Class 3 Science - Human Body Organ Systems - CBSE Worksheets Solutions

Name the following

Question 1:

• Helps in movement of body organs muscles.
• Helps in breakdown of food into simple pieces enzymes.
• Framework of bones the skeleton system .
• Helps circulation of digested food and oxygen in body red blood cells.
• Helps in breathing Diaphragm.

EduRev Tips:

• Muscles pull on the joints, allowing us to move. They also help the body do such things as chewing food and then moving it through the digestive system.
• Enzymes help in the breakdown of complex molecules like carbohydrates, protein, fats, etc. into simple molecules.
• The skeletal system is your body's central framework. It consists of bones and connective tissue, including cartilage, tendons, and ligaments.
• Red blood cells transport oxygen to cells in all parts of the body. Red blood cells are formed in the red marrow of bones.
• The main breathing muscle is the diaphragm.

MCQs

Question 2: Which of these organs controls all other organs of the body?
(a) Brain
(b) Kidneys
(c) Heart
(d) Stomach

Correct Answer is Option A.

The nervous system is the control center of the human body. It is made up of the brain, spinal cord, and nerves.

Question 3: The sense organ that enables us to feel hot and cold is:
(a) nose
(b) eyes
(c) skin
(d) ear

Correct Answer is Option C.

The skin helps us to differentiate between the things which are cold or hot or between the roughness or smoothness of different things also.

Question 4:  Which system converts food into a form in which it can be absorbed by the body?
(a) Circulatory
(b) Breathing
(c) Digestive
(d) Excretory

Correct Answer is Option C.

The digestive system converts the foods we eat into their simplest forms, like glucose (sugars), amino acids (that make up protein) or fatty acids (that make up fats).

Question 5:  Which of these is not a sense organ?
(a) Nerves
(b) Tongue
(c) Skin
(d) Ears

Correct Answer is Option A.

Nerves are not a sense organ.

Question 6:  Which of these is not a part of the circulatory system?
(a) Blood
(b) Stomach
(c) Blood vessels
(d) Heart

Correct Answer is Option B.

The circulatory system is composed of the heart, arteries, capillaries, and veins. This remarkable system transports oxygenated blood from the lungs and heart throughout the body via the arteries.

Question 7:  Which organ system protects the soft organs in our body?
(a) Nervous
(b) Skeletal
(c) Digestive
(d) Muscular

Correct Answer is Option B.

Bones provide a rigid framework, known as the skeleton, that supports and protects the soft organs of the body. The skeleton supports the body against the pull of gravity.

Fill in the blanks

Question 8: 

• The five sense organs in our body are skin, eyes, nose, tongue and ears.
• The circulatory system form a network of tubes which supply food and oxygen throughout the body.
• Our facial expression are caused by movement of muscles.
• Air enters the Larynx through the wind pipe.
• Breaking down food into tiny simple pieces is called digestion of food.

EduRev Tips:

• The sense organs are the body organs by which humans are able to see, smell, hear, taste, and touch or feel. The five sense organs are the eyes (for seeing), nose (for smelling), ears (for hearing), tongue (for tasting), and skin (for touching or feeling).
• The vascular system is made up of the vessels that carry blood and lymph fluid through the body. It's also called the circulatory system. 
• Facial expressions are vital to social communication between humans. They are caused by the movement of muscles that connect to the skin and fascia in the face.
• Larynx, also called voice box, a hollow, tubular structure connected to the top of the windpipe (trachea); air passes through the larynx on its way to the lungs.
• The digestive system converts the foods we eat into their simplest forms, like glucose (sugars), amino acids (that make up protein) or fatty acids (that make up fats).

True & False

Question 9: 

• The brain is the control system of our body. True
• Muscles and bones together enable us to move our body parts. True
• A group of tissues form a cell. True
• We can see with our eyes without the help of the brain. False
• Blood continuously takes nutrients and gases to all parts of our body. True

EduRev Tips:

• The brain is the control system of our bod
• Muscles are also necessary for movement: They're the masses of tough, elastic tissue that pull our bones when we move. Together, our bones, muscles, and joints — along with tendons, ligaments, and cartilage — form our musculoskeletal system and enable us to do everyday physical activities.
• Tissue is a group of cells that have similar structure and that function together as a unit.
• Our eyes do a really good job of capturing light from objects around us and transforming that into information used by our brains, but our eyes don't actually “see” anything.
• Blood brings oxygen and nutrients to all the parts of the body so they can keep working. Blood carries carbon dioxide and other waste materials to the lungs, kidneys, and digestive system to be removed from the body.

Answer the following questions in brief.

Question 10:  What gives shape to our body?

Skeleton gives shape and support to our body. It protects the important organs of the body. The bony framework in the head is called the "Skull". This protects the brain.

Question 11: List the organs of the nervous system and write its function.

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.

The nervous system has three broad functions: sensory input, information processing, and motor output.

Question 12: What is the role of excretory system in the body?

The Excretory system is responsible for the elimination of wastes produced by homeostasis. There are several parts of the body that are involved in this process, such as sweat glands, the liver, the lungs and the kidney system. Every human has two kidneys.

Question 13: How are the delicate organs like lungs and heart in our body protected from injury?

The bones of the chest namely the rib cage and spine protect vital organs from injury, and also provide structural support for the body. The rib cage is one of the body's best defenses against injury from impact. Flexible yet strong, the rib cage protects major vital organs such as the heart, lungs, and liver.

Question 14: Name the materials that the circulatory system takes from one place to another in the body.

• The circulatory system delivers oxygen and nutrients to cells and takes away wastes.
• The heart pumps oxygenated and deoxygenated blood on different sides.
• The types of blood vessels include arteries, capillaries and veins.

Question 15: Write the correct matching number below each picture.
(a) The Breathing System

(b) The Circulatory System
(c) The Digestive System
(d) The Excretory System
(e) The Nervous System