Question

28. Compared to ionotropic effects, metabotropic effects __________:

a. have more rapid onsets and persist for shorter periods of time.

b. have less rapid onsets and persist for shorter periods of time.

c. have more rapid onsets and persist for longer periods of time.

d. have less rapid onsets and persist for longer periods of time.

e. both a and c.

29. If the brain of a mammalian subject is bisected into its right and left hemispheres, revealing ​a lateral view of the internal structures of the brain, the section would be termed ​__________:

​a. a frontal section.

b. a dorsal section.

c. a mid-sagittal section.

d. a dorsal-lateral sagittal section.

30. In terms of anatomical directions, anything directed upwards toward the spinal column of a ​quadrupedal animal standing on all fours is oriented in the __________:

a. ventral direction.

b. lateral direction.

c. frontal direction.

d. dorsal direction.

31. All of the following are examples of important peptide neurotransmitters except ​__________:

a. neuropeptide Y.

b. substance P.

c. Gamma-Amino-Butyric-Acid.

d. endorphin.

32. Prior to the work of Santiago Ramon y Cajal, many scientists believed that __________:

a. nerves conducted impulses at the speed of light.

b. transmission across a synapse was just as fast as transmission along an axon.

c. the tip of an axon physically merged with the surface of adjacent neurons.

d. the behavior of nonhuman animals was entirely reflexive.

e. that the relationship between neurons was magnetically mediated.

Answer 1

Answer 28: “d” have less rapid onsets and persists for longer periods of time

Explanation: Ionotropic and metabotropic receptors both are activated by neurotransmitters. When ionotropic receptor is bound by a neurotransmitter it opens a channel for different ions.when metabotropic receptor is bound by a nerurotransmitter, there are series of events occurring and second messengers are generated. The metabotropic receptors can take longer time to open the channels and hence do not work in quick responses. The metabotropic receptors can open the channels from seconds to minutes.Ionotropic receptors can open the channel only for milliseconds, their effect is over a narrow range,only near the receptor.

Answer 29: “c” a mid sagittal section

Explanation: the mid sagittal section will divide the brain into right and left hemispheres revealing cerebrum, cerebellum and brain stem.

Answer 30: “c” frontal direction

Explanation: For a quadrupedal animal, the side towards the spinal column or the head will be considered as anterior or frontal side, the side opposite to that towards the tail will be considered as posterior side. The side of the abdomen will be the ventral side and the side opposite to that will be dorsal side.

Answer 31:”c” Gamma-amino-butyric acid

Explanation GABA is an amino acid, normally the neuropeptides are large molecules consisting of 3-36 amino acids. Molecules such as GABA glutamate,acetylcholine are much smaller than the peptides hence they are called as small molecule neurotransmitters.

Answer 32: “c” The tip of an axon physically merged with the surface of adjacent neurons.

Explanation: This is the reticular theory given by Gerlarch and propagated by Golgi. The theory states that nervous system forms a single network connected with each other.

This theory was disproved by Cajal (father of modern neuroscience) He proved that nervous tissues are made up of discrete cells the neurons.There is a gap between the neurons. This is also known as neuron doctrine.