Define RECEPTORS in man. Name different receptor organs in human body.

1 Answer

Answer :

In a sensory system, a sensory receptor is a sensory nerve ending that recognizes a stimulus in the internal or external environment of an organism.
Following are the different sensory receptors
 Ampullae of Lorenzini respond to electric fields, salinity, and to temperature, but function primarily as electroreceptors
 Baroreceptors respond to pressure
 Chemoreceptors respond to chemical stimuli
 Hydroreceptors respond to changes in humidity
 Mechanoreceptors respond to mechanical stress or mechanical strain
 Nociceptors respond to damage to body tissues leading to pain perception
 Osmoreceptors respond to the osmolarity of fluids (such as in the hypothalamus)
 Photoreceptors respond to light
 Proprioceptors provide the sense of position
 Thermoreceptors respond to temperature, either heat, cold or both
 Electromagnetic Receptors's respond to electromagnetic waves

Related questions

Description : Name the organs responsible for the following functions present in either elements, plants or human. a) Vision b) Reproduction c) Hormone secretion d) Blood pumping e) Food storage

Last Answer : Answers: a) Eye b) Gonades c) Glands d) Heart e) Stem and stomach

Description : What is Ozonoshpere? Discuss the human technologies which are causing its depletion. What harm to man this depletive state would cause?

Last Answer : Ozonosphere A layer in the stratosphere (at approximately 20 miles) that contains a concentration of ozone sufficient to block most ultraviolet radiation from the sun The ozone layer is a layer ... of the ozone layer. Wind patterns could change, resulting in climatic changes throughout the world.

Description : Name the parts of human body from where the following secreted:

Last Answer : (a) Insulin- Pancreas (b) thyroxin-thyroid gland (c) adrenalin- Adrenal Medulla (d) oestrogen- From ovaries (in females) (e) cortisol- From adrenal cortex (f) Testosterone- From testis (in males) and from adrenal cortex in both males and females.

Description : What are the deficiency effects of the following nutrients in the human body?

Last Answer : a) Iron Iron Deficiency Anemia b) Iodine Goiter c) Fluoride May cause increased dental caries and possibly osteoporosis d) Vitamin A Vitamin A is essential for night vision and improves ... also causes osteomalacia in the adults. Humans have the ability to synthesize vitamin D from sunlight.

Description : Which part/organ of the human body do the following belong: (i) Eustachian tube (ii) Cartilage (iii) Auricle (iv) Tendon (v) Dendrites

Last Answer : Answers: (i) Eustachian tube...... Ear (ii) Cartilage............ ... Connective tissue (iii) Auricle............... .. Ear (iv) Tendon ................Muscle (v) Dendrites... ........... Neuron

Description : Name any two glands which secretes hormones in human body

Last Answer : Ans. Thyroid and Pituitary , Pancreas

Description : What organ of human body controls the amount of water and salt in blood?

Last Answer : Ans. kidneys

Description : Why does a man fall forward when he jumps out of a running train or bus?

Last Answer : Answer: He is in motion while in the train or bus. When he jumps out, his feet comes to rest while touching the ground but his upper portion which is still in motion propels him forward.

Description : Give scientific reason of the following 1. rain water is more fertile than water from tube well 2. the man-hole covers are generally round 3. clothes of a moving dancer bulge 4. peoples are advised not to stand near a fast moving train 5. the image of a tree looks inverted on the bank of a lake

Last Answer : 1. rain water is more fertile than water from tube well after falling, the rain drops start moving on slope side, during this movements, the soluble salts and minerals solves from top soil in the ... a lake This is due to the law of reflection according to which image is formed far and inverted

Description : Give scientific reason of the following : a) Colour blindness is more common in men than in women b) Light coloured clothes are generally worn in summer c) A person is hurt more when he falls ... ground than on soft d) Deforestation causes more floods e) The man-hole covers are generally round

Last Answer : a) Colour blindness is more common in men than in women Women have the sex chromosomes XX, while men have the chromosomes XY. The gene for normal colour vision is found on the X- ... of flowing water. When these trees are cut the natural barriers ultimately vanish and more floods are caused

Description : Define the following a) Amphibion b) Synchronous satellite c) Big Dipper d) Fermentation e) Millennium Bug

Last Answer : (a) Amphibion cold-blooded vertebrate animal able to live both on land and water (b) Synchronous satellite A satellite in a synchronous orbit A synchronous orbit is one in which an orbiting object ... an inability in older computing software to deal correctly with dates of 1 January 2000 or later.

Description : Define ENERGY. Name four renewable sources of energy. How can our country come out of Energy Crisis?

Last Answer : Energy: In physics, energy ", is a scalar physical quantity that describes the amount of work that can be performed by a force, an attribute of objects and systems that is ... Administrative Improvement. -Utilization of largest deposits of coal. -Renewable sources of energy. -Public Awareness.

Description : define the following: (1) Vaccine: (2) Antibiotic: (3) Solar eclipse: (4) Exothermic:

Last Answer : (1) Vaccine: an antigenic preparation used to establish immunity to a disease. (2) Antibiotic: a drug that kills or prevents the growth of bacteria. (3) Solar eclipse: occurs when the moon passes ... sun. (4) Exothermic: A reaction that releases energy in the form of heat is called exothermic.

Description : Define any five of the following : Acoustics , Quartz , Cross Pollination , Allele , Optical Illusion , Ovulation , Aqua Regia

Last Answer : Acoustics : The science of sound dealing with the production, effects, and transmission of sound waves through various mediums. Includes the effects of reflection, refraction, diffraction, absorption, and ... ; it is just about one of the few substances that can dissolve gold and platinum.

Description : Define any five of the following terms using suitable examples :

Last Answer : a. Polymerization b. Ecosystem c. Antibiotics d. Renewable energy resources e. Gene f. Software

Description : Define any five of the following terms. a) Biogas b) Geothermal energy c) Vaccine d) Antibiotic e) Ceramics f) Light year

Last Answer : a) Biogas: Biogas is the result of the controlled microbial breakdown of organic materials such as animal manures or food scraps in an anaerobic digester.Biogas is a mixture of about 60-70% methane (natural ... 10 trillion km. More precisely, one light-year is equal to 9,500,000,000,000 kilometers.

Description : Give scientific reason of the following: (1) Pole star is always seen in the north. (2) We never see birds urinating. (3) Pasteurized milk has more nourishment than the ordinary boiled milk. (4) Bees die when they sting human beings. (5) Cloudy nights are usually warmer than the clear ones.

Last Answer : (1) Pole star is always seen in the north. Because the pole star, which we have in the south, is too faint that it cannot be seen from the naked eye. or Because the earths motion is from ... to get lost in the atmosphere, above the clouds. Ultimately, the heat produced in the vicinity is restored.

Description : Vitamin D is the essential component of the Body.

Last Answer : Ans: Vitamin D is responsible for the absorption of calcium and phosphorus in the bones..

Description : What are Endocrine Glands ? Name any two . From which of the body are the following secreted :

Last Answer : Group of organs and tissues of the body that release hormones. The endocrine glands and their hormones regulate the growth, development, and function of various tissues and coordinate ... Thyroxin: Thyroid Adrenaline: Adrenal medulla Estrogen: Ovaries Testosterone: Testes Cortisol: Adrenal cortex

Description : What are Endocrine Glands? Name any two. From which part of the body are the following secreted: a) Insulin b) Thyroxin c) Adrenaline d) Oestrogen e) Testosterone f) Cortisol

Last Answer : These are those glands which pour their secretions directly into the blood stream . Their secretions are called as Hormones which are the chemical substances produced by the cells of one part and transported ... and many other functions of body and mind. E.g. Pituitary Gland, Thyroid Gland etc.

Description : Which are plastics? Name their different types and processes by which they are manufactured. Discuss the impact of the use of plastics on the environment.

Last Answer : What is plastic? Plastic is a common name for Polymers: materials made of long strings of carbon and other elements. Each unit in a string is called a monomer, and is a chemical usually ... or hardened by heat. Some typical thermosets are: * Bakelite * Epoxy * Melamine * Polyester * Polyurethane

Description : Why is the water in an open pond cool even on a hot summer day?

Last Answer : Answer: As the water evaporates from the open surface of a pond, heat is taken away in the process, leaving the surface cool.

Description : Why does kerosene float on water?

Last Answer : Answer: Because the density of kerosene is less than that of water. For the same reason cream rises in milk and floats at the top.

Description : Why does moisture gather outside a tumbler containing cold water?

Last Answer : Answer: The water vapour in the air condenses on cooling and appears as droplets of water.

Description : Why does ice float on water?

Last Answer : Answer: The weight of the ice block is equal to the weight of the liquid displaced by the immersed portion of the ice.

Description : Why does a small iron sink in water but a large ship float?

Last Answer : Answer: The weight of water displaced by an iron ball is less than its own weight, whereas water displaced by the immersed portion of a ship is equal to its weight (Archimedes? Principle).

Description : Why does blotting paper absorb ink?

Last Answer : Answer: Blotting paper has fine pores, which act like capillaries. When a portion of blotting paper is brought in contact with ink, ink enters the pores due to surface tension (capillary action f liquids) and is absorbed.

Description : Why is one?s breath visible in winter but not in summer?

Last Answer : Answer: In winter, water vapor contained in the breath condenses into small droplets, which become visible but in summer they are quickly evaporated and not seen.

Description : Why does a swimming pool appear less deep than is actually is?

Last Answer : Answer: The rays of light coming from the bottom of the pool pass from a denser medium (water) to a rarer medium (air) and are refracted (bend away from the normal). When the rays return to the surface, they form an image of the bottom of the pool at a point, which is little above the real position.

Description : Why is a rainbow seen after a shower?

Last Answer : Answer: After a shower, the clouds containing water droplets act like a prism through which the white light is dispersed producing a spectrum.

Description : Why is water from a hand pump warm in winter and cold in summer?

Last Answer : Answer: In winter, the outside temperature is lower than that of water flowing out of the pump, and therefore, the water is warm. Whereas in summer, the outside temperature is higher than the water of the pump, and therefore, it feels cold.

Description : Why is a compass used as an indicator of direction?

Last Answer : Answer: The magnetic needles of a compass under the influence f the earth?s magnetic field lie in a north-south direction. Hence, we can identify direction.

Description : Why does an ordinary glass tumbler crack when very hot tea or milk is poured in it?

Last Answer : Answer: When a hot liquid is poured into a tumbler, the inner layer of the tumbler gets heated, it expands before the outer layer and an unequal expansion of both layers causes the tumbler to crack.

Description : Why does an electric bulb explode when it is broken?

Last Answer : Answer: The bulb encompasses partial vacuum and as it breaks, air rushes in causing a small explosion.

Description : Why does smoke curl up in the air?

Last Answer : Answer: Smoke contains hot gases which being lighter in weight, follows a curved path because of the eddy currents that are set up in the air.

Description : Why do we lean forward while climbing a hill?

Last Answer : Answer: In order to keeps the vertical line passing through our centre of gravity always between our feet, which is essential to attain equilibrium or stability.

Description : Why does a balloon filled with hydrogen rise in the air?

Last Answer : Answer: Weight of hydrogen is less than the weight of air displaced by it. In balloons hydrogen is normally filled because it is lighter than air.

Description : Why are water or mercury droplets always round when dropped on a clean glass?

Last Answer : Answer: The surface of a liquid is the seat of a special force as a result of which molecules on the surface are bound together to form something like a stretched membrane. They tend to compress the ... which causes the drop to take a round shape as for a given mass he sphere has minimum volume.

Description : Why cannot a copper wire be used to make elements in electric heater?

Last Answer : Answer: Copper melts at 108.3^0C and forms a black powder on reacting with atmospheric oxygen. For heater elements a metal should have more resistance to produce heat.

Description : Why is a small gap left at the joint between two rails?

Last Answer : Answer: To permit expansion of rails due to heat generated by friction of a moving train.

Description : Why does a corked bottle filled with water burst if left out on a frosty night?

Last Answer : Answer: Because of low temperature the water inside the bottle freezes. On freezing it expands, thereby its volume increases and pressure is exerted on the walls.

Description : Why do we bring our hands close to the mouth while shouting across to someone far away?

Last Answer : Answer: By keeping hands close to mouth the sound is not allowed to spread (Phenomenon of diffraction of sound) in all direction, but is directed to a particular direction and becomes louder.

Description : We never see birds urinating.

Last Answer : Ans: The birds do not have a urinary system like other living beings which possess urinary excretory organs. In the birds the urine is excreted from body without special organs.

Description : A geostationary satellite appears standstill to a viewer on the equator of earth.

Last Answer : Because these satellites are in the geosynchronous orbit (an orbit around the Earth with an orbital period matching the Earth's sidereal rotation period) Geostationary orbit is a type of geosynchronous orbit that is directly above the equator

Description : The manholes covers are generally round.

Last Answer : It is impossible to drop a round lid into a smaller round hole. It is because round is the only shape that if turned or flipped over, it still retains the same length across its center. If you used ... it on its edge. A round cover contains less metal than a same-sized cover of any other shape.

Description : The dogs pant, the birds open their mouth and the elephants move rapidly their ears.

Last Answer : I think all of these do not sweat, they use the above mentioned mechanisms to cool themselves

Description : Write briefly (a)Allotropy (b) Nebula (c) Enrichment of Uranium (d) Aqua Regia (e) Greenhouse effect (f) Igneous rocks

Last Answer : (a)Allotropy existence of a chemical element in two or more different forms For example, the element carbon has two common allotropes: diamond, where the carbon atoms are bonded together in a ... igneous rocks have been described, most of them formed beneath the surface of the Earth's crust.

Description : Sun is glorious star in our sky. Write down its characteristics with reference to the following date:

Last Answer : (a) Distance from earth 149,600,000 kilometers, or 92,960,000 miles (b) Mean distance from center of galaxy 26,000 light-years (c) Velocity around centre of galaxy 251 km ... the core temperature reaches around 100 million kelvins and will produce carbon, entering the asymptotic giant branch phase

Description : X-rays and Gamma rays

Last Answer : X-Rays - High energy electromagnetic radiation of wavelengths in the range 10 to 0.1 nanometres. X-rays are extra-nuclear and have two sources: (1). A characteristic (e.g.K- or L-) Xray photon is ... originate in the nucleus of atoms. A gamma ray is a photon, i.e. a discrete packet of many waves

Description : Periscope and perimeter

Last Answer : Periscope - optical scope that allows one to see objects that are located above one's line of sight perimeter - outer boundary of a figure or area; total length of the outer boundary