Test 8
 
36. With respect to the cells of the retina:
a. the horizontal cells form the anatomical basis of lateral inhibition 

b. the amacrine cells are an homogenous population of cells 

c.  the amacrine cells contribute to centre-surround characteristics of 
     ganglion cells 

d.  interplexiform cells are both pre- and post-synaptic to amacrine 
     processes and can synapse on amacrine cell bodies 

e.  the interplexiform cells are associated with the phasic reponse of 
     ganglion cells 

f.  Muller cells act as a store for calcium 
 


 
 
37. The autonomic nervous system:
a. can be divided into somatic and automatic 

b. has control centres in the thalamus and brainstem 

c. has myelinated preganglionic fibres and unmyelinated 
    postganglionic fibres 

d. has cell bodies of preganglionic neurones in the medial grey horns 
    of the spinal cord 

e.  is similar to the somatic nervous system, in that they are both 
    based on reflex arcs 

f. can be divided into sympathetic and unsympathetic parts 
 


 


38. The neurotransmitters involved in the autonomic nervous system:

a. are all inactivated by reuptake into the preganglionic neurone 

b. include acetylcholine acting on nicotinic receptors at the 
    postsynaptic junction in both the sympathetic and parasympathetic 
    systems 

c. include acetylcholine acting on nicotinic receptors at the
    presynaptic junction in both the parasympathetic and sypathetic 
    systems 

d. include acetylcholine acting on muscarinic receptors at the 
    postsynaptic junction in the sympathetic and parasympathetic 
    systems 

e. include acetylcholine acting on muscarinic receptors at the 
    postsynaptic junction in the parasympathetic system 

f. include serotonin released into the presynaptic junction in the 
   sympathetic system 
 


 
 

39. The medulla:
a. is part of the hindbrain 

b. is the most rostral part of the brainstem 

c. lies on the floor of the cranial cavity 

d. is attached to the cerebellum via the middle cerebellar peduncles 

e. contains the exit of cranial nerves III, IV & VI 
 


 
 

40. With respect to the internal tracts of the medulla:
a. the corticospinal tract is associated with control of crude, 
    unskilled movements 

b. the corticospinal tract lies anterolaterally to form the olives 

c. 75-90% of corticospinal tract fibres decussate in the caudal 
    medulla 

d. 10-25% of corticospinal fibres descend ipsilaterally and do not 
     cross 

e. the rubrospinal tract is involved in control of limb flexor tone 
 


 

 
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