WEEK 3- BIOLOGICAL BASIS OF BEHAVIOR.pdf

Biological Basis of Human Behavior Learning Objectives At the end of the discussion, the student is expected to: 1. Describe and explain how nature and nurture work 2. Differentiate how the Nervous System functions from the Endocrine System Neurons Neurons Neuron - a specialized cell of the nervo...

Biological Basis of Human Behavior Learning Objectives At the end of the discussion, the student is expected to: 1. Describe and explain how nature and nurture work 2. Differentiate how the Nervous System functions from the Endocrine System Neurons Neurons Neuron - a specialized cell of the nervous system that receives and transmits messages. Glial Cells - cells that remove dead neurons and waste products from the nervous system, nourish and insulate neurons, form myelin, and play a role in neural transmission of messages Parts of Neurons Dendrites - root-like structures, attached to the cell body of a neuron, that receive impulses, or incoming messages, from other neurons Axon - a long, thin part of a neuron that transmits impulses to other neurons from bulb-shaped structures called axon terminals or terminal buttons Myelin - a fatty substance that encases and insulates axons, facilitating transmission of neural impulses Neurons Afferent and Efferent Neurons Afferent Neurons - neurons that transmit messages from sensory receptors to the spinal cord and brain; also called sensory neurons. Efferent Neurons - neurons that transmit messages from the brain or spinal cord to muscles and glands; also called motor neurons.  Neural Impulse Neural Impulses – the electrochemical discharge of a nerve cell or neuron Polarize - to ready a neuron for firing by creating an internal negative charge in relation to the body fluid outside the cell membrane. Resting Potential - of a cell membrane from about 70 millivolts toward zero Depolarized - to reduce the resting potential of a cell membrane from about 70 millivolts toward zero Action Potential - the electrical impulse that provides the basis for the conduction of a neural impulse along an axon of a neuron  Synapse Synapse - a junction between the axon terminals of one neuron and the dendrites or cell body of another neuron. All-or-none principle - the fact that a neuron fires an impulse of the same strength whenever its action potential is triggered. Refractory period - a phase following firing during which a neuron is less sensitive to messages from other neurons and will not fire. Neurotransmitters Neurotransmitters - chemical substances involved in the transmission of neural impulses from one neuron to another Receptor site - a location on a dendrite of a receiving neuron tailored to receive a neurotransmitter Neurotransmitters Acetylcholine (ACh) - a neurotransmitter that is involve in muscle movement, memory, cognition, and other functions Dopamine - a neurotransmitter that affects the ability to perceive pleasure, voluntary movement, and learning and memory; it is involved in Parkinson’s disease and appears to play a role in schizophrenia. Norepinephrine - a neurotransmitter whose action is similar to that of the hormone epinephrine and that may play a role in depression Neurotransmitters Serotonin - a neurotransmitter involved in emotional arousal and sleep; deficiencies of serotonin have been linked to eating disorders, alcoholism, depression, aggression, and insomnia Gamma-aminobutyric acid (GABA) - an inhibitory neurotransmitter that apparently helps calm anxiety Endorphins – inhibitory neurotransmitters that occur naturally in the brain and in the bloodstream and are similar to the narcotic morphine in their functions and effects. Nervous System Divisions of Nervous System Peripheral Nervous System Peripheral Nervous System - the part of the nervous system consisting of: a. somatic nervous system b. autonomic nervous system. Somatic Nervous System The somatic nervous system contains: a. Sensory (afferent) b. motor (efferent) neurons. It transmits messages about sights, sounds, smells, temperature, body positions, and so on, to the central nervous system. Autonomic Nervous System This also has afferent and efferent neurons and regulates the glands and the muscles of internal organs. the division of the peripheral nervous system that regulates glands and activities such as heartbeat, respiration, digestion, and dilation of the pupils. Autonomic Nervous System Sympathetic Division - the branch of the ANS that is most active during emotional responses, such as fear and anxiety, that spend the body’s reserves of energy Parasympathetic Division - the branch of the ANS that is most active during processes (such as digestion) that restore the body’s reserves of energy Central Nervous System Spinal Cord - a column of nerves within the spine that transmits messages from sensory receptors to the brain and from the brain to muscles and glands throughout the body. Spinal Reflex - a simple, unlearned response to a stimulus that may involve only two neurons. Gray Matter - the grayish neurons and neural segments that are involved in spinal reflexes. White Matter - axon bundles that carry messages to and from the brain. Brain Cerebral Cortex cerebrum - the large mass of the forebrain, which consists of two hemispheres Cerebral cortex - the wrinkled surface area (gray matter) of the Cerebrum corpus callosum - a thick fiber bundle that connects the hemispheres of the cortex somatosensory cortex - the section of cortex in which sensory stimulation is projected. It lies just behind the central fissure in the parietal lobe motor cortex - the section of cortex that lies in the frontal lobe, just across the central fissure from the sensory cortex; neural impulses in the motor cortex are linked to muscular responses throughout the body Endocrine System Endocrine System Endocrine System - the body’s system of ductless glands that secrete hormones and release them directly into the bloodstream Hormones - a substance secreted by an endocrine gland that regulates various body functions Pituitary Gland - the gland that secretes growth hormone, prolactin, antidiuretic hormone, and other hormones Pituitary Gland Pituitary Gland - the gland that secretes growth hormone, prolactin, antidiuretic hormone, and other hormones. The master gland. Pineal Gland The pineal gland secretes the hormone melatonin, which helps regulate the sleep-wake cycle and may affect the onset of puberty. Thyroid Gland It produces thyroxin, which affects the body’s metabolism— the rate at which the body uses oxygen and produces energy. Some people are overweight because of hypothyroidism, a condition that results from too little thyroxin. Hyperthyroidism - which is characterized by excitability, insomnia, and weight loss. Adrenal Glands Your adrenal glands are endocrine glands located on top of your kidneys. They produce many important hormones, including cortisol, aldosterone and adrenaline. The adrenal hormones help regulate several bodily functions including metabolism, blood pressure and your body's response to stress. Testis and Ovaries Estrogen - fosters female reproductive capacity and secondary sex characteristics such as accumulation of fatty tissue in the breasts and hips. Progesterone - stimulates growth of the female reproductive organs and prepares the uterus to maintain pregnancy. Testosterone - plays a key role in the development of male reproductive tissues such as testicles and prostate, as well as promoting secondary sexual characteristics Heredity, Genetics and Bahavioural Genetics Evolutionary Psychology the branch of psychology that studies the ways in which adaptation and natural selection are connected with mental processes and behavior. Genetics and Heredity Genetics - the area of biology that focuses on heredity Heredity - the transmission of traits from parent to offspring by means of genes Gene, Chromosome and DNA Gene - a basic unit of heredity, which is found at a specific point on a chromosome Chromosome - a microscopic rod-shaped body in the cell nucleus carrying genes that transmit hereditary traits from generation to generation; humans normally have 46 chromosomes DNA acronym for deoxyribonucleic acid - the substance that forms the basic material of chromosomes; it takes the form of a double helix and contains the genetic code Sex Chromosomes - which determine whether we are female or male. Gene, Chromosome and DNA Genotype - that is, your full genetic potential. Phenotype - is the manner in which your genetic code manifests itself because of your experiences and environmental circumstances. Nature vs. Nature Nature - the inborn, innate character of an organism Nurture - the sum of all environmental factors that affect an organism from conception onward.