Physiology of the Nervous System

🧠⚡🔌 “Feel it, move it, think it—your nervous system runs the show!”

1. What is the Nervous System?

It’s your body’s communication highway—fast, accurate, and automatic.

It controls thoughts, emotions, movement, and vital processes.

Two major divisions:

Central Nervous System (CNS) 🧠🧱

Peripheral Nervous System (PNS) 🌐🕸️

2. The Central Nervous System (CNS)

It’s the command center made of:

a. Brain 🧠 – The Boss

Cerebrum: Thinking, memory, logic

Cerebellum: Balance & coordination

Brainstem: Controls heartbeat, breathing, and more

Hypothalamus: Hunger, thirst, temperature, emotions

Pituitary gland: The master gland (hormones)

b. Spinal Cord 🪜 – The Highway

Carries signals to and from the brain

Handles reflexes without bothering the brain!

3. The Peripheral Nervous System (PNS)

It connects the CNS to limbs & organs.

Two branches:

a. Somatic Nervous System 🏃💪

Voluntary actions (moving muscles)

Sensory signals from skin, muscles, joints

b. Autonomic Nervous System (ANS) 🛏️⚡

Involuntary actions (breathing, heartbeat, digestion)

Has two sub-parts:

Sympathetic ("Fight or Flight") 🥊

Increases heart rate, dilates pupils, boosts alertness

Parasympathetic ("Rest & Digest") 🧘

Slows heart rate, promotes digestion and calm

4. Neurons – The Messaging Ninjas ⚡🧩

Basic unit of the nervous system!

Each neuron has:

Dendrites – receive messages

Cell body – processes info

Axon – sends signals onward

Synapse – gap where chemicals (neurotransmitters) jump across!

Messages move at lightning speed ⚡ – up to 120 m/s!

5. Reflex Arc – Instant Reactions 🦵⚡

Reflexes don’t wait for the brain!

1. Receptor senses danger

2. Sensory neuron sends signal

3. Spinal cord processes it

4. Motor neuron sends action

5. Effector muscle reacts

Like touching a hot stove – you pull back before you feel the burn!

6. Neurotransmitters – The Chemical Messengers

Tiny molecules that help neurons communicate:

Dopamine – reward, motivation

Serotonin – mood, sleep

Acetylcholine – muscle control

GABA & Glutamate – balance excitement & calm

They shape how we feel, think, and act!

7. Nervous System Fun Facts

Your brain has 86 billion neurons!

Nerves can stretch over 100,000 miles in your body!

Your brain uses 20% of your body’s energy, even at rest!

A single neuron can send up to 1,000 messages per second!

Your Nervous System is Pure Magic

It lets you think, dream, move, feel, remember, an

d breathe—all at once!

🧠✨ Keep it healthy with good sleep, hydration, and mindfulness.