The Muscular System & Digestive System in Human Beings - Standard 7 - General Science - Balbharati
The Muscular System & Digestive System in Human Beings
Exercise
Q. 1 Fill in the blanks with the right word from the brackets.
(a) The process of digestion starts from the stomach.
(b) Eyelids have voluntary muscles.
(c) Production of blood cells is not a function of the muscular system.
(d) Muscles of the heart are cardiac muscles.
(e) Pushing forward the food that has been chewed is the function of the oesophagus.
Q. 2 Find a match for me.
| Group'A' | Answers |
|---|---|
| Cardiac muscles | we never feel tired. |
| Are brought about muscles. | chewing movements of jaws. |
| Pepsin | enzyme of the gastric juice. |
| Cramps | uncontrolled and painful contraction of muscles. |
| Skeletal muscles | always function. |
Q. 3 Who is telling a lie?
1. Tongue
My taste-buds can tell only a sweet taste.
Ans. Tongue is telling a lie because; its taste-buds can tell salty, bitter tastes as well.
2. Liver
Ans. Truth. The liver is the largest gland in the body.
3. Large intestine
I am 7.5 meter long.
Ans. The large intestine is telling a lie because; it is just 1.5 meter long.
4. Appendix
Digestion is impossible without me.
Ans. An appendix is telling a lie because; it is not required for the digestion process.
5. Lung
I play an important role in excretion.
Ans. Lung is telling a lie because; kidneys play an important role in excretion.
Q. 4 Give reasons.
(1) Food becomes acidic in the stomach.
Ans. Food becomes acidic in the stomach because;
1. The stomach secretes gastric juice containing hydrochloric acid (HCl).
2. The acidic environment helps in the breakdown of food, into smaller, digestible components.
(2) Cardiac muscles are said to be involuntary muscles.
Ans. Cardiac muscles are said to be involuntary muscles because;
1. Cardiac muscles are found in the heart, and their contraction is not under our will.
2. They function involuntarily to maintain a continuous and rhythmic pumping action of the heart to circulate blood throughout the body.
(3) Intoxicating substances should not be consumed.
Ans. Intoxicating substances should not be consumed because;
1. Intoxicating substances, such as alcohol and drugs, can impair cognitive function, coordination, and judgment.
2. Long-term consumption can lead to addiction, health problems, and a negative impact on overall well-being.
(4) Your muscles should be strong and efficient.
Ans. Your muscles should be strong and efficient because;
1. Strong muscles provide support to the skeletal structure and contribute to good posture and overall stability.
2. Efficient muscles support various body functions, like movement, metabolism, and maintenance of a healthy body.
3. Strong and well-toned muscles help prevent injuries, enhance physical performance, and contribute to overall health and fitness.
Q. 5 Answer the following.
(a) How many types of muscles are there? Which are those types?
Ans. There are three types of muscles:
1. Skeletal muscles: The two ends of each of these muscles are attached to two different bones. Examples of such muscles are muscles of the arms and legs. Their movements are voluntary. They are also responsible for holding the bones of the skeleton together and giving shape to our body.
2. Heart or cardiac muscles: These muscles. bring about the contraction and relaxation (beating) of the heart. Their movement is involuntary. Cardiac muscles cause our heart to relax and contract continuously at a rate of about 70 times per minute.
3. Smooth muscles: These muscles are present in the internal organs other than the heart. For example, muscles of the stomach, intestine, blood vessels, uterus, etc. Their movements are involuntary and slow. Various vital functions of our body, of which we remain quite unaware, are carried out by these special muscles.
(b) What causes the problem of acidity? What is its effect on the body?
Ans. 1. Acidity happens when there's too much stomach acid. Spicy foods, stress, and some medicines are some of the causes of it. Acid comes up into the food pipe, causing a burning feeling.
2. Over time, this can harm the food pipe. It leads to heartburn, indigestion, and can affect digestion.
(c) Name the different types of teeth. What is the function of each type?
Ans. There are four main types of teeth.
1. Incisors:
Function: Cutting and shearing. Incisors are the front teeth and are used for biting into food.
2. Canines:
Function: Tearing and holding. Canines are pointed teeth, designed for ripping and tearing food.
3. Premolars:
Function: Grinding and crushing. Premolars have flat surfaces and are used for grinding and crushing food.
4. Molars:
Function: Grinding. Molars are the large, flat teeth at the back of the mouth and are responsible for grinding and crushing food into smaller pieces.
Q. 6 Sketch and label a diagram of the digestive system and describe it in your own words.
Ans.
