Question

7. Which of the following ion(s) is in highest concentration outside the neuron cell membrane in a resting state?

a. Chloride (Cl) and potassium (K)

b. Potassium (K) only

c. Magnesium (Mg2)

d. Chloride (Cl) and sodium (Na)

e. Nitric oxide (NO)

8. A neurotransmitter may be described as “excitatory” (leads to depolarization) or “inhibitory” (no change or hyperpolarization). Which of the following determines the action of the neurotransmitter?

a. The type of charges (or¨)on the neurotransmitter

b. The type of pores in the presynaptic membrane

c. The width of the synaptic cleft

d. The receptors on the postsynaptic membrane

e. The active zones in the postsynaptic membrane

9. A 24-year-old woman suffering from a severe allergic reaction improves markedly after a subcutaneous injection of epinephrine. Transduction of this epinephrine chemical signal involves which of the following?

a. Binding of epinephrine to membrane-bound ?beta-adrenoreceptors

b. Dissociation of the alpha subunit from the beta -heterodimer of the G-protein complex

c. Binding of the G-protein alpha subunit to adenylyl cyclase

d. Stimulation of adenylyl cyclase to increase intracellular cyclic adenosine monophosphate levels

e. All of these steps

10. The MRI of a male newborn reveals cerebral hemispheres that have areas of small irregular gyri (microgyri) intermixed with areas containing very large gyri (pachygyri). Which of the following would most likely explain these developmental defects?

a. Failure of the anterior neuropore to close

b. Stenosis of the cerebral aqueduct

c. Agenesis of the corpus callosum

d. Improper migration of neuroblasts on the radial glia

e. Failure of microglia to invade the developing nervous system

11. A 19-year-old woman becomes ill rather suddenly with severe headaches, nausea and vomiting, and a progressively decreasing level of consciousness (all signs of increased intracranial pressure). MRI reveals a large pinealoma (pineoblastoma, an aggressive pineal tumor) that has blocked the cerebral aqueduct. The neurosurgeon explains to the family that the CSF must be drained immediately or she will die. Approximately how much CSF is produced in a 24-hour period in the average healthy adult?

a. 250 to 300mL

b. 300 to 350mL

c. 350 to 375mL

d. 450 to 500mL

e. 600mL

12. The neuropathologist examines a tumor removed from the ventricular system of a 36-year-old woman. He observes cells that appear completely normal but they do not sit on a continuous basal lamina. These cells are most likely which of the following?

a. Endothelial cells of the choroid plexus

b. Endothelial cells lining arteries

c. Ependymal cells

d. Endothelial cells lining veins

13. A sample of CSF is taken, by lumbar puncture, from a 27-year-old woman who presents with vague neurologic complaints. Which of the following would most likely represent an abnormal condition in the CSF of this patient?

a. 120mg/dL protein

b. Less than 5 lymphocytes per milliliter

c. Lower K and Ca2 than blood plasma

d. Higher Mg2 and Cl than blood plasma

14. Lumbar puncture of a 59-year-old man yields a sample of CSF containing large amounts of red blood cells. Which of the following is the most likely explanation of these cells in the CSF of this patient?

a. Astrocytoma

b. Multiple sclerosis

c. Bacterial meningitis

d. Rupture of an intracranial aneurysm

e. Meningeal syphilis

Answer 1

7, Inside the neurons , K+ ions are at high concentrations as compared to outside, while outside the cell, Na+ ions concentration is higher as compared to the inside of the cell.

8. The Neurotransmitters will activate the receptors present on the post synaptic membrane. Depending on whether the receptors on the post synaptic membrane is excitatory or inhibitory, The cells will react to the neurotransmitters.

9.Binding of G protein of adenyl cyclase auses its activation which results in the conversion of ATP into cAMP, which will increases the amount of cAMP.

11.the amount of CSF secreted is 0.2-0.7 ml per minute, or 600-700ml per day. The correct option is C.