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1 " "!, ' II, I THE NERVOUSSVSTEM po'rtpharalnervous ~m, I " ~v\'l.t 3 - "Be~CtVl.OUY, populatl.ov\,s tle 6I\,VLYO~~ell\,t Na~ crass _

2 . The diagram shows how the nervous system is organised. A B o (a) Complete the diagram by entering the names of parts A to D. (b) The parts of the autonomic nervous system are described as antagonistic. (i) What is meant by the term antagonistic? (ii) Explain how this antagonistic action controls the activity of the digestive system. r

3 _ ~ The diagrams below show two possible ways of classifying the nervous system...'.~ MARGIN: Structure Function (a) (i) Identify A to D. A B c D (ii}: Describe one function of the somatic nervous system. (b) The brain contains two cerebral hemispheres. (i) Name the structure which links these two hemispheres. (ii) The surfaces of the hemispheres are heavily folded to provide a large surface area. Explain the significance of this feature.

4 . (continued) MARGIN (c) The diagram below shows some of the nerve connections between the brain and three parts of the body. cerebrum heart small intestine (i) Identify the part of the brain labelled X. (ii) The sympathetic and parasympathetic systems are often described as antagonistic to one another. Explain the meaning of antagonistic. (iii) Complete the table to show the effect of sympathetic stimulation on the heart, sweat glands and small intestine. Part of body Sympathetic effect Heart Sweat glands Small intestine [Turn over

5 3. The diagram represents a motor neurone. iv/arks A (a) Name the nerve fibres A and B. A _ B (b) The table. below describes features of somatic and autonomic motor neurone function. Complete the table. Feature Somatic Autonomic type of control (conscious/unconscious) example of target muscle example of neurotransmitter uterine muscle noradrenaline (c) State the effect of sympathetic stimulation on the: heart rate _. I digestive system _ 3 skin arterioles 3 (d) The sympathetic and parasympathetic nervous systems often influence organs in opposite ways. What term describes this opposing effect?

6 4. Part of a neurone is shown in the diagram below. (a) State whether the neurone shown is a sensory or motor neurone and give a reason for your answer. Type of neurone Reason for answer (b) Name structure X and state its function. Name Function (c) (i) Name structure Y. (ii) Similar structures are found In the synaptic knob. What do they contain? r

7 4. (continued) (d) In the disorder Multiple Sclerosis, the myelin sheath is damaged by the body's own defence system. (i) 'What effect does this have on the function of the nerve fibre? THIS MARCtt.; (ii) What term is used to describe a disorder where the body's defence system destroys its own cells? I. ", (e) Draw an arrow on the diagram to show the direction of an impulse in a dendrite. (f) Diverging neural pathways always contain the type of neurone shown opposite. Explain how diverging pathways allow humans to perform a task such as threading a needle. I. [Turn over

8 5. The diagram below shows a motor neurone connected to some muscle fibres. Marhs x muscle fibre I. neuromuscular junction (a) What characteristic feature of muscle fibres is not shown in the diagram? I I I. I II () I I (b) (i) Name the part of the motor neurone labelled X. (ii) What is the function of the myelin sheath? () j! I I (c) At each.neuromuscular junction, a gap exists between the nerve ending and the muscle fibres. Describe how the arrival of a nerve impulse results in stimulation of the muscle fibre. () I, () r

9 6. The diagram below shows 3 motor neurone and its junction with skeletal muscle tissue. Iv/arks DO NOT WRITE IN THIS MAM(;IN A B myelin sheath (a) Name the parts of the neurone labelled A, Band C on the diagram. A B C (b) Neurotransmitters bind to receptors on skeletal muscle tissue triggering contraction. (i) Name two neurotransmitters. (ii) Explain why the release of neurotransmitter into a synaptic cleft may sometimes fail to trigger muscle contraction. (iii) Name the structural proteins in skeletal muscle tissue and describe how they interact to bring about muscle contraction. Proteins Description rxoo9j30] Page ucenty-six

10 6. (continued) (c) (i) State the importance of the myelin sheath 0 the transmission of impulses. oo NOT WRITI::IN THIS MARGIN (ii) Post-natal myelination is necessary for a child to go through the sequence of developmental stages leading to walking. What term describes this sequence of developmental stages? [Turn over (X009/30] Pag«tscenty-secen

11 7. The diagram shows a neuromuscular junction. myelin sheath muscle - filaments (a) Name the part of the nerve cell labelled P. (b) (i) What kind of substance is acetylcholine? (ii) What triggers the release of acetylcholine? (iii) State what happens to acetylcholine after it has acted on the muscle. (c) Name the two muscle proteins labelled Q and R. Q R _ (d) Describe what happens to these protein filaments when a muscle contracts.

12 8. The diagram below shows a neuromuscular junction. ""''I (a) How does the presence of the myelin sheath affect the transmission of the nerve impulse along the axon? () (b) (i) What type of substance is found in the vesicle? () (ii) Describe how the arrival of a nerve impulse at the neuromuscular junction results in stimulation of the muscle. () - (c) (i) State whether the muscle is contracted or relaxed. () - (ii) Name the two proteins found in the muscle filaments. and () -

13 9. (a) The diagram below shows a synapse which links a nerve cell with the sinoatrial node (SAN) in the heart. THIS MARGIN x Part of SAN (i) Where in the heart is the SAN located? (ii) Describe the function of molecule X. (b) One example of a neurotransmitter is acetylcholine. How is acetylcholine removed from the synapse? (c) (i) In which area of the brain does the sympathetic nervous system originate? (ii) Describe a situation which would lead to stimulation of the sympathetic nervous system.

14 0. The diagram shows a neuromuscular synapse. \'Y t(,.\a " it myelin sheath (a) (i) Name cell structure X. I (ii) Describe the role of structure X in exocytosis. (b) What is the function of molecule Y? (c) The areas on both sides of the synaptic cleft are rich In mitochondria. Explain why mitochondria arc needed in each area. (d) (i) Name protein filament Z. (ii) Describe what happens to the length of this filament when the muscle contracts.

15 J J. The diagram below shows two different neural pathways. Nerve impulses are travelling from left to right in both pathways. Marhs oi-llj.;)!\arcin Pathway A - -- PathwayB I- I - (a) (i) Name the types of pathway represented by A and B. A _ B (ii) Pathway A helps the hand to function. Explain how it does this. (b) Blinking is a reflex action. (i) What is a reflex action? (ii) The blinking reflex can sometimes be suppressed. What term refers to the ability of the nervous system to suppress reflexes?

16 . Rods and cones are light receptor cells found in the eye. The diagram below represents the arrangement of these cells. I----~(=~~=,,~~~~ _. to optic nerve In_.:::> (\IARCI~ ; Ii 'I I:. ".. -I " i ~, r 'J~ ~.'!i ~ ~.. -..:..., rods cones (0) In which region of the eye are rods and cones located?... (b) (i) What type of neural pathway links the rod cells to the optic nerve? (ii) Name gap A. (iii) Explain how the arrangement of rod cells increases the chances of a nerve impulse crossing gap A. (c) The optic nerve carries nerve impulses to the visual area of the brain. In which region of the brain is the visual area found? [Turn over

17 (~,..~What you should know -)-. i (Chapters 5-7) : (See table 7. for word bank.) , The human...._is large relative to body size. The is the largest part of the human brain. It is made up of two halves called _ which are connected by the callosum. This enables information to be transferred from one half to the other. 3 The nature of the cerebrum's surface allows a large number of nerve cell bodies to be located dose together, increasing the potential for exchange of information between them. 4 The cerebrum possesses three types of functional area: _ areas which receive information from receptors, association areas which analyse the information and._ areas which send out information to effectors. 5 Different Iunctions are localised in discrete areas of the cerebrum e.g. auditory, and motor areas. 6 The size of the region of motor area devoted to part of the body is in proportion to the relative of the body part and not to its actual size. 7 Evidence for the localisation of different brain functions comes from studies of EEGs. brain, split-brain patients and observations of people suffering brain injuries and _ 8 The human nervous system can be divided on a structural basis into the and peripheral nervous systems. 9 The human nervous system can be divided on a. basis into the somatic and _ systems. 0 Most of the control exerted by the somatic system is over actions. The autonomic system works automatically without involving the person' s conscious thought. The autonomic system is made of the _ and parasympathetic systems which are often 3 The sympathetic system arouses the body in preparation for ; the parasympathetic helps the body to conserve _ 4 The nervous system is composed of sensory, association and motor nerve cells ( ). i : i i _'. _..J I r--"~ What you should know i'~' (Chapters 5-n 5 Each neurone consists of a cell body and associated nerve fibres: one and several dendrites. 6 A nerve fibre is surrounded by d sheath whose presence greatly increases the at which nerve impulses can be transmitted through the fibre. 7 A.. is a tiny space between two neurones. Information is transmitted at a synapse by beinq released by the presynaptic neurone. This chemical combines with _ sites in the postsynaptic membrane. 8 Some receptor sites respond by having an effect on the postsynaptic membrane: others have an inhlbitory effect. 9 In a. _ neural pathway. the route along which a nerve impulse travels divides allowinq information to pass to several destinations; in a neural pathway. nerve impulses from 0 several sources are channelled towards and meet at a common destination. Sometimes the brain can suppress a reflex action Or block out certain sensory impulses, thereby demonstrating. _. of response. action diverging plasticity antagonistic excitatory receptor autonomic functional resources axon hemisphere scans hrain lesions sensory central mobility speed cerebrum motor sympathetic convoluted myelin synapse converging neuroncs visual corpus neurotransmitter voluntary Table 7. Word bank for chapters 5-7 ~, ; r

18 ~-- -_ Unit 3: Behaviour. Populations & the Environment Topic : The Nervous System Essay Questions. Describe the organisation of the nervous system under the following ',eadings: i) ii) nerve cell structure somatic and autonomic nervous system (4)) (6) (0). Describe the structure and (unction o(nerves (0) 3. Give an account of the transmission o(impuises under the following headings; i) ii) iii) the synapse converging pathways diverging pathways (6) () () (0) 4. Give an account o(the function ofa synapse under the following headings: i) ii) iii) Release of neurotransmitter Action 0/ neurotransmitter Removal of neurotransmitter (3) (3) (4) (/0) s. Give all account of the transmission ola nerve impulse at a synapse (0)