Psychology - The Nervous System

The first main component of the human nervous system. The central nervous system (CNS) involves: brain spinal cord interneurons

The second main component of the human nervous system. Consists of all nerves outside of the CNS, including sensory and motor neurons. The peripheral nervous system (PNS) ensures that signals can be transferred to and from the CNS. There are two parts of the PNS: Somatic nervous system Autonomic nervous system

The somatic nervous system receives sensory information front the body and controls voluntary movements of skeletal muscles. It is responsible for actions that we consciously control such as walking, talking, writing etc.

The autonomic nervous system controls involuntary movement. It is responsible for regulating the activity of the body’s internal organs and glands, usually vital for survival. The ANS is further divided into two systems: the sympathetic nervous system the parasympathetic nervous system

Known as the ‘emergency’ response system or the ‘flight or fight’ response. Includes increasing metabolism for increased energy, producing adrenaline, increasing heart rate etc.

Reverses the effects of the sympathetic nervous system. Often called the ‘rest and digest’ system. It also controls homeostasis, which is the state of equilibrium in the body. The body spends most of its time in this state.

Reflex actions help us avoid harm and keep us safe.

Receptors in the skin detect a stimulus (for example, heat). A signal is sent via sensory neurons to the spinal cord. The signal reaches interneurons in the spinal cord, which sends the signal directly to motor neurons. The motor neurons send signals to the muscle to produce a quick response. The muscle responds. The signal is still sent to the brain.