Study Guidelines 1. Describe the characteristics of the thalamic nuclei within the relay, association, and ‘non-specific’ nuclei groups. 2. List the afferent and efferent projections for the following relay nuclei: anterior, ventral lateral, ventral posterior, medial, and lateral geniculate bodies. 3. List the afferent and efferent projections for the dorsomedial nucleus. 4. Describe how the thalamic reticular nucleus differs from the other thalamic nuclei. 5. Discuss…

Study Guidelines 1. Outline the subdivisions and functions of the reticular formation. 2. Describe the location, type, and role of aminergic brainstem neurons of the neuromodulatory system. 3. Define a chemoreceptor and its role in respiratory control. 4. Summarise how the central nervous system monitors and controls respiration. 5. Define a baroreceptor and its role in cardiovascular control. 6. Summarise how the central nervous system monitors…

Study Guidelines General Because of the immense diagnostic and therapeutic importance of ocular muscle innervation, and because of its inherent complexity, neuro-ophthalmology has become its own branch of medicine. It is especially important to describe the way in which premotor centres can operate bilaterally to keep the gaze on target, even when the head is moving. Specific 1. Describe the function of cranial nerves (CN) III,…

Study Guidelines 1. Cranial nerve CN VII is the most commonly paralysed of all peripheral nerves, owing to the great length of its canal in the temporal bone, where it is at risk of compression when inflamed. Since CN VII supplies the muscles of facial expression, the effects of peripheral facial nerve paralysis are obvious to all. 2. Learn the distinctions between upper and lower motor…

Study Guidelines 1. The motor nucleus supplies the muscles of mastication. 2. The mesencephalic unipolar neurons are proprioceptive. 3. The neurons of the principal sensory nucleus receive sensory inputs from the face and underlying mucous membranes. 4. The spinal nucleus is of special clinical importance because of its large nociceptive territory. Trigeminal Nerve The trigeminal nerve has a very large sensory territory that includes the skin…

Study Guidelines 1. Describe the mechanism of how vibrations created by sound waves result in activation of the organ of Corti. 2. Be able to identify the scala vestibuli, scala tympani, and scala media and components of the spiral organ. 3. Reproduce the central auditory pathway from the spiral ganglion to the primary auditory cortex. 4. Describe the role of the olivocochlear bundle. Auditory System The…

Study Guidelines 1. Describe the components of the static labyrinth and its primary role. 2. Describe the components of the dynamic labyrinth and its primary role. 3. Describe the procedure for performing a warm water caloric test . Introduction The vestibulocochlear nerve is primarily composed of the centrally directed axons of bipolar neurons housed in the petrous portion of the temporal bone ( Fig. 19.1 ).…

Study Guidelines Comments on the last four cranial nerves in ascending order: 1. The hypoglossal nerve is the motor to the tongue. The spinal accessory nerve is the motor to the sternocleidomastoid and trapezius muscles. 2. The cranial accessory nerve supplies the intrinsic muscles of the larynx and pharynx and all palatine muscles, except the tensor veli palatini (supplied by the mandibular branch of the trigeminal…

Study Guidelines 1. This chapter largely deals with the identification of structures in transverse sections of the brainstem. A separate study guide is provided for the sections. 2. Four brainstem decussations should recall those described in Box 3.1 . 3. Note that in magnetic resonance images, brainstem orientation is the reverse of the anatomic convention. General Arrangement of Cranial Nerve Nuclei In the thoracic region of…

Study Guidelines 1. Reproduce the tracts descending the spinal cord and recall that each is strategically placed for access to its particular set of motor neurons, in accordance with the layout in Fig. 16.7 . 2. Identify target neurons selected by the lateral corticospinal tract. 3. Describe how the reticulospinal tracts are concerned with automatic movements and with postural fixation. 4. Summarise the Clinical Panels dealing…

Study Guidelines 1. Recognise that the mature spinal cord is not segmented internally. 2. Recall that the ventral horn cells take the form of columns rather than laminae. 3. Recognise that ‘unconscious sensation’ remove simply means that the ascending afferent impulse activity concerned does not generate any kind of perception. 4. Recognise that ‘conscious proprioception’ is more sensitive than either vision or the vestibular labyrinth in…

Study Guidelines 1. Describe the fate of immature neurons during embryonic development within the developing spinal cord (some send out ventral roots, others project along the marginal zone to form fibre tracts) and of the neural crest. 2. Outline the anatomy of a typical spinal nerve. 3. Explain the clinical implications of the mature vertebral canal relationship between the spinal column and respective spinal cord level;…

Study Guidelines 1. Resolve the paradox that, despite an outflow restricted to 14 or 15 ventral roots, all 31 spinal nerve trunks acquire sympathetic fibres. 2. Appreciate that the sympathetic ganglia along the abdominal aorta are activated by preganglionic fibres, as is the adrenal medulla. 3. Pay special attention to the autonomic innervation of the eye, discussed both here and in Chapter 23 . 4. Appreciate…

Study Guidelines 1. Review the electrical events of action potentials, described in Chapter 7 , as it applies to the basic principles described here. 2. Describe the performance of a motor or sensory nerve conduction study (NCS) and predict the results if there is an axonal injury or a dysfunction of myelin. 3. Define the relationship between a motor neuron and its corresponding motor unit action…

Study Guidelines 1. Define sensory unit, sensory overlap, receptive field, and receptor adaptation. 2. State locations and properties of the three kinds of encapsulated receptor. 3. Sketch a hair follicle with its nerve palisade and rings. 4. Name two kinds of mechanoreceptors used to discriminate textures—for example, to read Braille. 5. Consider a quick preview of the Clinical Panel on peripheral neuropathies in Chapter 12 .…

Study Guidelines 1. Be able to outline the differences in motor units with respect to movements of all kinds and with respect to the functional significance of their sizes and muscle chemistries. 2. Sketch a motor end plate, indicating the locations of transmitter, receptor, and hydrolytic enzyme. 3. Sketch an intrafusal muscle fibre, indicating the locations of two motor and three sensory nerve endings. 4. Describe…

Study Objectives 1. In a cross section of a peripheral nerve, be able to identify the different connective tissue sheaths. 2. Describe the anatomic classification of nerve fibres and its relationship to their function. 3. Describe the mechanism of myelination and be able to define internode, paranode, and the node of Ranvier. 4. Describe saltatory conduction and its relationship to myelination. 5. Describe the microscopic changes…

Study Guidelines 1. Contrast electrical and chemical synapses and describe the differences between ionotropic receptors and metabotropic receptors. 2. List the three major second messenger systems in the CNS and the functions of a second messenger. 3. List the criteria that must be fulfilled before a substance can be considered a neurotransmitter. 4. List the major types of neurotransmitters and provide an example of each. 5.…

Study Guidelines 1. List the different types of ion channels and provide a description of how they function. 2. Describe the resting potential with respect to the major ions involved in its formation. 3. Be able to distinguish and describe the following terms: electrotonic potential, spatial summation, temporal summation, threshold, and trigger point. 4. Discuss the ion channel changes that accompany the development of an action…

Study Guidelines 1. Give an account of neuronal structure. 2. Give an account of synaptic structure and function and outline the lock and key analogy used in pharmacology. 3. Explain how a demyelinating disorder can compromise conduction. 4. Draw up a structure–function list for neuroglial cells. 5. Gliomas interfere with brain function in the region they grow. Explain how they may exert effects at a ‘distance’.…