Murdoch - Neuroanatomy Flashcards
Identify this spinal tract.
- a. medial vestibulospinal
- b. lateral vestibulospinal
- c. rubrospinal
- d. reticulospinal
- e. tectospinal
= c. rubrospinal
Tract shown originates in the red nucleus, decussates in the ventral tegmentum of the midbrain, descends in the lateral funiculus and synapses on cell bodies of lower motor neurons in the ventral horn of spinal cord grey matter
- a. Hemilesion of cervical cord
- b. Right brainstem
- c. Right cerebral hemisphere
- d. Left cerebral hemisphere
- e. Left brainstem
= e. Left brainstem
- LMN damage to left side of head (this confirms it’s a left brainstem lesion - trigeminal and facial nerves are lesioned)
- UMN lesion symptoms are always CONTRALATERAL below lesion (shown on right)
- Loss of all sensation is always CONTRALATERAL below the lesion (shown on right)
- Ataxia is always on side of lesion as spinocerebellar pathways give cerebellum info on ipsilateral body
- a. turn head in response to light & sound
- b. increased tone of flexor muscles
- c. increased tone of extensor muscles
- d. thoracic diaphragm to contract
- e. increased tone of axial muscles
The correct answer is: turn head in response to light & sound
- cell body in the tectum of midbrain
- tract is decussating in the dorsal tegmentum of midbrain
- tract is passing through the dorsal aspect of the pons
- tract is passing through dorso-medial aspect of medulla oblongata
- tract is synapsing on LMN
- a. right cerebellar hemisphere
- b. right cerebral hemisphere
- c. left brainstem
- d. left cerebellar hemisphere
- e. left cerebral hemsiphere
- f. right brainstem
= e. left cerebral hemsiphere
- a. left middle cerebral
- b. left anterior cerebral
- c. left vertebral
- d. right posterior cerebral
- e. right anterior cerebral
- f. right vertebral
- g. left posterior cerebral
- h. right middle cerebral
= e. right anterior cerebral
precentral gyrus adjacent to the longitudinal fissue is highlighted
- a. lateral corticospinal
- b. vestibulospinal
- c. tectospinal
- d. anterior corticospinal
- e. reticulospinal
= a. lateral corticospinal
- a. lateral corticospinal
- b. vestibulospinal
- c. tectospinal
- d. anterior corticospinal
- e. reticulospinal
= a. lateral corticospinal
UMN in the yellow circle control muscles in what region?
- a. left leg
- b. left face
- c. right face
- d. right leg
- e. trunk
- f. right hand
- g. left hand
= f. right hand
- a. right spinal cord @T8
- b. left spinal cord @L2
- c. left spinal cord @T8
- d. right spinal cord @L2
= a. right spinal cord @T8
Laceration of this vessel will lead to:
- a. extradural haematoma
- b. intracerebral haemorrhage
- c. hydrocephalus
- d. subdural haematoma
- e. subarachnoid haematoma
= a. extradural haematoma
Cell death in the encircled region is characteristic of which condition?
- a. Hemiballismus
- b. Parkinson disease
- c. Multiple Sclerosis
- d. Hungtington disease
- e. Tabes Dorsalis
= b. Parkinson disease
In the indirect pathway, what is the efferent projection of neurons in the area encircled?
- a. inhibitory to thalamus
- b. excitatory to globus pallidus externus
- c. excitatory to globus pallidus internus
- d. inhibitory to the subthalamic nucleus
- e. inhibitory to globus pallidus externus
- f. excitatory to thalamus
= d. inhibitory to the subthalamic nucleus
The globus pallidus is encircled. In the indirect pathway, the GP externus is inhibitoy to the subthalamic nucleus.
What information does this pathway carry?
- a. vibration
- b. pain
- c. proprioception
- d. motor
- e. fine touch
= b. Pain
In the direct pathway, which nucleus do efferent neurons originating in the outlined region project?
- a. globus pallidus internus
- b. substantia nigra
- c. subthalamic nucleus
- d. thalamus
- e. globus pallidus externus
= a. globus pallidus internus
Identify the artery indicated.
- a. middle cerebral
- b. anterior cerebral
- c. internal carotid
- d. posterior cerebral
- e. superior cerebellar
= d. posterior cerebral
Blockage of which part of the ventricular system would lead to these features?
- a. interventricular foramen
- b. inferior horn of lateral ventricle
- c. lateral recess of fourth ventricle
- d. central canal of spinal cord
- e. cerebral aqueduct
= e. cerebral aqueduct
- lateral and third ventricles are dilated
- fourth ventricle appears normal
- blockage must be between third and fourth ventricles = cerebral aqueduct
UMN “A” synapses on LMN going to muscles in which region of the body?
- a. trunk
- b. head
- c. lower limb
- d. neck
- e. upper limb
= c. lower limb
What is the function of this cerebellar lobe?
- a. initiates movement
- b. stores procedural memory
- c. plans voluntary motor activity
- d. coordinates voluntary motor activity
- e. maintains balance
= e. maintains balance
Identify the outlined structure.
- a. fasciculus cuneatus
- b. lateral funiculus
- c. dorsal horn
- d. anterior funiculus
- e. fasciculus gracilis
= e. fasciculus gracilis
Occlusion of which artery results in these symptoms?
- a. middle meningeal
- b. anterior cerebral
- c. posterior cerebral
- d. superior cerebellar
- e. middle cerebral
= e. middle cerebral
What is the best method of clinically testing this pathway?
- a. pin prick test
- b. deep tendon reflexes
- c. rapid alternating movements of hand
- d. heel-shin test
- e. vibration of 128Hz tuning fork
= e. vibration of 128Hz tuning fork
Identify this nucleus
- a. amygdala
- b. caudate
- c. globus pallidus externus
- d. globus pallidus internus
- e. putamen
- f. subthalamic
= d. globus pallidus internus
- coronal section through brain
- medial nucleus of the lentiform nucleus
Identify tract “2”
- a. anterior spinothalamic
- b. dorsal spinocerebellar
- c. ventral spinocerebellar
- d. lateral spinothalamic
- e. rubrospinal
= d. lateral spinothalamic
Loss of neurons in the outlined structures is characteristic of which condition?
- a. Tabes dorsalis
- b. Multiple Sclerosis
- c. Dementia
- d. Parkinson’s disease
- e. Huntington’s disease
= e. Hungtington’s disease
A lesion in the encircled area would result in which of these symptoms?
- a. hyperkinesia
- b. clasp-knife paralysis
- c. flaccid paralyis
- d. dysdiadochokinesia
- e. bradykinesia
= e. bradykinesia
Damage is this region (the substantia nigra) will result in Parkinson disease and bradykinesia.
- A → Genu of corpus callosum
- B → Caudate nucleus - head
- C → Hypothalamus
- D → Midbrain
- E → Basal pons
- F → Medulla
- G → Body of corpus callosum
- H → Splenium of corpus callosum
- I → Thalamus
- J → Tectum - superior and inferior colliculi
- K → Fourth ventricle
Identify the central sulcus, precentral gyrus and postcentral gyrus on the brain models, specimens or images.
Lateral corticospinal: Conveys nerve impulses from the motor cortex to skeletal muscles on opposite side of body for precise, voluntary movements of the distal parts of the limbs.
Anterior corticospinal: Conveys nerve impulses from the motor cortex to skeletal muscles on opposite side of body for movements of the trunk and proximal parts of the limbs.
Corticobulbar: Conveys nerve impulses from the motor cortex to skeletal muscles of the head and neck to coordinate precise, voluntary movements.
Axons of UMNs descend from the cortex into the brain stem, where some decussate and others do not.
They provide input to the lower motor neurons in the nuclei of cranial nerves III, IV, V, VI, VII, IX, X, XI, and XII, which control voluntary movements of the eyes, tongue, and neck; chewing; facial expression; and speech.
Focal lesions of the supplementary motor area and premotor cortex often lead to motor ataxia – the inability to perform purposeful movements as opposed to more paralysis associated with damage to the precentral gyrus. This can be in the form of inability to execute a movement upon request (ideomotor ataxia) or inability to identify the sequence of movements to carrying out the movement. Damage to the left side would affect the right side of the body.
A lesion to the precentral gyrus would cause contralateral UMN effects.
Stimulation of motor cortex produces muscle contraction on contralateral side of body.
Body represented in inverted position with nerve cells controlling movement of feet in the upper part and those controlling movements of face and hands in the lower part.
A motor cortical homunculus, with areas proportional to respective cortical area. Note that ears are not well-represented, in marked contrast to the sensory homunculus.
In addition to the primary sensory area, there is a small secondary area laterally, and a very large part of the anterior parietal cortex more medial to this also responds strongly to somatosensory stimuli. All of the main sensory and motor areas of cortex actually comprise multiple areas, each with slightly different functions. They extend well beyond the limits of the areas usually shown in simplistic textbook diagrams, which usually only indicate the primary areas. Premotor and supplementary motor cortical areas, for example, take up nearly half the frontal lobe. Visual areas even extend into the temporal lobe.
The somatosensory association area is an integrating area, integrating information from various sources and making decisions based on the integration. It takes information from the surrounding sensory areas; somatosensory in front, visual behind, and auditory laterally. It processes all of this together and makes comparisons with stored ‘models’ of various objects, sounds, body sensations that have been learned over years.
You can therefore easily recognise common objects like a car, spoon or chair by sight, even if the specific object is new to them (most of us recognise a Mini, Bentley, or dunebuggy as cars, even if very different from each other); recognise a texture or an object by feel and shape, or remember a sound pattern. It’s all about PERCEPTION - not just of the basic stimuli coming in, but what it all means in context. Isolated damage here isn’t all that common, but damage of any kind is functionally serious. People with such damage may fail to recognise common objects, and in some cases will not respond to visual stimuli presented in the opposite half visual field, even though they can see them (visual cortex is intact). This is “visual neglect”. They may also fail to recognise the other side of their own body as belonging to them, even if they can still feel and move it (somatosensory and motor areas intact), and not wash or protect it. Needless to say this can be a major problem for carers. The perception of the world is haywire. For some reason this is usually worse with damage in the right hemisphere than the left.
Find the following features of the ventral/anterior aspect of the brainstem on the resources available:
- crus cerebri
- hypoglossal nerve
- infundibulum
- mammillary body
- medulla oblongata
- middle cerebellar peduncle
- olive
- optic chiasma
- pons
- pyramid
- pyramid decussation
- thalamus
Locate the dorsal/posterior features of the brainstem on the resources provided:
- cuneate nucleus
- floor of ventricle IV
- gracile nucleus
- inferior colliculus
- middle cerebellar peduncle
- pineal
- superior colliculus
- thalamus
- trochlear nerve
