Nervous System

Nervous system

• a complex network of organs, tissues, and cells that coordinate and control the functions of the human body

• It is responsible for receiving, processing, and responding to sensory input from the environment, as well as regulating and coordinating the body’s internal functions

Glial cell (neuroglia)

Support and protect neurons, and they also play a role in the formation and maintenance of the blood-brain barrier, which helps to protect the brain from toxins

Central Nervous System (CNS)

Brain and spinal cord

Peripheral Nervous System (PNS)

Consists of all the nerves that connect the CNS to the rest of the body

Brain

The control center of the nervous system and is responsible for processing and integrating sensory input and generating appropriate motor responses

Forebrain

Includes the cerebral cortex, which is responsible for conscious thought, sensation, and voluntary movement

Thalamus

Acts as a relay station for sensory information

Midbrain

Controls reflexes and eye movements

Hindbrain

Includes cerebellum, which coordinates movement and balance

Brainstem

Controls vital functions such as breathing, heart rate, and blood pressure

Spinal cord

• a long, thin bundle of nerve fibers that runs from the base of the brain down through the center of the back

• It serves as a conduit for sensory and motor information between the brain and the rest of the body

• Also responsible for coordinating some reflexes

1. Somatic nervous system

2. Autonomic nervous system

PNS is divided into two main branches:

Somatic nervous system

Controls voluntary movements and sensory input from the body’s surface

Autonomic nervous system

Regulates involuntary functions such as heart rate, digestion, and respiration

1. Sympathetic nervous system

2. Parasympathetic nervous system

Division of Autonomic NS:

Sympathetic nervous system

Prepares the body for “fight or flight” responses in times of stress

Parasympathetic nervous system

Promotes “rest and digest” activities during times of relaxation