Test: Our Body And Health - 1 - Class 5 MCQ

The Human Heart Chambers:
- The human heart has 4 chambers.
- These chambers are divided into two sides: the left side and the right side.
- Each side of the heart consists of an atrium (upper chamber) and a ventricle (lower chamber).
- The left side of the heart contains the left atrium and the left ventricle.
- The right side of the heart contains the right atrium and the right ventricle.
- The atria serve as receiving chambers for blood returning to the heart, while the ventricles act as the pumping chambers.
- The right atrium receives oxygen-depleted blood from the body and pumps it into the right ventricle.
- The right ventricle then pumps the oxygen-depleted blood to the lungs for oxygenation.
- The left atrium receives oxygen-rich blood from the lungs and pumps it into the left ventricle.
- The left ventricle then pumps the oxygen-rich blood to the rest of the body.
- The separation of the chambers prevents oxygen-rich and oxygen-depleted blood from mixing.
- Valves located between the chambers ensure the flow of blood in the correct direction.
- The heart's pumping action is essential for delivering oxygen and nutrients to all parts of the body.

Approximate Length of the Large Intestine:
The large intestine, also known as the colon, is the final part of the digestive system. It plays a crucial role in absorbing water and electrolytes, forming and storing feces, and eliminating waste from the body.
To answer the question regarding the approximate length of the large intestine, we can consider the following points:
1. Anatomy of the Large Intestine:
- The large intestine is divided into four main parts: the cecum, colon, rectum, and anal canal.
- The colon is further divided into several sections, including the ascending colon, transverse colon, descending colon, and sigmoid colon.
2. Length of the Large Intestine:
- The total length of the large intestine varies among individuals.
- On average, the large intestine is approximately 1.5 meters long.
- The length can range from 1.2 meters to 1.8 meters.
3. Absorption of Water and Formation of Stool:
- The large intestine absorbs the majority of water from the remaining undigested food material.
- This absorption process helps in the formation of stool, as water content is reduced and the feces become more solid.
Therefore, the correct answer is D: 1.5 m, as it represents the approximate length of the large intestine.

The longest bone in our body is the Femur.
Explanation:
- The femur is located in the thigh and extends from the hip to the knee.
- It is the largest and strongest bone in the human body.
- The average length of a femur in an adult is about 18-20 inches (46-51 cm).
- The femur is responsible for supporting the weight of the body, providing stability, and allowing for movement.
- It is crucial for activities such as walking, running, and jumping.
- The femur has a unique structure with a head, neck, shaft, and two condyles at the bottom that articulate with the tibia and patella.
- It is also a site for the attachment of several muscles, including those responsible for hip flexion, extension, and rotation.
- The femur is composed of dense and strong bone tissue, allowing it to withstand significant forces during daily activities.
- In cases of fractures or injuries to the femur, surgical intervention may be necessary to ensure proper healing and restoration of function.

Percentage of Water in the Adult Human Body

The percentage of water in the adult human body can vary depending on various factors such as age, sex, and body composition. However, on average, it is estimated that the adult human body is about 60% water.

Factors Affecting Percentage of Water

Several factors can influence the percentage of water in the human body, including:

• Age: The percentage of water tends to be higher in infants and decreases with age.


• Sex: Males generally have a higher percentage of water compared to females.


• Body Composition: The percentage of water can vary based on the amount of muscle mass and body fat.

Importance of Water in the Body

Water plays a crucial role in maintaining overall health and bodily functions, including:

• Hydration: Water is essential for maintaining proper hydration and regulating body temperature.


• Transportation of Nutrients: Water helps transport nutrients and oxygen to cells throughout the body.


• Waste Removal: Water is involved in the elimination of waste products through urine and sweat.


• Lubrication: Water acts as a lubricant for joints and helps prevent friction between organs and tissues.


• Digestion: Water aids in the digestion and absorption of food.

It is important to maintain proper hydration by drinking an adequate amount of water daily to support these vital bodily functions.

The Correct Answer is A: Arteries
Arteries are the blood vessels that carry oxygen-rich blood away from the heart to various parts of the body. The aorta, which is the largest artery in the body, originates from the left ventricle of the heart and branches out into smaller arteries that supply blood to different organs and tissues. Here is a detailed explanation of why the answer is A: Arteries:
Arteries:
- Arteries are thick-walled blood vessels that carry oxygenated blood from the heart to the rest of the body.
- They have a muscular and elastic wall that helps to maintain blood pressure and regulate blood flow.
- Arteries usually carry oxygenated blood, except for the pulmonary artery, which carries deoxygenated blood from the heart to the lungs.
- Arteries branch out into smaller arterioles, which further divide into tiny capillaries.
Veins:
- Veins are blood vessels that carry deoxygenated blood back to the heart from various parts of the body.
- Unlike arteries, veins have thinner walls and often have valves to prevent the backflow of blood.
- Veins usually carry deoxygenated blood, except for the pulmonary veins, which carry oxygenated blood from the lungs to the heart.
Capillaries:
- Capillaries are the smallest blood vessels in the body and connect arteries to veins.
- They are thin-walled and allow for the exchange of oxygen, nutrients, and waste products between the blood and surrounding tissues.
- Capillaries are found throughout the body, forming an extensive network.
All of these:
- While all three types of blood vessels (arteries, veins, and capillaries) play crucial roles in the circulatory system, the question specifically asks about the blood vessels that take blood away from the heart to different parts of the body.
- Arteries are the correct answer because they carry oxygenated blood away from the heart.
- Veins carry deoxygenated blood back to the heart, and capillaries facilitate the exchange of substances between the blood and tissues.

Benefits of Exercise:
Exercise has numerous benefits for our physical health. One of the correct benefits of exercise is that it increases the flow of blood to the muscles. Here are some detailed explanations:
1. Improved cardiovascular health: Regular exercise helps improve the health of our heart and blood vessels. It increases the flow of blood to the muscles, including the heart, which helps to strengthen the heart muscle and improve its efficiency.
2. Stronger muscles and bones: Exercise stimulates the growth of muscles and increases bone density. This can help prevent conditions like osteoporosis and reduce the risk of fractures.
3. Weight management: Exercise helps in maintaining a healthy weight by burning calories. When combined with a balanced diet, regular exercise can assist in weight loss or weight maintenance.
4. Mental well-being: Exercise is not just beneficial for physical health, but it also has a positive impact on mental well-being. It releases endorphins, which are natural mood elevators, and can help reduce symptoms of depression and anxiety.
5. Increased energy levels: Regular exercise improves blood flow and oxygen delivery to the muscles and tissues, leading to increased energy levels and reduced feelings of fatigue.
6. Improved sleep: Engaging in regular exercise can promote better sleep patterns. It can help you fall asleep faster, deepen your sleep, and wake up feeling more refreshed.
7. Reduced risk of chronic diseases: Regular exercise has been linked to a lower risk of developing chronic conditions such as heart disease, type 2 diabetes, and certain types of cancer.
In conclusion, exercise offers a wide range of benefits for good physical health. One of the correct benefits is that it increases the flow of blood to the muscles, which contributes to improved cardiovascular health and overall well-being.

What does HIV stand for?
The correct answer is C: Human immunodeficiency virus.
Explanation:
- HIV stands for Human Immunodeficiency Virus.
- It is a virus that attacks the immune system and weakens a person's ability to fight off infections and diseases.
- When a body is infected with HIV, it targets and destroys CD4 cells, which are a type of white blood cell that plays a crucial role in the immune system.
- As a result, the immune system becomes suppressed, leading to a condition called Acquired Immunodeficiency Syndrome (AIDS).
- AIDS is the advanced stage of HIV infection and is characterized by severe damage to the immune system, making individuals more susceptible to life-threatening infections and cancers.
- HIV is primarily transmitted through certain body fluids, such as blood, semen, vaginal fluids, and breast milk.
- It can be transmitted through unprotected sexual intercourse, sharing needles or syringes, mother-to-child transmission during childbirth or breastfeeding, and less commonly through blood transfusions or organ transplants.
- HIV can be managed with antiretroviral therapy (ART), a combination of medications that can help control the virus and prevent its progression to AIDS.
- However, there is currently no cure for HIV, and prevention through safe practices and education remains crucial in combating the spread of the virus.

Explanation:
The average body temperature of a human being is 37°C. This temperature is often referred to as the normal body temperature. It is important for the body temperature to remain constant in order for the body systems to function properly.
Reasoning:
The body temperature of a human being needs to remain constant in order for the body systems to function properly. If the body temperature deviates too much from the normal range, it can lead to various health problems.
Options:
A: 25°C - This temperature is too low and not within the normal range for a human body temperature.
B: 32°C - This temperature is also too low and not within the normal range for a human body temperature.
C: 37°C - This temperature is the correct answer. It is the average body temperature of a human being.
D: 42°C - This temperature is too high and not within the normal range for a human body temperature.
Conclusion:
The correct answer is option C: 37°C. This is the average body temperature of a human being.