Understanding Nervous System Coordination

Hi everyone, welcome to IGCSE Study Buddy where you can revise biology topics from the Cambridge IGCSE syllabus. If you're enjoying this video so far, please don't forget to hit the like button and subscribe to my channel. In this video, you are going to learn part 1 of topic 14, Coordination and Response. Organisms require proper coordination between various organs and systems to work together to keep them alive. They have to be able to sense changes in their environment and respond to them appropriately. The nervous system plays a key role in the coordination and regulation of body functions. It is responsible for receiving and processing information from the environment and from within the body and then generating appropriate responses to maintain homeostasis or the stable internal environment of the body. For example, when you are exposed to cold temperatures, your neurons detect the drop in temperature and send a signal to your brain which then triggers a response to generate heat through shivering to maintain your body temperature. The nervous system consists of millions of neurons or nerve cells. Information is sent through the nervous system as electrical impulsors that travel along neurons for quick communication. A bundle of neurons is known as a nerve. The mammalian nervous system is composed of the central nervous system which consists of the brain and the spinal cord shown in yellow and the peripheral nervous system consisting of all of the nerves in the body outside of the brain and the spinal cord shown in pink. There are three types of neurons. Sensory neurons carry impulses from the sense organs to the central nervous system, that is the brain or the spinal cord. Relay neurons are found inside the central nervous system and connect sensory and motor neurons. And motor neurons carry impulses from the central nervous system to effectors, that is the muscles or glands. So you are expected to identify in diagrams and images sensory, relay and motor neurons. So as you can see sensory neurons are long and have a cell body in the middle of the axon, relay neurons are short and have a small cell body at one end with many dendrites branching off it and motor neurons are long with a large cell body on one end and long dendrites branching off it. Next, we must learn the meanings of a stimulus, receptor and effector in order to understand the pathway of an impulse in the nervous system. A stimulus is any change in the environment that can be detected by sensory neurons, such as light, sound, touch, temperature or chemicals. So let's consider fire for this example. A receptor is a structure that can detect a stimulus. It generates an electrical impulse when it detects a stimulus which is then sent to the central nervous system. So in this example the receptors are in the skin of the hand. An effector is a structure, often a muscle or a gland, that responds to a signal from the nervous system, resulting in a specific action or behaviour. So in this case, the effector will be the muscles of the arm, which will carry out the response by pulling the arm away from the fire. Let's understand what a voluntary and involuntary response is before moving on to the reflex arc. A voluntary response is a conscious action, something you do on purpose because you choose to. So this response begins from your brain. An example of a voluntary response is deciding to raise your hand to answer a question in class. An involuntary response, on the other hand, is a quick and automatic reaction to a stimulus that happens without us having to think about it. Therefore, the brain is not needed to coordinate the response. So in this type of response, you are not aware that you carried it out until after it has happened. These quick responses are very important for survival since voluntary responses take longer. An example of an involuntary response is when we touch something hot and our hand quickly pulls away before we even realize it's hot. So as we just learned, an involuntary or reflex response is a fast and automatic reaction that doesn't involve the brain and it helps protect the body from harm. A reflex arc refers to the pathway that a nerve impulse follows in an involuntary or reflex response. So for example, let's say we accidentally touch fire. The stimulus will be the fire. The receptor cells on the skin will detect this stimulus. The sensory neuron sends electrical impulses to the spinal cord, the coordinator. The sensory neuron passes it on to the relay neuron in the spinal cord. The relay neuron connects to the motor neuron and passes the impulse on. The motor neuron carries the impulse to a muscle in the arm. that is the effector. The muscle will contract and pull the arm away from the fire. This is the response. Here's a simple diagram to show the reflex arc. The stimulus is detected by a receptor and converted into an electrical impulse. The electrical impulse travels along the sensory neuron It then passes on to the relay neuron which connects to the motor neuron and the motor neuron carries the impulse to the effector and the effector carries out the response. Therefore, A reflex action is a means of automatically and rapidly integrating and coordinating stimuli with the responses of effectors, that is muscles and glands. Next, synapses. A synapse is a junction between two neurons. Neurons never touch each other, so they have gaps in between them called synapses. Let's look at the structure of a synapse. These are vesicles containing neurotransmitter molecules. This is the synaptic gap and these are receptor proteins. So what happens at a synapse? Neurons have vesicles containing neurotransmitter molecules. Neurotransmitters are chemical messengers, so this is the only part of the nervous system where messengers are chemical instead of electrical. An impulse travels along the first neuron, neuron A, and stimulates the release of neurotransmitter molecules from vesicles into the synaptic gap. The neurotransmitter molecules diffuse across the gap. Neurotransmitter molecules bind with receptor proteins on the next neuron. An impulse is then stimulated in the next neuron. Synapses ensure that impulses travel in one direction only. So that concludes part 1 of chapter 14 coordination and response. Hope this video helped you. Please share your thoughts and suggestions in the comment section. Thank you for watching and please don't forget to subscribe to IGCSE study buddy for more biology revision videos. Bye.

Organisms require proper coordination between various organs and systems to work together to keep them alive. They have to be able to sense changes in their environment and respond to them appropriately. The nervous system plays a key role in the coordination and regulation of body functions.

It is responsible for receiving and processing information from the environment and from within the body and then generating appropriate responses to maintain homeostasis or the stable internal environment of the body. For example, when you are exposed to cold temperatures, your neurons detect the drop in temperature and send a signal to your brain which then triggers a response to generate heat through shivering to maintain your body temperature. The nervous system consists of millions of neurons or nerve cells. Information is sent through the nervous system as electrical impulsors that travel along neurons for quick communication. A bundle of neurons is known as a nerve.

The mammalian nervous system is composed of the central nervous system which consists of the brain and the spinal cord shown in yellow and the peripheral nervous system consisting of all of the nerves in the body outside of the brain and the spinal cord shown in pink. There are three types of neurons. Sensory neurons carry impulses from the sense organs to the central nervous system, that is the brain or the spinal cord. Relay neurons are found inside the central nervous system and connect sensory and motor neurons. And motor neurons carry impulses from the central nervous system to effectors, that is the muscles or glands.

So you are expected to identify in diagrams and images sensory, relay and motor neurons. So as you can see sensory neurons are long and have a cell body in the middle of the axon, relay neurons are short and have a small cell body at one end with many dendrites branching off it and motor neurons are long with a large cell body on one end and long dendrites branching off it. Next, we must learn the meanings of a stimulus, receptor and effector in order to understand the pathway of an impulse in the nervous system. A stimulus is any change in the environment that can be detected by sensory neurons, such as light, sound, touch, temperature or chemicals. So let's consider fire for this example.

A receptor is a structure that can detect a stimulus. It generates an electrical impulse when it detects a stimulus which is then sent to the central nervous system. So in this example the receptors are in the skin of the hand.

An effector is a structure, often a muscle or a gland, that responds to a signal from the nervous system, resulting in a specific action or behaviour. So in this case, the effector will be the muscles of the arm, which will carry out the response by pulling the arm away from the fire. Let's understand what a voluntary and involuntary response is before moving on to the reflex arc. A voluntary response is a conscious action, something you do on purpose because you choose to.

So this response begins from your brain. An example of a voluntary response is deciding to raise your hand to answer a question in class. An involuntary response, on the other hand, is a quick and automatic reaction to a stimulus that happens without us having to think about it.

Therefore, the brain is not needed to coordinate the response. So in this type of response, you are not aware that you carried it out until after it has happened. These quick responses are very important for survival since voluntary responses take longer.

An example of an involuntary response is when we touch something hot and our hand quickly pulls away before we even realize it's hot. So as we just learned, an involuntary or reflex response is a fast and automatic reaction that doesn't involve the brain and it helps protect the body from harm. A reflex arc refers to the pathway that a nerve impulse follows in an involuntary or reflex response. So for example, let's say we accidentally touch fire. The stimulus will be the fire.

The receptor cells on the skin will detect this stimulus. The sensory neuron sends electrical impulses to the spinal cord, the coordinator. The sensory neuron passes it on to the relay neuron in the spinal cord. The relay neuron connects to the motor neuron and passes the impulse on. The motor neuron carries the impulse to a muscle in the arm.

that is the effector. The muscle will contract and pull the arm away from the fire. This is the response.

Here's a simple diagram to show the reflex arc. The stimulus is detected by a receptor and converted into an electrical impulse. The electrical impulse travels along the sensory neuron It then passes on to the relay neuron which connects to the motor neuron and the motor neuron carries the impulse to the effector and the effector carries out the response. Therefore, A reflex action is a means of automatically and rapidly integrating and coordinating stimuli with the responses of effectors, that is muscles and glands.

Next, synapses. A synapse is a junction between two neurons. Neurons never touch each other, so they have gaps in between them called synapses.

Let's look at the structure of a synapse. These are vesicles containing neurotransmitter molecules. This is the synaptic gap and these are receptor proteins. So what happens at a synapse?

Neurons have vesicles containing neurotransmitter molecules. Neurotransmitters are chemical messengers, so this is the only part of the nervous system where messengers are chemical instead of electrical. An impulse travels along the first neuron, neuron A, and stimulates the release of neurotransmitter molecules from vesicles into the synaptic gap. The neurotransmitter molecules diffuse across the gap.

Neurotransmitter molecules bind with receptor proteins on the next neuron. An impulse is then stimulated in the next neuron. Synapses ensure that impulses travel in one direction only. So that concludes part 1 of chapter 14 coordination and response.

Hope this video helped you. Please share your thoughts and suggestions in the comment section. Thank you for watching and please don't forget to subscribe to IGCSE study buddy for more biology revision videos.

Bye.

Transcript for:Understanding Nervous System Coordination

Transcript for:
Understanding Nervous System Coordination