Getting The Message G9LS PDF

GETTING THE MESSAGE  How does the nervous sytem work? a change in the environment (either external or internal) NEURON  TYPE OF NEURONS CNS to EFFECTOR PNS to CNS CNS to CNS (muscle or gland) Sant...

GETTING THE MESSAGE  How does the nervous sytem work? a change in the environment (either external or internal) NEURON  TYPE OF NEURONS CNS to EFFECTOR PNS to CNS CNS to CNS (muscle or gland) Santiago Ramon y Cajal STRUCTURE OF A NEURON Make a neuron model and label its parts PARTS AND FUNTIONS OF THE HUMAN BRAIN Frontal lobe - Occipital lobe – Parietal lobe– Cerebellum – Brain stem – Temporal lobe  Parietal Lobe Frontal Lobe Occipital Lobe Cerebellum Temporal Lobe Brain Stem  Frontal Lobe The frontal lobe is at the front of the brain and is responsible for higher order thinking : ✘ Decision making ✘ Rewards ✘ Planning ✘ Motivation ✘ Good and bad actions (your conscience) How to remember: “You lead with your front” Your frontal lobe is at the front and leads your actions through evaluation and decision making.  Parietal Lobe The parietal lobe is on top of the brain and is responsible for major sensory input from the skin : ✘ Touch ✘ Temperature ✘ Taste ✘ Pain  Occipital Lobe The occipital lobe is at the back of the brain and is responsible for visual processing : ✘ “What” in your vision ✘ Colour perception ✘ Spatial awareness  Temporal Lobe The temporal lobe is on the side of the brain and is primarily responsible for auditory processing but also some areas of visual processing: ✘ Hearing ✘ Visual language (cues) ✘ Spoken language ✘ Verbal memory How to remember: “Your temporal lobe is close to what it connects to: your ears”  Cerebellum The cerebellum is at the base of the brain and is primarily responsible for motor control, although is also used for some more base emotions: ✘ Coordination ✘ Balance ✘ Equilibrium ✘ Attention ✘ Fine motor control ✘ Fear and pleasure  Brain Stem The brain stem is the connection of the spinal cord to the brain. It is responsible for unconscious body functions : ✘ Heart rate ✘ Consciousness ✘ Breathing How to remember: “When you’re asleep you lie on your neck, near where the brain stem is, and it keeps you alive while you’re unconscious” Think-pair-share: Decide if the following are reflex or voluntary: Knee jerk, falling, removing hand from hot water, coughing, sneezing, laughing, blinking, driving, shivering, eating, baby gripping, talking, running Reflex Voluntary Reflex Voluntary Blinking Laughing Coughing Running Sneezing Talking Baby gripping Driving Removing hand from hot Eating object Knee jerk Falling A detectable change (internal or external to the body) An organ that detects stimulus Nerve cells that send a signal from the sensory receptors to the CNS Cells that receive a signal from the CNS and transfer it to the effector An organ that bring about a response (muscle or gland) THE REFLEX ARC (INVOLUNTARY) CIRCUS OF EXPERIMENTS Stimulus:…....................... Processing by CNS Receptor: Effector: Response:…....................... VOLUNTARY INVOLUNTARY (REFLEX)  1 Person 1 keeps the right eye closed for a minute. Person 2 observes the left pupil of person 1 and then tells person 1 to remove the hand from the right eye. Observe the difference.  Reflexes demo experiments For each reflex, fill in the flowchart (identify the parts) For each reflex, explain WHY it is a ‘useful’ reflex  2 One person sits on the table, with legs dangling. The other person gently taps the knee with a hammer, just under the kneecap. Observe what happens. Be careful: this SHOULD NOT hurt!  Reflexes demo experiments For each reflex, fill in the flowchart (identify the parts) For each reflex, explain WHY it is a ‘useful’ reflex  PATELLAR REFLEX (MONOSYNAPTIC) https://www.youtube.com/watch?v=c-dD0N53QRg  3 Person 1 sits on a chair with a Perspex screen in front and looks straight ahead. Person 2 is position on the other side of the screen and throw a ball of paper, so that it hits the Perspex screen in front of person 1. Observe what happens to the eyes of the seated person.  Reflexes demo experiments For each reflex, fill in the flowchart (identify the parts) For each reflex, explain WHY it is a ‘useful’ reflex  4 Expose the skin on your arm and go outside. Observe what happens to the hairs and the skin of your arm.  Reflexes demo experiments For each reflex, fill in the flowchart (identify the parts) For each reflex, explain WHY it is a ‘useful’ reflex  5 Person 1 sits on a chair. Person 3 stands in front of person 1. Person 2 stands behind and suddenly claps the hands close to the back of person 1. Person 3 observes the movement of person 1.  Reflexes demo experiments For each reflex, fill in the flowchart (identify the parts) For each reflex, explain WHY it is a ‘useful’ reflex  6 One person sits on the table, with one arm rested on it. The other person hold a ruler vertically, with the zero at the level of the first person’s hand. The person let the ruler go. Check the level at which the person catches the ruler.  NEURONS FIRING!!!! HOW DOES THE IMPULSE TRAVEL IN A NEURON? ACTION POTENTIAL  MEXICAN WAVE HOW DOES IT START? (potential energy) DO YOU NEED A MINIMUM NUMBER OF PEOPLE? (threshold) HOW DOES IT PROPAGATE? (change in potential) REST ACTION THE STIMULUS IN THE NERVOUS SYSTEM IS TRANSMITTED THROUGH AN ELECTROCHEMICAL PROCESS When a signal is received by the dendrites, it is transmitted to the cell body/soma in the form of an electrical signal, and, if the signal is strong enough, it may then be passed on to the axon and then to the terminal buttons.  WHAT IS AN ELECTRIC POTENTIAL? The ELECTRIC POTENTIAL, or VOLTAGE, is the DIFFERENCE IN POTENTIAL ENERGY (difference in charge) between two locations.  NEURON POTENTIAL POTENTIAL = Voltage difference between the inside and the outside of the neuronal membrane. AT REST = -70mV ACTIVE = +30mV  THE ACTION POTENTIAL https://www.youtube.com/watch?v=FEHNIELPb0s 6.5.U4 An action potential consists of depolarization and repolarization of the neuron. is the reversal (depolarization) and restoration (repolarization) of the membrane Action potential potential as an impulse travels along it. 1 The sodium-potassium 2 In response to a stimulus (e.g. change in membrane pump (Na+/K+ pump) potential) in an adjacent section of the neuron some maintains the voltage gated Na+ channels open and sodium enters electrochemical gradient of the neuron by diffusion. If a sufficient change in the resting potential. Some membrane potential is achieved (threshold K+ leaks out of the neuron potential) all the voltage gated Na+ channels open. (making the membrane The entry of Na+ causes the membrane potential to potential negative, -70mv). become positive (depolarisation) http://www.ib.bioninja.com.au/_Media/action_potential_med.jpeg A bundle of neurons is called a nerve  How do nerve impulses travel? TED-ED: how do nerves work: The nerve impulse is an electrical signal, it travels along the axon, it is called an ‘action potential’. How neurons communicate https://www.youtube.com/watch?v=hGDvvUNU-cw  SYNAPSE When a nerve impulse reaches the end of an neuron, it needs to cross a tiny gap between two neurons. This gap is called a synapse.  SYNAPTIC TRANSMISSION If the action potential reaches the axon terminals, they are signalled to emit chemicals known as NEUROTRANSMITTERS, which communicate with other neurons across the spaces between the cells, known as SYNAPSES. SYNAPTIC TRANSMISSION  SYNAPTIC TRANSMISSION OF A STIMULUS 1. A nerve impulse travels as an action potential along the axon of the PRESYNAPTIC neuron. 2. When the nerve impulse reaches the end of the axon, chemical messengers called NEUROTRANSMITTERS are released (examples are acetylcholine, dopamine and serotonin). 3. These chemicals DIFFUSE across the synapse (the gap between the two neurons). The neurotransmitter binds with RECEPTOR molecules on the membrane of the DENDRITE of the POSTSYNAPTIC neuron. 4. The receptor molecules on the postsynaptic neuron can only bind to the SPECIFIC neurotransmitters released from the first neuron. 5. The binding of neurotransmitter to the receptors stimulates the postsynaptic neuron to transmit (or not*) an action potential along its axon. 6. The signal therefore has been carried from one neuron to the next. 7. Neurotransmitters do not stay in the synapse; they are broken down or re- absorbed (into vesicles) *excitatory or inhibitory synapses ACTING ON NEUROTRANSMITTERS VENOM BOTOX NEONICOTINOID ANESTHETIC COCAINE/HEROIN NICOTINE CAFFEINE ALCOHOL Choose a molecule and make a trump card to explain How it affects neurotransmission (synapse) How it affects the human body Name of the drug Does it generate addiction? Why? Add an image of: Does it stimulate or depress? Molecule Plant Long term negative effects Where it acts in the synapse Where it acts on the body What happens in the synapse? Does it generate addiction? Why? Is it a stimulant or depressant? What are the long term effects? REFLEX ARC Some responses may be involuntary and occur without conscious thought – these actions are called reflexes. Reflex actions do not involve the brain – instead sensory information is directly relayed to motor neurons within the spine. This results in a faster response, but one that does not involve conscious thought or deliberation.  Reaction time Reaction time is the time between the presentation of a stimulus and the initiation of the muscular response to that stimulus. How quick do you act after seeing something!!  What can influence reaction time? 1. age 2. gender 3. physical fitness 4. fatigue 5. distraction 6. Alcohol 7. whether the stimulus is auditory or visual 8. Diet WHAT FACTORS CAN AFFECT REACTION TIME? Age range Gender Physical fitness Distraction (sound) Dominant hand Personality Reward Both hands engaged in activity CAN YOU SUGGEST A METHOD TO MEASURE HUMAN REACTION TIME? RULER DROP TEST You may use the following formula to find the reaction times: 2d t = time (in seconds) d = distance (in cm) g = 980 cm/sec2 (acceleration due to gravity). https://humanbenchmark.com/tests/reactiontime MIT ILLUSIONS CHALLENGE VISUAL ILLUSION EXAMPLES Which central circle is bigger? The left one or the right one? Which line is longer? Compare the two tables. Which would be easier to get through a narrow door? Are the diagonal lines parallel? Which soldier is taller?