Endocrine System Practice Exam Questions and Answers

Endocrine System Practice Exam Questions and Answers Explain the process of synaptic transmission (ST) (4 marks) - ANSWER-- ST is the process by which one neuron communicates with another - Info is passed down axon as an electrical impulse known as action potential - Once action potential reaches end of axon it needs to be transferred to another neuron or tissue - It must cross over synaptic gap between presynaptic and post-synaptic neuron - At the end of neuron (in the axon terminal) there are synaptic vesicles, which contain neurotransmitters - When the electrical impulse (action potential) reaches these synaptic vesicles, they release their contents of neurotransmitters - Neurotransmitters then carry the signal across the synaptic gap - They bind to receptor sites on the post-synaptic cell, thereby completing the process of synaptic transmission Briefly outline how excitation and inhibition are involved in synaptic transmission (4 marks) - ANSWER-- Excitation occurs when receptor stimulation results in an increase in the positive charge of the postsynaptic neuron which increases the likelihood of the neuron firing - Inhibition occurs when receptor stimulation results in an increase in the negative charge of the postsynaptic neuron and decreases the likelihood of the neuron firing - Summation is the addition of positive and negative post-synaptic potentials - A nerve cell can receive both positive and negative potentials simultaneously - These potentials are summed and if the net effect on the postsynaptic neuron is inhibitory, the neuron will be less likely to fire - if the net effect is excitatory, the neuron will be more likely to fire Briefly outline one function of the endocrine system (2 marks) - ANSWER-- endocrine hormones help control mood, growth and development, the way our organs work, metabolism , and reproduction - endocrine system regulates how much of each hormone is released - This can depend on levels of hormones already in the blood, or on levels of other substances in the blood, like calcium Outline the structures and processes involved in synaptic transmission (6 marks) - ANSWER-- ST is the process by which one neuron communicates with another - Info is passed down axon as an electrical impulse known as action potential - Once action potential reaches end of axon it needs to be transferred to another neuron or tissue - It must cross over synaptic gap between presynaptic and post-synaptic neuron - At the end of neuron (in the axon terminal) there are synaptic vesicles, which contain neurotransmitters