Human Digestive System (2) – Grade 7 Science Worksheets
Human Digestive System worksheet is part of the premium Grade 7 science worksheet package.
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What are the organs of the digestive system?
How does food move through the digestive system?
The Digestive system is also called alimentary canal and it is supported by organs like teeth, tongue, liver, and others. The digestive system helps to convert food into energy and nutrients to nourish the body. The food we take in is thoroughly digested and absorbed by our body and the wastes are eliminated through the excretory system. The alimentary canal is a lengthy tube through which the food goes down to our system. It starts at the mouth or the oral cavity going through the pharynx, esophagus or food pipe, stomach, small intestines, large intestines, rectum and anus. The food particles get digested in every stage of the alimentary canal as they move.
Oral /Mouth and the Buccal Cavity
The mouth has many accessory organs such as the tongue, teeth, and salivary glands, which help in the digestion of food. Food starts the first step of digestion in the mouth, also known as the buccal cavity or the oral cavity. Food is grinded by the teeth. Salivary amylase is the digestive juices given off by the salivary glands. This moistens the food, and break the food down into usable and absorbable components and then the food is pushed down into the pharynx.
The pharynx acts as a passage for the chewed food from the mouth to the esophagus. It has a flap of tissue known as the epiglottis preventing the food from getting into the wind pipe and helps us from getting choked while we eat.
Esophagus or Food Pipe
The esophagus is a tube joining the pharynx to the stomach. It is made of flexible muscle to help pushing of food easily. It carries swallowed food down its long tube and pushes it to the stomach.
The stomach is a thick-wall made of muscle in the form of a bag that is located on the left side of the abdominal cavity. It is the largest part of our digestive system. Stomach acts as a storage place for food. And slowly digests food. It gets food from the food pipe and sends it to the small intestine. The stomach has digestive acids which help reduce food into further absorbable substances. Mucous protects the inner walls of the stomach. This can otherwise get damaged while digesting food. Because the acid reacts with the bacteria and kills it that enters our body with food. The digestive enzymes break down proteins into simpler substances.
The small intestine is just named small. But it is the longest part our digestive system. It is made in such a way that it is highly coiled; it’s quite thin tubular form but still about 7.5 meters long. (The length of the small intestine depends on the diet of the organism.) A major proportion of digestion takes place in the small intestines. Nutrients get digested here. The walls of the small intestine also secrete juices for digesting food. The enzymes in the intestine convert the carbohydrates into glucose, proteins to amino acids and fats into fatty acids and glycerol.
The liver releases bile. This neutralizes the acidity level of the food. The pancreatic juice digests the proteins and lipids. Once the food is broken down into the simple particles, it is ready to be absorbed by the body. The absorbed food is then carried to different parts of the body through the blood vessels for cell activities.
The large intestine is a thicker tube than the small intestine. The large intestine absorbs water and left over nutrients from the remaining food with the help of many bacteria in it. The remaining food waste passes into the rectum, where it is ready to get out as semi-solid wastes. Feces then are excreted by the body through the anus.
I. Fill in the blanks –
- The ……………………..……………is the long tube through which the food that we eat is passed.
- The flap of tissue known as the ……………… present in pharynx prevents food from entering into the wide pipe.
- The enzymes in the intestine convert the ………………. into glucose, proteins to …………….. and fats into fatty acids and glycerol.
- The liver releases ………. juice which neutralizes the acidic food received from the stomach and also converts the fat.
- The ……………… ……… digests the proteins and lipids.
II. State True or False –
- The digestive system of is a system of organs working together to eliminate waste products out of the body.
- The esophagus is a tube joining the pharynx to the stomach made of flexible muscle to ease pushing of food.
- Mucous protects the lining of the stomach while acid kills bacteria that enter the body along with the food.
- The small intestine is the smallest part of the human digestive system.
- A major proportion of digestion takes place in the large intestines.
I. Fill in the blanks –
- Alimentary canal
- Carbohydrates , Amino acids
- Pancreatic juice
II. State True or False –