Olympiad Test: Human Body -1 - Class 4 MCQ

The digestive process starts in your mouth when you chew. Your salivary glands make saliva, a digestive juice, which moistens food, so it moves more easily through your esophagus into your stomach.

Molars are specially designed for crushing and chewing plant foods into easily swallowable and digestible pieces. They also help to maintain the proper positioning of the jaws. They enable them to slice and grind their food efficiently. 

Blood carries oxygen to all body parts.

The respiratory system consists of all the organs involved in breathing. These include the nose, pharynx, larynx, trachea(windpipe), bronchi, and lungs.

Kidneys belong to the excretory system. The organs of the excretory system include the kidneys, renal pelvis, ureters, bladder and urethra.

The correct answer is (B) Fainted.
Explanation:
Soni most likely fainted, and her friend gave her an immediate first-aid treatment to help her recover. The first aid given to Soni, which involved lying down with her legs raised and her head lower than her body, is a common first-aid method for someone who has fainted. This position helps:
- Increase blood flow to the brain: Raising the legs increases blood flow to the brain, which can help restore consciousness.
- Prevent further fainting: This position helps prevent further fainting episodes by ensuring that the brain receives adequate blood supply.
- Promote recovery: Lying down can help the person feel more comfortable and recover faster after fainting.
Other options such as electric shock, insect bite, or burns would require different first-aid treatments and would not typically involve raising the legs and lowering the head.

The brain controls what you think and feel, how you learn and remember, and the way you move and talk. But it also controls things you're less aware of — like the beating of your heart and the digestion of your food.

Running will increase our heart rate as it requires more energy from our body which needs quick pumping of blood from the heart.

The lungs and respiratory system allow us to breathe. They bring oxygen into our bodies (called inspiration, or inhalation) and send carbon dioxide out (called expiration, or exhalation). This exchange of oxygen and carbon dioxide is called respiration.

The innermost layer or lining (mucosa) contains the glands that release digestive juices. This is the first and innermost layer or lining. It contains the glands that release digestive juices. These are called hydrochloric acid and pepsin

The digested food is absorbed into the blood in the human body. After digestion, the absorption occurs in the small intestine through the finger-like projections called villi present on the wall of the intestine.

The small intestine absorbs digested food and sends it to the blood in our body, which transfers it to various parts of our body.

C in the diagram represents Urinary Bladder, where the urine is stored before releasing.

In our body, the dirty blood is filtered in the kidneys by the glomerulus present in them. In addition, kidneys regulate and filter minerals from blood.

An image of kidney (brown coloured)

The nervous system consists of the brain, spinal cord, sensory organs and all of the nerves that connect these organs with the rest of the body. Together, these organs are responsible for the control and coordination of the activities of all the systems in our body.

The two lower chambers are called ventricles

• Mouth: Food starts to get broken down when you chew and mix it with saliva.
• Esophagus (Food Pipe): This just moves the food from your mouth to your stomach.
• Stomach: Food gets mixed with strong acids and enzymes that break down proteins, but it’s not fully digested here.
• Small Intestine: This is where the real digestion happens. The food mixes with digestive juices and is broken down into nutrients that your body can absorb. Most of the digestion and nutrient absorption happens here.
• Large Intestine: This is where the remaining waste gets rid of extra water and forms stool.

So, digestion is mostly completed in the small intestine.

Anus is the opening at the lower end of the digestive tract through which solid waste is excreted.

Adults have more teeth than children; most adults have 32 teeth.