Chapter 3 Biological Psychology Approximately how many neurons do researchers believe the brain contains How many neuronal connections synapses 85 billion neurons in the brain and 160 trillion neuronal connections Axon Terminal Dendrite Nucleus Soma Myelin Sheath on a Myelin Sheath Dendrite structures neuron that receive electrical messages These messages come in two forms 1 Excitatory 2 Inhibitory the part of the neuron that sends information to another neuron Axon The axon has two parts the main part we just call the axon the tube like part The second part is called the terminal branches of the axon Information has to travel within the neuron down the axon before the information gets shared is a layer of fatty tissue It surrounds the axon fibers of some neurons Myelin acts like insulation around a wire This insulation helps speed up the transmission of information down the axon more efficient transmission of information stores various neurotransmitters that are released at the synapse A voltage dependent calcium channel regulates the release Vesicles are essential for spreading nerve impulses between neurons and are constantly recreated by the cell an area outside of the cell that receives chemical electrical signals When such signals bind to a receptor site they cause a specific response within that cell transfer of electric activity information from one cell to another Synapse Synaptic Vesicle Receptor Site Synaptic Vesicles Receptor Site Axon Terminal Synaptic Cleft This is all considered Synapse Glials Cells supporting cells that are plentiful in the brain roughly 1 1 ratio with neurons glials means glue There are two types 1 Astrocytes they are most abundant Communicates with neurons increases reliability of neuron communication and controls blood flow in the brain 2 Oligodendrocytes promotes new neuronal connections aids in healing and produces myelin sheath for CNS neurons Action Potential n atio olariz p e D R e p o l a r i z a t i o n Threshold Resting Potential A b s o l u t e r a c t o r y R e f i o d P e r Resting State Resting Potential Threshold Action Potential when there is enough of a positive charge inside the neuron when no neurotransmitters are acting upon the neuron the axon membrane is at resting potential Inside cell negative charge outside cell positive charge electrical charge is created that opens ion channels further down the axon This is the neuron firing an all or none response Neurons can fire 100 1000 times per second absolute refractory period a time when action potentials are impossible In between neuron firings there is a very brief Absolute Refractory Period GABA Glutamate Neurotransmitters the brain chemicals that allow for transmission of signals from the main inhibitory neurotransmitter that increases the chance neurons the main excitatory neurotransmitter that decreases the chance neurons will one neuron to the next across synapses will communicate Participates in relay of sensory information and learning CNS communicate CNS sleep motor function and reward mood and temperature regulation aggression and sleep cycles enhance immune system and reduce pain and stress natural high muscle contraction PNS and cortical arousal CNS brain arousal and other functions including mood hunger and pain reduction and increase in appetite Dopamine Serotonin Anandamide Endorphin Acetylcholine Norepinephrine Plasticity development learning following an injury degeneration the nervous system s ability to change Changes occur during What four ways does the network of neurons in the brain change over the course of development 1 Growth of Dendrites and Axons 2 Synaptogenesis 3 Pruning 4 Myelination formation of new synapses underused neurons and synapses are eliminated Central Nervous System CNS Peripheral Nervous System PNS consists of nerves inside the brain and spinal cord consists of all nerves in the body outside the brain and spinal cord 2 divisions 1 Somatic Nervous System conveys information between the CNS and the body controlling and coordinating voluntary movement Interacts with external environment by sending signals from sense organs ears eyes tongue etc and skin CNS skeletal muscles directing voluntary movement 2 Autonomic Nervous System controls the involuntary actions of our organs and glands Regulation of the internal environment Connects CNS to smooth involuntary muscles and organs heart stomach liver etc and to the body s hormone producing glands 2 divisions 1 Sympathetic Nervous System Fight or Flight Pupils dilate salivary glands inhibit saliva production heart increases heart rate lungs dilate and stomach slows digestion 2 Parasympathetic Nervous System Rest and Digest Pupils constrict salivary glands stimulates saliva production heart slows heart rate and decreases breathing rate lungs constrict small and large intestines increase digestion and bladder muscles relax Cerebral Cortex occipital lobe parietal lobe and frontal lobe the largest part of the brain composed of the temporal lobe Parietal Lobe Occipital Lobe Limbic Lobe Amygdala Hippocampus Frontal Lobe Temporal Lobe Cerebellum Brain Stem Spinal Cord Thalamus Hypothalamus Midbrain Medulla Pons problem solving selective attention organizing planning problem sensation perception and integrating sensory input mainly visual Frontal Lobe Parietal Lobe solving behavior emotions and personality system Temporal Lobe Occipital Lobe Cerebellum Limbic Lobe Thalamus high level auditory processing visual processing center controlling motor functions and muscle coordination motivation emotion learning and memory consciousness sleep and sensory interpretation links the nervous system to the endocrine system via the pituitary center for emotions emotional behavior and motivation spatial navigation and memory long term memory regulation of heart rate breathing eating and sleeping vision hearing motor control sleep wake arousal alertness and Hypothalamus Amygdala Hippocampus Brain Stem Midbrain gland temperature regulation swallowing Spinal Cord information to various places within the body Pons Medulla bridge between various parts of the nervous system regulate breathing heart and blood vesselfunction digestion sneezing and conducts sensory information from PNS to brain and relays motor Brain Mapping connections between neurons activity to determine possible problems includes MRI fMRI EEG PET etc Allows researchers to study Chapter 4 Sensation and Perception Sensation Perception the interpretation
View Full Document
Unlocking...