NEET PG/NEXT (MCQs)

2021-10-04 17:45:02 Explanation

• The movements at the atlanto-axial joint allow a person to look left and right
• The atlanto-axial joints include 3 synovial joints.
• Median atlanto-axial joint: The central pivot joint between the dens of axis ad a ring formed by the anterior arch and transverse atlantal ligament.
• Lateral atlanto-axial joints: Plain synovial joints between lateral masses of atlas and upper facets of the body of axis.
• Movements: Movements at the atlanto-axial joint almost exclusively is rotation around the axis, which help side-to-side rotation of the head. The normal range of atlanto-axial rotation is about 40 degree. Open / Comment

2021-08-31 18:16:02 Explanation

• 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

2021-08-30 18:15:03 Explanation

• Smooth muscles in the GI tract are innervated by both parasympathetic and sympathetic nerves.
• Smooth muscles in the wall of the blood vessels and erector pili muscles in hair follicles are innervated only by sympathetic nerves.
• Muscles that act at the elbow joint and muscles enclosed by epimysium are skeletal muscles that are innervated by somatic motor nerves Open / Comment

2021-08-29 18:15:01 Explanation

Toxic Megacolon (Megacolon toxicum)

• It is an acute form of colonic distension.
• It is characterized by a very dilated colon(megacolon), accompanied by abdominal distension(bloating) and sometimes fever, abdominal pain or shock
• Toxic megacolon is usually a complication of inflammatory bowel disease such as ulcerative colitis and more rarely Crohn’s disease. Open / Comment

2021-08-28 18:15:01 Explanation

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