Class: ( Name: 16 ) Date: Coordination in humans 16.1 The human nervous system (Book 2, p. 16-3) There are two coordinating systems in humans: the (1) _______________ system (神經系統) and the (2) _______________ system (內分泌系統). A The general plan of the nervous system (Book 2, p. 16-3) Our nervous system consists of two main parts: - The (3) _______________ nervous system (CNS) (中樞神經系統), which consists of the (4) _______________ and the (5) _______________ _______________ (脊髓). - The (6) _______________ nervous system (PNS) (外圍神經系統), which consists of (7) _______________ nerves (腦神經) and (8) _______________ nerves (脊髓神經). B The basic unit of the nervous system (Book 2, p. 16-4) (9) _______________ (神經元) are the basic unit of the nervous system. 1 Structure of a neurone (10) _____________ _____________ (細胞體): (15) _____________ _____________ (髓鞘): - - contains a nucleus and cytoplasm with other organelles a layer of fatty material surrounding nerve fibres (11) _______________ (樹突): (13) _______________ (軸突): - - transmits nerve impulses transmits nerve impulses (12) _____________________ (14) _____________________ (towards / away from) the cell body (towards / away from) the cell body nerve fibres (神經纖維) Key: New Senior Secondary Mastering Biology (Second Edition) - 69 - transmission of nerve impulse Oxford University Press 2015 The myelin sheath protects and (16) _______________ the nerve fibres. This serves to: 2 - prevent the transmission of nerve impulses to the (17) _______________ - (18) _______________ _______________ the transmission of nerve impulses. Types of neurones Type of neurone Direction of nerve impulse transmission Location of cell body Appearance From (22) ____________ Has a (19) ______________ (20) _____________ (Outside / Inside) (23) ____________ neurone (感覺神經元) to the the CNS dendron and a (21) _____________ (24) ____________ axon From the (28) ____________ Has very (25) ______________ (26) _____________ to (Outside / Inside) (29) ____________ neurone (運動神經元) (27) _____________ the CNS dendrons and a (30) ____________ axon From a (34) ____________ Has short dendrons and (32) _____________ (Outside / Inside) short axons (31) ______________ neurone to a the CNS (中間神經元) (33) _____________ neurone or other interneurones C The structure of a nerve A (35) _______________ (神經) is a (Book 2, p. 16-6) a nerve connective tissue bundle of nerve fibres wrapped in connective tissue. a nerve fibre myelin sheath blood vessels ▲ Structure of a nerve New Senior Secondary Mastering Biology (Second Edition) - 70 - Oxford University Press 2015 16.2 Transmission of nerve impulses between neurones (Book 2, p. 16-7) Nerve impulses are (1) _______________ messages transmitted along nerve fibres at high speed. Nerve impulses are transmitted from the axon of a neurone to the dendron or cell body of the next neurone across a (2) _______________ (突觸). dendron axon nerve Key: transmission of nerve impulse A nerve impulse arrives. axon The (3) _______________ mitochondria _______________ (突觸小體) releases (4) _______________ (神經遞質). synaptic knob The neurotransmitter (5) _______________ synaptic vesicle containing neurotransmitter across the (6) _______________ _______________ (突觸間隙). synaptic cleft The neurotransmitter stimulates the dendron to generate a (7) _______________ cell body or dendron of next neurone _______________. ▲ Transmission of nerve impulses across a synapse The importance of the synapses They ensure that nerve impulses travel in (8) _______________ direction only. They allow a neurone to (9) _______________ with many other neurones. New Senior Secondary Mastering Biology (Second Edition) - 71 - Oxford University Press 2015 16.3 The central nervous system A How is the CNS protected? (Book 2, p. 16-9) (Book 2, p. 16-9) The central nervous system (CNS) consists of the brain and the spinal cord. They are protected by: - (1) _______________: The brain is enclosed by the (2) _______________ (顱). The spinal cord is protected by the (3) _______________ _______________ (脊柱). - (4) _______________: The CNS is covered by three membranes. - (5) _______________ _______________ (腦脊髓液): This fluid fills the space between the inner and middle membranes and the (6) _______________ _______________ (中央管) of the spinal cord. (7) _______________ three (8) _______________ brain cavity filled with (9) _______________ spinal cord _______________ central canal central canal spinal cord spinal nerve three (10) _______________ (11) _______________ _______________ Ventral Dorsal ▲ Structures protecting the brain and the spinal cord Functions of the cerebrospinal fluid: - Provides nutrients and oxygen to the (12) _______________ and removes waste from them - Serves as a (13) ______________ ______________ - Provides (14) ______________ support to the brain and the spinal cord. New Senior Secondary Mastering Biology (Second Edition) - 72 - Oxford University Press 2015 B The brain (Book 2, p. 16-10) The brain consists of three main parts: (15) _______________ (大腦) (16) _______________ (小腦) (17) _______________ _______________ (延髓) Part of the brain Cerebrum Structural feature Function Highly (18) _______________ at the Site of surface to hold more neurones, so (22) _______________ (智力) that (19) _______________ can be Controls more efficient (23) _______________ actions Outer layer made up of (隨意動作) (20) ______________ matter (灰質) ; writing e.g. speaking and inner layer made up of (21) ______________ matter (白質) Cerebellum Highly (24) _______________ (27) _______________ muscular Outer layer made up of movements for maintaining (25) _______________ matter; (28) _______________ inner layer made up of _______________ when we move (26) _______________ matter Medulla Outer layer made up of (31) _______________ centre (29) _______________ matter; (反射中樞) inner layer made up of (反射動作), (30) _______________ matter swallowing and coughing oblongata for many reflex actions e.g. saliva secretion, Controls other (32) _______________ actions (不隨意動作), e.g. breathing and heart beat New Senior Secondary Mastering Biology (Second Edition) - 73 - Oxford University Press 2015 The grey matter consists mainly of the (33) _______________ _______________ of neurones. Their nuclei give a grey colour to this region. The white matter consists of (34) _______________ _______________. Their (35) _______________ _______________ give the white colour to this region. The outer layer of the cerebrum is called the (36) ______________ ______________ (大腦皮層), which is divided into different functional areas: legs, trunk, arms, face, tongue touch, hearing, smell, taste sight thinking, judgement memory B Label A B C C A B Area in cerebral cortex A Function (37) _______________ Receives nerve impulses from receptors to give area (感覺區) (38) _______________ (39) _______________ Sends nerve impulses to effectors to produce area (運動區) (40) _______________ (41) _______________ area (聯合區) (42) _______________ information from different sensory areas, so that the brain can make decisions before sending nerve impulses to motor areas Go to Practical 16.1 Examination of a human brain model (Book 2, p. 16-13; Practical Workbook for SBA 2, p. 16-1) C The spinal cord (Book 2, p. 16-15) The outer region of the spinal cord is made up of (43) _______________ matter. The inner H-shaped region is made up of (44) _______________ matter. At the centre of the grey matter is the central canal which is filled with cerebrospinal fluid. New Senior Secondary Mastering Biology (Second Edition) - 74 - Oxford University Press 2015 (45) _______________ matter: (46) _______________ matter: - - consists of nerve fibres consists mainly of the cell bodies of neurones (47) _______________ neurone nerve fibres central canal dorsal root spinal nerve ventral root (50) _______________ _______________ (48) _______________ _______________ (背根節): (49) _______________ - neurone contains cell bodies of sensory neurones Key: transmission of nerve impulse ▲ Structure of the spinal cord Functions of the spinal cord: - It (51) _______________ nerve impulses between the brain and other parts of the body. - It is the (52) _______________ centre for many reflex actions involving the trunk and limbs. 16.4 Reflex action and voluntary action A What is a reflex action? (Book 2, p. 16-18) (Book 2, p. 16-18) A (1) _______________ _______________ is an inborn, rapid and automatic response to a stimulus. It is also stereotyped (有固定形式的). All reflex actions are involuntary because they do not involve the (2) _______________. Reflex actions produce (3) _______________ (slow / fast) responses. They protect us from danger. Example of reflex action Parts of CNS involved Withdrawal reflex (退縮反射) and (4) _______________ _______________ and knee jerk reflex (膝躍反射) (5) _______________ _______________ Saliva secretion, swallowing and coughing New Senior Secondary Mastering Biology (Second Edition) (6) _______________ _______________ - 75 - Oxford University Press 2015 B 1 Examples of reflex actions (Book 2, p. 16-19) The withdrawal reflex from brain to brain motor neurone V spinal cord ventral root interneurone VI IV dorsal root sensory neurone I Step II III Key: transmission of nerve impulse Description I a The hand touches a sharp object. II b The arm muscle (effector) contracts. III c The hand withdraws to prevent damage. IV d Nerve impulses travel along the sensory neurone to the spinal cord. V e Pain receptors in the skin are stimulated and they generate nerve impulses. VI f Nerve impulses travel along the interneurone and the motor neurone to the arm muscle. I: (7) __________ II: (8) __________ III: (9) __________ IV: (10) _________ V: (11) _________ VI: (12) _________ The withdrawal reflex does not involve the (13) _______________, but nerve impulses are transmitted to the brain via another nervous pathway. Hence, we (14) _______________ (can / cannot) feel the pain. The hand has already withdrawn before we can feel the pain. This (15) _______________ the body from damage. New Senior Secondary Mastering Biology (Second Edition) - 76 - Oxford University Press 2015 2 The knee jerk reflex to brain dorsal root III II sensory neurone knee cap spinal cord I ventral root motor neurone IV Key: Step transmission of nerve impulse V VI Description I a Nerve impulses travel along the sensory neurone. II b The tendon just below the knee cap is tapped. III c The leg kicks. IV d Stretch receptor in the upper leg muscle is stimulated. V e Nerve impulses travel along the motor neurone to the leg muscle. VI f The leg muscle (effector) contracts. I: (16) __________ II: (17) __________ III: (18) __________ IV: (19) _________ V: (20) _________ VI: (21) _________ The knee jerk reflex helps maintain (22) _______________ and (23) _______________. We can feel the tapping when nerve impulses are transmitted to the brain via another nervous pathway. The nervous pathway that brings about a reflex action is called a (24) _______________ _______________ (反射弧). It involves a sensory neurone, an interneurone (absent in some reflex arcs) and a motor neurone. New Senior Secondary Mastering Biology (Second Edition) - 77 - Oxford University Press 2015 C What is a voluntary action? (Book 2, p. 16-22) A voluntary action is under (25) _______________ control of the cerebrum of the brain. Voluntary actions may also be (26) _______________ by the cerebrum directly without involving any stimuli. Nervous pathway of voluntary actions: - After detecting a stimulus, the (27) _______________ generates nerve impulses which are transmitted to the (28) _______________. (Some voluntary actions are initiated by the (29) _______________ without involving any stimuli.) - The information is processed and (30) _______________ in the cerebrum which then generates other nerve impulses. - These nerve impulses are transmitted to the (31) _______________ to produce a response. 16.5 Differences between reflex actions and voluntary actions (Book 2, p. 16-25) Reflex actions Voluntary actions Involves the (1) _____________ Always involves the (3) _______________ _____________ or the Nervous pathway (2) _____________ _____________, but not the cerebrum A receptor is always involved May not involve any (4) _______________ if the action is initiated by the cerebrum directly (5) ____________________ (7) ____________________ (Under / Not under) conscious (Under / Not under) conscious control control (i.e. (6) ______________) Nature of response (8) ____________________ (9) ____________________ (Inborn / Not inborn) (Inborn / Not inborn) The same stimulus always results in The same stimulus may result in (10) ______________ (the same / (12) ______________ (the same / different) different) response(s) (i.e. a response(s) (11) _______________ response) Speed of response Always (13) _______________ New Senior Secondary Mastering Biology (Second Edition) May be fast or slow, depending on the nervous pathway involved and the nature of response - 78 - Oxford University Press 2015 16.6 The human endocrine system (Book 2, p. 16-26) The endocrine system consists of a number of (1) ______________ _____________ (內分泌腺), which produce (2) _______________ (激素). A What is an endocrine gland? (Book 2, p. 16-26) Differences between endocrine glands and (3) _______________ ______________ (外分泌腺): Endocrine gland Exocrine gland secretion diffuses directly into the blood secretion is released through a duct duct inflow of blood outflow of blood secreting cell Way of releasing secretions secreting cell capillary Diffuse directly into the Through (5) _______________ (4) _____________ Pituitary gland (垂體), thyroid gland Example and substance produced adrenal glands (腎上腺), Salivary glands that produce saliva, and pancreas, ovaries and testes that gastric glands that produce gastric juice (甲狀腺), produce various (6) _____________ Hormones are mostly (7) _______________ or (8) _______________ in nature. They are important for the (9) _______________ of body processes and internal environment. B How does hormonal coordination work? (Book 2, p. 16-28) Hormones serve as chemical messengers. They are produced in very (10) _______________ (large / small) amounts. They diffuse into the blood from their site of production, and then circulate in the (11) _______________ throughout the body. They will only act on (12) _______________ organs. The action of hormones is (13) _______________. One hormone may affect several target organs at the same time. Their duration of effect is usually (14) ____________-____________. New Senior Secondary Mastering Biology (Second Edition) - 79 - Oxford University Press 2015 An example of hormonal coordination: II I pancreas cell insulin capillary glucose liver cell V IV Step III Description I a Insulin diffuses into the blood. II b The carbohydrates ingested are broken down into glucose. Glucose is absorbed into the blood. III c Cells in the liver (target organ) receive insulin and are stimulated to convert excess glucose to glycogen (response). The blood glucose level returns to normal. IV d Receptors in the pancreas detect an increase in blood glucose level (stimulus). The pancreas (endocrine gland) produces more insulin (hormone). V e Insulin is transported by blood to all parts of the body. I: (15) __________ II: (16) __________ IV: (18) _________ V: (19) _________ New Senior Secondary Mastering Biology (Second Edition) - 80 - III: (17) __________ Oxford University Press 2015 16.7 Comparison between hormonal coordination and nervous coordination (Book 2, p. 16-30) Both hormonal coordination and nervous coordination are important for transmitting messages to (1) _______________ to give proper (2) _______________. Differences between hormonal coordination and nervous coordination: Hormonal coordination Nervous coordination System involved (3) _______________ system (4) _______________ system Components of the system Endocrine glands, blood Neurones, nerves, brain, spinal cord (5) _______________ (6) _______________ (hormones) (nerve impulses along nerve fibres) Nature of message Chemical ((7) _______________ across synapses) Route of transmission Blood stream Nerve fibres Speed of transmission (8) _______________ (9) _______________ (Rapid / Slow) (Rapid / Slow) (10) _______________, one (11) _______________, restricted hormone may affect several target to places with nerve supply Areas of response organs at the same time Duration of effect Body processes involved Usually (12) _______________- (13) _______________- _______________ _______________ Reproduction, growth and Voluntary actions, reflex actions development, regulation of internal and other involuntary actions environment (always (14) _______________) New Senior Secondary Mastering Biology (Second Edition) - 81 - Oxford University Press 2015 Answers Ch 16 Coordination in humans 16.1 1 nervous 2 endocrine 3 central 4 brain 5 spinal cord 6 peripheral 7 cranial 8 spinal 9 Neurones 10 cell body 11 dendron 12 towards 13 axon 14 away from 15 myelin sheath 16 insulates 17 surroundings 18 speed up 19 Sensory 20 receptors 21 CNS 22 Outside 23 long 24 short 25 Motor 26 CNS 27 effectors 28 Inside 29 short 30 long 31 Interneurone 32 sensory 33 motor 34 Inside 35 nerve 5 diffuses 5 Cerebrospinal fluid 16.2 1 electrical 2 synapse 3 synaptic knob 4 neurotransmitter 6 synaptic cleft 7 nerve impulse 8 one 9 communicate 16.3 1 Bones 2 cranium 3 vertebral column 4 Membranes 6 central canal 7 cranium 8 membranes 9 cerebrospinal fluid 10 membranes 11 vertebral column 12 neurones 13 shock absorber 14 mechanical 15 cerebrum 16 cerebellum 17 medulla oblongata 18 folded 19 coordination 20 grey 21 white 22 intelligence 23 voluntary 24 folded 25 grey 26 white 27 Coordinates 28 body balance 29 white 30 grey 31 Reflex 32 involuntary 33 cell bodies 34 nerve fibres 35 myelin sheaths 36 cerebral cortex 37 Sensory 38 sensations 39 Motor 40 responses 41 Association 42 Integrates 43 white 44 grey 45 white 46 grey 47 sensory 48 interneurone 49 motor 50 dorsal root ganglion 51 relays 52 reflex 2 cerebrum 3 fast 4 Spinal cord / Spinal nerves 6 Medulla oblongata 7 a 8 e 16.4 1 reflex action 5 spinal nerves / spinal cord 9 d 10 f 11 b 12 c 13 cerebrum 14 can 15 protects 16 b 17 d 18 a 19 e 20 f 21 c 22 posture / balance 23 balance / posture 24 reflex arc 25 conscious 26 initiated 27 receptor 28 CNS 29 cerebrum 30 integrated 31 effector New Senior Secondary Mastering Biology (Second Edition) - 82 - Oxford University Press 2015 16.5 1 spinal cord / medulla oblongata 2 medulla oblongata / spinal cord 3 cerebrum 4 receptors 5 Not under 6 automatic 7 Under 8 Inborn 9 Not inborn 10 the same 11 stereotyped 12 different 13 fast 16.6 1 endocrine glands 2 hormones 3 exocrine glands 4 blood 5 ducts 6 hormones 7 protein / lipid 8 lipid / protein 9 regulation 10 small 11 blood 12 target 13 widespread 14 long-lasting 15 b 16 d 17 a 18 e 19 c 16.7 1 effectors 2 responses 3 Endocrine 4 Nervous 5 Chemical 6 Electrical 7 neurotransmitter 8 Slow 9 Rapid 10 Widespread 11 Localized 12 long-lasting 13 Short-term 14 involuntary New Senior Secondary Mastering Biology (Second Edition) - 83 - Oxford University Press 2015