Week 2 Psychology. The Brain and Behavior

Transcription

1 Week 2 Psychology The Brain and Behavior In this lesson, we will focus on the nervous system. We will learn about the Nervous System and its Command Center the Brain Characteristics and Divisions of the Nervous System Identify the structure of the Neurons and their functions Structures of the Brain and their functions Identify the Endocrine System and its function Understand Genetics and Behavior What is the Nervous system? The nervous system is the body s electrochemical communication circuitry. The field that studies this system is call neuroscience. The brain and the nervous system tend to guide our interactions with the world, moving the body and directing our adaptation to our environment. The characteristics include: complexity, integration, adaptability, and electrochemical. Select each tab to know more. The human brain and the nervous system are very complex systems. sing, dance, write, walk, and much more. Thanks to the billion of nerve cells in the brain allow you to Neuroscientist Steven Hyman (2001) calls the brain the great integrator. This is because the brain does a wonderful job of pulling information together: sounds, sights, touch, taste, genes, and environment. Brain activity is integrated across different levels and many different parts through countless interconnections of brain cells and extensive pathways. Adaptability refers to the ability to function in a changing world. It is the term plasticity that denotes the brain s special capacity for change. For example, when you change the way you think, you literally change the brain s physical processes as well as changes it shape.

2 The electrical impulses and chemical messengers power our brain and nervous system. This impulse travels electrically down the nerve cells or neuron and at the end of the line the communication begins. There are four major divisions of the Human Nervous System. They are better known as the central nervous system CNS, the peripheral nervous system PNS, somatic nervous system, and autonomic nervous system. Select each of the sections below to learn more. The Central Nervous System is a very elegant system. It is highly ordered and organized and made up of the brain and spinal cord. 99% of the nerve cells are located here. The Peripheral Nervous System is the network of nerves, which connect the brain and spinal cord to other parts of the body. It actually brings information to and from the brain and spinal cord and carries out various commands of the CNS to carry out many muscular and glandular activities. Our bodies consist of sensory nerves whose function is to relay information from the skin and muscles to the central nervous system. This is called the somatic system. For instance, pain and temperature is conveyed through this system. The autonomic system is different from the somatic because this system takes messages from the body s internal organs, monitoring such processes as breathing heart rate, and digestion. The last two systems are the sympathetic and parasympathetic systems. One arouses the body to mobilize it for action and thus is involved in the experience of stress (sympathetic) and the other calms the body (parasympathetic). The Neuron is the nerve cell that handles the information processing function. Our brain contains approximately 100 billion neurons. Each Neuron consists of dendrites, an axon, the myelin sheath and neurotransmitters. Dendrites are tree-like fibers projecting from a neuron, which receive information and orient it toward the neuron s cell body. The Axon is the part of the neuron that carries information away from the cell body toward other cells.

3 While the axon is the part of the neuron that carries information away from the cell body toward other cells and myelin sheath is a layer of fat cells that encases and insulates most axons. Neurotransmitters are chemical substances that are stored in very tiny sacs within the terminal buttons and involved in trans mitting information across a synaptic gap to the next neuron. Tiny spaces between neurons are referred to as synapse gaps. The process begins with the neural impulse, which travels down the axon toward the dendrites of the next neuron. The impulse then triggers the release of neurotransmitters into the synaptic gap which comes from the terminal button. Finally, at the receptor site on the dendrite of the receiving neuron, the neurotransmitter causes channels to open and creates an action potential. How is the brain organized? It starts in the human embryo develops inside its mother s womb, the nervous starts forming as a long, hollow tube on the neck of the embryo s back. After about three weeks cells make up the tube differentiate into a mass of neurons, which most then develop into three major regions: Hindbrain, Midbrain, and Forebrain. The hindbrain is located at the skull s rear, the lowest portion of the brain, consisting of the medulla, cerebellum, and pons. The midbrain is located between the hindbrain and forebrain, an area in which many nerve-fiber systems ascend and descend to connect the higher and lower portions of the brain; it relays information between the ears and eyes. The forebrain is the largest division and it s most forward part. The human forebrain s most important structures consist of the limbic system, thalamus, basal ganglia, hypothalamus, and cerebral cortex. The human brain shares certain structures with other mammals such as rats, cats and chimpanzees. These are the Cerebellum, Cerebral Cortex, and the Brain stem. The cerebral cortex is part of the forebrain, the outer layer of the brain. What is the function of the cerebral cortex? It is responsible for the most complex mental functions, such as thinking and planning.

4 Lobes are the wrinkled surface of the Cerebral Cortex. This structure is located in the back of the head that respond to the visual stimuli. Genes and Genetics Genetics is a relatively considered the young science. Its origination goes back as far as the mid-nineteenth century, studied by George Mendel. Within the psychological processes there are other aspects of our physiology, which also have consequences to the process. Learn more about Genes by selecting each of the sections below. Genes are a powerful force in an organism. The units of heredity information, consisting of segments of chromosomes composed of DNA. DNA, or Deoxyribonucleic Acid is (other than being one of the most difficult words to pronounce) a complex molecule in the cell s chromosomes that carries genetic information. Chromosomes are threadlike structures that come in 23 pairs, one member of each pair originating from each parent, and that contain DNA. In other words, you have 23 chromosomes from your mother and 23 from you father. Additional Content Watch the video on The effects of neurotransmitters and Epilepsy Watch the video on Brain transplants as a treatment for Parkinson s disease. Complete the Apply It! question on Page 76 and justify your answer. Discussion questions Do you believe there has been an increasing interest in hemispheric specialization (the difference in right-brained and leftbrained functions) in the public? Why or why not? What behaviors do you want to pass on to your children and why?

5 Read an article on the Minnesota Twin Study What does the article tell you about behavior genetics?