Nervous System - Revision

1. The diagram below is of a nerve cell or neuron.

i. Add the following labels to the diagram. Axon; Myelin sheath; Cell body; Dendrites; Muscle fibers; ii. If you like, colour in the diagram as suggested below. Axon - purple; Myelin sheath - yellow; Cell body - blue; Dendrites - green; Muscle fibers – red; iii. Now indicate the direction that the nerve impulse travels.

2. There are three different kinds of neuron or nerve cell. Match each kind with its function.

A. Motor neuron; B. Sensory neuron; C. Relay neuron;

Kind of neurone Function

The nerve cell that carries impulses from a sense receptor ...... to the brain or spinal cord.

...... The nerve cell that connects sensory and motor neurons

The nerve cell that transmits impulses from the brain ...... or spinal cord to a muscle or gland 3. Match the descriptions in the table below with the terms in the list.

A. Synapse; B. Axon; C. Myelin sheath; D. Nerve impulse; E. Sense receptor; F. Response; G. Reflex; H. Cell body; I. Dendrite; J. Nerve; K. Neurotransmitter; L. Axon terminal

Term Function

...... 1. The long fibre that carries the nerve impulses.

...... 2. A bundle of axons.

...... 3. The connection between adjacent neurons.

...... 4. The chemical secreted into the gap between neurons at a synapse.

...... 5. A rapid automatic response to a stimulus.

...... 6. The covering of fatty material that speeds up the passage of nerve impulses.

7. The structure at the end of an axon that produces neurotransmitters to transmit the nerve impulse ...... across the synapse.

...... 8. The high speed signals that pass along the axons of nerve cells.

...... 9. The branching filaments that conduct nerve impulses towards the cell.

...... 10. The sense organ or cells that receive stimuli from within and outside the body.

...... 11. The reaction to a stimulus by a muscle or gland.

...... 12. The part of the nerve cell containing the nucleus. 4. The diagram below shows a cross-section of the spinal cord. Add the following labels to the diagram.

Central canal; White matter; Dorsal root; Grey matter; Ventral root; Skin; Muscle; Sensory neuron; Relay neuron; Motor neuron; Pain receptors in skin

a) List in order the 3 different neurons involved in a reflex arc from the stimulus to the response.

Stimulus ...... Response 6. Indicate whether the following parts of the nervous system are part of the Central Nervous System CNS) or the Peripheral Nervous System (PNS).

Part of nervous system CNS or PNS?

Brain ......

Autonomic nervous system ......

Spinal nerves ......

Spinal cord ......

Cranial nerves ......

10. Match the descriptions below with the parts of the nervous system in the list. You may need to use some terms more than once.

A. Autonomic nervous system; B. Central nervous system; C. Peripheral nervous system; D. Parasympathetic nervous system; E. Sympathetic nervous system

Description Part of the nervous system

1. Part of the nervous system that is composed of the brain and the spinal cord......

2. Part of the nervous system that is composed of the cranial and spinal nerves......

3. The part of the peripheral nervous system that regulates the activity of the heart ...... and smooth muscle.

4. The part of the autonomic nervous system that increases heart and respiratory ...... rates, increases blood flow to the skeletal muscles and dilates the pupils of the eye.

5. The part of the autonomic nervous system that increases gut activity and decreases ...... heart and respiratory rates.