Knowledge Class

[...] There are two designs of nervous system in the animal kingdom. Diffused Nervous System. Centralized Nervous System. Diffused Nervous System These are found in  cnidarians  ( [...]

[...] and the total organism movement is called locomotion. Movements in animals are coordinated by nervous system and hormonal system. Unlike animals, plants do not possess nervous system and rely entirely [...]

[...] The nervous system is made up of highly specialized cells whose function is to: (1) receive stimuli from [...]

[...] The structural and functional unit of the nervous system are neurons. Most long fibers are covered by tightly packed spirals of neuroglial cells. [...]

[...] regard to temperature. Most aquatic organisms, including non-vertebrates and fish have a body temperature which varies according to the temperature of the water, though some active fishes such as [...]

[...] ). It is characterized by lethargy, weight gain, loss of hair, slower pulse rate, lower body temperature and thickness and puffiness of hand and skin. Goiter The disease goiter is the enlargement [...]

[...] autonomic system also helps regulate body temperature by dilating blood vessels in the skin when we are hot. Increased blood flow to the skin [...]

[...] beat (c) blood pressure (d) hormone level (e) water balance for the regulation of pH (f) body temperature. These show the importance of a negative feedback mechanism for existence of an animal.  [...]

[...] A nerve impulse is the way a neuron transmits information. The nature of a nerve impulse has been studied by using excited axons and an instrument called voltameter. Voltage (mV = [...]

[...] Muscle contraction is initiated by nerve impulse arriving at the neuromuscular junction. All the fibers innervated by a single motor neuron are [...]

[...] in activity in an organism is called stimulus (plural: stimuli) or anything that starts a nerve impulse. Reaction to the stimulus is known as response. The stimulus is received by a receptor. The [...]

[...] Receptors are structures specialized to receive certain environmental stimuli and generate nerve impulse. The receptors may be a cell or neuron ending or organ. According to stimuli in human, [...]

[...] though individual members of the species die. There are two types of reproduction: (a) Asexual Reproduction (b) Sexual Reproduction Asexual Reproduction Asexual reproduction is the production of [...]

[...] Asexual Reproduction in Plants The most common form of asexual reproduction in plants is called vegetative propagation. Examples are bulbs, corms, rhizomes, stolons, [...]

[...] Animals reproduce both asexually and sexually. Asexual Reproduction Binary fission, multiple fission, budding fragmentation, regeneration, parthenogenesis, [...]

[...] Syngamy: This type of sexual reproduction involves the fusion of two gametes to form the zygote. Depending upon the source of fusing [...]

[...] to low temperature continue vegetative growth indefinitely and do not initiate sexual reproduction. Low temperature stimulates production of vernalin hormone which induces [...]

[...] Sexual reproduction involves the fusion of two sets of DNA to form a zygote. Development is the series of [...]

[...] of the species die. There are two types of reproduction: (a) Asexual Reproduction (b) Sexual Reproduction Asexual Reproduction Asexual reproduction is the production of offspring from a single [...]

[...] , coma and eventually death. Ammonia may be excreted immediately or converted to urea or uric acid. Lower quantities of nitrogen are excreted in the form of other compounds such as creatine, a [...]

[...] . Spiracles have valves to reduce water loss. (c) The excretory product is semisolid i.e. uric acid. (d) The embryo develops inside an egg with a relatively impermeable shell that prevents water [...]

[...] calcium oxalate mixed with calcium phosphate, 15% are magnesium ammonium phosphate and 10% are uric acid. The cause of forming the stones is formation of metabolic wastes. Hyprcalcemia: It is the high [...]

[...] molecules or nitrogenous wastes includes urea, produced from deamination of amino acids. Uric acid is formed from the breakdown of nucleic acids. Creatinine is derived from a nitrogen containing [...]

[...] causes structural and functional changes in the uterus. Luteotropic Hormone It is secreted by pituitary gland. LTH is also called prolactin. It stimulates the development and secretion of milk in the [...]

[...] blood pressure, menstrual cycle and the sleep wake cycle. The hypothalamus also controls the pituitary gland and thereby serves as a link between the nervous and endocrine system. Limbic System The [...]

[...] secreted by ripening follicles whose development has been initiated by FSH from the anterior pituitary gland. Estrogen performs the following functions (1) Estrogen secreted at the time of puberty is [...]

[...] by the thyroid gland. In this example the detector is the hypothalamus, the regulator is the pituitary gland and the effector is the thyroid gland. 12. Positive Feedback: It is rare in biological [...]

[...]   synaptic knob. 2.       Synaptic knob membrane becomes more permeable to calcium ions and they            diffuse inward. 3.       In the presence of calcium [...]

[...] of spinal cord and neurons. Cramping seems to be due to lack of ATP needed to pump calcium ions back into the sarcoplasmic reticulum and to break the linkages between the actin and myosin [...]

[...] iodine has successfully replaced surgery as treatment for hyperthyroidism. Calcitonin High calcium ions concentration in the blood causes stimulation of the synthesis and release of calcitonin, low [...]