nervous system is sensitive to pressure, taste, hormone levels, and light, sound and blood ph levels...

The Nervous System Nervous system is

sensitive to pressure, taste, hormone levels, and light, sound and blood pH levels

Converted to signals and sent to the brain via the spinal cord

Response is made and converted to action like changing heart rate, releasing hormones or the basic movement

It DOES Matter if You’re Grey or White

Grey Matter – Outside of cerebrum; inside of spinal cord.• Composed of

neuronal somas. White Matter –

Inside of cerebrum; outside of spinal cord. • Composed of axons• Myelinated axons

give it white colour.

A Tale of Two Nervous Systems Central Nervous

System (CNS) includes the Brain and Spinal Cord• Coordinates reactions

Peripheral Nervous System (PNS) is a collection of nerves that connects the CNS to the other parts of the body• Displays reflexes

A Quick Note On Terminology Afferent nerves

carry information towards the CNS/PNS.

Efferent nerves carry information towards the body.

Identify each fibre as afferent or efferent

CNS Protected by the

skull, 3 layers of meninges (connective tissue) and vertebrae

The brain is the main part of the CNS, and also consists of three parts: The Cerebrum, Cerebellum and the Brain Stem.

The CerebrumDivided into left and

right hemispheresInterprets signals from

the body and forms responses (hunger, pain, emotion etc.)

Outer layer is known as cerebral cortex.

•Interprets information from sensory organs and generates responses..

Underneath cortex are many smaller structures with different functions

Cerebral Cortex is partitioned into Lobes

Lobes are groups of neurons that work together to perform specific tasks• Frontal – Personality, reasoning, judgement,

some voluntary movement, speech production

• Parietal – Interprets and coordinates sense of touch

• Temporal – Speech interpretation, hearing, some memory

• Occipital – Visual processing

On Lobes… Many tasks are a result of

coordination between lobes. • Eg) Petting a kitten is interpreted by Parietal

lobe but the actual act of petting is coordinated by the Frontal lobe

The Cerebellum Second largest part

of the brain• Hangs below the brain

like a bell! Controls muscle

coordination and maintains posture and balance by working with Frontal lobe

The Brain Stem Connects brain to

spinal cord Controls basic life

functions (breathing, heartbeat, swallowing etc.)

Consists of midbrain, pons and medulla oblongata

The Spinal Column Runs along the

dorsal (ie. back) side of the body

Consists of the spinal cord encased in vertebrae and meninges.

This is where the PNS connects to the CNS• Links the brain to

nerves found throughout the body.

Peripheral Nervous System You will summarize 889 – 890 of the

text to make your own notes for the PNS.

Ensure you cover these topics:• Does the PNS function separately from the

CNS, does it relay information to the CNS or both? Explain.

• What are the two divisions of the PNS and what are their functions?

• What is meant by the “fight or flight system”? How does this differ “from the rest and digest” response (ie. Parasympathetic system)