Nervous System In Mammals - SS3 Biology Lesson Note

The nervous system in mammals is a complex network of specialized cells and structures that coordinates and regulates the body's functions and responses to stimuli. It consists of two main components: the central nervous system (CNS) and the peripheral nervous system (PNS).

1.       Central Nervous System (CNS):

a.       Brain: The brain is the command centre of the nervous system, responsible for processing and integrating sensory information, initiating motor responses, and controlling higher cognitive functions. It is divided into different regions, each with specific functions, such as the cerebrum, cerebellum, and brainstem.

b.       Spinal cord: The spinal cord is a long, cylindrical structure that extends from the brainstem down the vertebral column. It serves as a conduit for transmitting nerve signals between the brain and the rest of the body. The spinal cord also plays a role in reflex actions, where sensory information is rapidly processed and produces an immediate motor response without involving the brain.

2.       Peripheral Nervous System (PNS):

c.       Somatic Nervous System: The somatic nervous system controls voluntary movements and sensory perception. It consists of sensory neurons that transmit information from sensory receptors (e.g., touch, temperature, pain) to the CNS, and motor neurons that send signals from the CNS to skeletal muscles, allowing for conscious movement.

d.       Autonomic Nervous System: The autonomic nervous system regulates involuntary bodily functions and is further divided into the sympathetic and parasympathetic divisions. The sympathetic division prepares the body for "fight or flight" responses in stressful situations, while the parasympathetic division promotes rest, digestion, and energy conservation.

Neurons, the specialized cells of the nervous system, transmit electrical signals, known as action potentials, to communicate information. These signals travel along the axons, which are long, slender extensions of neurons, and are transmitted between neurons at junctions called synapses using chemical messengers called neurotransmitters.

(news-medical.net)

The mammalian nervous system enables a wide range of functions, including sensory perception, motor control, learning, memory, and complex behaviours. It allows mammals to interact with their environment, coordinate bodily processes, and respond adaptively to changes and challenges in their surroundings.