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Chapter 2 Biology of the Mind Mind Slide 2 Neural Communication The bodys information system is built from billions of interconnected cells called neurons. Slide 3 Neural Communication Humans and Animals operate similarly when processing information. Note the similarities in the brain regions, which are all engaged in information processing. Slide 4 The Neuron Slide 5 Parts of a Neuron Cell Body life support center of the neuron Dendrites branching extensions at the cell body that receive messages from other neurons. Axon long single extension of a neuron, covered with the Myelin Sheath to insulate and speed up messages through the neuron. Terminal Branches of the Axon branched endings of an axon that transmit messages to other neurons. Slide 6 Action Potential Travel https://youtu.be/SdUUP2p MmQ4 Slide 7 The Synapse Synapse a junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron. This tiny gap is called the synaptic gap. Slide 8 The Synaptic Gap Slide 9 Synthesis of the Neurotransmitter Slide 10 Neurotransmitters Neurotransmitters chemicals that are released from the sending neuron, travel across the synapse and bind to receptor sites on the receiving neuron, thereby influencing the receiving neuron to generate an action potential. Action Potential- a neural impulse consisting of a brief electrical charge that travels down the axon and is generated by the movement of atoms in and out of the axons membrane. Slide 11 Reuptake Neurotransmitters in the synapse are reabsorbed into the sending neurons through the process of reuptake. This process is like applying brakes to a neurotransmitters action. Slide 12 Common Neurotransmitters Slide 13 Neurotransmitters Slide 14 The Lock & Key Mechanism Neurotransmitters bind to the receptors of the receiving neuron in a lock & key mechanism. Slide 15 Agonists This agonist molecule is similar enough in structure to the neurotransmitter molecule that it mimics its effects on the receiving neuron. Morphine, for instance, mimics the action of endorphins by stimulating receptors in the brain areas involved in mood and pain sensation. Slide 16 Antagonists This antagonist molecule has a structure similar enough to the neurotransmitter to occupy its receptor site and block its action, but not similar enough to stimulate the receptor. For example, Curare poison paralyzes a person by blocking Ach receptors involved in muscle movement. Slide 17 http://www.brainfacts.org/Brain-Basics/Cell-Communication/Articles/2013/Neuroglia-and-the- Brain Neuroglia (Glial) Cells Slide 18 The Nervous System Central Nervous System (CNS) Peripheral Nervous System (PNS) Slide 19 The Nervous System Nervous System - consists of all the nerve cells. It is the bodys speedy electrochemical communication system. Central Nervous System the brain and spinal cord. Peripheral Nervous System the sensory and motor neurons that connect the central nervous system to the rest of the body. Slide 20 The Central Nervous System The brain has neural networks of interconnected neurons. These networks modify and grow with experience and physical development. Slide 21 The Endocrine System Endocrine System is the bodys slow chemical communication system. Communication is carried out by hormones synthesized by a set of glands. Hormones are chemicals synthesized by the endocrine glands that are secreted in the bloodstream. Hormones affect the brain and many other tissues of the body. For example, epinephrine (adrenaline) increases heart rate, blood pressure, blood sugar, and feelings of excitement during emergency situations. Slide 22 Structure of the Brain The Brainstem is the oldest part of the brain, beginning where the spinal cord swells and enters the skull. It is responsible for automatic survival functions. Slide 23 Parts of the Brainstem The Medulla is the base of the brainstem that controls heartbeat and breathing Slide 24 Parts of the Brainstem The Thalamus is the brains sensory switchboard, located on top of the brainstem. It directs messages to the sensory areas in the cortex and transmits replies to the cerebellum and medulla Slide 25 Parts of the Brainstem Reticular Formation is a nerve network in the brainstem that plays an important role in controlling arousal. Slide 26 Parts of the Brainstem Cerebellum is known as the little brain and is attached to the rear of the brainstem. It helps coordinate voluntary movements and balance. Slide 27 Studying the Brain Electroencephalogram (EEG) is an amplified recording of electrical waves sweeping across the brains surface. Can be measured by electrodes placed on the scalp. Slide 28 Studying the Brain PET Scan (positron emission tomography) is a visual display of brain activity that detects a radioactive form of glucose while the brain performs a given task. Slide 29 Studying the Brain MRI (magnetic resonance imaging) uses magnetic fields and radio waves to produce computer generated images that distinguish among different types of brain tissue. The top images show ventricular enlargement in a schizophrenic patient. The bottom image shows brain regions when a participant lies. Slide 30 The Limbic System The Limbic System is a doughnut shaped system of neural structures at the border of the brainstem and cerebrum, associated with emotions such as fear, aggression, and drives for food and sex. It includes the hippocampus, amygdala, and hypothalamus. Slide 31 The Amygdala The Amygdala consists of two lima bean sized neural clusters linked to the emotions of fear and anger. Slide 32 The Hypothalamus The Hypothalamus lies below the thalamus. It directs several maintenance activities like eating, drinking, body temperature, and control of emotions. It also helps govern the endocrine system via the pituitary gland. Slide 33 The Cerebral Cortex The intricate fabric of interconnected neural cells that covers the cerebral hemispheres. It is the bodys ultimate control and information processing center. Slide 34 The Cerebral Cortex Slide 35 Slide 36 Structure of the Cortex Each brain hemisphere is divided into four lobes that are separated by prominent fissures. Frontal Lobe Forehead Parietal Lobe Top of Head Occipital Lobe Back of Head Temporal Lobe Side of Head Slide 37 Functions of the Lobes Frontal Lobe Associated with reasoning, planning, speech, emotions, and problem solving. Parietal Lobe Associated with movement, orientation, recognition, perception of stimuli. Occipital Lobe Associated with visual processing. Temporal Lobe Associated with perception and recognition of auditory stimuli, memory, and speech. Slide 38 Functions of the Cortex The Motor Cortex is the area at the rear of the frontal lobe that controls voluntary movements. The Sensory Cortex (parietal cortex) receives information from skin surface and sensory organs. Slide 39 Association Areas More intelligent animals have increased uncommitted or association areas of the cortex. Slide 40 Brain Injuries Aphasia is an impairment of language, usually caused by left hemisphere damage. Slide 41 The Brains Plasticity The brain is sculpted by our genes, but also by our experiences. Plasticity refers to the brains ability to modify itself after some types of injury or illness. Slide 42 Our Divided Brain Our brain is divided into two hemispheres. The left hemisphere processes reading, writing, speaking, mathematic, and comprehension skills. The right brain processes imagination, artistic awareness, creativity, and insight. This is not without exception.