Transcript File
Neuropsychology Essential Question 1 How do nerve cells generate impulses, communicate with other nerve cells, and become influenced by neurotransmitters? Neural Anatomy ‣ The body’s information system is built from billions of interconnected cells called neurons ‣ Interconnected neurons make up a nerve Action Potential ‣ A brief electrical charge that travels down a neuron ‣ Sodium-potassium pumps pump positive ions out from the inside of the neuron, making them ready for another action potential • Depolarization occurs when positive ions enter the neuron, making it more prone to firing an action potential • Hyperpolarization occurs when negative ions enter the neuron, making it less prone to firing an action potential Action Potential ‣ Threshold: Minimum electrical current required to fire an action potential ‣ All-or-None Response: When the positive ions minus the negative ions exceed the threshold, the neuron fires an action potential • ‣ ‣ If the current fails to exceed the threshold, a neuron will not fire Intensity of an action potential remains the same throughout the length of the axon Refractory Period: After a neuron fires it pauses for a short period to recharge itself to fire again Neurotransmitters ‣ Synapse: Junction between an axon terminal of a sending neuron and a dendrite or cell body of the receiving neuron ‣ Neurotransmitters (chemicals) released from the sending neuron travel across the synapse and bind to receptor sites on the receiving neuron generating an action potential ‣ Reuptake: Neurotransmitters in the synapse are reabsorbed into sending neurons Neurotransmitters ‣ Neurotransmitters bind to the receptors of a receiving neuron in a lock and key mechanism ‣ Agonists mimic neurotransmitters • ‣ Example - Morphine mimics endorphins as a pain reliever Antagonists block neurotransmitters • Example - Curare (poison) blocks ACh receptors involved in muscle movement Neurotransmitters Essential Question 2 What are the functions of the nervous and endocrine systems? Nervous System ‣ The nervous system consists of all nerve cells and is the body’s speedy, electrochemical communication system ‣ Central Nervous System • Brain and spinal cord ‣ Peripheral Nervous System • Sensory and motor neurons that connect the central nervous system to the rest of the body Central Nervous System ‣ Interconnected neurons form networks in the brain and spinal cord • Networks are complex and modify with growth and experience Central Nervous System • Sensory (afferent) neurons send information from the body’s tissues and sensory organs inward to the CNS • Interneurons communicate within the CNS and intervene between the sensory inputs and the motor outputs • Motor (efferent) neurons carry outgoing information from the CNS to the body’s tissues and organs Peripheral Nervous System ‣ Somatic Nervous System • Controls the body’s voluntary movement ‣ Autonomic Nervous System • Controls the glands and involuntary muscles - Sympathetic Nervous System: Arouses the body, mobilizing its energy in stressful situations - Parasympathetic Nervous System: calms the body, conserving its energy Endocrine System ‣ The body’s “slow” chemical communication system ‣ Hormones (chemicals produced by endocrine glands) are secreted into the bloodstream • Example - epinephrine (adrenaline) increases heart rate, blood pressure, blood sugar and feelings of excitement during emergency situations Endocrine System ‣ Hypothalamus - maintains body’s homeostasis ‣ Pituitary Gland - master gland • Monitors hormones in the blood and corrects imbalances • Secretes growth hormone ‣ Pineal Gland - regulates activity levels with melatonin ‣ Thyroid (Para) Gland - regulates metabolic and calcium rate ‣ Adrenal Glands - secretes epinephrine and norepinephrine and regulates salt and carbohydrate metabolism ‣ Pancreas - secretes insulin and glucagon to balance sugar ‣ Gonads - involved in sex determination, sex development, secondary sexual characteristics, and sexual motivation • Ovaries: female reproductive glands; secrete estrogen • Testes: male reproductive glands; secrete androgen (testosterone) • Both genders produce both hormones Immune System ‣ Monitors the body internally for the presence of foreign and harmful material and attempts to eliminate it • Autoimmune disorders: immune system attacks normal cells Essential Question 3 What are the functions or each of the components of the brain stem and limbic system? History of the Mind ‣ Plato correctly placed the mind in the brain ‣ Phrenology - Franz Gall suggested that bumps of the skull represented mental abilities ‣ Today we believe mind and brain coincide Research Strategies ‣ Story of Phineas Gage ‣ A brain lesion can experimentally destroy brain tissue to study resulting behaviors • Frontal labotomies use to be used to calm patients ‣ Clinical observations record behaviors of disorders Research Technologies ‣ EEG - recording of electrical waves sweeping across the brain ‣CAT scan - similar to an X-ray but uses cross-sections of the brain ‣ MRI - computer generated images that distinguish among different types of brain tissue • CAT scans and MRIs show brain structure, not function or activity ‣ PET Scan - visual display of brain activity while the brain performs a given task Brain Regions ‣ Brainstem - responsible for autonomic survival functions • Reticular Formation (RAS) - controls arousal • Medulla - controls heartbeat and breathing • Pons - regulates breathing and sleep (dreams) • Thalamus - directs messages to areas of the cortex • Cerebellum - coordinates voluntary movement and balance Brain Regions ‣ Limbic System - associated with emotions and drives • Amygdala - controls emotion • Hippocampus - consolidates memory • Hypothalamus - directs maintenance activities - Eating, drinking, body temperature, and control of emotions - Helps govern the endocrine system via the pituitary gland Essential Question 4 What are the regions and functions of the cerebral cortex? Brain Lobes ‣ Cerebral Cortex (cerebrum) - intricate fabric of interconnected neural cells that functions as the brain’s information processing center divided into lobes • Frontal - logic, reasoning, personality, creativity, LTM, speech • Parietal - integrates senses, language - More intelligent animals have increased “uncommitted” or association areas • Occipital - visual info • Temporal - auditory info Cortical Areas ‣ Motor Cortex - controls voluntary movements ‣ Sensory Cortex - receives information from sense organs ‣ Homunculus Cortical Areas ‣ Aphasia - Language disorder caused by left hemisphere damage • Broca’s area - impaired speaking • Wernicke’s area - impaired understanding Neuroplasticity ‣ The brain’s ability to modify itself after injury or illness • Due to changes in behavior or the environment ‣ The brain changes throughout life; Not static Essential Question 5 How does split-brain research help us understand the functions of the two brain hemispheres? Hemispheric Specialization ‣ Corpus callosum - bundle of neural fibers connecting the left and right cerebral hemispheres facilitating communication ‣ With the corpus callosum severed, objects in the right visual field can be named while objects in the left visual field cannot ‣ Split brain patients might suffer from severe epilepsy Hemispheric Specialization ‣ Our brain is divided into two hemispheres • Left - processes reading, writing, speaking, mathematics, and comprehension skills - Dominant brain • Right - processes perceptual and spatial tasks Essential Question 6 What is the interaction between heredity and environment? Read pages 95-106 in the text Essential Question 7 How do evolutionary psychologists use natural selection to explain individual differences? Read pages 107-113 in the text