Biology 'Homeostatis' (Short Questions)Part B
Assalam-o-Alaikum
Q.25. How ADH increase the reabsorption of water?
Ans. A hormone ADH (Antidiuretic hormone) or vasopressin which increases the permeability of collecting duct in this way reabsorption of water increases.
Q.26. Which hormones are responsible for the reabsorption of sodium ions and calcium ions?
Ans. Another hormone Aldosterone which is secreted from adrenal gland increases the reabsorption of sodium ions Parathormone secreted from parathyroid glands maintains the level of calcium after increasing reabsorption of calcium ions.
Q.27. What is the percentage of infective renal stones and what is their biochemical compositions?
Ans. About 20% of calcium are termed as infective stones. Such calculi consists of combination of calcium, magnesium and ammonium phosphate. Some stones about 5% are formed by uric acid.
Q.28. What is lithotripsy?
Ans. It is the advance method of removing stones from kidneys and urinary bladders. In this method shock waves and ultra sonic waves are used for breaking stones in the body. After being broken small broken fragments of are passed in urine.
Q.29. What is renal failure and what are their major signs and symptoms?
Ans. It is the condition in which kidney are unable to filter blood to remove waste materials. In this way waste materials accumulate in blood, which leads to symptoms such as nausea, vomiting loss of appetite, weakness, breathlessness etc. In severe cases coma and death.
Q.30. What is haemodialysis?
Ans. Haemodialysis means “cleaning the blood”. In this procedure blood is circulated through a machine which contains a fluid dialyzer whose composition is mentioned.
Q.31. How many types of dialysis are there?
Ans. There are two types of dialysis
1. Haemodialysis
2. Peritoneal dialysis
Q.32. How haemodialysis is carried out?
Ans. Dialyzer has two spaces separated by their semipermeable membrane. Blood passes from one side of the membrane and dialyzer on the other side. The wastes and excess water pass from the blood through the membrane into the dialyzer. There after the blood is returned to circulation.
Q.33. What peritoneal dialysis?
Ans. During this method, there is inserted in the peritoneal cavity of abdomen after making an incision. Through this cathoter dialyze is filled in to the peritoneal cavity for several hours. As a consequen waste from the blood vessels lining the peritoneal cavity seep through peritoneal membrane into the cavity and mixes with dialyzer. The fluid is then drain out through the catheter.
Q.34. What is thermoregulation?
Ans. The regulation of body temperature within the stable normal constant limits of the body against the harsh fluctuating circumstances for the maintenance of homeostasis is called Thermoregulation.
Q.35. How many types of thermoregulation?
Ans. Thermoregulation among animals of two types.
1. Behavioral Thermoregulation
2. Physiological Thermoregulaton
Q.36. What is behavioural thermoregulation?
Ans. This regulation involves behavior of the animals in hot and cold weathers for e.g. animal increases or decreases heat loss by changing their locations. They will bask in the sun or in warm rock during winter and find wet cool area in summer.
Q.37. What is physiological thermoregulation?
Ans. Its involves the regulation of body temperature by some biological means. It is exhibited by the change in blood circulation, body metabolism, heat loss by evaporation of sweat.
Q.38. What are Poikilotherms?
Ans. Those animals which change their body temperature with respect to the change of temperature of surroundings. e.g. all invertebrates, fishes, amphibians and reptiles fall into this category.
Q.39. What are Homotherms?
Ans. Those animals which have constant body temperature which is independent to the changes in the temperature of surroundings.
Q.40. What are Ecotherms?
Ans. Those animals which maintain their body temperature by absorbing heat from the environment. E.g. Lizard basking in the sun.
Q.41. What are Endotherms?
Ans. Those animals which maintain their body temperature by generating heat in their bodies are called endotherms.
Q.42. What are Heterotherms?
Ans. Those animals which generate heat in their bodies to keep their body temperature to wider range. E.g. Bats, Humming Birds.
Q.43. How mammals control their body temperature physiological means during cold environment?
Ans. Thermoregulation in cold temperature.
Physiological Mechanism
(a) Non-Shivering Thermogenesis
i. Erection of Hairs: During cold weather hair of bodies becomes erect due the contraction in erector pilli muscles in skin. Vertical hair trap air near to skin which reduces heat loses from skin.
ii. Subcutaneous Fact Acelmulation: Mammals live in colder regions of world have thick layer of adipose tissues under their skin. These adipose tissues work as insulator and reduce head loss.
iii. Reduction in Blood Flow Through Skin: In cold temperature, arteries and veins in skin become narrow due to which blood circulation in skin decreases and heat loss is reduced due to radiation.
(b) Shivering Thermogenesis
In colder weather brain starts involuntary muscle movement called shivering which helps in generating heat to increase the body temperature.
Q.44. How mammals regulate their body temperature by behavioural means during cold environment?
Ans. Thermoregulation in Cold Temperature
Behavioural Mechanism.
In colder weather animals move towards warm places to maintain their body temperature.
Q.45. How mammals control their body temperature by physiological means during hot environment?
Ans. Thermoregulation in Hot Temp
Physiological Mechanism
i. Lowering of Hair: In hot weather animals lower their hair to reduce insulating effect.
ii. Increase in Blood Flow Towards Skin: Arteries and veins of skin become dilate due to which blood circulation increases in skin and heat loss occurs due to radiation.
iii. Sweating: In summer sweet glands secrete sweat, which when evaporates body looses heat.
Q.46. How mammals regulate their body temperature by behavioural means during hot environment?
Ans. Behavioral Mechanims:
Animal during summer move towards colder region to maintain their body temperature.
Q.47. How hypothalamus act as a Thermostate for the body.
Ans. Role of Brain in Temperature Regulation
Hypothalamus is the part of brain which regulates the body temperature. In this way this is called the most at of body. Hypothalamus receives messages from thermo receptor present in the skin. When any change in the temperature is detected by the hypothalamus, instructions are sent to the particular organ to bring the body temperature back to normal. For example in summer body promotes heat loss by evaporation of sweat from skin. But during winter body generates heat by different mechanism.
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