Revision: The Muscular System and Digestive System in Human Beings Science SSC (English Medium) 7th Standard Maharashtra State Board

Muscles are long bundles of contractile tissue, which has a fixed end (Origin) and a movable end which pulls some other part.

The organisms which cannot prepare their own food and depends on ready-made food synthesized by green plants are called heterotrophs.

Examples - animals and human beings.

Holozoic nutrition is a mode of nutrition in which an organism takes complex organic food materials into its body by ingestion; the ingested food is digested and then absorbed into the organism's body cells.

The process of converting complex food substances into simpler and smaller units so that they can be easily utilised by the body is defined as digestion.
E.g. proteins are converted to amino acids.

Assimilation — The process of using the digested food by the body is called assimilation.

The process by which all organisms obtain or synthesize their food and convert it into simpler substances, so that it can be absorbed and utilized by the cells of the body is called nutrition.

Digestion — The process of breaking the food into smaller and simpler substances so that they can be easily used by the body is called digestion.

Egestion — The process of removal of the undigested food from the body is defined as egestion.

A kilocalorie is a unit of energy. It is the energy required to raise the temperature of 1 kg of water by 1 Celsius.

Absorption of substances which are built into other compounds in the organisms. 

Omnivores are organisms that consume both plants and animals.

Pylorus is the passage at the lower end of the stomach that opens into the duodenum.

Peristalsis is the rhythmic contraction and relaxation of the muscles of the alimentary canal that pushes the food along the gut.

The organisms that feed on plants only are termed as herbivores.

Examples - sheep, cow, goat, etc.

These are the organisms which prepare organic food in their body from simple inorganic materials like carbon dioxide, water, etc.

Example - green plants and certain protests.

The organisms which feed on all kinds of plant and animal food are called omnivores.

Examples - Cockroach and human beings.

It is the breaking down of complex insoluble food components into simple soluble substances.

A nutrient can be defined as a substance which an organism obtains from its surroundings and uses as a source of energy or for the biosynthesis of its body constituents (like tissues and organs).

The organisms which feed upon other animals and animal products.

Examples - tiger, lion, cat, etc.

Beta cells are specialized endocrine cells located within the islets of Langerhans in the pancreas. They are critical to human metabolism because they are the primary source of insulin production in the body.

• Glands that discharge secretions into ducts are known as exocrine glands.
• Sebaceous glands in the skin, salivary glands in the buccal cavity, etc. are examples of exocrine glands.

Diabetes mellitus is a chronic metabolic condition characterised by elevated blood glucose (hyperglycemia). It occurs when the body either cannot produce enough insulin or cannot use the insulin it produces effectively.

Hyperglycemia is a medical condition characterized by an abnormally high level of glucose (sugar) in the bloodstream.

The organisms which cannot prepare their own food and depends on ready-made food synthesized by green plants are called heterotrophs.

Examples - animals and human beings.

Holozoic nutrition is a mode of nutrition in which an organism takes complex organic food materials into its body by ingestion; the ingested food is digested and then absorbed into the organism's body cells.

The process of converting complex food substances into simpler and smaller units so that they can be easily utilised by the body is defined as digestion.
E.g. proteins are converted to amino acids.

Assimilation — The process of using the digested food by the body is called assimilation.

The process by which all organisms obtain or synthesize their food and convert it into simpler substances, so that it can be absorbed and utilized by the cells of the body is called nutrition.

Digestion — The process of breaking the food into smaller and simpler substances so that they can be easily used by the body is called digestion.

Egestion — The process of removal of the undigested food from the body is defined as egestion.

A kilocalorie is a unit of energy. It is the energy required to raise the temperature of 1 kg of water by 1 Celsius.

Absorption of substances which are built into other compounds in the organisms. 

Omnivores are organisms that consume both plants and animals.

Pylorus is the passage at the lower end of the stomach that opens into the duodenum.

Peristalsis is the rhythmic contraction and relaxation of the muscles of the alimentary canal that pushes the food along the gut.

The organisms that feed on plants only are termed as herbivores.

Examples - sheep, cow, goat, etc.

These are the organisms which prepare organic food in their body from simple inorganic materials like carbon dioxide, water, etc.

Example - green plants and certain protests.

The organisms which feed on all kinds of plant and animal food are called omnivores.

Examples - Cockroach and human beings.

It is the breaking down of complex insoluble food components into simple soluble substances.

The organisms which feed upon other animals and animal products.

Examples - tiger, lion, cat, etc.

A nutrient can be defined as a substance which an organism obtains from its surroundings and uses as a source of energy or for the biosynthesis of its body constituents (like tissues and organs).

• Digestion is the conversion of complex food into soluble forms that can be absorbed into the blood.
• The digestive system has two main components: the alimentary canal (mouth to anus) and associated digestive glands.
• The alimentary canal is a long muscular tube about 9 m in adults, including mouth, pharynx, oesophagus, stomach, small intestine, large intestine, rectum and anus.
• Salivary glands, liver and pancreas are accessory digestive glands that open into this canal and secrete juices needed for digestion.
• Different organs of the digestive system act in sequence; each stage of digestion occurs in a specific organ that performs a specialised mechanical or chemical role.

• The stomach is a muscular J‑shaped sac in the upper left abdomen, between oesophagus and small intestine.
• It has four regions: cardiac, fundus, body and pyloric, each with specific roles in food storage and mixing.
• The body region mainly stores food, churns it and mixes it with gastric juice to form chyme.
• The pyloric region opens into the duodenum and its pyloric sphincter controls the release of chyme.
• The cardiac (lower oesophageal) and pyloric sphincters prevent backflow and regulate movement of food, so regurgitation is avoided.

• The large intestine has a wider diameter than the small intestine.
• It is the terminal part of the alimentary canal.
• It is divided into three main parts: caecum, colon and rectum.
• The rectum opens to the outside through the anus.
• Only minimal digestion occurs here, but water and electrolytes are absorbed efficiently.

• Pancreas functions both as an exocrine gland (secreting pancreatic juice into the duodenum) and an endocrine gland (secreting hormones into the blood).
• The Islets of Langerhans contain beta cells (secrete insulin) and alpha cells (secrete glucagon), which regulate blood sugar levels.
• Insulin lowers blood glucose by promoting glucose uptake by cells and storing excess glucose as glycogen in the liver and muscles.
• Under-secretion of insulin causes diabetes mellitus (hyperglycemia), with symptoms like excessive urination, thirst, weakness, and sugar in urine.
• Glucagon raises blood sugar by converting glycogen to glucose in the liver; overdose of insulin can lead to hypoglycemia or insulin shock.

• Digestion is the conversion of complex food into soluble forms that can be absorbed into the blood.
• The digestive system has two main components: the alimentary canal (mouth to anus) and associated digestive glands.
• The alimentary canal is a long muscular tube about 9 m in adults, including mouth, pharynx, oesophagus, stomach, small intestine, large intestine, rectum and anus.
• Salivary glands, liver and pancreas are accessory digestive glands that open into this canal and secrete juices needed for digestion.
• Different organs of the digestive system act in sequence; each stage of digestion occurs in a specific organ that performs a specialised mechanical or chemical role.

• The large intestine has a wider diameter than the small intestine.
• It is the terminal part of the alimentary canal.
• It is divided into three main parts: caecum, colon and rectum.
• The rectum opens to the outside through the anus.
• Only minimal digestion occurs here, but water and electrolytes are absorbed efficiently.