heart sounds During each cardiac cycle two prominent sounds are produced which can be easily heard through a stethoscope. First Heart Sound (LUBB) Second Heart Sound (DUB) 1. It is produced by closing of AV valves (tricuspid valves) during ventricular systole. 1. It is produced by closing of semilunar valves at the beginning of ventricular … Read more
Meiosis (Reductional Division) Definition:- The tem meiosis was coined by Farmar and Moore in 1905. The division was studied by Van Benedin Winiwarter and Strassburger. Meiosis or meio is “to lessen” , hence meiosis is a double division in which a diploid cell form four haploid cells, each having half the number of chromosomes. Meiosis … Read more
muscles INTRODUCTION Muscles is a specialized tissue originating from from the mesoderm germ layer. The muscular tissue is made up of specialized cells called myocytes. These cells are bound together by a connective tissue and form muscular tissue. It brings about different types of movements in internal and external body … Read more
lichens Lichens are dual (composites) or entities which contain a permanent association of a fungal partner or mycobiont and an algal partner or mycobiont. Mycobiont is dominant partner and mostly belongs to ascomycetes (Ascolichens- e.g. Graphis, Cladonia, Parmelia, Usnea etc) or sometimes basidiomycetes (Basidiolichens- e.g., Corella, Cora etc). Phycobiont is mostly a member of Chlorophyceae … Read more
respiratory system INTRODUCTION It is a system consisting of respiratory passage and respiratory organs. Respiratory organs are a pair of lungs. Respiratory passage:- It is a passage that takes air from outside to the respiratory surface of lungs. It is consists of a pair of nostrils, nasal cavity, apair of internal nares, pharnx, larynx, trachea, … Read more
KINGDOM: Protista This kingdom formed a link between kingdom Monera on one hand and other three kingdoms i.e. Plantae, Fungi and Animalia on the other hand. Protistians are ancestors of all multicellular eukaryotes (plants, fungi, animals). Kingdom: Protista includes- Protista ↓ (1) Autotrophic (2) Consumer (3) Protozoans or e.g Dinofagellates e.g. Cellular slime … Read more
blood group There are certain molecules on the surfaces of cell in the body that can be recognized as foreign by the immune system of another individual and hence can induce the immune system of latter. These molecules are known as antigens. As part of the immune response, particular lymphocytes, secretes a class of protein … Read more
thyroid gland It is largest endocrine gland situated in the neck close to the trachea. The gland is butterfly or H shape and consists of two elongated oval lobes joined by a narrow band called isthmus. It is highly vascular organ and contains many spherical or oval sac-like follicles. Cells lining the thyroid follicles secrete … Read more
INTRODUCTION Mitochondria are cylindrical or sausage-shaped double membrane organelles distributed in the cytoplasm They are not easly visible under the microscope. Thus, they are stained by a vital stain Janus green to make them visible for observation. Mitochondria show a great degree of variability in their shape, size and number. Mitochondria are double-membraned organelles found … Read more
DISORDER (i) Myasthenia Gravis:- It is an autoimmune disorder in which the antibodies produced in the body start attacking its own body cells. The antibodies recognize the body cells as foreign material and start acting against it. In myasthenia gravis, the antibodies start attacking the acetylcholine receptors present on sarcolemma, due to which the neurotransmitter … Read more