PSY 211 1st Edition Lecture 5Outline of Current Lecture I. Introduction to the BrainII. Neurons and Neural CommunicationIII. Major Structures of the Human BrainCurrent LectureThe human brain weighs about 3 pounds, and is a pinkish grey color. It is a convoluted surfaces which is made of gyrus, sulcus, and fissure. There are two hemispheres, 100 billion neurons, 1 trillion glial cells. Cerebral cortex is 80% percent of the volume of the brain; so most of the weight. 30 billion neurons are in the cortex alone, with 10,000 connections for each cortical neurons. The cortex is high functioning and complex, with more than 100 trillion connection.Facts and Myths: - It is not true that we only use 10% of our brain because all parts of the brain are used fordifferent functioning- The left hemisphere is logical and verbal while the right is creative and spatial is generally true. However, both sides of the brain have partial control of all these things.- ADHD reflects under-arousal of the brain and can be treated with stimulants. - People with bigger brains are not necessarily more intelligent. - People are not born with all the brain cells they’ll ever have. It’s known now that neurons grow throughout your life. o Neurogenesis- occurs in hippocampus, neurons grow from stem cells.The NeuronThe base of the cell is called the soma, it contains the nucleus and DNA. Dendrites receive information from other neurons.Axon hillockis that last site in the soma where membrane potentials propagated from synaptic inputs are summated before being transmitted to the axon.Axon carry action potential from the soma towards axon terminals.Terminal buttons send signals to neurotransmitters. Neurons come in a variety shapes and sizes, depending on their function. The synapse is the physical gap between neurons. Presynaptic neurons contain the terminal button, synaptic vesical, synaptic cleft.Post synaptic neuronrefers to the region that receives and responds to neurotransmitters. Postsynaptic membrane is the specialized membrane on the surface of the nerve cell that receives information by responding to neurotransmitters from the presynaptic neurons.Glial cells support the health, operation of neurons, guide growing neurons, and transport nutrients. Also, the repair damaged neurons.Blood brain barrier is very complex so the glial cellsfacilitated neural transmission through myelin sheath; which is what they are most known for. Myelin Sheath insulates axons for faster neural transmission. Myelinated neurons have a white fatty substance, and un-myelinated neurons are grey These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.Neural communication Neurons receive signals at dendrites, neurons send signals via axons, signals travel to the end of axon (terminals). This causes release of neurotransmitters; neurotransmitters travel across synapse and bind with the post synaptic membrane. Binding changes electrical prop creating currents.Major Structures of the Human BrainBrain Stem- Inner core of brain; sits on top of the spinal cord. Critical for basic life-support functions.Hindbrain is made up of the pons which control motor control and sensory nuclei, and cranial nerves. Also the medullawhich controls basic autonomic function like breathing, heart rate, sneezing and blood pressure. The reticular formation and the cerebellum are also a part of the hindbrain. The cerebellum controls fine movement and timing.Midbrain- visual and auditory reflexes, rewards and motivation. Forebrain- Diencephalono Hypothalamus- biological motives, the four F’s (fleeing, fighting, feeding, and fornicating), endocrine systemo Thalamus- relay station for all sensory information, and attention, lateral geniculate nucleus- eye and primary visual cortex- Basal gangliao Mediating movement; stores patterns of movemento Cognition- motor learning, sequencing, problem solving- Limbic systemo Amygdala- controls emotiono Hippocampus- learning and memory; stores codes linked with other areas of the braino Cingulate gyrus- mediates between limbic system and the cortex, helps prefrontal cortex with “executive functions” - The Cerebral Cortexo The outer layer of the braino Gyri (ridges) and Sulci (valleys)o Cerebral Hemispheres- longitudinal fissures. o Corpus Collosum- transmits information from the left hemisphere to the right