Ch 12 Exam 5 HW Questions And Verified Answers

In in the initial segment, an action potential is generated if the membrane potential reaches the - threshold value Neurons integrate multiple synaptic inputs by the process of - propagation if several EPSPs occur at a synapse over a short period of time, they undergo ______ at the initial segment - temporal summation The all or none law refers to the fact that action potentials will only occur if the initial segment reaches - threshold The conductive segment of a neuron is the - total length of the axon A positive change in the membrane potential is called - depolarization ____ is the return of polarity from positive back to negative (RMP) - repolarization during ______ ______ an axon is either incapable of generating an action potential or requires a larger than normal stimulus - refractory period A change in membrane potential insufficient to cause an action potential is known as a - subthreshold value The process by which postsynaptic potentials are added together at the initial segment is known as - summation The main activity of the ___ is propagation of an action potential along the axolemma - conductive segment The functions of astrocytes are to - help form the BBB assist neuronal development regulate the composition of interstitial fluid Which segments of a neuron contain large numbers of voltage-gated potassium channels and voltage-gated sodium channels? - the initial segment the conductive segment During an actin potential, voltage gated potassium channels open after voltage-gated sodium channels. The effect this has on the membrane potential is - it becomes less positive and more negative Neuron cell bodies in the PNS are found clustered in - ganglia Nervous tissue is composed of - glial cells and neurons ____ are large cells that ensheath many different axons - oligodendrocytes The myelin sheath is made of a high percentage of - lipids The electrical gradient in a resting neuron is such that the ___ of the cell is negative relative to the ____ - inside of the cell is negative relative to the outside Which terms are used for the structural classification of nerves? - cranial and spinal The components of the somatic sensory division are stretch or organ walls taste joints and muscles hearing - taste joints and muscles hearing ____ are considered "nerve glue" - neuroglial cells A fascicle is surrounded by a layer of dense irregular CT called - perineurium The plasma membrane of an axon is called - axolemma Which ions have leak channels on a neuron plasma membrane? - Na+ K+ _____ are unique channels in that they have three states; resting, activation and inactivation - voltage gated channels If you were moving across a neuron's membrane from the receptive segment toward the transmissive segment, in the ___ is where you would first encounter large numbers of voltage gated Na+ and K+ channels - initial segment What are the two divisions of the sensory nervous system? - visceral division and somatic division _____ occurs when the inside of a cell becomes more negative that the RMP - hyperpolarization The net diffusion of a given ion is dependent upon its - electrochemical gradient Sensory nerves carry information where - to the CNS Neurons are classified ___ depending on the direction the nerve impulse travels - functionally Neurolemmocytes create the myelin sheath in the ____ NS - PNS Voltage is a measure of relative - potential energy