pop nero Flashcards
a) Name 6 parts/tests in a basic neurological exam (6)
- Level of consciousness
- Speech
- Mental state and cognitive function
- Sensory function
- Motor function
- Cranial nerve function
a) Explain briefly what an EEG looks at/measures (1)
Electroencephalography measures the electrical potentials measured at scalp generated by underlying neurones
a) In what condition would an EEG be used as a major diagnostic tool? (1)
Epilepsy and coma
Give 2 ways in which the differences between MRI and CT scans might lead to using one in favour of the other in neurological diagnosis (2)
- MRI has greater soft tissue detail, while CT has greater hard tissue detail.
- MRI has no radiation while CT uses ionising radiation.
- CT is quicker and more available in more hospitals + less expensive than MRI.
What parts of the brain would you find:
a) in the anterior cranial fossa?
b) The posterior fossa?
c) The middle fossa? (3)
Frontal lobe
Cerebellum
Temporal lobe
Where would you find (5):
a) the corpus callosum
b) the pons
c) the cerebellum
d) a basal ganglion
e) a dorsal horn
a) the corpus callosum – between the cerebral hemispheres
b) the pons is in the hindbrain (or middle part of brainstem)
c) the cerebellum is in the hindbrain
d) a basal ganglion is in the cerebral hemisphere
e) a dorsal horn is in the spinal cord
e) Explain what the difference between a primary and association cortex is (2)
Primary cortex = area that controls voluntary movement; it is the main processing centre for sensory information.
Association cortex = the brain integrates information and relates these to past experiences before a decision is made. Meaningful perception of the world enabling us to interact effectively. Involved in the higher functions of the brain.
b) Describe the function of the dorsal ganglia (2)
- The dorsal root ganglia contains the cell bodies of the sensory neurons which are coming from the sensory receptors in the effector organ towards the spinal cord.
- Relays somatosensory information from the afferent sensory neurons to the dorsal horn of the grey matter within the spinal cord.
- Nerve endings have a role in detecting pain/chemo/mechanoceptors.
What are the regions of the association cortex?
- Broca’s area – involved in producing intelligible speech
* Wernicke’s area – involved in comprehension of language
c) Indicate the direction of the roots and nerve of the spinal cord (3)
Dorsal roots – towards spinal cord (afferent)
Ventral – towards effector (efferent)
Spinal nerve – both directions. (Both afferent and efferent)
d) Between which vertebrae would you do a lumbar puncture? (2)
Why is this?
Between L3 and L4 or L4 and L5. This is because the spinal cord terminates at L2 before it reaches the end of the vertebral column and therefore no risk of damage to the spinal cord.
a) Describe the function of (i) dendrites and (ii) axons, and talk about characteristic features they have (2 x 3 marks)
i) Dendrites (Major area of reception of incoming information) – receives incoming signals from other neurons via synapses – neuronal input
• Branch frequently (greatly increases the surface area of the neuron)
• Often covered in spines which receive the majority of synapses from other neurons. They can integrate signals from multiple sources
ii) Axons (Conduct impulses away from cell body) – neuronal output
• Usually only one axon per cell
• Contain abundant neurofilaments and microtubules
• Can be myelinated or unmyelinated
• Emerges at axon hillock
b) Describe two ultrastructure features of neurones indicating that they’re metabolically active, highly organised cells (2)
- Large nucleus
- Prominent nucleolus
- Abundant rough ER
- Well-developed golgi apparatus
- Abundant mitochondria
- Highly organised cytoskeleton
a) Name a disease caused by death of neurones, and one caused by neuronal dysfunction (2)
Death – Parkinsons’s disease, Alzheimer’s disease
Neuronal dysfunction – Multiple Sclerosis, Epilepsy
a) Label the parts of the plane in a saggital plane of the brain. It was in a practical with the brainstem. (4)
Aqueduct, Third ventricle, fourth ventricle, cerebral hemisphere, infundibulum, pons, midbrain, spinal cord, medulla oblongata.
a) Give the functions of the Microglia?
- Resident macrophage population of the CNS
- Involved in immune surveillance
- Present antigens to invading immune cells
- First cells to react to infection or damage
- Role in tissue modelling
- Synaptic stripping
a) Give the functions of the Schwann cells?
- Myelin producing cells of the PNS
- Each Scwann cell produces only one myelin sheath
- Promote axon regeneration
a) Give the functions of the Astrocytes?
- Scaffold for neuronal migration and axon growth during development
- Formation of blood-brain barrier
- Transport of substances from blood to neurons
- Segregation of neuronal processes (synapses)
- Removal of neurotransmitters
- Synthesis of neurotrophic factors
- Neuronal-glial and glial neuronal signalling
- Potassium ion buffering
- Glial scar formation
a) What’s the difference in the white and grey matter? (2)
Grey matter contains neuronal cell bodies.
White matter comprises ascending and descending axon tracts to and from the brain.
What’s difference between ganglia and nuclei?
Ganglion - a group of neuronal cell bodies in the PNS.
Nuclei - A group of neuronal cell bodies in the CNS.
*One exception to this rule is basal ganglia.
a) How are motor neurons affected by Multiple Sclerosis and how does it lead to defects? (2)
- Chronic inflammatory demyelinating disease of the CNS
- Nerve conduction is slowed as there are no nodes of Ranvier and therefore salutatory conduction cannot occur. Conduction is slower via unmyelinated neurons.
- If enough myelin is lost = nerve block/no conduction. Leads to loss of motor function i.e. inability to innervate the muscles so no voluntary movement.
MS results from inflammation and disruption of myelin in the CNS.
What is another example of myelin disease?
Another example of myelin disease – Adrenoleukodystrophy
b) Which ion’s equilibrium potential is the membrane potential closest to in a real neuron at rest?
K+ because the membrane is most permeable to K+.
c) Which ion’s equilibrium potential is the membrane potential closest to at the peak of the action potential?
Na+ because the membrane is most permeable to Na+.