Module 4: Incredible Nervous System A-F

1. Module 4: Incredible Nervous System A-F By Sergio Romero Period 1

2. A. Genes & Evolution Genetic instruction Evolution of the human brain

3. Genetic Instruction Your brain and body develop according to complex chemical instructions that were written in a human cell no larger than a grain of sand 1. Fertilization: human life begins when a father�s sperm penetrates a mother�s egg. 2. Zygote: is the cell that results when an egg is fertilized. A zygote contains 46 chromosomes arranged in 23 pairs. It�s the largest human cell and contains the equivalent to 300,000 pages of typed-written instructions. 3. Chromosomes: is a short, rodlike, microscopic structure that contains tightly coiled strands of chemical DNA. 4. Chemical alphabet: The chemical alphabet is used to write instructions for the development and assembly of the 100 trillion highly specialized cells that make up the brain and body. 5. Genes and proteins: Genes determine physical traits (eye color, shapes of ear lobes) as well as contribute to the development of emotional, cognitive, and behavioral traits. Proteins are chemical building blocks from which all the parts the brain and body are constructed. 6. Genome: the human genome project mapped all the human genes. 7. An error in instruction: Fragile X syndrome, an inherited developmental disability, is due to the defect in the X chromosome. It can result in physical changes, such as a relatively large head with protruding ears.

4. Evolution Of the Human Brain Theory of evolution: says that different species arose from a common ancestor and that those species that survived were the best adapted to meet the demands of the environment. According to the theory of evolution, present-day humans descended from a creature that split off from apes millions of years ago

5. B. Studying The Living Brain Brain Scans Brain Scans: MRI &FMRI Brain Scans and Cognitive Neuroscience Tools Versus Animals

6. Brain Scans In the past 10 years researchers have developed several brain scanning techniques that can look through the thick skull and picture the brain with astonishing clarity yet cause no damage to the extremely delicate brain cells. By using these techniques, researchers are mapping a variety of cognitive functions as well as sites of emotional feelings and hunger sensations.

7. Brain Scans: MRI &FMRI MRI: or magnetic resonance imaging, involves passing nonharmful radio frequencies through the brain. A computer measures how theses signals interact with brain cells and transforms this interaction into an incredibly detailed image of the brain (or body). MRI�s are used to study the structures of the brain. The �f� in FMRI (functional magnetic resonance imaging) stands for the functional and measures the activity of specific neurons that are functioning during cognitive tasks, such as thinking, listening, or reading.

8. Brain Scans and Cognitive Neuroscience Cognitive neuroscience involves using imaging techniques to literally light up your thoughts and feelings. PET scans involves injecting a slightly radioactive solution into the blood and then measuring the amount of radiation absorbed by brain cells called neurons. Different levels of absorption are represented by colors- red and yellow indicate maximum activity of neurons, while blue and green indicate minimal activity.

9. Tools Versus Animals Thinking of animals occurs in the back of the brain. Thinking of tools occurs in the front of the brain. Researchers concluded that you are able to identify thousands of objects, in large part, because the brain has two separate built-in systems: one for thoughts about naming animals, which involves distinguishing between size, shapes, and colors, and another for thoughts about naming tools, which involves thinking about how tools are used.

10. C. Organization of the Brain Divisions of the Nervous System Major Parts of the Brain

11. Divisions of the Nervous System Major divisions of the nervous system are: The central nervous system-CNS: is made up of the brain and spinal cord. You are capable of many complex cognitive functions-such as thinking, speaking, and reading, as well as moving, feeling, seeing, and hearing-because of your central nervous system. The peripheral nervous system-PNS: includes all the nerves that extend from the spinal cord and carry messages to and from various muscles, glands, and sense organs located throughout the body. The PNS has two subdivisions, the somatic and autonomic nervous system. Somatic nervous system: consists of a network or nerves that connect either to sensory receptors or to muscles that you can move voluntarily. ANS-Autonomic nervous system: regulates heart rate, breathing, blood pressure, digestion, hormone secretion, and other functions. The ANS usually functions without conscious effort, which means that only a few of its responses, such as breathing, can be controlled voluntarily. The ANS also has two subdivisions, the sympathetic division and parasympathetic division. Sympathetic division: is triggered by threatening or challenging physical or psychological stimuli, increases physiological arousal and prepares the body for action. Parasympathetic division: returns the body to a calmer, relaxed state and is involved in digestion.

12. Major Parts of the Brain Midbrain: has a reward or pleasure center, which is stimulated by food, sex, money, music, looking at attractive faces, and some drugs (cocaine); has areas for visual auditory reflexes, such as automatically turning your head toward a noise. Hindbrain: has three distinct structures: the pons, medulla, and cerebellum. It is also a primitive part of the brain. Pons: functions as a bridge to interconnect messages between the spinal cord and brain. The pons also makes chemicals involved in sleep. Medulla: which is located at the top of the spinal cord, includes a group of cells that control vital reflexes, such as respiration, heart rate, and blood pressure. Cerebellum: which is located at the very back and underneath the brain, is involved in coordinating motor movements but not in initiating voluntary movements. Forebrain: which is the largest part of the brain, has right and left sides that are called hemispheres. The hemispheres, which are connected to a wide band of fibers, are responsible for learning and memory, speaking and language, etc.

13. D. Control Centers: Four Lobes Overall View of the Cortex Frontal Lobe: Functions Parietal Lobe: Functions Temporal Lobe: Functions Occipital Lobe: Functions

14. Overall View of the Cortex The cortex is the thin layer of cells that essentially covers the entire surface or the forebrain. The vast majority of our neurons are located in the cortex, which folds over on itself so that it forms a large surface area. The cortex is divided into four separate areas, or lobes, each with different functions. The frontal lobe: is involved with personality, emotions, and motor behaviors. The parietal lobe: is involved with perception and sensory experiences. The occipital lobe: is involved with processing visual information. The temporal lobe: is involved with hearing and speaking.

15. Frontal Lobe: Functions The frontal lobe, which is located in the front part of the brain, includes a huge area of the cortex. The frontal lobe is involved in many functions: performing voluntary motor movements, interpreting and performing emotional behaviors, behaving normally in social situations, maintaining a healthy personality, paying attention to things in the environment, making decisions, and executing plans. Because the frontal lobe is involved in making decisions, planning, reasoning, and carrying out behaviors, it is said to have executive functions.

16. Parietal Lobe: Functions The parietal lobe is located directly behind the frontal lobe. The parietal lobe�s functions include processing sensory information from body parts, which include touching, locating positions of limbs, and feeling temperature and pain, and carrying out several cognitive functions, such as attending to and perceiving objects.

17. Temporal Lobe: Functions The temporal lobe is located directly below the parietal lobe and is involved in hearing, speaking coherently, and understanding verbal and written material. The primary auditory cortex, which is located on the top edge of each temporal lobe, receives electrical signals from receptors in the ear and transforms these signals into meaningless sound sensations, such as vowels and consonants. The auditory association area transforms basic information, such as noises or sounds, into recognizable auditory information, such as words or music. Wernicke�s, which is located in the left temporal lobe, is necessary for speaking in coherent sentences and for understanding speech.

18. Occipital Lobe: Functions The occipital lobe is located at the very back of the brain and is involved in processing visual information, which includes seeing colors and perceiving and recognizing objects, animals, and people. The primary visual cortex receives electrical signals from receptors in the eyes and transforms these signals into meaningless basic visual sensations, such as lights, lines, shadows, colors, and textures. The visual association area transforms basic sensations, such as lights, lines, colors, and textures, into complete, meaningful visual perceptions, such as persons, objects, or animals.

19. E. Limbic System: Old Brain Structures and Functions Autonomic Nervous System

20. Structures and Functions The limbic system refers to a group of about half a dozen interconnected structures that make up the core of the forebrain. The limbic system�s structures are involved with regulating many motivational behaviors such as, obtaining food, drink, and sex; with organizing emotional behaviors such as fear, anger, and aggression; and with storing memories. Important parts of the limbic system: Hypothalamus: regulates many motivational behaviors, including eating, drinking, sexual responses; emotional behaviors, such as arousing the body when fighting or fleeing; and the secretion of hormones, such as occurs at puberty. Amygdala: receives input from all the senses. Thalamus: is involved in receiving sensory information, doing some initial processing, and then relaying the sensory information to areas of the cortex. Hippocampus: is involved in saving many kinds of fleeting memories by putting them into permanent storage in various parts of the brain.

21. Autonomic Nervous System The sympathetic division, which is one part of the ANS, is triggered by threatening or challenging physical stimuli, such as a snake, or by psychological stimuli, such as the thought of having to give a public speech. Once triggered, the sympathetic division increases the body�s physiological arousal. The fight-or-flight response, which is a state of increased physiological arousal caused by activation of the sympathetic division, helps the body cope with and survive threatening situations. The parasympathetic division, which is the other part of the ANS, decreases physiological arousal and helps return the body to a calmer, more relaxed state. It also stimulates digestion during eating.

22. F. Endocrine System Definition Control Center Other Glands

23. Definition  The endocrine system is made up of numerous glands that are located throughout the body. These glands secrete various chemicals, called hormones, which affect organs, muscles, and other glands in the body.

24. Control Center In many ways, the hypothalamus, which Is located in the lower middle part of the brain, controls much of the endocrine system by regulating the pituitary gland, which is located directly below and outside the brain. The hypothalamus is often called the control center of the endocrine system

25. Other Glands Pituitary gland: a key component of the endocrine system, it is divided into anterior and posterior sections. Posterior pituitary: the rear portion of the pituitary regulates water and salt balance. Anterior pituitary: the front part of the pituitary regulates growth through secretion of growth hormones and produces hormones that control the adrenal cortex, pancreas, thyroids, and gonads. Pancreas: this organ regulates the level of sugar in the bloodstream by secreting insulin Thyroid: this gland, which is located in the neck. Regulates metabolism through secretion of hormones. Adrenal glands: the adrenal cortex secretes hormones that regulate sugar and salt balances and helps the body resist stress; they are also responsible for growth of pubic hairs. The adrenal medulla secretes two hormones that arouse the body to deal with stress and emergencies. Gonads: in females, the ovaries produce hormones that regulate sexual development, ovulation, and growth of sex organs. In males, the testes produce hormones that regulate sexual development, production of sperm, and growth of sex organs.