Neurons, Neurotransmitters and Action Potential

• A pseudo unipolar neuron is essential for conducting action potentials registering touch, temperature, pain pressure toward the central nervous system
• With one exception, all sensory information is accepted by the thalamus, which sorts and sends each of these sensory inputs to the appropriate area of the cerebral cortex to begin decoding the information.
• Astrocytes are glial cells surrounding individual neurons that give these neurons mechanical support and that associate with capillaries to establish the blood-brain barrier
• GABA (gamma aminobutyric acid) is a neurotransmitter released from an axon terminal of one neuron that diffuses across the synaptic cleft and binds ligand gated chloride ion channels imbedded within the membrane of the receiving neuron, GABA is derived from glutamic acid, one of the 20 naturally occurring amino acids

Action Potential

• Voltage gated potassium ion channel; potassium ion moving out of the cell drives the change of membrane potential indicated by the bracket labeled "D"
• The portion labeled "A" is the absolute refractory period
• The portion labeled "B" is the relative refractory period
• Voltage gated sodium ion channel; sodium ion moving into the cell drives the change of membrane potential indicated by the bracket labeled "C"
• The central sulcus separates the parietal lobe from the frontal lobe
• The central sulcus also separates the precentral gyrus from the postcentral gyrus
• Depolarizations from synaptic inputs across a neuron cell body toward the trigger zone can summate
• Acetylcholinesterase is an automatic “off-switch" that is a counterweight to neuromuscular junction activation and therefore prevents over-stimulation of the muscle cell beyond what the neuron intends.
• Damage to the prefrontal cortex could result in changes of personality, intellectual functioning, planning for the future and executive functioning
• For a single twitch, the power stroke is the event occurring during the contraction period of the twitch that is responsible for increasing tension
• Type IIa and Type IIb are fiber types that is (are) relatively high in glycogen
• The midbrain orchestrates the "startle reflex" and automatic visual reflexes.
• Ependymal cells line the ventricles
• Somatic motor neuron cell bodies populate the ventral horn of the spinal cord
• Microglial cells are glial cells that are specialized mobile immune cells that respond to injured areas where they can attack microbial invaders and take part in the removal of cells damaged or killed by trauma
• The cerebral cortex in Wernicke's area decodes/interprets speech in real time so that it can be understood if someone is fluent in the language
• The lateral ventricles, 3rd ventricle, and 4th ventricle are regions that contain cerebral spinal fluid
• Trauma that damages the corpus callosum could potentially compromise the ability of the left cerebral hemisphere to harmoniously communicate with the right hemisphere and vice versa
• Potassium leakage channels are most consequential in contributing the ion flow that is most impactful in establishing the resting membrane potential
• Lactate is an end-product of glycolysis produced by anaerobic glycolysis
• A vigorously working muscle that undergoes a lowering of sarcoplasmic ATP could be in danger of undergoing all of the following:
  • A physiological contracture
  • A block of crossbridge cycling that occurs between the end of the power stroke and ATP induced crossbridge release
  • A fusion of myosin heads to the active sites on thin filaments
• The numbered steps in the proper order they occur as listed from left to right, other than “exposure of myosin head binding sites, are
  • Crossbridge formation
  • Power stroke
  • ATP induced crossbridge release
  • ATP hydrolysis by myosin head
  • Recovery stroke
• The cerebellum is(are) at the center of ones ability to make adjustments of their leg movements without even thinking about it and these adjustments allow you to stop your fall and regain your normal walking posture when walking down the street and your foot hits a crack in the sidewalk causing you to immediately loose balance
• None of the above is the "autopilot" of consciously planned movement of the brain
• Type IIa and Type IIb are fast twitch fibers
• Telencephalon is a synonym for cerebrum
• Creatine kinase is all of the following
  • Transfers a phosphate from one molecule to another molecule
  • Transfers a phosphate from ATP to creatine, producing creatine phosphate and ADP in order to build a creatine phosphate pool when the muscle is at rest
  • Transfers a phosphate from creatine phosphate to ADP to make ATP and creatine starting about 4 seconds after movement.
• Damage to the occipital lobe of the brain from trauma could potentially impact vision
• The correct order of events as they occur as listed from left to right associated with the activation of the neuromuscular junction are:
  • Action potential induced opening of voltage gated calcium channels embedded in the axon terminal
  • Exocytosis of acetylcholine
  • Diffusion of acetylcholine from the axon terminal toward the motor end plate
  • Binding of acetylcholine to acetylcholine gated sodium ion channels
  • Depolarization of the motor end plate
  • Destruction of acetylcholine by acetylcholinesterase
• Action potentials propagating down sarcolemma/t-tubules and down axons of neurons have all of the following qualities:
  • Are self-propagating, self-reinforcing phenomenon
  • Contain a refractory period that imparts directionality, prevents them from splitting in two separate action potentials moving in opposite directions and guarantees an action potential will not "reflect backwards" upon reaching the end of the axon
  • Once initiated, will travel from the point it is initiated to the end of the cell, however long that may be
• The pons bridges between the midbrain and medulla oblongata