• Biology,  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…

  • Biochemistry

    DIGESTIVE SYSTEM

    DIFFERENT MODE OF DIGESTION IN ORGANISMS The collective processes by which a living organism takes food which are necessary for their growth, maintenance and energy needs is called nutrition. The chemical substances present in the food are called nutrients. It is important to know the different modes of nutrition in all living organisms in order to understand energy flow within the ecosystem. Plant produces high energy organic food from inorganic raw materials. They are called autotroph and the mode of nutrition is known as autotrophic nutrition. Animals feed on those high energy organic food, are called as heterotrophs and their mode of nutrition is known as heterotrophic nutrition. Heterotrophic nutrition…

  • Biology

    Phylum Cnidaria/Coelenterata

    Kingdom: Animalia Habitat: aquatic, mostly marine. Habit: solitary or colonial. Each individual is known as zooid. Symmetry: radially symmetrical Grade of organization: tissue grade of organization. Germ layer: diploblastic, outer ectoderm and inner endoderm. Mesogloea separates these two layers. The body has a single opening called hypostome surrounded by sensory tentacles. Coelom: gastrovascular cavity or coelenteron. Nematocyst: organ for capturing and paralyzing pray, present in tentacles Nutrition: holozoic Digestion is both intracellular and extracellular. Respiration and excretion are accomplished by simple diffusion. Circulatory system: absent Nervous system: poorly develop Many forms exhibit polymorphism ie. Polyp and medusa Polyps are sessile, asexual stage Medusa are free swimming, sexual stage Metagenesis: asexual…

  • Biochemistry

    Phylum Porifera

    Kingdom: Animalia Habitat: Aquatic, mostly marine, few are terrestrial Habit: They are solitary or colonial. Grade of organization: cellular grade of body Shape: Body shape is variable, mostly cylinder shaped Symmetry: Asymmetrical or radially symmetrical. Germ layer: Diploblastic animals. The adult body wall contains two layers, outer dermal layer and inner gastral layer. In between these two layers, there is a gelatinous and non-cellular mesoglea containing numerous free amoeboid cells. Coelom: Absent; acoelomate but spongocoel is present Surface of the body has numerous perforation called ostia (for the entry of water) and a large pore at the apex called osculum (for the exit of water). Water canal system present Endoskeleton:…

  • 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 skull and is supplied by optic nerve. There are 6 sets of muscles attached to outer surface of eyeball which helps to rotate it in 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. Anatomical structure of Eye Eye ball consists of three layers Outer fibrous…