Haseeb Ullah

  Definition Platyhelminthes, commonly known as flatworms, are a phylum of invertebrates that are characterized by their flattened, bilaterally symmetrical bodies. This group includes both freeliving and parasitic species. The parasitic flatworms are of significant medical importance and include classes such as Trematoda (flukes) and Cestoda (tapeworms).   Lifecycle in Humans The lifecycle of parasitic platyhelminths varies depending on the species. Here are the general lifecycles for common humaninfecting flatworms:   Trematodes (Flukes) 1. Eggs: Eggs are released into the environment through human feces or urine. 2. Larval Stages: Eggs hatch into miracidia, which infect specific intermediate hosts (usually snails). 3. Cercariae: Within the snail, the miracidia develop into cercariae, which are released into the water. 4. Human Infection: Cercariae penetrate human skin or are ingested, depending on the species. 5. Adult Stage: Cercariae migrate to ...

   Definition Nematodes, also known as roundworms, are a diverse group of helminths (parasitic worms) belonging to the phylum Nematoda. They are characterized by their cylindrical, elongated, and unsegmented bodies. Nematodes can inhabit a variety of environments, including soil, water, and as parasites in plants and animals, including humans.   Lifecycle in Humans The lifecycle of parasitic nematodes in humans can vary depending on the species. Here is an overview of the lifecycle stages for common human infecting nematodes: 1. Ingestion or Penetration: Humans can become infected by ingesting nematode eggs or larvae through contaminated food, water, or soil. Some species penetrate the skin directly. 2. Larval Migration: Once inside the human body, larvae migrate through different tissues. For instance, hookworm larvae penetrate the skin, enter the bloodstream, and travel to the lungs. From there, they ascend the respiratory tract, are swallowed, and reach the...

  Definition Toxoplasma gondii (T. gondii) is a parasitic protozoan that causes toxoplasmosis, a disease transmitted through the ingestion of cysts in uncooked meat or food contaminated by cat feces. Life cycle The life cycle of Toxoplasma gondii involves various hosts and environments. Cats, as definitive hosts, play a crucial role in completing the parasite's sexual cycle. Oocysts shed in the feces of infected animals can be ingested by other hosts. Once ingested, oocysts transform into tachyzoites, which spread to different tissues via the bloodstream. Toxoplasmosis, caused by T. gondii, can also be transmitted through various means such as ingestion of raw or undercooked meat, congenital transfer, blood transfusion, or tissue transplant. Pathogenesis & Epidemiology Toxoplasma gondii is primarily acquired through the ingestion of cysts present in uncooked meat or food contaminated with cat feces. Transplacental transmission from an infected mother to the fetus is also ...

    Leishmania donovani: The Causative Agent of Kalaazar (Visceral Leishmaniasis) Lifecycle Leishmania donovani's life cycle, relies on sandflies as vectors and various mammals, including dogs, foxes, and rodents, as reservoirs. Female sandflies, requiring blood meals for egg maturation, ingest macrophages containing amastigotes when feeding on an infected host Inside the sandfly, the amastigotes transform into promastigotes in the gut, multiply, and migrate to the pharynx and proboscis, ready to be transmitted during the next bite. This sandfly phase takes about 10 days. Upon biting a human, the sandfly injects promastigotes, which are engulfed by macrophages and transform back into amastigotes (Figure 1). Amastigotes evade destruction by preventing the fusion of the vacuole with lysosomes, leading to the infection of other macrophages and reticuloendothelial cells. The cycle completes when another sandfly ingests macrophages containing amastigotes.    ...

Medical Procedures and Instruments: Phlebotomy, Syringes, Blood Grouping, Cell Wash, Microscopy Phlebotomy: Definition: Phlebotomy denotes the procedural act of incising a vein, typically in the arm, employing a cannula for the extraction of blood. It encompasses venipuncture, utilized also in intravenous therapy. Application: Phlebotomy is indispensable across diverse medical contexts, encompassing diagnostic testing, blood donation, and therapeutic interventions. It facilitates the acquisition of blood samples for subsequent laboratory analysis. Principle: The underlying principle of phlebotomy entails the safe access to a vein, the retrieval of blood, and meticulous labeling and handling of samples. Procedure/Methods : In the course of phlebotomy, a proficient practitioner: - Identifies a suitable vein, typically in the arm. - Sterilizes the site with an antiseptic solution. - Introduces a sterile needle into the vein to draw blood. - Captures the blood in a recep...

  Tolerance and its induction: - Tolerance is the immune system's ability to recognize and tolerate self-antigens. - Induced centrally in the thymus (T cells) and bone marrow (B cells) during development. - Mechanisms include negative selection, receptor editing, anergy, regulatory T cells (Tregs), and immune privilege.   Autoimmune diseases and their factors and mechanisms: - Autoimmune diseases occur when the immune system attacks the body's own tissues. - Factors include genetic predisposition, environmental triggers, and immune dysregulation. - Mechanisms include molecular mimicry, breakdown of tolerance, aberrant lymphocyte activation, and inflammation. - Examples: rheumatoid arthritis, lupus, type 1 diabetes, multiple sclerosis.   Tumor immunity and associated antigens: - Tumors express tumor-specific antigens (TSAs) or tumor-associated antigens (TAAs). - Immune responses target tumors through CTLs, NK cells, and tumor-infiltrating lymphocy...

  Thrombotic and Thrombocytopenic Purpura Definition: TTP occurs in familial or acquired forms. Pathogenesis: Deficiency of ADAMTS13 metalloprotease leads to ULVWF multimers. Causes: Familial forms involve ADAMTS13 mutations; Acquired forms result from inhibitory IgG autoantibodies. Clinical Features: Pentad of symptoms: thrombocytopenia, microangiopathic hemolytic anemia, neurological abnormalities, renal failure, fever. Treatment: Plasma exchange with FFP or cry supernatant, rituximab, alacizumab, and immunosuppressive therapies. TTP is type of Thrombocytopenia mean platelets count decrease its normal count. TTP is rare blood disorder characterized by clotting in small blood vessels (Thromboses) but unnecessary clot   resulting in a low platelet count . Normally clotting present in tissue & vessels injury . In TTP, Patient have defect in   (ADAMTS13) enzyme. ( For clearing the VWF multimers) Normally Gene to code for different protei...

Introduction •       Our digestive system is a network of organs that help us digest and absorb nutrition from your food. •       It includes your gastrointestinal (GI) tract and your biliary system. •       Our GI tract is a series of hollow organs that are all connected to each other,      leading from your mouth to your anus. •       Your biliary system is a network of three organs that deliver bile and enzymes through to your GI tract your bile ducts. Function of GIT         •       Ingestion •       Mechanical Processing •       Digestion •       Secretion •       Absorption •       Excretion v   Ingestion o    Occurs when materials enter to digestiv...