Transcript T/F
Communication • Arousal States • Neurons • Neurotransmitters • Experience and Plasticity True or False? T/F The human brain is larger than that of any other animal. T/F A single cell can stretch all the way from your spine to your toe. T/F Messages travel in the brain by means of electricity. T/F A brain cell can send out hundreds of messages each second, and manage to catch some rest in between. T/F Fear can give you indigestion. T/F If a surgeon were to stimulate a certain part of your brain electrically, you might swear that someone hade stroked your leg. Nervous System Our nervous system consists of two main bodies: • Central Nervous System • Peripheral Nervous System “The more flexible we can form associations the more humanlike we are. This is what makes us special.” (Remark considering left frontal lobe specialization) Nervous System Central Nervous System: (CNS) • Brain • Spinal cord: Collection of neurons and supportive tissue running from the base of the brain down the center of the back, protected by a column of bones. – Spinal reflexes are automatic Peripheral Nervous System: (PNS) • All portions of the nervous system outside the brain and spinal cord. • Sensory Nerves (Afferent Impulses) • Motor Nerves (Efferent Impulses) • Contains: – Somatic Nervous System – Autonomic Nervous System Somatic and Autonomic Nervous Systems Somatic Nervous System: (connects) Sensory receptors Skeletal muscles • AKA: Skeletal Nervous System Autonomic Nervous System: Regulates the internal organs and glands. • Contains: – Sympathetic Nervous System – Parasympathetic Nervous Systems Arousal States Sympathetic Nervous System (SNS): Physical Changes Increase in norepinephrin Pupil dilation Increased heart-rate Sweating Decrease in digestion Vein dilation in periphery Pilo erection Elements All elements necessary for survival Fight-or-Flight instinct Activated during anxiety and stress Parasympathetic Nervous System (PNS): Physical Changes Increased digestion Opposite of SNS Elements Conserves energy Tired/Relaxed Nervous System Nervous System Spinal Cord Reflex Not regulated by the brain. Neurons Neurons: • Specialized nerve cell that receives, processes, and transmits information to other cells in the body. Neurons Three Types of Neurons: • Sensory (afferent) neurons: Carry messages from sense organs to the spinal cord or brain. • Interneurons (association neurons): Carry messages from one neuron to another. • Motor (efferent) neurons: Carry messages from the spinal cord or brain to the muscles and glands. Neurons Structure: • Soma: cell body, processing center – Nucleus: contains DNA • Neurites: structures that extend from the soma – Dendrites: receives information and sends to soma – Axon: transports messages from the soma • Dentrite Divisions: – Spine: receives NT message • Also known as a receptor site • Axon Divisions: – Hillock: initiates action potential – Myelin Sheath: fatty covering on axon – Node of Ranvier: unmyelinated space – Axon Terminal: sends message to terminal buttons – Terminal Button: site where vesicles are released • Terminal Button Divisions: – Synaptic Vesicles: carries NT to synapse – Neurotransmitter: chemical messenger – Synapse: Space between buttons and spines • Also known as synaptic gap or synaptic cleft. Neurons Neurons • In what ways are neurons like other cells? • Which features are unique to neurons? Neurons Presynaptic Neruon: Sends the message. Postsynaptic Neuron: Receives the message. Neurons Neurons Glia Cells: (Support Cells) • CNS – Astrocytes • Phagocytosis • Blood Brain Barrier – Oligodendrocytes • Myelination • Increase speed and insulate – Ependymal • Line walls of the ventricles • Create cerebrospinal fluid – Endothelial • Help with BBB – Radial • Aide in neuronal migration • PNS • Schwann Neurotransmitters Chemical messengers in the brain. Catecholamines: Norepinephrine, Epinephrine, Dopamine Indoleamines: Serotonin Neurotransmitters Neurotransmitters Locations of production sites for major NT’s: • Dopamine- Substantia Nigra • Norepinephrine- Locus Coeruleus • Serotonin- Raphe Nuclei Experience and Plasticity Endorphins and Hormones Endorphins: Pain reduction, pleasure, contentedness, memory. Endogenous opiate peptides. Hormones: Affects the functioning of organs. Released directly into the blood stream. Promote growth, increase digestion, and regulate metabolism. Secreted by organs called glands. Produced primarily in endocrine glands. Melatonin: Secreted by the pineal gland, helps regulate daily biological rhythms and promotes sleep (seasonal depression). Adrenal Hormones: Produced by adrenal glands, emotion and stress. Sex Hormones: Secreted in gonads (testes and ovaries), produce androgens (testosterone) and estrogens (progesterone). Genetics • Traits: Characteristics on which organisms differ. • Heredity: Transmission of traits from one generation to the next. • Genes: Elements that control the transmission of traits; they are found on the chromosomes. • Chromosomes: Pairs of threadlike bodies within the cell nucleus that contain the genes. • Deoxyribonucleic acid (DNA): The main ingredient of chromosomes and genes that forms the code for all genetic information. Genetics • Dominant: Member of a gene pair that controls the appearance of a certain trait. • Recessive: Member of a gene pair that can control the appearance of a certain trait only if it is paired with another recessive gene.