14.Coordination and Response(Part 1)(1/4)(Cambridge IGCSE Biology 0610 for exams in 2026, 2027,2028) — Transcript

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1. 0:00hi everyone welcome to IGCSE study buddy
2. 0:03where you can revise biology topics from
3. 0:06the Cambridge IGCSE syllabus
4. 0:10if you're enjoying this video so far
5. 0:13please don't forget to hit the like
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7. 0:19in this video you are going to learn
8. 0:22part 1 of topic 14 coordination and
9. 0:26response
10. 0:28organisms require proper coordination
11. 0:31between various organs and systems to
12. 0:35work together to keep them alive
13. 0:38they have to be able to sense changes in
14. 0:41their environment and respond to them
15. 0:44appropriately
16. 0:47the nervous system plays a key role in
17. 0:50the coordination and regulation of body
18. 0:53functions
19. 0:55it is responsible for receiving and
20. 0:58processing information from the
21. 1:00environment and from within the body and
22. 1:03then generating appropriate responses to
23. 1:07maintain homeostasis or the stable
24. 1:10internal environment of the body
25. 1:15for example when you are exposed to cold
26. 1:18temperatures your neurons detect the
27. 1:21drop in temperature and send a signal to
28. 1:24your brain which then triggers a
29. 1:26response to generate heat through
30. 1:29shivering to maintain your body
31. 1:31temperature
32. 1:33the nervous system consists of millions
33. 1:36of neurons or nerve cells
34. 1:39information is sent through the nervous
35. 1:43system as electrical impulses that
36. 1:46travel along neurons for quick
37. 1:48communication
38. 1:50a bundle of neurons is known as a nerve
39. 1:55the mammalian nervous system is composed
40. 1:58of the central nervous system which
41. 2:02consists of the brain and the spinal
42. 2:04cord shown in yellow
43. 2:09and the peripheral nervous system
44. 2:11consisting of all of the nerves in the
45. 2:13body outside of the brain and the spinal
46. 2:16cord shown in pink
47. 2:22there are three types of neurons
48. 2:25Sensory neurons carry impulses from the
49. 2:28sense organs to the central nervous
50. 2:31system that is the brain or the spinal
51. 2:33cord
52. 2:36relay neurons are found inside the
53. 2:39central nervous system and connect
54. 2:41sensory and motor neurons
55. 2:45and motor neurons carry impulses from
56. 2:49the central nervous system to effectors
57. 2:51that is the muscles or glands
58. 2:58so you are expected to identify in
59. 3:01diagrams and images sensory relay and
60. 3:05motor neurons so as you can see Sensory
61. 3:08neurons are long and have a cell body in
62. 3:11the middle of the Axon
63. 3:13relay neurons are short and have a small
64. 3:16cell body at one end with many dendrites
65. 3:20branching off it
66. 3:23and motor neurons along with a large
67. 3:26cell body on one end and long dendrites
68. 3:29branching off it
69. 3:36next we must learn the meanings of a
70. 3:39stimulus receptor and effector in order
71. 3:42to understand the pathway of an Impulse
72. 3:45in the nervous system
73. 3:48a stimulus is any change in the
74. 3:51environment that can be detected by
75. 3:53Sensory neurons such as light sound
76. 3:57touch temperature or chemicals so let's
77. 4:01consider fire for this example
78. 4:06a receptor is a structure that can
79. 4:08detect a stimulus it generates an
80. 4:12electrical impulse when it detects a
81. 4:14stimulus which is then sent to the
82. 4:17central nervous system so in this
83. 4:19Example The receptors are in the skin of
84. 4:22the hand
85. 4:27an effector is a structure often a
86. 4:30muscle or a gland that responds to a
87. 4:33signal from the nervous system resulting
88. 4:36in a specific action or behavior so in
89. 4:40this case the effector will be the
90. 4:42muscles of the arm which will carry out
91. 4:44the response by pulling the arm away
92. 4:47from the fire
93. 4:52let's understand what a voluntary and
94. 4:55involuntary response is before moving on
95. 4:59to the reflex arc
96. 5:01a voluntary response is a conscious
97. 5:04action something you do on purpose
98. 5:07because you choose to so this response
99. 5:10begins from your brain
100. 5:12an example of a voluntary response is
101. 5:15deciding to raise your hand to answer a
102. 5:18question in class
103. 5:24an involuntary response on the other
104. 5:27hand is a quick and automatic reaction
105. 5:29to a stimulus that happens without us
106. 5:33having to think about it
107. 5:36therefore the brain is not needed to
108. 5:39coordinate the response
109. 5:41so in this type of response you are not
110. 5:44aware that you carried it out until
111. 5:47after it has happened
112. 5:49these quick responses are very important
113. 5:52for survival since voluntary responses
114. 5:55take longer
115. 5:57an example of an involuntary response is
116. 6:00when we touch something hot and our hand
117. 6:03quickly pulls away before we even
118. 6:05realize it's hot
119. 6:12so as we just learned an involuntary or
120. 6:15reflex response is a fast and automatic
121. 6:18reaction that doesn't involve the brain
122. 6:21and it helps protect the body from harm
123. 6:25a reflex arc refers to the pathway that
124. 6:30a nerve impulse follows in an
125. 6:32involuntary or reflex response
126. 6:38so for example let's say we accidentally
127. 6:40touch fire
128. 6:44the stimulus will be the fire
129. 6:47the receptor cells on the skin will
130. 6:50detect the stimulus
131. 6:55the sensory neuron sends electrical
132. 6:58impulses to the spinal cord the
133. 7:01coordinator
134. 7:05the sensory neuron passes it on to the
135. 7:08relay neuron in the spinal cord
136. 7:14the relay neuron connects to the motor
137. 7:17neuron and passes the impulse on
138. 7:21the motor neuron carries the impulse to
139. 7:24a muscle in the arm that is the effector
140. 7:27the muscle will contract and pull the
141. 7:30arm away from the fire this is the
142. 7:33response
143. 7:37here's a simple diagram to show the
144. 7:39reflex arc
145. 7:41the stimulus is detected by a receptor
146. 7:45and converted into an electrical impulse
147. 7:49the electrical impulse travels along the
148. 7:53sensory neuron
149. 7:55it then passes on to the relay neuron
150. 8:01which connects to the motor neuron
151. 8:05and the motor neuron carries the impulse
152. 8:08to the effector
153. 8:12and the effector carries out the
154. 8:14response
155. 8:22therefore a reflex action is a means of
156. 8:26automatically and rapidly integrating
157. 8:29and coordinating stimuli with the
158. 8:32responses of effectors that is muscles
159. 8:35and glands
160. 8:39next synapses a synapse is a junction
161. 8:43between two neurons
162. 8:46neurons never touch each other so they
163. 8:49have gaps in between them called
164. 8:51synapses
165. 8:54let's look at the structure of a synapse
166. 8:59these are vesicles containing
167. 9:02neurotransmitter molecules
168. 9:07this is the synaptic gap
169. 9:11and these are receptor proteins
170. 9:18so what happens at a synapse
171. 9:22neurons have vesicles containing
172. 9:25neurotransmitter molecules
173. 9:27neurotransmitters are chemical
174. 9:29Messengers so this is the only part of
175. 9:32the nervous system where messages are
176. 9:35chemical instead of electrical
177. 9:41an Impulse travels along the first
178. 9:44neuron Neuron a and stimulates the
179. 9:48release of neurotransmitter molecules
180. 9:50from vesicles into the synaptic gap
181. 9:56the neurotransmitter molecules diffuse
182. 9:59across the gap
183. 10:04neurotransmitter molecules bind with
184. 10:07receptor proteins on the next neuron
185. 10:14an Impulse is then stimulated in the
186. 10:17next neuron
187. 10:23synapses ensure that impulses travel in
188. 10:28One Direction only
189. 10:33so that concludes part 1 of chapter 14
190. 10:36coordination and response
191. 10:41hope this video helped you please share
192. 10:44your thoughts and suggestions in the
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