Human nervous system : Biology

What does the human nervous system do ?

Sends signals too and from the brain

What are the 2 parts of the nervous system ?

Central nervous system

Peripheral nervous system

What does the central nervous system do ?

Send signals through the brain and spinal cord

What does the Peripheral nervous system do ?

The neurones carry information between receptors the central nervous system and effectors

What is the Stimulus ?

The change in the environment

How does a nervous response start ?

It satarts with a stimulus being detected by specialised receptors cells and convert into any impulse

What do Neurones do ?

Adapt to carry electrical messages around the body

What are the 3 types of Neurones ?

Sensory

Relay

Motor

What is the long axon used for when transferring information ?

Used to transmit electrical impulses over a long distance around the body

What do Dendrites do ?

Used at each end allowing conduction between neurones

What does the Myelin Sheath provide ?

Insulation to speed up messages

Receptors ?

Cell that receives a stimulus

Sensory neurone ?

Neurone that carries electrical impulses from the receptor cells towards the CNS

Motor neurone ?

Neurone that carries electrical impulses effector from the CNS

Effector ?

Muscle or gland that reproduces to nervous impulses

Response ?

Action of an effector due to a stimulus

When do we use a reflex arc ?

When we need to respond to a stimulus extremely quickly

What doe s a reflex arc skip ?

Skips the CNS so impulses from the sensory neurone instead pass through a short relay neurone in the spinal cord

Why may we use a reflex arc ?

To avoid danger

3 facts about Voluntry response ?

Longer pathway slower response

Requires CNS

Impulse passes through the brain

3 facts about Reflex arc ?

Shorter pathways for faster response

Secondary info informs the CNS

Impulse passes through the relay neurone

What is the name of the gap between neurones ?

Synapse

What happens when an impulse reaches the end of a neurone ?

It triggers the release of chemicals called neurotransmitters across the synapse

What do neurotransmitters reach ?

The other side of the synapse and trigger a new electrical impulse in the next neurone

Why is reaction time important ?

Bc we need to react to danger quick to avoid hurting ourselves and others

2 differences between prokaryotic and eukaryotic cells ?

Prokaryotic has a pili

Eukaryotic has mitochondria

Similarities between eukaryotic and prokaryotic cells ?

Both have genetic material

Both have ribosomes

What type of enzyme is produced in the stomach ?

Protease eg: pepsin