3.4 The Brain, Spinal cord, and nerves

What is the brain

The brain is the central organ responsible for info integration

• contains 2 hemispheres and 4 lobes (each hemisphere has part of each lobe)

Key roles of the brain

1) process info from multiple inputs

2) Learn

3) Form memory

What are the four lobes

• frontal

• parietal

• temporal

• occipital

CNS vs PNS

• CNS: consists of the brain and spinal cord, acting as the bodys main control centre for information

• PNS: Consists of all nerves outside of the brain and spinal cord relaying messages between the body and the CNS

Components of PNS

• Somatic: voluntary movement of skeletal muscles

• Autonomic: (Sympathetic/Parasympathetic) involuntary movements

what is the spinal cord

integrating centre for unconscious processes

• protected by spinal column

key roles of spinal cord

• help transmit impulses between brain and body

• facilitate reflex actions

What is a neuron and what are the different types

Neuron = excitable cells that conduct signals between tissues

• Sensory neurons- (CNS ←→ receptor cells)

• Motor neurons - (CNS ←→ muscle fibres)

Neurons can be myelinated or non-myelinated which means they can either be covered in a protective sheath or not

How to draw neuron

See notes*

Nerve fibre vs Nerve

Nerve fibre = a bundle of neurons

Nerve = a bundle of nerve fibres

What are reflexes

The spinal cord is given permission to respond to injury creating a reflex which is a response created involuntarily without brain involvement

Draw a reflex

see notes*

What is the cerebellum

Responsible for muscle coordination and movement

What is neuroplasticity

The brains ability to adapt to disadvantages

what is the eye and how does it work

Organ that focuses light entering through pupils on to photoreceptors that send information to brain to create an image.