Question

In the peripheral nervous system, the division _____________ controls voluntary movements, whereas the _____________ division controls organs that keep us alive and function without our awareness.

Short answer

The somatic nervous system controls voluntary movements, whereas the autonomic nervous system controls organs that keep us alive and function without our awareness.

Step-by-step solution

Understanding The Peripheral Nervous System

First, understand that the peripheral nervous system (PNS) is one of the two major divisions of the nervous system. The PNS connects the central nervous system (CNS) to the rest of the body. The PNS has two subdivisions: the somatic nervous system and the autonomic nervous system.

Identify The Division That Controls Voluntary Movements

The somatic nervous system controls voluntary movements. It is part of the PNS and involves consciously controlled movements, actions, and reactions. So the first blank should be filled with 'somatic nervous system'.

Identify The Division That Controls Organs Functioning Without Our Awareness

The autonomic nervous system controls the functions of our organs that happen without our awareness. It regulates functions like heartbeat, digestion, and breathing. Thus, fill the second blank with 'autonomic nervous system'.

Key concepts

Somatic Nervous System

The somatic nervous system is a key player in our everyday actions. It is a part of the peripheral nervous system (PNS) and is responsible for controlling voluntary movements. This means it handles all the things we do consciously, such as walking, grabbing objects, or typing on a keyboard. The somatic nervous system acts like a bridge, connecting our central nervous system with the muscles that allow these movements.

It functions by relaying signals from the brain and spinal cord to our skeletal muscles. Here’s how it works:

• Neurons, which are the building blocks of the nervous system, carry signals from the brain.
• These signals travel through nerve fibers to reach specific muscles.
• The muscles then contract, producing the desired movement.

Understanding how this system works helps us appreciate how seamless our daily actions are, often without us even noticing the effort behind them. This control over our muscles allows us to perform everything from complex motor skills, like playing a musical instrument, to simple ones like nodding our head.

Autonomic Nervous System

The autonomic nervous system is a different branch of the peripheral nervous system. It manages the vital functions of our body that we do not control consciously. This includes critical activities like regulating our heartbeat, digestion, and maintaining body temperature. All these actions are essential for sustaining life but happen without us needing to think about them.

This system is further divided into two parts:

• Sympathetic nervous system - Often referred to as the "fight or flight" system, it prepares the body for stressful situations by increasing heart rate and energy levels.
• Parasympathetic nervous system - Known as the "rest and digest" system, it helps relax the body after stressful events, slowing down the heart rate and promoting digestion.

Both parts work together to ensure that our body functions smoothly across different scenarios. For instance, your heart pumps faster when you need more oxygen during exercise and slows down when you rest, thanks to the autonomic nervous system.

Voluntary Movements

Voluntary movements are actions that we take under our conscious control. These movements range from simple tasks, like raising your hand, to complex actions, such as dancing or playing a sport. In the realm of the nervous system, voluntary movements are primarily governed by the somatic nervous system.

Here's how the process works:

• The brain initiates a movement by sending a signal through the nervous system.
• The signal travels via nerve pathways to the relevant muscles.
• The muscles execute the movement, enabling us to perform the intended action.

This process involves careful coordination and precision, allowing us to execute activities smoothly and efficiently. It allows us to interact with our environment, express ourselves, and accomplish personal and professional tasks. The beauty of voluntary movements is evident in the variety of activities they support, making them a fascinating subject of study within the nervous system.