16 Coordination in humans

Transcription

1 Class: Name: ( ) Date: 16 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 ): - contains a nucleus and cytoplasm with other organelles (15) ( 髓鞘 ): - a layer of fatty material surrounding nerve fibres (11) ( 樹突 ): - transmits nerve impulses (12) (towards / away from) the cell body (13) ( 軸突 ): - transmits nerve impulses (14) (towards / away from) the cell body nerve fibres ( 神經纖維 ) Key: transmission of nerve impulse (Second Edition)

2 The myelin sheath protects and (16) the nerve fibres. This serves to: - prevent the transmission of nerve impulses to the (17) - (18) the transmission of nerve impulses. 2 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 (Book 2, p. 16-6) A (35) ( 神經 ) is a bundle of nerve fibres wrapped in a nerve connective tissue connective tissue. a nerve fibre myelin sheath blood vessels Structure of a nerve (Second Edition)

3 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 mitochondria synaptic knob synaptic vesicle containing neurotransmitter synaptic cleft cell body or dendron of next neurone The (3) ( 突觸小體 ) releases (4) ( 神經遞質 ). The neurotransmitter (5) across the (6) ( 突觸間隙 ). The neurotransmitter stimulates the dendron to generate a (7). 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. (Second Edition)

4 16.3 The central nervous system (Book 2, p. 16-9) A How is the CNS protected? (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) cavity filled with (9) central canal three (10) brain spinal cord central canal spinal cord spinal nerve (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. (Second Edition)

5 B The brain (Book 2, p ) The brain consists of three main parts: (15) ( 大腦 ) (16) ( 小腦 ) (17) ( 延髓 ) Part of the brain Structural feature Function Highly (18) at the surface to hold more neurones, so Site of (22) ( 智力 ) Cerebrum that (19) can be more efficient Outer layer made up of (20) matter ( 灰質 ) ; Controls (23) actions ( 隨意動作 ) e.g. speaking and writing inner layer made up of (21) matter ( 白質 ) Cerebellum Highly (24) Outer layer made up of (25) matter; (27) muscular movements for maintaining (28) inner layer made up of when we move (26) matter Outer layer made up of (29) matter; (31) centre ( 反射中樞 ) for many reflex actions inner layer made up of ( 反射動作 ), e.g. saliva secretion, Medulla (30) matter swallowing and coughing oblongata Controls other (32) actions ( 不隨意動作 ), e.g. breathing and heart beat (Second Edition)

6 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 thinking, judgement sight memory B C A B A Label Area in cerebral cortex Function A B C (37) area ( 感覺區 ) (39) area ( 運動區 ) (41) area ( 聯合區 ) Receives nerve impulses from receptors to give (38) Sends nerve impulses to effectors to produce (40) (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 ; Practical Workbook for SBA 2, p. 16-1) C The spinal cord (Book 2, p ) 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. (Second Edition)

7 (45) matter: - consists of nerve fibres nerve fibres central canal (46) matter: - consists mainly of the cell bodies of neurones (47) neurone dorsal root (48) (49) neurone Structure of the spinal cord spinal nerve ventral root (50) ( 背根節 ): - contains cell bodies of sensory neurones Key: transmission of nerve impulse 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 Reflex action and voluntary action (Book 2, p ) A What is a reflex action? (Book 2, p ) 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 Withdrawal reflex ( 退縮反射 ) and knee jerk reflex ( 膝躍反射 ) Saliva secretion, swallowing and coughing Parts of CNS involved (4) and (5) (6) (Second Edition)

8 B Examples of reflex actions (Book 2, p ) 1 The withdrawal reflex from brain to brain V motor neurone ventral root spinal cord VI interneurone IV I II III sensory neurone Key: dorsal root transmission of nerve impulse Step 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. (Second Edition)

9 2 The knee jerk reflex to brain dorsal root sensory neurone III knee cap II spinal cord motor neurone ventral root IV I V Key: transmission of nerve impulse VI Step 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. (Second Edition)

10 C What is a voluntary action? (Book 2, p ) 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 Differences between reflex actions and voluntary actions (Book 2, p ) Nervous pathway Nature of response Speed of response Reflex actions Involves the (1) or the (2), but not the cerebrum A receptor is always involved (5) (Under / Not under) conscious control (i.e. (6) ) (8) (Inborn / Not inborn) The same stimulus always results in (10) (the same / different) response(s) (i.e. a (11) response) Always (13) Voluntary actions Always involves the (3) May not involve any (4) if the action is initiated by the cerebrum directly (7) (Under / Not under) conscious control (9) (Inborn / Not inborn) The same stimulus may result in (12) (the same / different) response(s) May be fast or slow, depending on the nervous pathway involved and the nature of response (Second Edition)

11 16.6 The human endocrine system (Book 2, p ) 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 ) Differences between endocrine glands and (3) ( 外分泌腺 ): Endocrine gland secretion diffuses directly into the blood Exocrine gland secretion is released through a duct duct inflow of blood outflow of blood secreting cell capillary secreting cell Way of releasing secretions Example and substance produced Diffuse directly into the (4) Pituitary gland ( 垂體 ), thyroid gland ( 甲狀腺 ), adrenal glands ( 腎上腺 ), pancreas, ovaries and testes that produce various (6) Through (5) Salivary glands that produce saliva, and gastric glands that produce gastric juice 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 ) 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) -. (Second Edition)

12 An example of hormonal coordination: I II pancreas cell insulin capillary glucose V liver cell IV III Step 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) III: (17) IV: (18) V: (19) (Second Edition)

13 16.7 Comparison between hormonal coordination and nervous coordination (Book 2, p ) 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) (hormones) (6) (nerve impulses along nerve fibres) Nature of message Chemical ((7) across synapses) Route of transmission Blood stream Nerve fibres Speed of transmission (8) (Rapid / Slow) (9) (Rapid / Slow) Areas of response (10), one hormone may affect several target organs at the same time (11), restricted to places with nerve supply Duration of effect Usually (12) - (13) - Body processes involved Reproduction, growth and development, regulation of internal environment Voluntary actions, reflex actions and other involuntary actions (always (14) ) (Second Edition)

14 Answers Ch 16 Coordination in humans 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 electrical 2 synapse 3 synaptic knob 4 neurotransmitter 5 diffuses 6 synaptic cleft 7 nerve impulse 8 one 9 communicate Bones 2 cranium 3 vertebral column 4 Membranes 5 Cerebrospinal fluid 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 reflex action 2 cerebrum 3 fast 4 Spinal cord / Spinal nerves 5 spinal nerves / spinal cord 6 Medulla oblongata 7 a 8 e 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 (Second Edition)

15 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 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 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 (Second Edition)