Entrance Exams
Govt. Exams
Acetylcholinesterase breaks down acetylcholine in the synaptic cleft, terminating signal transmission; its inhibition causes acetylcholine accumulation and sustained contraction.
Taste is mediated by cranial nerves (VII, IX, X) which are not affected by cervical spinal cord injury. Cervical injury affects arms, legs, and potentially breathing.
Right shift (Bohr effect) occurs with decreased pH, increased CO2, increased temperature, and elevated 2,3-DPG, facilitating oxygen release to tissues.
In Cushing's syndrome, elevated cortisol fails to inhibit CRH and ACTH secretion, disrupting the normal negative feedback loop of the HPA axis.
Kidneys reabsorb filtered HCO3- and secrete H+ ions, regulate ammonia production, and adjust acid-base balance through selective reabsorption and secretion.
The spinothalamic tract carries pain and temperature sensation, crossing at the spinal cord level. Damage results in contralateral loss of pain sensation below the injury.
During intense exercise, muscles use phosphocreatine to rapidly regenerate ATP and switch to anaerobic glycolysis, producing lactate. Aerobic metabolism is insufficient initially.
ADH binds to V2 receptors on collecting duct cells, triggering cAMP production that moves aquaporin-2 water channels to the apical membrane, increasing water permeability.
High-frequency stimulation causes calcium to accumulate in the sarcoplasm faster than it can be reuptaken by SR, maintaining sustained actin-myosin interactions.
SSRIs block serotonin reuptake transporters, preventing reabsorption of serotonin from the synaptic cleft and increasing its availability for receptor binding.