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Limbic System Biological Psychology Unit Two AB Mr. Cline Marshall High School Psychology * The Brain • What happens in your nervous system when you react to stimuli? • Did you know that the brain is sometimes uninvolved with reflexes? • Central Nervous System • Not everything we do is decided by our brains. • There are some automatic reactions that don't involve your brain. • I know that seems weird, but think about how your leg involuntarily kicks when the doctor taps your knee with a rubber mallet. • Your spinal cord is responsible for this knee-jerk reaction, not your brain. • Your spinal cord is made up nerves, which are in turn made up of bundles of neurons. • You can think of all of these neurons as baseball players passing balls, which are chemical signals. * The Brain • Sometimes sensory neurons carry messages to the brain. • Other times, like when you accidentally touch a hot burner on the stove, they only get as far as the spinal cord before producing a natural reflex, or an action that is performed as a response to a stimulus and without conscious thought. • Your spinal cord sends signals to your motor neurons without any input from your brain so you can pull your hand back before you get burned. • No time is wasted 'thinking' about what to do. • When every moment counts, the nerves in your spinal cord take control! • Don't get me wrong, your brain gets involved most of the time when you touch something. • For example, when you feel a mosquito land on your arm, your sensory neurons send signals to interneurons in your brain. • Then, your brain sends signals to your motor neurons to swat the mosquito. * The Brain • Together, your brain and your spinal cord make up your central nervous system. • `At the core of your body, they are the center of the control system. • Peripheral Nervous System • Your sensory neurons and your motor neurons make up your peripheral nervous system. • Your central nervous system is like the coach and your peripheral nervous system is like the team. • The coach calls the plays, but the team is on the front line of action, and sometimes players have to react on their own. • Your peripheral nervous system is made up of sensory neurons (which take in information about what you see, hear, taste, touch and smell) and motor neurons (which send information to your muscles and glands so you can react). * The Brain • The sensory neurons are the ones that tell your brain there's a mosquito biting you, and then your brain tells your motor neurons to swat it with your hand. • Just as your central nervous system has both conscious and unconscious reflexes (remember the knee jerk?), your peripheral nervous system has some functions that you're aware of while they're happening, and others (like digesting food) that you do without thinking. • The things you're conscious of involve your somatic nervous system. • When you swat a mosquito, it's your somatic nervous system kicking in. • It controls your external muscles and skin. But, other internal activities happen more or less automatically, like your mouth watering or sweating. • While it is possible to regulate how fast your heart is beating or how fast you're breathing, these are primarily the realm of the autonomic nervous system; they happen whether you're paying attention to them or not. • Autonomic responses are automatic. * The Brain • Okay, so we can break down these automatic responses further, into sympathetic and parasympathetic responses. • Your sympathetic nervous system gets you ready to fight or flee when you're faced with a crisis, and your parasympathetic nervous system calms you down and allows you to relax. • So, when you hear the fire alarm go off in your building, your sympathetic nervous system gets your heart racing to ready you to act. • But, when you realize it's a false alarm, your parasympathetic nervous system slows your heart back down and allows you to relax. • The Parts of the Brain • Mr. Cline is now going to help you remember the parts of the brain! • Let's start with the oldest parts of the brain, which are responsible for basic functions, like breathing and walking. * The Brain • The Parts of the Brain • Here's a phrase that can help you remember the four oldest parts of the brain: • Boys Totally Rule Cool • Since boys are the coolest and most fashionable of the two genders, then this phrase makes sense. • And, if you disagree with this, then the phrase will still stick with you! • But, the first letter in each of these words will also help you remember the first letters in the four oldest parts of the brain, which are: • Brainstem, • Thalamus, • Reticular formation and • Cerebellum * The Brain • The Parts of the Brain • Got it? Great. But they're just fancy words unless we know what they do. • Let's explore these parts of the brain from the bottom up. • Your brainstem is the 'stem' of your brain. • It's located at the top of your spinal cord, where it enters your skull. • It controls how fast your heart beats and how quickly you breathe. • B stands for Boys and brainstem. • A boy’s brainstem allows him to breathe. • Your thalamus sits on your brainstem. • It receives information from your senses and forwards them on to other parts of your brain. * The Brain • The Parts of the Brain • T stands for totally and thalamus. • Your thalamus totally tells your brain about touch and taste. • Your reticular formation is made up of nerve cells that run from your spinal cord through your brainstem and thalamus. • Your reticular formation is at work when you eat, sleep and become aroused. • Its job is to filter stimuli and pass on important signals. • R stands for rule and reticular formation. • Your reticular formation is responsible for ruling the reactions when you roughhouse. * The Brain • The Parts of the Brain • Your cerebellum is behind your brainstem. • It helps you walk and remember. • C stands for cool and cerebellum. • The cerebellum controls a smooth and cool coordination. • Boys Totally Rule Cool can help you remember Brainstem, Thalamus, Reticular formation and Cerebellum • One more time: Brainstem, Thalamus, Reticular formation, Cerebellum • Got it? • Now, let's move on to the core of the brain and see how your psychology friends can help you remember the four parts of the limbic system. * The Brain • The Parts of the Brain • The limbic system is the part of your brain that controls motivations and emotions. • You can use the phrase, “Hungry Hounds Ate Pavlov” to help you remember the four parts of the limbic system: • Hypothalamus, Hippocampus, Amygdala, Pituitary • In a famous experiment about behavior conditioning, Ivan Pavlov trained dogs to drool when they heard a bell ring instead of when they saw food. • You can imagine how hungry these dogs might have gotten, to the point of taking matters into their own paws. • Your hypothalamus helps regulate hunger, so it makes sense that hungry stands for hypothalamus. * The Brain • The Parts of the Brain • The hypothalamus also influences your sex drive, thirst and body temperature. • Your hippocampus processes long-term memory. • Use your hippocampus to create an association between hounds and hippocampus. • This is how we store information for use later on the test. • Your amygdala is responsible for your feelings of fear and anger. • Hungry hounds acted on their aggression and ate Pavlov when they found out that he was conditioning them with a bell. • Your pituitary gland is a master gland that helps regulate the release of hormones. * The Brain • The Parts of the Brain • In our imaginary scenario, Pavlov may have overlooked the influence of the pituitary glands in the dogs' reaction to the stressful experiments. • Poor Pavlov! • Hungry Hounds Ate Pavlov! • This phrase can help you remember the four parts of the limbic system that are responsible for motivations and emotions: • Hypothalamus, Hippocampus, Amygdala, Pituitary • One more time: Hypothalamus, Hippocampus, Amygdala, Pituitary • Finally, let's look at the names of the last part of the brain. Your cerebral cortex is made up of four lobes. • And the four lobes of the brain can be memorized using the phrase: * The Brain • The Parts of the Brain • Freud Tore his Pants Off, which stands for Frontal, Temporal, Parietal and Occipital • It makes sense that Sigmund Freud, a famous psychologist who thought that many of our impulses are driven by sex, would decide to do away with clothing altogether. • Okay Let's look at what each of these four lobes do, working from front to back. • The frontal lobe of your brain helps you speak, coordinate your movements and is also involved when you plan. • The temporal lobe of your brain processes information about what you hear. • The parietal lobe of your brain processes information about what you touch. * The Brain • The Parts of the Brain • And, the occipital lobe of your brain processes information about what you see. .
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