Study Notes

The Sliding Filament mechanism of muscle contraction. When a muscle contracts the light I bands disappear and the dark A bands move closer together. This is due to the sliding of the actin and myosin myofilaments against one another. The Z-lines pull together and the sarcomere shortens   The thick myosin bands are not single myosin proteins but are made of multiple myosin molecules. Each myosin molecule is composed of two parts: the globular "hea…

The Submandibular Glands Each of these U-shaped salivary glands is about the size of a thumb and lies along the body of the mandible. It is partly superior and partly inferior to the posterior 1/2 of the base of the mandible. It is partly superficial and partly deep to the mylohyoid muscle. The submandibular duct arises from the portion of the gland that lies between the mylohyoid and hyoglossus muscle. The duct passes deep and then superf…

Non-barbiturate sedatives 1- Chloral hydrate is trichlorinated derivative of acetaldehyde that is converted to trichlorethanol in the body. It induces sleep in about 30 minutes and last up to 6 hr. it is irritant to GIT and produce unpleasant taste sensation. 2- Ramelteon melatonin receptors are thought to be involved in maintaining circadian rhythms underlying the sleep-wake cycle. Ramelteon is an agonist at MT1 and MT2 melatonin receptors , useful in patient…

Tuberculosis Causative organism -Mycobacterium tuberculosis  -Strict aerobe  -Pathogenic strains -hominis, bovis, avium, murine& cold blooded vertebrate strain  Koch’s bacillus -small slender, rod like bacillus, 4umnon-motile, aerobic -high lipid content  -divides every 16 to 20 hours, an extremely slow rate  -stains very weakly Gram-positive or does not retain dye due to the high lipid & mycolicacid content of i…

Bone Healing: Primary vs. Secondary Intention Bone healing is a complex biological process that can occur through different mechanisms, primarily classified into primary healing and secondary healing (or healing by secondary intention). Understanding these processes is crucial for effective management of fractures and optimizing recovery. Secondary Healing (Callus Formation) Secondary healing is characterized by the formation …