12th Zoology

Minerals – Water – Role of water


Along with complex organic substances, such as carbohydrates
proteins and lipids, our body needs substances such as minerals, vitamins and
water as accessory food factors.

Of the minerals certain elements are found in greater concentration. They
are sodium, calcium, potassium, magnesium, phosphorus, sulphur and chlorine.
Certain other minerals are required in slightly lower concentration for performing
useful functions. These include, iron, copper, zinc, cobalt, manganese, iodine and
fluorine(trace elements).

Of these minerals, larger portion of certain minerals are
concerned with body building activities such as formation of bones and teeth
(Calcium, Magnesium and Phosphorus). Trace elements and other minerals are
useful in physiological activities such as oxygen transport (Iron), hormone
synthesis (Iodine) and intermediary metabolism (Manganese, Copper, Zinc).

Some of the elements remain as constituents of the body fluids (Chlorine,
Sodium and Potassium). Presence of certain minerals is essential for

neuro-muscular irritability (Magnesium, Sodium and Potassium), blood clotting
(Calcium), cardiac functions (Potassium and Calcium).


Water is a major costituent in the body of all mammals. The
proportion of water in the lean body mass (mass of the body – fat content) is
constant at around 71 to 78 % in animals including human beings.
The total body water content varies with age, sex and body weight.
In a new born child it is 85 to 90 % of body weight. In young adults it ranges
from 55 – 60 %.
Of the total body water, about 2/3 is found as intra-cellular fluid (ICF)
and 1/3 as extra-cellular fluid (ECF). About 25% of ECF is the plasma of
The body water content is kept constant by maintaining a proper
balance between water intake and loss. Intake of water happens through
drinking of water and beverages, water in the food consumed and water
generated during metabolism. The average water intake is around 2500 ml/
day (as water 1400 ml).
Water loss happens through four routes. They are
1. Urine (about 1400ml),2. Expiration (400ml), 3. Through skin
(600ml), 4. Loss in faeces (100ml)

Role of water

1. It is an essential constituent of all the cells of the body.
2. It serves as a transport medium for nutrients and excretory products.
3. It serves as a site for chemical reactions.
4. It is a valuable solvent for electrolytes, enzymes, hormones and
5. It plays a vital role in the maintenance of body temperature.
6. It helps to maintain form and texture of tissues.

Related Topics in Zoology:

Bio Zoology All Important Topics

  1. Human Physiology Introduction

  2. Nutrition

  3. Carbohydrates Poly hydroxyaldehydes (or) ketones

  4. Proteins (Polypeptides)

  5. Lipids

  6. Vitamins – Functions Of Vitamins

  7. Deficiency of Vitamin

  8. Minerals – Water – Role of water

  9. Balanced diet

  10. Obesity

  11. Digestive System

  12. Dental Caries (Tooth decay)

  13. Root Canal Treatment

  14. Peptic ulcer

  15. Hernia and Types

  16. Appendicitis (Appendix)

  17. Gall Stones

  18. Hepatitis

  19. Fractures – Types of fractures

  20. Mechanism of fracture

  21. Dislocation of joints

  22. Arthiritis

  23. Rickets and Osteomalacia – Orthopedics

  24. Muscles

  25. Mechanism of muscle contraction

  26. Types of muscle contraction

  27. Myasthenia Gravis

  28. Respiration – Process of pulmonary respiration

  29. Mechanism of Breathing

  30. Regulation of Respiration

  31. Pneumonia Tuberculosis Symptoms Treatment

  32. Bronchitis – Acute bronchitis, Chronic Bronchitis Causes

  33. Circulatory System – Functioning of Human heart

  34. Cardiac Cycle

  35. Coronary blood vessel and its significance

  36. Myocardial infarction

  37. Angina pectoris

  38. Angiogram – Angioplasty

  39. Atherosclerosis

  40. Heart block Echo cardiography Heart Valves

  41. Rheumatic Heart Disease (RHD), ICCU – (Intensive Coronary Care Unit)

  42. Blood Pressure

  43. Heart transplantation

  44. Pulse rate

  45. Cardio Pulmonary Resuscitation (CPR)

  46. Blood – Composition of plasma – Blood cells

  47. Clotting of Blood or Haemostasis

  48. Thrombosis

  49. Nervous system Co-ordination systems

  50. The Brain – Fore Brain, Midbrain, Hindbrain

  51. Memory

  52. Sleep – Types of sleep

  53. Stroke – Brain haemorrhage

  54. Alzheimer – Meningitis (Brain fever)

  55. Conditioned reflex

  56. Electroencephalography EEG

  57. Right and Left brain concept

  58. Spinal cord functioning

  59. Chemical co-ordination – Functions of Endocrine glands

  60. Hypothalamus

  61. Pituitary gland – hormone

  62. Hormones of Neurohypophysis – vasopressin

  63. Thyroid gland

  64. Parathyroid Gland

  65. Pancreas

  66. Adrenal gland

  67. Gonads

  68. Receptor Organs – Eye

  69. Photochemistry of Retinal visual Pigments

  70. Errors of refraction

  71. Optometry – Retinopathy

  72. Cataract – Lens Replacement – Glaucoma – Nyctalopia

  73. Eye Infections and Eye Care

  74. Ear

  75. Mechanism of hearing

  76. Defects of the ear

  77. Hearing Aid – Noise pollution

  78. Skin and functions of skin

  79. Melanin functions

  80. Effects of solar radiation / UV radiation – Skin grafting

  81. Dermatitis

  82. Tongue – Mechanism of Stimulation

  83. Excretion Ureotelism Nephron

  84. Mechanism of urine formation

  85. Renal Failure, Dialysis, Kidney Machines

  86. Kidney stone – Kidney transplantation

  87. Diabetes mellitus

  88. Functioning of male reproductive system

  89. Functioning of female reproductive system

  90. Ovulation and fate of the ovum – Menstrual cycle

  91. Fertilization

  92. Birth control

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