NEET MDS Shorts
218414
General MedicineSumatriptan is a serotonin (5-HT) receptor agonist that is specifically indicated for the treatment of migraines with or without aura.
866271
AnatomyThe largest resting membrane potential is observed in skeletal muscle.
Resting membrane potential (RMP) is the electrical potential difference across
the membrane of a cell when it is not undergoing an action potential or a
similar excitation. It is crucial for the functioning of excitable cells, such
as neurons and muscle cells, as it is the basis for the transmission of
electrical signals. The RMP is primarily determined by the concentration
gradients of ions across the cell membrane and the permeability of the membrane
to those ions.
In skeletal muscle cells, the resting membrane potential is typically around -90
millivolts (mV). This relatively high negative value is due to the higher
concentration of potassium ions (K+) inside the cell compared to the outside,
and the lower concentration of sodium ions (Na+) inside the cell compared to the
outside. The cell membrane is more permeable to K+ than to Na+ at rest, which
allows K+ to leak out through potassium channels and sets up the resting
membrane potential.
Smooth muscle cells, on the other hand, have a resting membrane potential that
is generally less negative than that of skeletal muscle cells. The typical RMP
in smooth muscle cells ranges from -40 to -70 mV, which is closer to the
threshold for depolarization and makes these cells more responsive to stimuli
that could cause contraction. The difference in RMP between smooth and skeletal
muscle is due to variations in ion channel expression and the activity of ion
pumps, which control the ionic composition of the intracellular and
extracellular environments.
To summarize:
1. Skeletal muscle cells have a resting membrane potential of approximately -90
mV.
2. Smooth muscle cells have a resting membrane potential that is generally more
positive than skeletal muscle cells, typically ranging from -40 to -70 mV.
311671
General Medicine
ETEC are the principal cause of traveler’s diarrhe1) They produce both a heat-labile toxin (LT) and a heat-stable toxin (ST) that act on the intestinal mucos1) The LT is similar to cholera toxin and increases intracellular cGMP levels, leading to enhanced fluid and electrolyte secretion into the lumen and thus diarrhe1) The ST acts by a different mechanism but also enhances fluid and electrolyte secretion.
511595
Dental MaterialsThe average particle size of powered gold used in dental restorations is 15 ?ms. This size allows for the gold to be manipulated and condensed properly within the cavity preparation to achieve the desired restorative outcome.
368171
PhysiologyThe osmolarity of the tubular fluid leaving the ascending limb of the loop of Henle is 100mOsm/L, as it is impermeable to water and reabsorbs solutes.
934439
Oral SurgeryNerve membrane stabilization action of local anaesthetic agents is due to preventing conductance of Na ions from the exterior of the nerve to the interior.
992117
RadiologyDead bone appears on a radiograph as radiopaque.
601094
General MedicineThe description of a painless, red, scaly rash that spares the face, palms, and soles and involves the trunk and limbs is characteristic of psoriasis. The lesions are typically well-demarcated and have a "salt-and-pepper" appearance due to the presence of scales.