💚 LEAVING CERT HIGHER LEVEL BIOLOGY - THE NERVOUS SYSTEM

What does the peripheral nervous system do?

transmits information to and from the central nervous system

What do sensory neurons do?

They carry impulses from sense organ to CNS

What do interneurons do?

Carry information between sensory and motor neurons.

What do motor neurons do?

Carry impulses from CNS to muscles.

How do impulses move along a neuron?

If the sufficient strength for stimulus is met, the impulse moves by means of neurons.

True or false: Electrical impulses can cross the synapse.

False, neurotransmitters pass across instead.

What happens when an electrical impulse travels to the neurotransmitter swellings?

The vesicles secrete neurotransmitters (e.g. ACh)

What does the cell body do?

Contains the nucleus and mitochondria. Produces neurotransmitters.

What are dendrites?

Fibres that receive and carry impulses to the cell body.

What do axons do?

Carry impulses away from cell body.

What is the myelin sheath and what does it do?

Fat-rich membrane, insulates the impulses.

What do neurotransmitter swellings do?

Release neurotransmitters to carry impulse across the synapse.

What is the cerebellum?

Heavily folded, learns involuntary responses.

What is the medulla oblongata?

Connects spinal cord with brain.

What is the thalamus?

The sorting centre for the brain.

What is the hypothalamus?

Link between the mind and the brain

What does the hypothalamus control?

Homeostasis which includes temperature and blood pressure

What does white matter contain?

Axons and myelin.

What are the two nervous systems?

Central and peripheral

What does the central nervous system do?

Controls the brain and spinal cord

What are the three types of neuron?

sensory, motor, interneurons

What is the name for the broad region between neurons?

Synapse.

What is the name for the miniscule gap between neurons?

Synaptic cleft.

Where are neurotransmitters made?

The cell body.

What is the nucleus?

The control centre.

What are the three functions of the synapse?

To ensure the direction of impulse can only go in one direction, to prevent overstimulation of effectors, to block certain impulses to treat pain.

The brain

Protected by the skull, has three membrane tissues surrounding it called the meninges.

Cerebrum

Largest part of the brain, controls conscious thought and stores memory.

What do each hemisphere of the brain control?

Each control one side of the body.

What does the cerebellum control?

Muscular coordination and balance.

What does the medulla oblongata control?

Involuntary actions such as breathing, coughing and sneezing.

Where is the thalamus located?

Below the cerebrum.

What does the spine consist of?

Vertebrae and cartilage.

What is the function of the spine?

To protect the spinal cord.

What does grey matter contain?

Cell bodies

What is an example of a nervous system disorder?

Parkinson's disease

What is the cause of Parkinson's disease?

Failure to produce dopamine.

What are the symptoms of Parkinson's disease?

Trembling, stiff or rigid muscles.

What is the prevention of Parkinson's disease?

No known prevention.

What is the treatment of Parkinson's disease?

Exercise, physiotherapy and drugs that stimulate dopamine

What is reflex action?

An automatic, involuntary, unthinking response to stimuli