Every Science topic covered below covers revision notes for your school competitive and goverment exam . Science notes with diagram , tricks and short key-notes to score more marks in your exams, prepared by expert Science teachers from the latest edition of NCERT books and best other books .
What is a Cell ? Cell is the fundamental structural and functional unit of all living organisms. Cell in latin word means “small room” . Just like bricks are the building blocks of a house or school , cells are the building blocks of life . Because you are alive, you are made up of … Read more
Adrenals gland Origin. Adrenal gland have mesoderm and ectoderm. This gland also called suprarenal gland or ‘life-saving glands’ or essential endocrine glands. It is because the absence of adreno-cortical hormones causes death within 3 to 15 days and absence of adreno-medullary hormones, decrease the resistance to mental and physical stress. Adrenal gland Location. The adrenal gland … Read more
Pancreas Origin. The pancreas develops from the endoderm of the embryo. Pancreas Location. The pancreas lies below the stomach. Pancreas Structure. The pancreas is an elongated, yellowish gland. It consists largely of lobules (acini, alveoli) that secrete pancreatic juice. Interspersed at random among the acini are islands of Langerhans which produce hormones. The islands of … Read more
Thyroid gland Origin. The thyroid gland originates from the endoderm of the embryo. Thyroid gland Location. The thyroid gland surrounds the front of the larynx and upper part of the trachea in the neck . Structure. The thyroid is the largest endocrine gland. It is a bilobed, highly vascular organ. The two lobes are connected … Read more
Hypothalamus Origin. Hypothalamus develops from the ectoderm of the embryo. Hypothalamus Location. It is the base of the diencephalon, a part of the forebrain. Structure of hypothalamus. The hypothalamus is composed of nervous tissue. It is connected with anterior lobe of the pituitary gland by hypophysial portal blood vessels and with the posterior lobe of … Read more
Pituitary gland Origin. Pituitary gland originates from the ectoderm of the embryo. Location. The pituitary gland is a small, red-grey, of pea-shaped gland attached to the hypothalamus of the brain by a stalk or infundibulum in front of the pons. Structure of pituitary gland The pituitary gland consists of three lobes : anterior lobe or … Read more
What is endocrine glands ? Majority of vertebrates possess certain specialised glands which lack definite duct for the transportation of their secretions but discharge them into the bloodstream. These glands are, therefore, known as ductless glands or endocrine glands , Some endocrine glands (i.e. thyroid, parathyroid, pituitary, etc. are strictly ductless and have no outlet … Read more
Endocrine system Endocrine system is a control system of ductless glands The that secrete chemical messengers called hormones that circulate within the body via the bloodstream to affect distant cells within specific organs. Endocrine glands secrete their products immediately into the blood or interstitial fluid, without storage of the chemical. Hormones act as ‘messengers‘ and … Read more
Definition Hormones are informational molecules secreted by the endocrine cells in one part of the body in response to changes in external or internal environment, and carried by blood to another part , where they stimulate or inhibit specific physiological processes for the good of the body as a whole. In other words, the hormones … Read more
The organs of hearing and equilibrium convert mechanical energy to receptor (action) potential. Therefore, they are called mechanoreceptors. “The mechanoreceptors contain hair cells that generate receptor potential when the hair are bent by moving fluid or by particles. The study of structure, function and diseases of the ear is called otology (G. ous = ear, logos … Read more