Module 4 Incredible Nervous System

GENES & EVOLUTION Genetic information –Brain/body develop according to complex chemical instructions written in a human cell no larger than a grain of sand

GENES & EVOLUTION (CONT’D) Fertilization –Human life has its beginnings when the father’s sperm, which contains ________________, penetrates the mother’s egg, which contains 23 chromosomes

GENES & EVOLUTION (CONT’D)

Zygote –The largest human cell, about the size ________________ –A zygote is a cell that results when an egg is fertilized –A zygote contains ________________ arranged in 23 pairs

GENES & EVOLUTION (CONT’D) Chromosomes –A short, rod-like, microscopic structure that contains a tightly coiled strand of the chemical DNA, which is an abbreviation for deoxyribonucleic acid

GENES & EVOLUTION (CONT’D)

Chemical alphabet –Each chromosome contains a long, coiled strand of DNA, which resembles a ladder that has been twisted over and over upon itself –Each rung of the DNA ladder is made up of four chemicals –The order in which the four different chemicals combine to form rungs creates a microscopic alphabet

GENES & EVOLUTION (CONT’D)

Genes and proteins –Gene ________________________________________ –Proteins ________________________________________ ________________________________________ ________________________________________

GENES & EVOLUTION (CONT’D) Polymorphic genes –______________________________ (e.g. eye color) –Combination of genes sibling receives from parents, resulting in two siblings having different eye colors Dominant and recessive genes –Dominant gene: __________________________________________ __________________________________________ __________________________________________ –Recessive gene: __________________________________________ __________________________________________ __________________________________________ ___________________________

GENES & EVOLUTION (CONT’D) Genome –The Human Genome Project –Began in 1995 and cost over $2.7 billion –Reached its first goal in 2003 of mapping all the human genes –Researchers found only about 30,000 human genes instead of the estimated 100,000

GENES & EVOLUTION (CONT’D) Genetic factors –Researchers are discovering how genetic factors interact with the environment in the development of mental retardation, emotional and personality traits, mental disorders, and various cognitive abilities Fragile X syndrome –An inherited developmental disability due to a defect in the X chromosome Genetic testing –Involves taking a blood, hair, skin, or other sample and then examining donor’s genes to look for specific diseases or disorders

EVOLUTION OF THE HUMAN BRAIN Evolution of the human brain –1859, Charles Darwin published The Origin of Species Theory of evolution –Different species arose from a common ancestor and that those species that survived were best adapted to meet the demands of their environment –Humans and chimpanzees share at least 98% of their DNA

EVOLUTION OF THE HUMAN BRAIN (CONT’D)

Genetic mutations –__________________________________________ __________________________________________ __________________________________________ Natural selection –__________________________________________ __________________________________________ ______________ –__________________________________________ __________________________________________ __________________________________________

EVOLUTION OF THE HUMAN BRAIN (CONT’D) Adaptations –Common features of a species that provide it with improved function Evolutionary approach –Voluntary ideas, such as adaptation and natural selection, explain human behaviors and mental processes

STUDYING THE LIVING BRAIN Brain scans –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 –Researchers are mapping a variety of cognitive functions attention, language, memory, motor skills sites of emotional feelings and appetite MRI and fMRI

STUDYING THE LIVING BRAIN (CONT’D) MRI _____________________________ __________________________________________ fMRI functional magnetic resonance imaging __________________________________________ __________________________________________ __________________________________________

STUDYING THE LIVING BRAIN (CONT’D)

Brain scans and cognitive neuroscience –PET scan –Positron emission tomography –__________________________________________ __________________________________________ __________________________________________ _

STUDYING THE LIVING BRAIN (CONT’D) Neuroimaging –PET and fMRI scans are used to identify and map the living brain’s neural activity as a person performs complex behavioral and cognitive tasks, such as seeing moving thinking speaking empathizing trusting even reacting to TV violence

STUDYING THE LIVING BRAIN (CONT’D)

ORGANIZATION OF THE BRAIN Central nervous system (CNS) –Made up of the ____________________________ –Bottom of brain is where spinal cord emerges –Made up of neurons, bundles of axons, and dendrites that carry information back and forth between the brain and the body

ORGANIZATION OF THE BRAIN (CONT’D)

Peripheral nervous system (PNS) –__________________________________________ __________________________________________ __________________________________________ ______________________ Subdivisions of the PNS –Somatic nervous system –Autonomic nervous system (ANS) –Sympathetic division –Parasympathetic division

ORGANIZATION OF THE BRAIN (CONT’D)

Somatic nervous system –Network of nerves that connect either to sensory receptors or to muscles that you can move voluntarily, such as muscles in your limbs, back, neck, and chest –Nerves contain two kinds of fibers afferent –_____________________________________ efferent –_____________________________________ _____________________________________ _____________________________________

ORGANIZATION OF THE BRAIN (CONT’D) Autonomic nervous system (ANS) –Regulates heart rate, breathing, blood pressure, digestion, hormone secretion, and other functions –Sympathetic division 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

ORGANIZATION OF THE BRAIN (CONT’D) Major parts of the brain –Forebrain –Midbrain –Hindbrain pons medulla cerebellum

ORGANIZATION OF THE BRAIN (CONT’D)

Forebrain –Largest part of the brain –Has right and left sides called hemispheres –Hemispheres are responsible for a number of functions, including learning and memory, speaking and language, emotional responses, experiencing sensations, initiating voluntary movements, planning, and making decisions

ORGANIZATION OF THE BRAIN (CONT’D) Midbrain –Has a reward or pleasure center, which is stimulated by __________________________________________ __________________________________________ –Has areas for visual and auditory reflexes –Contains the __________________, which arouses the forebrain so that it’s ready to process information from the senses

ORGANIZATION OF THE BRAIN (CONT’D) Hindbrain –Has three distinct structures pons medulla cerebellum

ORGANIZATION OF THE BRAIN (CONT’D) Pons –Functions as a bridge to interconnect messages between the spinal cord and brain Medulla –Located on top of the spinal cord –Includes a group of cells that control vital reflexes, such as respiration, heart rate, and blood pressure Cerebellum –Located in the very back and underneath the brain –Involved in coordinating motor movements but not in initiating voluntary movements

CONTROL CENTERS: FOUR LOBES Wrinkled cortex –A thin layer of cells that essentially covers the entire surface of the forebrain

CONTROL CENTERS: FOUR LOBES (CONT’D)

Frontal lobe –__________________________________________ _________________________________________ Parietal lobe –__________________________________________ Occipital lobe –__________________________________________ Temporal lobe –__________________________________________ _

CONTROL CENTERS: FOUR LOBES (CONT’D)

Anencephaly –Condition of being born _______________________ –If some brain or nervous tissue is present, it’s totally exposed and often damaged because the top of the skull is missing –Survival is limited to days

CONTROL CENTERS: FOUR LOBES (CONT’D)

Frontal lobe: functions –Located in front part of brain –Includes huge area of cortex –Many functions 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, executing plans executive functions

CONTROL CENTERS: FOUR LOBES (CONT’D) Phineas Gage Frontal lobotomy –__________________________________________ __________________________________________ __________________________________________ __________________________________________

CONTROL CENTERS: FOUR LOBES (CONT’D)

Frontal lobe: functions –Motor cortex –Narrow strip of cortex that’s located on the back edge of the frontal lobe and extends down its side –Involved in the ______________________________ –Right side controls left –Left side controls right

CONTROL CENTERS: FOUR LOBES (CONT’D) Other functions of frontal lobe –Much knowledge of other frontal lobe functions comes from individuals who had damage to that area –Frontal lobes are involved in paying attention, organizing, planning, deciding, and carrying out various cognitive tasks and social-emotional behaviors –Executive function

CONTROL CENTERS: FOUR LOBES (CONT’D) Parietal lobe: function –Location of somatosensory cortex –Narrow strip of cortex that’s located on the front edge of the parietal lobe and extends down its side

CONTROL CENTERS: FOUR LOBES (CONT’D)

Other functions of parietal lobe –Sensory integration –Spatial orientation –Language abilities –Visual and auditory attention –Memory –Numerical processing (counting)

CONTROL CENTERS: FOUR LOBES (CONT’D) Temporal lobe: functions –Primary auditory cortex –Located on top edge of each temporal lobe, __________________________________________ __________________________________________ __________________________________________ __________________________________________ __________________________________________

CONTROL CENTERS: FOUR LOBES (CONT’D)

Temporal lobe: functions –Auditory association area –Located directly below the primary auditory cortex –Transforms basic sensory information, such as noises or sounds, __________________________________________ __________________________________________ __________________________________________

CONTROL CENTERS: FOUR LOBES (CONT’D) Temporal lobe: functions –Broca’s area located in left frontal lobe necessary for combining sounds into words and arranging words into meaningful sentences damage: Broca’s aphasia –person can’t speak in fluent sentences but can understand written and spoken words

CONTROL CENTERS: FOUR LOBES (CONT’D) –Wernicke’s area located in the left temporal lobe necessary for speaking in coherent sentences and for understanding speech damage: Wernicke’s aphasia –Difficulty understanding spoken or written words and difficulty putting words into meaningful sentences

BROCA’S v. WERNICKE’S

CONTROL CENTERS: FOUR LOBES (CONT’D) Occipital lobe: functions –Vision –Primary visual cortex –Located at the very back of the occipital lobe –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

CONTROL CENTERS: FOUR LOBES (CONT’D)

Occipital lobe: functions –Visual association area –__________________________________________ __________________________________________ __________________________________________ __________________________________________ __________________________________________ __________________________________________

CONTROL CENTERS: FOUR LOBES (CONT’D) Visual agnosia –Individual fails to recognize some object, person, or color –Has ability to see and even describe pieces or parts of some visual stimulus

CONTROL CENTERS: FOUR LOBES (CONT’D)

Neglect syndrome –Refers to the failure of a patient to see objects or parts of the body on the side opposite the brain damage –May dress only on one side of body –May deny that opposite body parts are theirs

CONTROL CENTERS: FOUR LOBES (CONT’D)

LIMBIC SYSTEM: OLD BRAIN Group of about half a dozen interconnected structures that make up the core of the forebrain Involved with regulating many motivational behaviors, such as obtaining food, drink, and sex Organizing emotional behaviors, such as fear, anger, and aggression; storing memories Structures and functions –Hypothalamus –Amygdala –Thalamus –Hippocampus

LIMBIC SYSTEM: OLD BRAIN (CONT’D)

Hypothalamus –Regulates many ______________ behaviors, including eating, drinking, and sexual responses; emotional behaviors, such as arousing the body when fighting or fleeing; and secretion of hormones, such as occurs at puberty Amygdala –Located in the tip of the temporal lobe –__________________________________________ –Evaluates __________________________________________ __________________________________________ __________________________________________

LIMBIC SYSTEM: OLD BRAIN (CONT’D) Thalamus –__________________________________________ –Involved in receiving sensory information, doing some initial processing, and then relaying the sensory information to areas of the cortex Hippocampus –__________________________________________ –Involved in saving many kinds of fleeting memories by putting them into permanent storage in various parts of the brain

LIMBIC SYSTEM: OLD BRAIN (CONT’D) Autonomic nervous system –Sympathetic –Parasympathetic

LIMBIC SYSTEM: OLD BRAIN (CONT’D) Autonomic nervous system –Sympathetic ________________________________________ ________________________________________ ________________________________________ –Fight or flight state of increased physiological arousal caused by activation of the sympathetic division helps body cope and survive threatening situations –Physiological responses increased heart rate, increased blood pressure, and dilated pupils

LIMBIC SYSTEM: OLD BRAIN (CONT’D) Autonomic nervous system –Parasympathetic _____________________________________ ______________________________________ –Physiological responses ________________________________________

LIMBIC SYSTEM: OLD BRAIN (CONT’D) Autonomic nervous system –Homeostasis sympathetic and parasympathetic systems work together to keep the body’s level of arousal in balance for optimum functioning

ENDOCRINE SYSTEM Endocrine system –Made up of numerous glands located throughout the body –Glands secrete various chemicals called hormones pituitary pancreas thyroid adrenal glands gonads

ENDOCRINE SYSTEM (CONT’D)

Pituitary gland –Hangs below the hypothalamus –Divided into anterior and posterior Posterior (rear portion) –Regulates water and salt balance Anterior (front portion) –Regulates growth through secretion of growth hormone –Produces hormones that control the adrenal cortex, pancreas, thyroid, and pancreas

ENDOCRINE SYSTEM (CONT’D)

Pancreas –Regulates the level of sugar in the bloodstream by secreting insulin Thyroid –Located in the neck –Regulates metabolism through secretion of hormones

ENDOCRINE SYSTEM (CONT’D) Adrenal glands –Adrenal cortex (outside part) –Secretes hormones that regulate sugar and salt balance –Adrenal medulla (inside part) –Secretes two hormones that arouse the body to deal with stress and emergencies –Epinephrine (adrenaline) –Norepinephrine (noradrenaline)

ENDOCRINE SYSTEM (CONT’D) Gonads –Females ovaries produce hormones that regulate sexual development, ovulation, and growth of sex organs –Males testes produce hormones that regulate sexual development, production of sperm, and growth of sex organs