nervous system exam questions

Question 1

explain why neurons can only transmit information in one direction at a synapse (3 MARKS)

Answer 1

the synaptic vesicles containing the neurotransmitters are only present on the presynaptic membrane, which then diffuse across the synaptic cleft, down concentration gradient and carry the signal across the synaptic gap, which are detected by receptors on the postsynaptic neuron

Question 2

briefly outline how excitation and inhibition are involved in synaptic transmission (4 MARKS)

Answer 2

Neurotransmitters can be excitatory or inhibitory. if the neurotransmitter is excitatory, then the post synaptic neuron is more likely to a fire an impulse. whereas, if the neurotransmitter is inhibitory, then the post synaptic neuron is less likely to fire an impulse. the excitatory and inhibitory influences are summed, if the net effect on the post synaptic neuron is inhibitory, the neuron will be less likely to fire etc

Question 3

outline the role of the central nervous system and autonomic nervous system (2 MARKS)

Answer 3

the autonomic system is a involuntary system and governs vital functions such as maintaining heart rates and breathing rates. the central nervous system is the control center for mental and physical activities of the body. it controls the body response to signals from the rest of the body and is made up of the brain and spinal cord

Question 4

explain how sensory, relay and motor neurons would function when digging and hitting a rock with a spade (6 MARKS)

Answer 4

the sensory neurons send information from the sense to the brain. the receptors on Jeremy hand would sense the jolt of the spade hitting the rock and send that information via the PNS to his CNS. relay neurons connect with other neurons and mostly found in the brain. they would be involved in analysis of the sensation, what it means, deciding about how to respond to it, this acting between the sensory and motor neurons. motor neurons send messages from the brain to the muscles or effectors. a message from the brain instructs Jeremy arm muscles to stop working and stop digging

Question 5

statements about the divisions of the nervous system (2 MARKS)

Answer 5

the CNS consists of the brain and spinal cord/the somatic nervous system controls voluntary movements