1. The diagram below is of a nerve cell or neurone.
- i. Add the following labels to the diagram.
- Axon; Myelin sheath; Cell body; Dendrites; Muscle fibres;
- ii. If you like, colour in the diagram as suggested below.
- Axon - purple;
- Myelin sheath - yellow;
- Cell body - blue;
- Dendrites - green;
- Muscle fibres – red;
- iii. Now indicate the direction that the nerve impulse travels.
2. There are three different kinds of neurone or nerve cell. Match each kind with its function.
- A. Motor neuron; B. Sensory neuron; C. Relay neuron;
|Kind of neurone||Function|
|B. Sensory neuron||
The nerve cell that carries impulses from a sense receptor
to the brain or spinal cord.
|C. Relay neuron||The nerve cell that connects sensory and motor neurons|
|A. Motor neuron||
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.
|B. Axon||1. The long fibre that carries the nerve impulses.|
|J. Nerve||2. A bundle of axons.|
|A. Synapse||3. The connection between adjacent neurons.|
|K. Neurotransmitter||4. The chemical secreted into the gap between neurons at a synapse.|
|G.Reflex||5. A rapid automatic response to a stimulus.|
|C. Myelin sheath||
6. The covering of fatty material that speeds up
the passage of nerve impulses.
|L. Axon terminal||
7. The structure at the end of an axon that produces neurotransmitters
to transmit the nerve impulse across the synapse.
|D. Nerve impulse||8. The high speed signals that pass along the axons of nerve cells.|
|I. Dendrites||9. The branching filaments that conduct nerve impulses towards the cell.|
|E. Sense receptor||
10. The sense organ or cells that receive stimuli from
within and outside the body.
|F. Response||11. The reaction to a stimulus by a muscle or gland.|
|H. Cell body||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||sensory neuron||relay neuron||motor neuron||Response|
- b) Name 3 different reflexes found in animals.
Reflex 1. Blink reflex.
Reflex 2. Paw pinch reflex.
Reflex 3. Swallowing reflex, plus many others.
6. The diagram below shows the nervous system of a horse. Add the following labels.
- Brain; Spinal cord; Cranial nerves; Spinal nerves; Sciatic nerve; Nerves of the autonomic nervous system; Vagus nerve; Network of nerves to forelimb.
7. 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?|
|Autonomic nervous system||PNS|
8. The diagram below shows a section of a dog’s brain. Add the labels
in the list below and, if you like, colour in the diagram as suggested.
- Cerebellum - blue;
- Spinal cord - green;
- Medulla oblongata - orange;
- Hypothalamus - purple;
- Pituitary gland - red;
- Cerebral hemispheres – yellow.
9. Match the descriptions below with the terms in the list. You may need to use some terms more than once.
|E. Hypothalamus||1. Controls water balance and body temperature.|
|D.Medulla oblongata||2. Where the respiratory rate is controlled.|
|C. Cerebellum||3. Where posture, balance and voluntary muscle movements are controlled.|
|A. Cerebral hemispheres||
4. Contains centres governing mental activity, including intelligence,
memory, and learning.
|H. Meninges||5. The tough fibrous envelope enclosing the brain and spinal cord.|
|F. Pituitary||6. The “master” gland of the endocrine system.|
|Cerebral hemispheres/cortex||7. Responsible for instigating voluntary movements.|
|J. Cerebrospinal fluid||8. The fluid that surrounds the brain and spinal cord.|
|G. Grey matter||9. Composed of cell bodies and nuclei.|
|B. White matter||10. Composed of axons.|
|Cerebral hemispheres/cortex||11. Where the sensations of sight, sound, taste etc. are interpreted.|
|I. Ventricles||12. Spaces in the brain filled with cerebral spinal fluid.|
|K. Sulcus||13. A fold in the cerebral cortex.|
|L. Carotid artery||14. The artery that supplies the brain with oxygenated blood.|
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.
|Description||Part of the nervous system|
1. Part of the nervous system that is composed of the
brain and the spinal cord.
|B. Central nervous system|
2. Part of the nervous system that is composed of the
cranial and spinal nerves.
|C. Peripheral nervous system|
3. The part of the peripheral nervous system that regulates
the activity of the heart and smooth muscle.
|A. Autonomic nervous system|
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.
|E. Sympathetic nervous system|
5. The part of the autonomic nervous system that increases gut activity
and decreases heart and respiratory rates.
|D. Parasympathetic nervous system|
11. Name the nerves described below using the choices in the list.
1. The 8th cranial nerve that carries impulses from the organs of
balance and hearing to the brain.
2. The 2nd cranial nerve that carries nervous impulses from the
retina of the eye to the brain.
|Sciatic nerve||3. The largest nerve in the body serving the muscles of the leg.|
4. The 1st cranial nerve that carries impulses from the organ of smell
in the nose to the brain.
5. The 10th cranial nerve that supplies the pharynx, lungs, heart,
stomach and most of the abdominal organs.