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Health Psychology Chapter 3: Biological Foundations of Health and Illness Aug 31-Sep 5, 2007 Classes #6-7 Biological Roots of Behavior Franz Gall (1758-1828) – Austrian physicist who invented phrenology – He felt that bumps on the skull could reveal our mental abilities and character traits – Introduced as being scientific but its use was exploited by “quacks on gullible individuals” – Became similar to that of astrology, palm-reading and tarot – Although, ill-fated theory was laughed at by scientific community of that day – it may have had some validity – Localization of brain functions somehow hit the mark The Nervous System Electrochemical communication system that enables us to think, feel, and behave Complex beyond comprehension Although, human brains are more complex our nervous systems and those of animals operate in a similar fashion – advantage of this is experimentation The Nervous System Allows researchers to study simple animals such as squids and sea slugs to help us better understand the organization of our own brains Divisions of the Nervous System Consists of two systems – Central Nervous System Brain and spinal cord – Peripheral Nervous System Which connects the CNS to the rest of the body Organization of the Nervous System Peripheral Nervous System Two components: – Somatic Nervous System Transmits sensory input to the CNS from the outside world and directs motor output – Autonomic Nervous System Controls glands and muscles of our internal organs – “automatic pilot” Autonomic Nervous System Dual system: – Sympathetic Nervous System Arouses the body – Parasympathetic Nervous System Calms us down Endocrine System: Taking the slow lane Unlike the speedy nervous system which zips messages from eyes to brain to hand in a fraction of a second, endocrine messages use the slow lane May take several seconds or more as bloodstream carries a hormone from an endocrine gland to its target tissue Endocrine System Hormones are chemical messengers Influence all aspects of our lives – growth, metabolism, reproduction, moods, etc. Strives for homeostasis (balance) by responding to stress, exertion, internal thoughts, etc. Epinephrine Involved in energy and glucose metabolism Illnesses Associated With Epinephrine Depression – too low levels Norepinephrine Plays a role in attention and arousal Used by sympathetic nervous system to prepare us for action Illnesses Associated With Norepinephrine Depression – Chronic stress depletes this neurotransmitter and can lead to depression Note: – Aerobic Exercise is found to protect the brain from this depletion – so go out and run a mile or two if your down in the dumps How does the brain govern behavior? 3 Principle layers of the brain: – Brainstem – Limbic System Hippocampus Amygdala Hypothalamus – Cerebral Cortex Brainstem (or Hindbrain) The brain’s innermost region… – Begins where the spinal cord enters the skull and swells slightly forming the medulla – Towards the rear of the brainstem is the cerebellum – this is linked to memory and its major function is muscular control Limbic System Hippocampus – This structure plays a key role in allowing us to store new information – Problems here may cause Alzheimer's – these individuals have trouble processing declarative memories – Milner (1968): the classic case of H.M. Limbic System Amygdala – Emotional control center of the brain – major influence on aggression and fear – Emotional memories as well – Alzheimer’s ??? Kluver and Bucy (1939) Demasio (1994) Limbic System Hypothalamus – Major influence on hunger, thirst, body temperature, and sexual behavior Olds and Milner (1954) Cerebral Cortex Makes us distinctively human – much higher developed than in animals – Motor Cortex – involved in the conscious initiation of voluntary movements in specific parts of the body including hand, knee, foot and head Fritsch and Hitzig (1870) Delgado (1969a) Delgado (1969b) Penfield (1975) Cerebral Cortex Sensory Cortex – receives information from our senses Visual cortex – visual info Auditory cortex – auditory info Somatosensory cortex – info from skin Association cortex – involved in complex cognitive tasks associating words with images Broca’s area (aphasia) Wernicke’s area (aphasia) Function of the Cardiovascular System Assist in gas transport. Deliver nutrients, hormones Remove waste products from the cells Assist in temperature regulation Assist in balancing body fluids and helps prevent dehydration Systems of the Heart The heart functions to contract and propel blood through the two blood transport systems. Pulmonary system Systemic system Pulmonary System Within the pulmonary system blood is transported to and from the lungs. The right ventricle propels deoxygenated, carbon dioxide rich, blood to the lungs where carbon dioxide is released and oxygen is picked up. After gas exchange the blood returns to the left atrium of the heart. Impact of Cardiovascular Disease Affects more than 60 million Americans each year Results in nearly 1 million deaths each year Cost nearly $275 billion Cardiovascular Disease Cardiovascular disease (CVD) is the number one cause of death in the United States. Most reported deaths are related to coronary artery disease Forms of Cardiovascular Disease Coronary artery disease Hypertension (Chronic high blood pressure) Cerebral vascular accidents (strokes) Peripheral vascular disease Valvular heart disease Congenital heart disease Congestive heart failure Coronary Artery Disease Primary form of heart disease A disease involving waxy plaque build-up in the arteries Coronary Risk Factors Primary Risk Factors: Factors that have been definitively associated with or directly cause coronary artery disease. Smoking, inactivity, hypertension Secondary Risk Factors: Factors believed to contribute to or advance the severity of CAD. Gender, age The Respiratory System At the level of the individual cell: respiration involves energy-producing chemical reactions that require oxygen At the level of the whole organism, respiration is the process of taking in oxygen from the environment and ridding the body of carbon dioxide. The Lungs Left and right lungs: are in left and right pleural cavities The base: inferior portion of each lung rests on superior surface of diaphragm The Right Lung Has 3 lobes: superior, middle, and inferior separated by horizontal and oblique fissures The Left Lung Has 2 lobes: superior and inferior are separated by an oblique fissure Relationship between Lungs and Heart Figure 23–8 Lung Shape Right lung: is wider is displaced upward by liver Left lung: is longer is displaced leftward by the heart forming the cardiac notch Components of the Digestive System Digestive Tract Gastrointestinal (GI) tract or alimentary canal Is a muscular tube Extends from oral cavity to anus 6 Functions of the Digestive System Ingestion: 1. occurs when materials enter digestive tract via the mouth Mechanical processing: 2. crushing and shearing makes materials easier to propel along digestive tract 3. Digestion: is the chemical breakdown of food into small organic fragments for absorption by digestive epithelium Secretion: 4. is the release of water, acids, enzymes, buffers, and salts by epithelium of digestive tract by glandular organs Absorption: 5. movement of organic substrates, electrolytes, vitamins, and water across digestive epithelium into interstitial fluid of digestive tract 6. Excretion: removal of waste products from body fluids THE IMMUNE SYSTEM We all get sick sometimes...but then we get better. What happens when we get sick? Why do we get better? ANATOMY OF THE IMMUNE SYSTEM The immune system is localized in several parts of the body immune cells develop in the primary organs bone marrow and thymus (yellow) immune responses occur in the secondary organs (blue) ANATOMY OF THE IMMUNE SYSTEM Thymus – glandular organ near the heart – where T cells learn their jobs Bone marrow – blood-producing tissue located inside certain bones blood stem cells give rise to all of the different types of blood cells Spleen – serves as a filter for the blood removes old and damaged red blood cells removes infectious agents and uses them to activate cells called lymphocytes Lymph nodes – small organs that filter out dead cells, antigens, and other “stuff” to present to lymphocytes Lymphatic vessels – collect fluid (lymph) that has “leaked” out from the blood into the tissues and returns it to circulation PASSIVE IMMUNITY While your immune system was developing, you were protected by immune defenses called antibodies. These antibodies traveled across the placenta from the maternal blood to the fetal blood. Antibodies (Y) are also found in breast milk. The antibodies received through passive immunity last only several weeks. reign invaders - viruses, bacteria, allergens, toxins and rasites- constantly bombard our body. YOUR ACTIVE IMMUNE DEFENSES Innate Immunity Adaptive Immunity - invariant (generalized) - early, limited specificity - the first line of defense - variable (custom) - later, highly specific - ‘‘remembers’’ infection What influences one’s behavior: Nature or Nurture? The age-old debate: Is it genes or is it the environment? Twin Studies Monozygotic Identical twins (one-egg) Dizygotic Not identical (fraternal) twins Resemble one another as much as any brother or sister would “The Jim Twins” Thomas Bouchard’s University of Minnesota twin studies Extraordinary similarities between Jim Springer and Jim Lewis Uncanny coincidences? Any limitations to this study? These guys shared a flushing the toilet gene… Bouchard (1979) Part of Bouchard’s twins study… Oskar Stohl and Jack Yulfe were raised in environments with more obvious differences And you thought it was because you were incompatible… Is there a genetic risk of divorce? McGue and Lykken (1992) 1516 pairs of same-sex twins 722 MZ and 794 DZ MZ > DZ What is a gene made out of? Genes are made from chromosomes. People have 23 pairs of chromosomes. DNA consists of a double helix, whose parallel strands consist of both pairs held together by hydrogen bonds. Each chromosome in the DNA contains instructions for stringing together amino acids. These instructions are used in different combinations with the chemicals adenine (A), thiamine (T), guanine (G) and cytosine (C). Conception Fertilized egg with two pronuclei Within 72 hours it’s divided into 8 cells Once the sperm penetrates the egg, the two nuclei fuse to become one, with 23 chromosomes from the father and 23 chromosome from the mother A zygote is the single cell formed from the fusing of the sperm and ovum. After four days there are about 100 cells and it is now called a blastocyst The organism’s genetic inheritance is set for life once the chromosomes pair up Is it a boy or a girl? In the 23rd pair of chromosomes women are XX and men are XY Every ovum that the woman produces is XX Men will produce half Y sperm and half X sperm because his 23rd pair contain both 1. 2. 3. Different factors can determine the sex of the embryo such as when: A man carries a gene that causes his X or Y gene to be immobile The alkaline or acidity levels of a woman’s uterus can help either the X or Y gene Stress can cause an XY embryo to be expelled 1. 2. 3. 4. A zygote may split in the early stages of development, which creates separate identical zygotes Monozygotic twins are identical because they originate from the same zygote Dizygotic twins are formed when two separate ova are fertilized by two separate sperm. They share half their genes, similar to siblings. Factors that can increase the chances of twins are: A woman’s age A woman’s ethnic group Medical intervention A family history of having twins Let’s split! Mary-Kate and Ashley Olsen What else do genes do? Once the zygote reaches it’s eight-cell stage, cells begin to specialize to become different parts of the body Genes code protein so that they can give instructions to other genes to shut on and off at different stages of life. For instance, to absorb nourishment, to multiply and to die Phenotype is a person’s actual appearance and behavior, which are the results of both genetic and environmental influences How do gene’s interact? Additive genes interact additively so that there are fairly equal contributions from all the genes involved. They affect traits such as skin color and height A dominant gene is the member of an interacting pair of alleles whose influence is more evident in the phenotype A recessive gene is the member of an interacting pair of alleles whose influence is less evident in the phenotype X-linked genes are genes located on the X chromosome Genotype vs. Phenotype Genotype is an organism’s entire genetic inheritance, or genetic potential. For instance, you might have inherited the genes that could lead you to become a great mathematician. Another example is that you may have inherited blue eyes. Phenotype is a person’s actual appearance and behavior, which are the result of both genetic and environmental influences. For instance, you might have the genes to become a great mathematician, but without the right environment, your talent may never be recognized. What is behavior genetics? Behavior genetics is the study of the genetic origins of psychological characteristics, such as personality patterns, psychological disorders and intellectual abilities Sadness is one personality trait that is studied in behavior genetics Behavioral Genetics This field studies the relationship between heredity and behavior… Research in behavioral genetics has shown that even newborn infants exhibit differences in temperament Some are emotionally placid, others are emotionally reactive How it applies to the development of personality… Initial differences in temperament might contribute to the development of differences in personality… They might affect how infants respond to other people and, in turn, how other people respond to them For example, a placid infant would be less responsive to other people As a consequence, others would be less responsive to the infant This might predispose the infant to become less sociable later in childhood, laying the groundwork for an introverted adult personality Conclusion Which plays a bigger role in human development, heredity or environment? Is Kate Hudson’s ability as an actor influenced by her environment or genes? Do you think her environment or her genes influenced her career choice? Credits http://www.clt.astate.edu/amooneyhan/WebPresentations/WebCh4Cardio%20SysII-New.PPT http://www.coe.unt.edu/mcnair/ClassNotes/Spring2006/Ch%2023%20The %20Respiratory%20System.ppt#4 http://www.coe.unt.edu/mcnair/ClassNotes/Spring2006/Ch%2024%20The %20Digestive%20System.ppt http://www.nbtc.cornell.edu/mainstreetscience/immunity_and_you/IMMUN OLOGY_LECTURES/Lecture_1_Innate_Immunity.ppt#13