The Anatomy and Physiology of Animals/Nervous System Worksheet/Worksheet Answers
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.
|Vestibular nerve||1. The 8th cranial nerve that carries impulses from the organs of
balance and hearing to the brain.
|Optic nerve||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.|
|Olfactory nerve||4. The 1st cranial nerve that carries impulses from the organ of smell
in the nose to the brain.
|Vagus nerve|| 5. The 10th cranial nerve that supplies the pharynx, lungs, heart,
stomach and most of the abdominal organs.