PSB2000 Final Exam Review Study Questions Cells Of The Nervous System 1 What is an organelle Which organelles store DNA An organelle is any organized structure within a living cell The nucleus stores DNA 2 What are the two main types of cell in the CNS The two main types of cells in the central nervous system are prokaryotic and eukaryotic 3 Be able to label and know the function of the following dendrites soma nucleus axon hillock axon myelin axon terminal synapse Dendrites receive signals Soma the cell body Nucleus contains DNA located within the soma Axon Hillcock connects the cell body to the axon synaptic inputs are summated here decision to fire an action potential is made here Axon conducts electrical impulses away from the soma Myelin insulates the axon to speed up action potentials Axon terminal transmits neurotransmitters from one neuron to another Synape transfer electric information from one cell to another 4 What does myelin do and what cells form it Myelin insulates the axon to speed up action potentials Schwann cells form myelin outside the central nervous system Glial cells form myelin inside the CNS 5 What does the cell membrane do How can things cross it The cell membrane encloses the organelles Some molecules can cross through it through protein channels 6 What are the three types of glia and what are their functions Oligodendrocytes form a myelin sheath around the axon which lets axons propagate more quickly Astrocytes takes up chemicals and releases them back to the axons which helps synchronize the activity of axons Microglia removes waste viruses and fungi 7 What is an action potential The change in electrical potential associated with the passage of an impulse along the membrane of a muscle cell or nerve cell 8 What is the blood brain barrier A filtering mechanism of the capillaries that carry blood to the brain and spinal cord tissue blocking the passage of certain substances Neuroanatomy 1 What are the meninges and what do they do What is the function of cerebrospinal fluid The meninges are tissue that protects the brain and spinal cord Cerebrospinal fluid provides fluid protection and carries nutrients to CNS tissues 2 Where do motor movement signals exit the spinal cord and when do sensory touch signals enter What do the cranial nerves do Motor signals exit the spinal cord through the ventral root and sensory signals enter through the dorsal root Cranial nerves transmit all sensory information that comes through your head 3 What are the locations and general functions of each of the following brain areas thalamus hypothalamus The thalamus is located in the forebrain and its function is vision and sound processing The hypothalamus is located in the forebrain and its function is controlling the bodys glands and instinctual behaviors hunger thirst sex 4 What are two diseases specifically associated with the basal ganglia Parkinson s and Huntington s disease 5 What does the limbic system do What areas are commonly associated with memory and emotion respectively The limbic system is the border between the cortex and the lower brain areas Memory hippocampus Emotion Amygdala 6 What are the gyri and sulci of the cortex What is their function The gyri are folds and the sulci are grooves Their function is to give the brain a larger surface area 7 What are the four main brain lobes What is the basic function of each Frontal movement logic personality Parietal sensation visual auditory processing Temporal memory visual auditory processing Occipital visual processing 8 How many layers are in the cortex Why it the cortex wrinkled Six It is wrinkled to increase surface area 9 What is the corpus callosum and why is it important The corpus callosum is a band of nerve fibers that join the two hemispheres of the brain It is important because it allows the exchange of information between the hemispheres The Cell Membrane and Action Potentials 1 What is the cell membrane What is it permeable to What is it impermeable to The cell membrane surrounds the cell and is impermeable to charged particles and selectively permeable to ions 2 Is a neuron s resting potential positive or negative How can they be hyperpolarized and depolarized A neuron s resting potential is negative A neuron can be hyperpolarized if it becomes more negative A neuron can become depolarized if it becomes less negative 3 What two forces determine which way an ion wants to move Anions and Cations 4 What are the differences between a postsynaptic potential and an action potential Postsynaptic potentials are how a neuron makes a calculation Action potentials are how the neuron transmits that calculation 5 What is an EPSP What is an IPSP What ions and channels are involved in each An EPSP is an excitatory postsynaptic potential It depolarizes the neuron and makes it more likely to fire more quickly An IPSP is an inhibitory postsynaptic potential It hyperpolarizes the neuron and makes it less likely to fire or fire more slowly In EPSP a neurotransmitter opens up a ligand gated Na Sodium ion channel In IPSP a ligand gated Cl Chlorine ion channel is opened 6 What are the two general types of ion channel Ligand gated ion channels and voltage gated ion channels 7 Where is the decision to fire an AP made In the axon hillcock 8 How does myelin assist in AP conduction What is saltatory conduction Myelin can increase the speed of the action potential Saltatory conduction is the propagation of action potentials along myelinated axons from one node of ranier to the other 9 What is a synapse What are the steps of the neurotransmitter cycle Synapses are how neurons communicate They are formed by the junction of an axon terminal and a postsynaptic cell The steps of the neurotransmitter cycle are Vesicle fills with neurotransmitter Vesicle docks with membrane Action potential melds vesicle with the membrane Neurotransmitter is released into synapse Neurotransmitter binds to receptor Receptor affects postsynaptic cell Neurotransmitter brought back up into presynaptic cell Vesicle fills with neurotransmitter 10 What does an excitatory synapse do What ion causes excitation depolarization What about inhibitory synapses An excitatory synapse opens up ligand gated Na channels that depolarizes the cell An inhibitory synapse opens up ligand gated Cl channels that hyperpolarize the cell 11 What is the difference between an action potential and a postsynaptic potential An action potential is the signal that the neuron sends A
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