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The Human Body: Skeletal and Muscular System - Care of bones and muscles

Grade 5ICSE

Review the key concepts, formulae, and examples before starting your quiz.

🔑Concepts

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A balanced diet rich in Calcium (CaCa) and Phosphorus (PP) is essential for maintaining bone density and strength.

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Vitamin D (CalciferolCalciferol) is crucial as it helps the body absorb calcium from the food we eat. Sunlight is a natural source that helps our skin produce Vitamin D.

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Regular physical exercise, such as running and weight-bearing activities, strengthens the muscles and increases the mineral content of the bones.

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Maintaining a correct posture while sitting, standing, and walking ensures that the spine maintains its natural 'SS' curve and prevents undue pressure on the vertebrae.

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Proteins are necessary for the growth and repair of muscle tissues. Muscles are made of fibers that require amino acids from proteins to rebuild after exercise.

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Rest and sleep are vital for the body to repair worn-out tissues and for the muscles to recover from fatigue caused by the accumulation of lactic acid (C3H6O3C_3H_6O_3).

📐Formulae

Ca3(PO4)2 (Calcium Phosphate - the primary mineral in bones)Ca_3(PO_4)_2 \text{ (Calcium Phosphate - the primary mineral in bones)}

Ca10(PO4)6(OH)2 (Hydroxyapatite - gives bones their rigidity)Ca_{10}(PO_4)_6(OH)_2 \text{ (Hydroxyapatite - gives bones their rigidity)}

Bone Health=Balanced Diet+Regular Exercise+Correct Posture\text{Bone Health} = \text{Balanced Diet} + \text{Regular Exercise} + \text{Correct Posture}

💡Examples

Problem 1:

Why do doctors recommend spending time in early morning sunlight for healthy bones?

Solution:

Sunlight helps the skin synthesize Vitamin DVitamin\ D.

Explanation:

Without Vitamin DVitamin\ D, the body cannot effectively absorb Calcium (CaCa) from the digestive system. Even if a child consumes enough milk, a lack of Vitamin DVitamin\ D can lead to weak bones or conditions like Rickets.

Problem 2:

A student often carries a heavy school bag on only one shoulder. What effect could this have on their skeletal system?

Solution:

It can lead to an abnormal curvature of the spine, such as ScoliosisScoliosis.

Explanation:

Uneven weight distribution puts excessive pressure on one side of the vertebral column. Maintaining a balanced posture and using both shoulder straps helps keep the spine aligned in its natural state.

Problem 3:

Identify the mineral deficiency that makes bones brittle and easy to break.

Solution:

Deficiency of Calcium (Ca2+Ca^{2+}).

Explanation:

Bones act as a reservoir for minerals. If the diet lacks Ca3(PO4)2Ca_{3}(PO_{4})_{2}, the body may draw calcium from the bones, making them porous and brittle.