NEET PG/NEXT (MCQs)

2021-02-20 18:00:03 Alpha waves

• In adult humans who are awake but at rest with the mind wandering and the eyes closed, the most prominent component of the EEG is fairly regular pattern of waves at an frequency of 8-12 Hz and an amplitude of 50-100 V when recorded from the scalp
• This pattern is the alpha rhythm.
• It is most marked in the parieto-occipital area, though it is sometimes observed in other locations. Open / Comment

2021-02-19 18:00:03 Pectinate line

• Anal values together form a transverse line that runs all around the anal canal called the pectinate line
• Arterial supply of anal canal above the anal valves is by superior rectal artery whereas inferior rectal artery supplies the entire thickness of the anal canal below the anal values
• Venous drainage of the mucous membrane of the anal canal upto the anal valves is by internal venous plexus whereas the area below the anal valves is drained by the external venous plexus. Open / Comment

2021-02-18 18:00:04 Westermark sign is due to focus of oligemia in pulmonary embolism. The sign develops due to following reasons:

• Dilation of pulmonary arteries proximal to the embolus
• Collapse of distal vasculature creating the appearance of a sharp cut off on chest X-ray

The chest X-ray is normal in the majority of Pulmonary Embolism cases, the Westermark sign is seen in 2% of patients. Open / Comment

2021-02-17 18:00:04 Antipyschotics targeting positive symptoms probably act by blocking the postsynaptic dopamine(D2) receptors in the mesolimbic system. Other receptors such as 5-HT, muscarinic receptors and GABA are also probably important. Atypical antipsychotics are also called as Serotonin Dopamine Antagonists (SDAs) due of their action on both dopamine and 5-HT

Overactivity of DA receptor causes positive symptoms

Their blockage of D2 antagonist relieves from positive symptoms

Underactivity of NMDA receptor is responsible for negative symptoms. Open / Comment

2021-02-16 18:00:03 Doxacuronium is the longest acting neuromuscular blocking agent.

Duration of action is 120 minutes

Atracuronium duration of action: 45 minutes

Vecuronium duration of action: 25-40 minutes

Pancuronium duration of action: 85-100 minutes

Most potent skeletal muscle relaxant: Doxacuronium

Least potent skeletal muscle relaxant: Succinylcholine

Least potent non depolarizing muscle relaxant: Rocuronium

Most commonly used muscle relaxant for routine surgery: Vecuronium Open / Comment