Neurons and stimuli response

Nervous system:

The organs responsible for a fast response to immediate environmental stimuli, danger, and internal changes through nerve impulses.

FOR EX:

• fight-or-flight scenarios (increased heart rate/breathing),

• reflex actions (e.g., pulling away from heat),

• rapid sensory processing like light, sound, or pain detection.

Reflex vs. Conscious response

Reflex:

rapid, automatic, and involuntary protective responses that bypass the brain by traveling through the spinal cord.

• pulling your hand away immediately from extreme heat to prevent burning

• instantaneous to prevent harm

Conscious:

voluntary, slower actions initiated by the brain after processing information.

• Deciding to pull your arm away from heat

• slower due to brain processing

• voluntary and under control

Nerve Cell (Neurons)

SPECIFIC ABILITIES AS A SPECIALISED CELL

sends electrical signals to the body.

• the long axon reduces the number of cells needed for transmission, so makes the transmission of a nerve impulse much faster to another cell or neuron.

• Dendrites are adapted for the ability to receive multiple signals at the same time.

• The myelin sheath insulates the axon which enables faster signals (no signal is lost)

• Axon terminals transfer the signals (nerve endings)

• Node of ranvier is the gap between the schwann cells which allows the signal to jump, increasing the speed of transfer of nerve signals across the axon.

What is a specialised cell?

In multicellular organisms, generic cells can transform into specialized cells meant to do specific tasks in the body. For example: A nerve cell, white blood cells, and muscle cells.

• In the cell growth process, it is after the simple cell growth process of mitosis where the cell functions normally – INTERPHASE.