PSL 310 Unit 2 Exam with 100% correct answers 2024

What is the presynaptic neuron? correct answers the neuron that conducts the impulse TO the synapse What is the postsynaptic neuron? correct answers the neuron that conducts the impulse AWAY FROM the synapse What is the synaptic cleft? correct answers the space between the presynaptic and postsynaptic neurons What is the synaptic knob? correct answers the swelled-up tip of the axon terminal of the presynaptic neuron What are the synaptic vesicles? correct answers - sacs within the swollen synaptic knob - membrane bound sacs that contain neurotransmitters What is a neurotransmitter? correct answers chemicals within synaptic vesicles; the chemical messengers of neurons What is the subsynaptic membrane? correct answers the postsynaptic membrane underneath the synaptic knob What are chemically gated ion channels? correct answers ion channels that open due to a chemical binding to it (chemical=neurotransmitter) What happens from an action potential in the synaptic knob of the presynaptic neuron to to opening of chemically gated ion channels in the subsynaptic membrane of the postsynaptic neuron? correct answers 1) action potential in the synaptic knob 2) AP causes opening of voltage-gated Ca2+ channels so Ca2+ can diffuse in 3) Ca2+ causes release of a neurotransmitter into the synaptic cleft by exocytosis 4) Neurotransmitter diffuses across the cleft to bind to receptors on the subsynaptic membrane 5) Binding of neurotransmitter to receptor causes ion channels to open Why is the chemical synapse almost always 1 way? correct answers because the presynaptic neuron is the one with the transmitter that gets released and the subsynaptic membrane of the postsynaptic neuron is the one with the receptor for the neurotransmitter How is acetylcholine released? How is it broken down/removed? correct answers - released by neurons in the CNS that innervate skeletal muscle (also found in ANS)