• Share
  • Email
  • Embed
  • Like
  • Save
  • Private Content
B6 lesson part one
 

B6 lesson part one

on

  • 1,707 views

 

Statistics

Views

Total Views
1,707
Views on SlideShare
1,707
Embed Views
0

Actions

Likes
0
Downloads
0
Comments
0

0 Embeds 0

No embeds

Accessibility

Upload Details

Uploaded via as Microsoft PowerPoint

Usage Rights

© All Rights Reserved

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Processing…
Post Comment
Edit your comment

    B6 lesson part one B6 lesson part one Presentation Transcript

    • B6 The Brain and mind. Route map Over the next 12 lessons you will study : Friday 21 October 2011 B6.1 What is Behaviour ? B6.2 Simple reflexes in humans B6.3 Your nervous system B6.4 Receptors and effectors End of module test B6.5 Control of reflexes B6.6 Synapses B6.7 The brain B6.8 Learned behaviour B6.9 Human learning B6.10 What is memory ? B6.11 Stored memory B6.12 Active memory
    • B6.1 What is behaviour ? Decide whether the following statements are true or false:
      • Lesson objectives:
      • Understand what behaviour is in organisms ranging form bacteria to humans
      • Understand how simple behaviour helps animals survive in their environments and to be able to recall examples of simple behaviour in some organisms.
      We will focus on. Friday 21 October 2011 First activity: What does your body do when it gets too hot or too cold? Make 2 lists showing how your body changes when it gets a) too hot and b) too cold. Literacy: Behaviour, response, stimulus, behaviour, simple reflexes, involuntary, complex, predator, prey, shivering. Numeracy: The youngest child to have thought to be arrested for unlawful behaviour was a 13 year old boy in 2008. PLTS Creative thinkers Reflective learners We will focus on linking behaviour of an animal and it survival. Team workers Effective participators Self managers Independent enquirers
    • B6.1 What is behaviour ? Decide whether the following statements are true or false: Introduction: When it is too cold you shiver but if you get too hot you sweat. These actions are responses to changes in the atmosphere – the stimulus. Unless animals can respond to changes in the environment then their survival may be threatened. Reflexes cannot be controlled and are involuntary. However animals, like mammals, birds and fish can often choose how to behave. This is more complex behaviour and is a conscious decision, such as putting more clothes on if you are cold. Extension questions: 1: What action do you do everyday that you no longer think about doing ? 2: Describe something you often do that you have to concentrate on every time you do it ? 3: Name 3 simple reflex actions ? 4: Name as many reflexes that animals do and not humans ? 5: Explain how a single cell Amoeba behaves differently to an animal like a giant octopus ? Know this: a: Know that simple behaviour can be shown even in unicellular organisms like bacteria and amoeba. b: Know that simple reflex behaviour helps animals find food, shelter and escape from predators. Friday 21 October 2011
    • Key concepts Look at the photograph and information and answer all the questions: Look at the results of the woodlice in the choice chamber...explain their behaviour ? What advantages does the woodlice benefit from by making their choices in the natural habitats ? In their natural environment, woodlice will responds to different conditions like humidity, and light levels. To investigate choice of environment by woodlice a round choice chamber is divided into four compartments, which are connected to each other. The woodlice are then allowed to make choices in which microenvironment they favour. B6.1 a Simple behaviour in woodlice
    • Key concepts Look at the photograph and information and answer all the questions: Explain how simple reflexes to changing light, salt or even water levels helps survival in amoeba ? Look at the two pictures above (above right) explain how amoeba feed ? An amoeba consists of a single blobby cell surrounded by a porous cell membrane. Amoeba can respond to stimuli like light and water level it its own micro-habitat. Amoebas eat algae, bacteria, plant cells, and microscopic protozoa. They eat by surrounding tiny particles of food with pseudopods, forming a bubble-like food vacuole. The food vacuole digests the food. Wastes and excess water are transported outside the cell. B6.1 b Simple reflexes in amoeba
    • Key concepts Look at the photograph and information and answer all the questions: Remarkably flies are not that simple swat with over 80% of ‘fly swats’ being unsuccessful. Why the high failure rate...well its all down to some pretty fast simple reflexes found in the housefly. The fly will fly off when light levels reduce because of a swatter strike. The best success rates are produced if the human anticipates the fly’s movement as picture above. B6.1 C Simple reflexes in flies Explain why the fly is able to respond to changing light levels detected by its compound eye ? If you were designing fly swatters, how might you change your design know about a fly’s response to changing light levels ?
    • B6.1 Plenary Lesson summary: reflexes actions stimulus detect Friday 21 October 2011 Newborn babies have a number of simple reflexes that allow them to survive. Human newborns will be able to suckle milk, grasp objects and even hold their breath for a short amount of time. These disappear after a few months as they are being nurtured by a parent. In other animals these reflexes can last a lot longer. How Science Works: Find out what SIDS is and what mother’s can do to try and prevent it happening. Preparing for the next lesson: Living things will respond to a change in the ___________. Flies have sensitive eyes that allow them to ________ a change when they are about to be swatted. Simple animals like Amoebas have simple _________ only, while mammals, birds and fish can consciously control some of their _________. Decide whether the following statements are true or false : False True 3: A response to a drop in temperature would be your hairs standing on end ? False True 2: A simple reflex is something that must be learned ? False True 1: All living things will have responses to a change in stimulus ?
    • B6.2 Simple reflexes in humans Decide whether the following statements are true or false:
      • Lesson objectives:
      • Understand the range of simple reflexes found in new born babies.
      • Understand how these simple reflexes can help newborns survive.
      • Understand how SIDS (cot death) could be attributed to a lack of simple reflexes in the newborn.
      We will focus on. Friday 21 October 2011 First activity: Unlike newborn animals that are very much able to survive form birth onwards, when a baby is first born they are very vulnerable and have developed a number of simple reflexes to help them survive the first few weeks of life. List actions that newborn wild animals can do more quickly than human babies and why they need to do these things in the wild ? Literacy: Newborn, simple reflexes, pupil reflex, stepping, grasping, startle, sucking, rooting, swimming, SIDS, knee jerk, nervous system and survival. Numeracy: About 0.7 per 1000 babies born dies from SIDs (cot death). More babes die from SIDS each year than from everyone who dies from cancer. More than 7000 babies die each year. PLTS We will focus on learning the different reflexes in newborn babies. Independent enquirers Creative thinkers Reflective learners Team workers Effective participators Self managers
    • B6.2 Simple reflexes in humans Friday 21 October 2011 Extension questions: 1: List the reflexes that a baby has when it is first born ? 2: Explain why it is important for a newborn baby to grasp at something placed in its hand ? 3: Describe two reflexes in all humans and what would happen if we did not have these reflexes ? 4: Parents are advised to place babies on their backs when they sleep. Why is this ? 5: Why are premature babies at a higher risk of death from SIDS ? Know this: a: Know the range of simple reflexes in babies that help them survive in the first few months of life. b: Know that a lack of reflexes has been linked to risk of death from SIDs (cot death) There are around 0.7 deaths for every 1000 births from SIDS. Introduction: Throughout our lives but especially in the first few months of life, humans require a variety of simple reflexes top help them survive. In bright light what happens ? Your pupils constrict to stop light penetrating the eye and causing damage. This is not voluntary – we do not think about it but our body does this to stop us from damaging ourselves. When a baby is born the nurse will check for a set of reflexes. These reflexes are present for only a short time after birth but if they are not all there or they do not disappear in the recommended time then there may be a problem with the child's nervous system. If a baby did not have these reflexes – sucking, grasping, stepping, startle, rooting and swimming then the newborn may not be able to survive. Sudden Infant Death Syndrome (SIDs) has been linked to problems with reflexes.
    • Key concepts Look at the photograph and information and answer all the questions: You have many reflexes that are able to protect you from injury or danger. These responses or reflexes occur very quickly and without you think. This is because the reflex pathway through the nervous system misses the brain. Newborns have even more reflexes to aid their survival in the first few months of life. These reflexes include the morro reflex, the grasping reflex and the suckle reflex. B6.2 a Simple reflexes in newborns Babies who have a weak suckle reflex are at more risk of dying...explain why ? At the moment of birth a scream or crying reflex helps the newborn to do what ?
    • Key concepts Look at the photograph and information and answer all the questions: B6.2 b SIDs or cot death in premature babies Around 300 babies die suddenly in the UK every year. Cot death can happen to any baby, but babies between one and four months, premature babies and boys are more at risk. It usually happens when the baby is asleep in his cot at night (between midnight and 9am), but can also happen during any other period of sleep such as when in the pram or even in a carer's arms. SIDS may be caused when a baby’s airway is covered by a blanket or duvet. What reflex would usually stop this happening ? Babies with a low birth weight are more at risk from SIDS. Nurses would check their reflexes more carefully. Why is this ?
    • B6.2 Plenary Lesson summary: grasp develop simple SIDS Friday 21 October 2011 Most reflexes don't have to travel up to your brain to be processed, instead they travel through the spinal cord before triggering a response. This is why they take place so quickly. A reflex action often involves a very simple nervous pathway called a reflex arc, examples of which are the blink, pupil and knee jerk reflex. How Science Works: Research about the parts of the nervous system and find out about how a nerve cell or neuron is adapted to suit its job . Preparing for the next lesson: All humans have _______ reflexes that help us survive. We are born with a number of reflexes that change and ________ as we grow. Newborn babies will be able to ________, suck and swim for the first few months of their lives involuntarily. ______ is thought to be caused by a problem with reflexes. Decide whether the following statements are true or false : False True 3: SIDS only occurs in premature babies ? False True 2: Newborn babies have all the same reflexes as adults ? False True 1: All reflexes are voluntary ?
    • B6.3 Your nervous system Extension questions: 1: What key parts or organs makes up the central nervous system ? 2: Briefly explain how a reflex arc works ? 3: Why is a nerve cell perfectly adapted to do its job ? 4: Describe the difference between a sensory and motor neuron ? 5: What would happen if one part of a reflex arc stopped working ? 6:The brain has been likened to a computer's central processor...why ? Know this: a: Know the anatomy and function of each part of the nervous system. b: Know that that a sensory neuron takes impulses to the CNS and motor neurons take the impulses away from the CNS. Friday 21 October 2011
      • Introduction:
      • Your reflexes are controlled by your central nervous system. Your nerve cells carry nerve impulses around your body allowing different parts to communicate with each other. In a simple reflex, impulses are passed from one part of the nervous system to the next in a reflex arc.
        • The change in stimulus is detected by a receptor cell.
        • Nerve impulses get carried by a sensory neuron to the central nervous system , which is made up of your brain and spinal cord.
        • Nerve impulses then get carried along a motor neuron to an effector that carries out the response.
    • B6.3 Your nervous system Decide whether the following statements are true or false:
      • Lesson objectives:
      • Understand the different parts of your nervous system including the brain, spinal cord and peripheral nerves.
      • Understand how some reflexes can be controlled.
      We will focus on. Friday 21 October 2011 First activity: Name as many reflex actions (including newborn reflexes) as you can and describe how the neuron (nerve cell) is specialised to fulfil its role as a cell that carries electrical impulses to or from the brain ? Literacy: Nerve, neuron, brain, CNS, impulse, reflex, central nervous system, reflex arc, stimulus, receptor, effector, sensory, peripheral, fatty sheath, coordinates, axon. Numeracy: There are over 1 billion nerves in the human body, which carry electrical impulses that act as messages or signal which control both your voluntary and involuntary actions. PLTS Independent enquirers Creative thinkers Reflective learners We will focus on describing how the central nervous system works. Team workers Effective participators Self managers
    • B6.3 a Look at the photograph and information and answer all the questions: The nervous system allows us to process lots of information and react quickly. Compared how the nervous system works when compared to the hormones ? How do you think a reflex arc would be effected if a person broke their back or neck causing paralysis ? The central nervous system, comprising of the brain and spinal cord is connected to a vast network of effectors (muscles and glands) and sensors (colour, taste temperature and sound) by peripheral nerves cells called neurons. Your brain coordinates all basic information provided by sensors located around the body and intrinsic thoughts formed in the brain and determines an appropriate response. Therefore it is able to make sense of all the thousands of bits of data that it continuously creates or receives and processes. The nervous system Key concepts
    • B6.3 b Look at the photograph and information and answer all the questions: All involuntary actions that support life (i.e. heart rate, blood pressure & hormone levels) are coordinated by your nervous system. This coordination can be divided into two different parts: Parasympathetic and sympathetic parts of your nervous system. One responds (sympathetic), the other calms (parasympathetic) Answer the following questions: a) Which part of the nervous system is in use after eating a meal ? b) Which part of the system causes increases in your heart rate ? c) When you are meditating, which system will you try and control ? d) During an asthma attack which part of your nervous system is responsible for constricting your airways ? e) Which part of the nervous system do anti-blood pressure drugs treat ? f) If there is no pupil reflex after a traffic injury what does this tell you about the brain ? The nervous system Key concepts
    • Key concepts Look at the photograph and information and answer all the questions: The main building block of the nervous system is the neuron or nerve cell. Nerve cells are very different from other cells. Although they do have a cell membrane, nucleus and cytoplasm like other cells, their shape reflects their communicating function. Part of the cell is stretched to form the axon which can be over one metre long. They carry information using electrical signals . B6.3 c The nerve cell What is the difference between the a) the brain and the spinal cord and b) the axon and a nerve cell ? What is the part of the nerve cell called the branches to form connections with other nerve cells ?
    • B6.3 Plenary Lesson summary: motor fatty impulses axon Friday 21 October 2011 The knee jerk reflex takes about 50 milliseconds between the tap and the start of the leg kick. That is fast! The tap below the knee causes the thigh muscle to stretch. Information is then sent to the spinal cord. After one synapse in the ventral horn of the spinal cord, the information is sent back out to the thigh muscle that then contracts. How Science Works: Research and prepare a fact-sheet on an animal of your choice showing all its reflexes and how they help the animal survive, hunt and feed. Preparing for the next lesson: A reflex arc is a pathway of nerve _______, co-ordinated by the central nervous system. There are 2 types of neurons – nerve cells – called the sensory and the _______ neurons. Both of these contain a long extension, an _____ which is covered by an insulating _______ sheath which speeds up the impulse. Decide whether the following statements are true or false : False True 3: Axons carry the electrical nerve impulses ? False True 2: Your central nervous system (CNS) co-ordinates all information ? False True 1: A change in stimulus is detected by an effector ?
    • B6.4 Receptors and effectors Decide whether the following statements are true or false:
      • Lesson objectives:
      • Understand how receptors respond to changes in stimulus, or changes in the environment.
      • Understand that a response is through an effector organ which can either be glands or muscles.
      We will focus on. Friday 21 October 2011 First activity: Describe how is a shark able to tell where it’s prey is and why they are better predators than tuna fish ? Literacy: Nervous system, senses, stimuli, glands, muscles, receptors, effectors, hormones, monitors, nerve cell, neuron, brain, spine and peripheral nerves. Numeracy: Eagles have the best eye sight of all the animal species. They can spot an animal clearly at a distance of 3km which is 4 times better than a human. PLTS Independent enquirers Creative thinkers Reflective learners We will focus on learning how our body is adapted to cope with changes in environment. Team workers Effective participators Self managers
    • B6.4 Receptors and effectors Extension questions: 1: Name 3 kinds of stimulus that animals can detect and humans cannot ? 2: What are the 2 different types of effectors and what do they do ? 3: There are 5 main changes in stimuli that humans can detect – what are they ? 4: If you were being chased, what effectors are being used and what would be the message given to them ? 5: What would happen if your effector cells were damaged ? Know this: a: Know that the human body can detect changes in its environment by a network of receptors b: Know that humans can detect changes in sound, texture, smell, temperature and light and that their are two types of effectors are glands and muscles. Friday 21 October 2011 Introduction: An important part of our reflexes are the receptor and effector cells. The receptor cells can respond to a change in the environment – called a stimulus. In some animals their receptors can detect very slight changes in the environment, which humans cannot eg a falcon can detect a small object from 1.5km away. The response to the change in stimulus is carried out by the glands and muscles, the effectors. So a hormone could be released that makes us sweat if we are hot, or we will move our arm away from something hot that we have touched.
    • Key concepts B6.4 a Look at the photograph and information and answer all the questions: What is the role of a) the fatty sheath surrounding the axon and b) the synapse ? Explain why each nerve cell must be insulated from one another ? Nerve cells are very different from other cells. Their shape reflects their function. Part of the cell is stretched to form the axon which carries electrical signals. Nervous tissue forms a complex number of pathways allowing communication from sensors to the brain and effectors like muscles and endocrine glands. The messages that are carried by the neurons are called nerve impulses. These are electrical signals. They travel at relatively high speeds along the axon of the nerve cell. An impulse can be repeated if the stimulus repeats The nerve cell
    • Key concepts Look at the photograph and information and answer all the questions: The eye allows colour and light vision so that you can make sense of your environment and your place in it. The eye relies on a number of specialised cells and tissues to focus an image, determine its colour, size, shape and position and send this information to the brain. These specialised cell are found located on the retina and are called the rod and cone cells. B6.4 b Why is it important for human sigh to respond to both colour and light ? Once the rod or cone cells are triggered by light or colour, how does that message travel to the brain ? Sight and the human eye
    • Key concepts Look at the photograph and information and answer all the questions: The body’s response to stimuli are always carried by effectors. These effectors are either muscle or glands. When impulse travel and trigger these effectors the following will happen: Muscles will contract and move a part of our body. Glands will release a chemical like a hormone, for example adrenalin. You are threatened with a knife explain your body’s response to that threat and which hormone does the body release to help those responses ? If your blood pressure becomes dangerous low how might your body respond to that drop in blood pressure ? Which effectors are you using when a) you kick a ball b) use a keyboard and c) get angry ? B6.4 c Effectors gland or muscles nerve impulse response action Muscle
    • B6.4 Plenary Lesson summary: detect stimulus receptor change Friday 21 October 2011 From the moment that it touches insect larva with its proboscis, the mole takes just 230 milliseconds to check that it is edible and gobble it up. This is the fastest known reaction time in the animal kingdom, taking less than half the 650 milliseconds that a human driver needs to brake for a red light. How Science Works: Make a list of as many things that you have LEARNED to do since being born. Highlight those things that you still always have to think about when doing them. Preparing for the next lesson: You can only respond to a change if you can ______ it. Receptors inside and outside your body detect _________ that trigger a response. The ________ cells detect the change in stimulus and the effector organs – the glands and muscles carry out an action to respond to the _________. Decide whether the following statements are true or false : False True 3: Receptor cells only detect changes in temperature ? False True 2: Some animals have lower levels of receptors to survive in the wild ? False True 1: The two effector organs are the muscles and glands ?
    • B6.5 Conscious control Decide whether the following statements are true or false:
      • Lesson objectives:
      • Understand the difference between voluntary and involuntary control and some common examples in humans.
      • Understand that conscious control can stop normal reflexes.
      We will focus on. Friday 21 October 2011 First activity: Draw out a simple reflex arc of a person touching a hot stove. Include the words stimulus, receptor, central nervous system, motor, sensory, neuron and effector ? Literacy: Voluntary, involuntary, actions, brain, conscious, reflex, complex, thought, nerve cell, neuron, nerve impulse and overcomes. Numeracy: We all have many reflexes that protect us form serious injury, but we can overcome these reflexes, for example, a reflex response will remove skin touching objects hotter than 55º C but we can overcome this if necessary. PLTS Independent enquirers Creative thinkers Reflective learners We will focus on how we can overcome reflex reactions. Team workers Effective participators Self managers
    • B6.5 Conscious control Extension questions: 1: Name 2 reflexes that can be controlled and 2 that cannot ? 2: A baby cannot control when it urinates, but as it grows older the baby will learn to control this. Draw a simple pathway showing how this is done ? 3: What reflexes would you need to play a sport like rugby ? 4: How is it possible for humans to have control of some of their reflexes whereas some animals do not ? Know this: a: Know the difference between voluntary and involuntary control b: Know that some reflexes can be stopped and controlled. Friday 21 October 2011 Introduction: You do not think about your reflexes. When a bright light is shined into your eye you do not control the constriction of the pupil – it is involuntary. However, some reflexes can be controlled. Think of carrying a hot plate. Even though your brain is detecting that the plate is too hot you can still hold on to it as you consciously tell yourself that you do not want to drop the food on to the floor. Therefore, we control the reflex and do not drop the plate. Our conscious control overcomes the reflex action. There are hundreds of complex pathways in the brain which allows us to detect and process highly complicated information. Parts of the brain store information that can be used to make decisions in the future.
    • Key concepts B6.5 a Look at the photograph and information and answer all the questions: Explain why a reflex arc has evolved to avoid needing the brain to produce a simple protective response like remove your hand from a hot object ? What would happen to use if we did not have our reflexes to hot objects ? The reflex arc You have many reflexes that are able to protect you from injury or danger, for example the blink reflex, the cough reflex and the knee jerk reflex. These responses or reflexes occur very quickly. This is because the reflex pathway through the nervous system misses the brain. Reflexes in humans are a protective adaptation that helps us survive and avoid serious injury. A reflex is a rapid response to a stimuli that follows a particular route from stimulus (hot object) to response (moving away your hand.)
    • Key concepts Look at the photograph and information and answer all the questions: B6.5 b Controlling and overriding our simple reflexes Give an example of a reflex that we can control and explain how the normal reflex arc is changed ? Why is it important for humans to be able to ‘override’ their reflexes ? In animals display more complex behaviour, their brain cortex gets bigger and becomes more folded. The enlarged cortex takes on additional higher-order functions, such as information processing, speech, thought and memory. This also allows humans to override our simple reflexes, for example not dropping a hot plate until you can put it down safely. reflex arc is overridden by the brain and higher thinking
    • B6.5 c Look at the photograph and information and answer all the questions: Animal behaviour can change when they are kept in captivity in small cages for long periods of time. Most Zoos now provide the big cats with large enclosures and live prey to try and replicate what happens in the wild. There are still some zoos and circuses that have little regard for the well being of their animals, with their animals often showing signs of stress like pacing Explain why large carnivores like tigers, lions and polar bears suffer most in small cages found in city zoos ? Explain why it is important for all zoos to replicate a large carnivores habitat and even how it feeds in the wild ? In the picture below left is a ‘sniffer dog’ trained to find drugs or even explosives materials...explain how you would train him from puppy to adult ? At work At play Key concepts
    • B6.5 Plenary Lesson summary: reflexes consciously involuntary survive Friday 21 October 2011 Like sharks, dogs understand the world best by smelling it. A dog’s brain also has a region called the neocortex, unique to all mammal brains that supports greater intelligence. Although a dog's neocortex is much smaller than a human's, the odour-processing region is about four times larger. This allows us to train dogs to sniff out illicit material like drugs, money and guns. How Science Works: Research into how nerve impulses travel form one neuron to the next through the pre and post synaptic membrane. Research into the role of brain neurotransmitters. Preparing for the next lesson: Reflexes are _________ actions – you do not think about them happening as they are designed to help you _______. However these reflexes can be __________ controlled. This is where our brain overrides _________ so that we change them. Decide whether the following statements are true or false : False True 3: Complex behaviour comes from having a number of complex nerve pathways ? False True 2: All animals brains are made of the same sized sections ? False True 1: No reflexes can be controlled ?
    • B6.6 Synapses Decide whether the following statements are true or false:
      • Lesson objectives:
      • Understand how nerve impulses pass from one neuron to the next through the synaptic clef using neurotransmitters.
      • Understand how some drugs effect the neuron pathways.
      We will focus on. Friday 21 October 2011 First activity: Many drugs are illegal as they do too much damage to your body and brain. Cannabis is said to harm the brain – especially in children – leading to longer reaction times and slower responses. Using what you know about reflex arcs suggest a reason and explain why you think cannabis does this. Literacy: Synapses, neuron, nerve cell, synaptic clef, neurotransmitters, receptors molecules, nanometres, serotonin, dopamine, adrenalin, stimulants, depressants and depression. Numeracy: Nerve impulses actually travel at 400 metres per second. The fastest man in the world – Usain Bolt runs at just over 10 metres per second. PLTS Independent enquirers Creative thinkers Reflective learners We will focus on explaining how nerve impulses travel. Team workers Effective participators Self managers
    • B6.6 Synapses Extension questions: 1: Draw a flow diagram showing what happens when a nerve impulse arrives at a synapse. 2: Serotonin is a chemical released at one type of synapse in the brain. Explain how the release of this chemical is important for survival. 3: If a receptor on a motor neuron is blocked by a drug how would this effect the muscles linked to this neuron ? 4: How can Prozac help depression ? Know this: a: Know how a nerve impulse pass from one neuron to the next neuron. b: Know that a synapse is a gap between neurons and that chemicals carry the nerve impulse across a synapse. Friday 21 October 2011 Introduction: Neurons do not touch each other, they are not connected to each other. This means the impulse has to overcome tiny gaps. These gaps are called synapses. The impulse does not jump the gap, instead chemicals are used to pass the impulse from one neuron to the next. This does slow down the impulse to about 15 metres per second – but is still pretty fast! Certain drugs can affect how chemicals travel across a synapse. Serotonin, a chemical linked to depression my be blocked or released by different drugs and thereby altering your mood. Long term use, however can cause depression and addiction as the synapse is damaged.
    • Key concepts Look at the photograph and information and answer all the questions: There are many millions of synapses in the brain that carry on the impulses between neurones. Our synapse use chemical called neurotransmitters that travel between neurons that excite a impulse in the connecting neuron. The activity of synapses can be affected by drugs (stimulants and depressants) like painkillers, cocaine or alcohol. Painkillers like aspirin block pain, by stopping the release of chemical neurotransmitters. B6.6 a Explain how the synapse and its chemical transmitters allows the nerve impulse to continue from neuron to neuron ? Explain who drugs like Prozac or ecstasy affect the balance of neurotransmitters in our brain ? The synapse connecting neurons In stage one the nerve impulse reaches the pre-synaptic membrane In stage two a neuro- transmitter is release which travels across the synapse In stage three the nerve impulse on the post synaptic membrane is created
    • Key concepts Look at the photograph and information and answer all the questions: The chemical neurotransmitter is manufactured at the terminal axon and is released into the synaptic gap. It then begins to diffuse across the gap to the next neurone or effector like a muscle or gland. It takes about one hundredth of a second to diffuse across the membrane. When the neurotransmitter lands on the next neuron or effector, it triggers the next impulse or a response. B6.6 b How do stimulants like cocaine and depressants like alcohol affect our synapses ? The synapse Write down a sentence to describe a synapse ?
    • B6.6 Plenary Lesson summary: chemicals depression synapses drugs Friday 21 October 2011 Prozac capsules and liquid contain the active ingredient fluoxetine, which is a type of antidepressant known as a selective serotonin reuptake inhibitor (SSRI) Antidepressant medicines act on nerve cells in the brain that prolong the time that neurotransmitter function across the synapse. This helps depressives as their levels of neurotransmitters have been found to be low or short lived. How Science Works: Research into how the brain works in humans and how brain imaging has helped scientists discover what areas of the brain we use for specific tasks. Preparing for the next lesson: The way we think, feel and behave involves a series of _________ travelling across ________ between neurons. Different chemicals and ______ can damage and effect how the synapse works and so can lead to feeling of ____________. Decide whether the following statements are true or false : False True 3: All drugs cause damage to synapses ? False True 2: Nerve impulses are able to jump across a synapse ? False True 1: Prozac works by causing serotonin to build up in the brain ?