Nervous System – Overview

Nervous System – Overview

The nervous system is a complex network that controls all activities of the body, from voluntary actions to automatic reflexes. It can be divided into three main parts:

1. Central Nervous System (CNS):

• Includes the brain and spinal cord.

• Serves as the control center, processing information and issuing commands for bodily functions.

• Brain components include:

• Cerebrum: The center of cognition, memory, and language.

• Diencephalon: Regulates autonomic functions such as sleep, hunger, and thirst.

• Cerebellum: Controls balance and coordination of movement.

• Midbrain: Controls visual and auditory reflexes.

• Pons: Connects the cerebrum, cerebellum, and spinal cord.

• Medulla Oblongata: Controls autonomic functions such as breathing rate, heart rate, and blood pressure.

• Spinal cord: Connects the brain to the periphery, controlling simple reflexes and transmitting information to the brain.

2. Peripheral Nervous System (PNS):

• Connects the CNS to other organs and parts of the body.

• Includes:

• Spinal nerves: 31 pairs of nerves originating from the spinal cord, controlling movement and sensation of the lower body.

• Cranial nerves: 12 pairs of nerves originating from the brain, controlling movement and sensation of the head, face, and sensory organs.

• Autonomic nervous system: Controls involuntary functions of the body such as heart rate, digestion, and sweating.

3. Enteric Nervous System:

• A complex nervous system located within the gut, controlling digestive activity.

Structure of the Nervous System:

• Neuron (nerve cell): The basic functional unit of the nervous system. Consists of the cell body containing the nucleus and axon that transmits information.

• Neuron classification:

• By function: Motor neuron, sensory neuron, interneuron.

• By shape: Multipolar neuron, bipolar neuron, unipolar neuron, anaxonic neuron.

• Gray matter: Primarily composed of neuron cell bodies, few branched cells, and star-shaped cells.

• White matter: Primarily composed of neuron axons and glial cells.

• Ganglion: A mass of gray matter in the PNS.

• Nucleus: A mass of gray matter in the brain and spinal cord with the same function.

Basic Functions of the Nervous System:

• Sensation: Perceiving stimuli from the external and internal environments.

• Movement: Controlling muscles to generate movement.

• Information processing: Analyzing, processing, and storing information.

• Information storage: Remembering events, knowledge, and experiences.

Additionally:

• Endocrine system: A system of glands that produce hormones that regulate bodily functions.

• Major endocrine glands: Pituitary gland, thyroid gland, adrenal glands, pancreas.

Note: This is a basic overview of the nervous system. To gain a deeper understanding of its functions and structures, further research on specific parts and functions is required.