• Human anatomy

    EXCRETORY SYSTEM IN HUMAN

    Except for urinary bladder which is endodermal in origin, the whole excretory system is Except urinary bladder which is endodermal in origin, the whole excretory system is Except mesodermal. In human the kidney is retroperitoneal i.e., the kidney is located outside the coelomic cavity and is covered by peritoneum (coelomic epithelium) from the ventral side only. The size of each kidney is ~10 cm and it weighs is ~150 g. The two kidneys are asymmetrical, the Rt. being posterior to the Lt. Each kidney is bean-shaped with a groove (hilus) in the middle. The hilus is absent in frog’s kidney. The white fibrous connective tissue-covering around kidney is called renal…

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    Human anatomy

    Urine Formation

    3−steps are involved in the formation of urine A) Ultra filtration It is filtration under pressure. Glomerular capillary pressure (45 mm of Hg) favours filtration. The Colloidal osmotic pressure (due to plasma proteins, particularly albumin) acts against filteration. Its value is ~20 mm of Hg. The Capsular filtrate pressure, due to the glomerular filtrate in the Bowman’s capsule, also acts against filtration. Its value is ~10 mm of Hg. Net filtration pressure = 45 − (20+10) mm of Hg = 15 mm of Hg or 10 − 20 mm of Hg. Only 1/5 of plasma (20%) gets filtered from glomerulus per unit time. It is about 125 ml per minute.…

  • Human anatomy

    An overview of Pituitary Gland

    It is called master gland (master of endocrine orchestra) as it regulates the functioning of other endocrine glands like thyroid, Adrenal cortex, testes and ovaries etc. However, the secretions of pancreas, thymus and pineal body are not regulated by the hormones of the pituitary. Pituitary is a single or unpaired gland weighing about 0.5 gm. It is present in the ‘Sella tursica’ cavity of Basi-sphenoid bone and is attached to the floor of Diencephalon (hypothalamus) of forebrain through a stalk called Infundibulum. As it is present below diencephalon of fore-brain it is also known as Hypophysis cerebri. In mammals, it is ectodermal in origin. It consists of two-parts – (1)…

  • Human anatomy

    HUMAN DIGESTIVE SYSTEM

    Digestion involves the breaking of complex organic food molecules into simpler one by hydrolysis. Carbohydrates, proteins, fats and nucleic acids are large complex organic food molecules. They are insoluble and polymeric in nature. During digestion different enzymes helps in the breakdown of these complex polymers into soluble monomers which are required for energy generation.The different steps of digestion involve: Movement of food through the alimentary tract Secretion of digestive juices and digestion of food Absorption of water, various electrolytes, vitamins and digestive end products. Human digestive system mainly consists of two parts: 1) Alimentary tract and 2) secretory glands Alimentary tract It provides continuous supply of nutrients, vitamins, electrolytes and…

  • Human anatomy

    Human Eye: Anatomy, parts and structure

    The eye is the photo-receptor organ. Size and shape: Human eye is spherical about 2.5 cm in diameter. Location: it is situated on an orbit of the skull and is supplied by the optic nerve. There are 6 sets of muscles attached to the outer surface of the eyeball which helps to rotate it in a different direction. Four sets of these muscles are straight muscles; superior, inferior, medial and lateral rectal muscle and two sets are oblique muscles; superior and inferior oblique muscles. Structurally two eyes are separated but some of their activities are coordinated so that they function as a pair. The anatomical structure of Eye Eyeball consists…

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