science nervous system ya

Nervous system

complex, highly specialized network of cells and organs that serves as the body’s primary command and communication center. feeling, and body process

Central nervous system

Integration and processing center of the body

Brain

Housed inside the skull. Controls higher-level cognitive functions, memory, emotion, voluntary movements, language, and sensory interpretation.

Spinal cord

A thick column of nerve tissue running down the vertebral column. Serves as the primary transmission line between the brain and the rest of the body, while also governing rapid, involuntary actions (reflexes).

Somatic nervous system

Governs voluntary control, relaying sensory inputs from the skin, sensory organs, and skeletal muscles to the CNS and directing voluntary muscle movements.

Peripheral nervous system

The sensory and motor network made of cranial and spinal nerves extending outside the CNS.

Autonomic nervous system

Controls involuntary functions of internal organs, cardiac muscle, and smooth muscle tissues.

sympathetic division

•Activates the "fight-or-flight" response during stress or emergencies (dilates pupils, increases heart rate, opens airways).

Parasympathetic divison

•Governs the "rest-and-digest" state during periods of calm (slows heart rate, stimulates digestion, conserves energy).

Neuron

the structural and functional unit of the nervous system.

Dendrites

They act as the primary reception antennae of the neuron.

neurotransmitters

Dendrites receive chemical signals (____________) from the axon terminals of preceding neurons and convert them into electrical graded potentials, carrying the signal toward the cell body.

Soma

(also called as cell body) It maintains the overall health and life of the cell, synthesizes proteins, and processes the incoming electrical signals collected by the dendrites

Nuclues

Houses the cell's genetic material (DNA) and directs the synthesis of proteins and neurotransmitters essential for neuronal function and repair.

Axon hillock

Acts as the neural trigger zone or decision-making center. It tallies up all excitatory and inhibitory graded potentials; if the combined voltage exceeds the threshold limit (typically around -55 mV), an action potential is fired down the axon.

Axon

Conducts electrical nerve impulses (action potentials) rapidly away from the soma toward other neurons, muscles, or glands.

Myeline sheath

A whitish, fatty insulating layer formed by specialized glial cells (Schwann cells in the Peripheral Nervous System and oligodendrocytes in the Central Nervous System) that wraps around sections of the axon.

Nodes of ranvier

Allow ions to flow across the cell membrane. Instead of traveling smoothly, the electrical impulse "jumps" rapidly from node to node, drastically increasing the speed at which messages travel.

Axon terminal

Form junctions (synapses) with other cells. When an action potential reaches the terminal, it triggers the release of stored neurotransmitters into the synaptic cleft, chemically passing the signal on to the next neuron or target effect or organ.

Schwann cells in the Peripheral Nervous System

what’s inside of the Peripheral Nervous System?

oligodendrocytes

what’s inside in the Central Nervous System