each muscle contraction. To coordinate your motions, your cerebellum integrates this data with signals from your inner ears and eyes.

This knowledge helps your cerebellum ensure that you move in the manner you intend. Although the cerebellum does not initiate activities, it is always informed when an activity begins by signals from the rest of the central nervous system. The cerebellum contrasts the orders with the action that resulted. Then, in order to repair any mistakes, it sends its own signals to the muscle. In order to slow down the activity of the biceps, the cerebellum can thus instruct the triceps muscles to contract somewhat. It could also communicate with the biceps to lessen their contractions. Every time you move, such controls take place.

Key Points:

• A large portion of muscular control occurs subconsciously.
• Two areas of the brain, the brainstem and cerebellum, control balance and fluidity of motions.
• The brainstem receives signals from the inner ear and sends impulses to muscles to maintain equilibrium.
• Signals are sent to leg, stomach, and back muscles depending on whether sitting or standing.
• The cerebellum perfects all movements by integrating sensory neuron data with signals from the inner ear and eyes.
• The cerebellum receives signals from the central nervous system when an activity begins and contrasts orders with the resulting action.
• The cerebellum sends signals to muscles to repair mistakes, such as instructing triceps to contract to slow down biceps activity.
• These controls take place every time a person moves.

Developing Skilled Movements 

By repeatedly practising the necessary motions, you may pick up various skills. A simple example is learning how to tie your shoes. Once you mastered it, tying your shoes became second nature. You had become accustomed to the many movements required to tie your shoes. Your brain stores the steps it takes to complete a job in a unique format called an engram. Similar to a computer programme is an engram. It keeps track of a pattern of expert movements. The engram instructs the body to repeat the precise pattern when it is triggered. Now, in order to tie your shoes, you summon an engram that activates the appropriate motor neurons. Your brain is informed by sensory nerves about how your body is truly moving. Small modifications are performed as necessary after comparing the feelings to the engram directives.

Numerous engrams are created and stored in your brain's cerebrum during your life. These can be called upon to carry out many intricate actions. Many engrams are needed for writing, playing an instrument, and participating in sports. You can develop new skill patterns throughout your life. You need to repeatedly practise a skill in order to accumulate enough engrams to become an expert. After that, you move without giving them any attention.

Key Point:

• Repeated practice helps in picking up skills
• Skills become second nature once mastered
• Brain stores the steps required to complete a job in a format called an engram
• Engram is similar to a computer programme and keeps track of a pattern of expert movements
• Engram instructs the body to repeat the precise pattern when triggered
• Sensory nerves inform the brain about how the body is moving
• Small modifications are made by comparing feelings to engram directives
• Numerous engrams are created and stored in the cerebrum for various actions
• Repeated practice is needed to accumulate enough engrams to become an expert
• Once expert, skills become automatic and don't require attention.

Lesson Review

The capacity to make several movements flow smoothly together is known as coordination. The brain stem and cerebellum are mostly in charge of coordination. It is possible to learn complex movements by repeatedly practising them up until a movement pattern is encoded in an engram.

1. What term describes a rapid, automatic response to the envi ronment that occurs without the action of the brain?
2. What two parts of the brain control your balance?
3. Describe an engram.