Self Assessment 2 Flashcards
The Metencephalon corresponds to the pons and medulla.
A. True
B. False
A. False
Explanation:
The metencephalon corresponds to the pons and cerebellum. The myelencephalon corresponds to the medulla.
Which of the following neurotransmitters is implicated in brain excitotoxicity?
A. Dopamine
B. Glutamate
C. Acetylcholine
D. Glycine
A. Glutamate
Explanation:
Dopamine is a catecholamine that regulates many brain functions, including motor, cognitive and emotional processes. Its most common post-synaptic effect is excitatory. It is implicated in many psychiatric disorders, substance abuse, and movement disorders.
Post-synaptic potentials always result in the generation of an action potential.
A. True
B. False
B. False
Explanation:
The above statement is false: Post-synaptic potentials can be excitatory or inhibitory. It is the sum of these excitatory post-synaptic and inhibitory post-synaptic potentials that is critical to the generation of an action potential. If the sum of these potentials results in the neuron reaching its threshold potential, then an action potential will be fired.
Which of the following statements regarding an action potential is false?
A. An action potential is triggered when the membrane potential reaches a predetermined range called the threshold potential.
B. Action potentials are regenerative due to the opening of voltage-gated K+ ion channels.
C. Action potentials are propagated in one direction due to the delayed opening of voltage-gated K+ channels, and the inactivation of Na+ channels.
D. During the absolute refractory period a 2nd action potential cannot be triggered.
B. Action potentials are regenerative due to the opening of voltage-gated K+ ion channels.
Explanation:
D is true: A second action potential cannot be triggered during the absolute refractory period. During the relative refractory period a second action potential can be triggered, but it would require a much larger than normal stimulus.
Schwann cells are responsible for myelination of axons in the central nervous system.
A. True
B. False
B. False
Explanation:
This statement is false because Schwann cells are responsible for myelination of axons in the PNS. Oligodendrocytes are responsible for myelination of axons in the CNS.
Which of the following defects is associated with failure of the posterior neuropore to close during the process of neurulation?
A. Meningoencephalocele
B. Anencephaly
C. Meningomyelocele
D. Meningohydroencephalocele
C. Meningomyelocele
Explanation:
The answer is not B: In anencephaly the brain is not formed and the surrounding meninges and skull may be absent. Facial abnormalities are present and neonatal death is inevitable. This is due to failure of the anterior neuropore to close.
Neuroblasts proliferating in the neural tube will migrate to form anteriorly located basal plates. These plates will become which of the following fully developed structures?
A. Posterior (dorsal) horn of the spinal cord
B. The anterior (ventral) horn of the spinal cord
C. Sensory Cranial Nerve Nuclei
D. Both A and C
B. The anterior (ventral) horn of the spinal cord
Which of the following structures connects the third and fourth ventricles?
A. Intraventricular foramen
B. Median aperture (Foramen of Magendie)
C. Lateral apertures (Foramina of Luschka)
D. Cerebral Aqueduct
D. Cerebral Aqueduct
An epidural hematoma is a collection of blood within the dura mater usually due to a tear of a vein as it enters the dural sinuses.
A. True
B. False
B. False
Explanation:
The above statement is false: An epidural hematoma is a collection of blood between the periosteal dura and the skull. It is most frequently due to a head injury that results in the tearing of the periosteal dura from the skull, resulting in damage to an artery.
A subdural hematoma is a collection of blood within the dura matter (dura-arachonid interface). This is usually due to a tear of a vein as it enters the dural sinuses.
