Blood of grasshopper is made up of two components. Plasma and hemocytes.
(i) Plasma: Plasma is a colorless liquid. It does not contain hemoglobin. It contains protein, sugar, glycerol, amino acid, glucose, organic acid, ester, sterol, triglyceride, urea, uric acid, nitrogen, sodium, calcium, magnesium, potassium, phosphate, hemoxanthin, trihalose, diglyceride, tyrosine, trihalase etc. Dr. Siddiq Publications
(ii) Haemocytes or Blood Cells: Grasshopper blood contains only white blood cells or Haemocytes (15,000-60,000). It does not contain red blood cells. Haemocytes can be divided into three types. Prohemocyte, transitional hemocyte and giant hemocyte. Prohemocytes 6-9 mµ (23%), transitional hemocytes 9-19 mµ (68%) and giant hemocytes 19-23 mµ (9%).
Hemolymph function
(i) Haemolymph acts as a water reservoir. It contains 92% water.
(ii) It transports nutrients, minerals, hormonal secretions.
(iii) Maintains water balance in the body.
(iv) Wings help in circulation and shedding of shells.
(v) Hemocytes ingest microbes by the process of phagocytosis. As a result, disease is prevented.
(vi) Haemocytes help in blood clotting and wound healing.
(vii) Haemocytes secrete mucopolysaccharides to form connective tissue.

The system through which blood flows is called circulatory system. The circulatory system of grasshoppers is free-type (grasshoppers, grasshoppers, shrimps, mosquitoes, flies, spiders, snails, oysters, octopuses). The circulatory system in which blood is freed from the heart through the ostia or ducts into the body cavity or sinuses and returns to the heart through the ostia or ducts is called free circulatory system. It consists of four main parts. Hemolymph or blood, hemocele, dorsal vessels and accessory pulsating organs.
1. Hemolymph: Blood of grasshopper is made up of two components. Plasma and hemocytes.
(i) Plasma: Plasma is a colorless liquid. It does not contain hemoglobin. It contains protein, sugar, glycerol, amino acid, glucose, organic acid, ester, sterol, triglyceride, urea, uric acid, nitrogen, sodium, calcium, magnesium, potassium, phosphate, hemoxanthin, trihalose, diglyceride, tyrosine, trihalase etc. Dr. Siddiq Publications
(ii) Haemocytes or Blood Cells: Grasshopper blood contains only white blood cells or Haemocytes (15,000-60,000). It does not contain red blood cells. Haemocytes can be divided into three types. Prohemocyte, transitional hemocyte and giant hemocyte. Prohemocytes 6-9 mµ (23%), transitional hemocytes 9-19 mµ (68%) and giant hemocytes 19-23 mµ (9%).
Hemolymph function
(i) Haemolymph acts as a water reservoir. It contains 92% water.
(ii) It transports nutrients, minerals, hormonal secretions.
(iii) Maintains water balance in the body.
(iv) Wings help in circulation and shedding of shells.
(v) Hemocytes ingest microbes by the process of phagocytosis. As a result, disease is prevented.
(vi) Haemocytes help in blood clotting and wound healing.
(vii) Haemocytes secrete mucopolysaccharides to form connective tissue.
2. Haemocoel: The word haemocoel is formed from the Greek words haema meaning blood and coel meaning cavity. A body cavity filled with hemolymph is called a hemocele. Their hemocele is called myxocele. It is divided into three chambers or sinuses by the dorsal membrane and digital membrane. These are-
(i) Pericardial sinus: It is located above the dorsal membrane. It contains the heart.
(ii) Perivisceral sinus: It is located below the dorsal membrane. The alimentary canal is located in it. Dr. Siddiq Publications
(iii) Perineural sinuses: It is located under the digital membrane. It contains nerve fibers.
3. Dorsal canal: The dorsal canal consists of three parts. These are-
(i) Dorsal aorta: The first chamber of the heart narrows to form a cylindrical part. This is called the dorsal aorta. It extends from the forehead to the head. It does not contain ostia.
(ii) Heart or heart: The heart of the grasshopper is located in the pericardial sinus. It is composed of several funnel-shaped chambers. The first 3 chambers are located in the thorax and the last 10 chambers are located in the abdomen. In the region between the two chambers, the cardiac wall folds from both sides and enters the cardiac cavity. Each fold has a hole. It is called Ostia. Each chamber is connected to the pericardial sinus by ostia. A pore between two adjacent cells is called an intercellular pore.
(iii) Alary muscle: The triangular muscle that is attached to the heart is called Alary muscle. These muscles arise from the digital floor of the targum. Its broad end is attached to the heart. Alary muscles (6 pairs in total) contract and expand the heart.
4. Accessory Vibrating Organs: Antennae, legs and base of wings have accessory organs. Each appendage consists of an ampulla and a duct. They pulsate the hemolymph from the sinuses into the appendages.

The walls of the mesentery and hepatic ceca contain absorptive cells. These cells absorb most nutrients. Most of the glucose is absorbed in the hepatic cecum. The rectal wall absorbs excess water, minerals and amino acids from the stool. Grain-shaped feces are excreted in the anus. Dr. Siddiq Publications

Grasshoppers eat green vegetables and foliage. Food is crushed by the mandible and maxilla. Then it is slippery mixed with lalars. Digestion of food by different parts of the alimentary canal is discussed below-
1. Digestion in crop: Food mixed with saliva is broken down into small particles due to contraction and expansion of the crop wall. Carbohydrates are converted into glucose by amylolytic (invertase, maltase, lactase) enzymes. Proteins are converted into amino acids under the influence of proteolytic (trypsin, protease, peptidase) enzymes. Lipolytic enzymes convert lipids into fatty acids and glycerol.
2. Digestion in the gizzard: As a result of the contraction and expansion of the gizzard, the food becomes very small particles.
3. Digestion in the Mesentery: Various enzymes are secreted from the hepatic caeca of the mid alimentary canal. All these enzymes digest food.
(i) Proteins are broken down into peptides under the action of trypsin enzyme. The peptide is then broken down into amino acids with the help of the enzyme eropsin.
(ii) Sugars are broken down into maltose under the action of amylase enzyme. Maltose is then broken down into glucose with the help of maltase enzyme.
(iii) Lipid is broken down into fatty acids and glycerol by the action of lipase enzyme.
Absorption of nutrients
The walls of the mesentery and hepatic ceca contain absorptive cells. These cells absorb most nutrients. Most of the glucose is absorbed in the hepatic cecum. The rectal wall absorbs excess water, minerals and amino acids from the stool. Grain-shaped feces are excreted in the anus. Dr. Siddiq Publications

Grasshoppers have two main digestive glands. Salivary Gland and Gastric Cica
1. Salivary Glands: A pair of compound leaf-like salivary glands are present on either side of the alimentary canal crop. Saliva is secreted from salivary glands. Saliva participates in food digestion.
2. Gastric sica: At the junction of gizzard and mesenteron there are 7-8 hepatic sica. Their inner mouth is open to the postural canal and the outer mouth is closed. Acid is secreted from the gastric sac. Nutritious foods aid in digestion. Dr. Siddiq Publications

The posterior part of the middle esophagus is the posterior esophagus. There are 10–15 Malpighian ducts at the junction of the middle and posterior alimentary canals. The posterior alimentary canal consists of four parts. Ileum, colon, rectum and anus. Dr. Siddiq Publications
(i) Ileum: Ileum is narrow, short and tube like part. Its inner wall is furrowed and folded. These folds act like eyelids. Ileum digests food and absorbs nutrients.
(ii) Colon: The long irregular portion next to the ileum is called the colon. The diameter of the colon is greater than that of the ileum. It absorbs food.
(iii) Colon: The most posterior part of alimentary canal is called colon. It is swollen and thick-walled. Its inner wall has 6 folds. These folds are called rectal papillae. It absorbs excess water, mineral salts, amino acids etc. from stool. It also stores the undigested part of the food.
(iv) Anus: The opening at the end of the rectum is called the anus. It removes waste food from the body.

The part from gizzard to proctodeum is called mesenteron. The junction of the gizzard and the mesentery is called the cardia. The mesentery is called the stomach. The anterior and posterior ends of the stomach have muscular rings or sphincters. It is short and syntactic. It arises from the endoderm and is covered by the peritrophic membrane. The peritrophic membrane prevents food from sticking to the intestinal wall. It protects the intestines from damage. At the junction of the anterior and middle alimentary canal are 6 pairs of hepatic or gastric sica. Hepatic caeca are long, hollow and twisted. Stomach holds food and digests food. Hepatic cica helps in food absorption. Dr. Siddiq Publications

The posterior extension of the crop is called gizzard. It is a thick, muscular and triangular sac. Its wall is made up of tough, thick and circular muscles. The anterior part of the gizzard is called the armarium and the posterior part is the stomodium captica. Armarium wall folded longitudinally to form six leaf-like teeth. There is a pad-like layer behind the teeth. These leaves have fine bristles or hairs. Longitudinal folds contain bristles in deep pits. Gizzard teeth crush food. Bristle or Rome serves as strainer. Kapatika prevents reverse flow of food.

The part from the stomata to the gizzard is called the anterior alimentary canal. It consists of six parts. These are:
(i) Mukhashidra: The openings in front of the alimentary canal are called mukhashidras. Food enters through it
(ii) Oral cavity: The part enclosed by the oral cavity after the oral cavity is called oral cavity. Food is mixed with saliva in the mouth. It takes the food from the mouth to the pharynx.
(iii) Pharynx: The small, muscular, narrow and cylindrical part located behind the mouth is called pharynx. Through this, food enters the esophagus.
(iv) Esophagus: The narrow, long and cylindrical part after pharynx is called esophagus. It is covered by a thin wall. It transports the food to the crop.
(v) Croup: Esophagus swells to form a sac-like croup. It is thin walled. Food is temporarily stored in it. Food digestion starts from here. Dr. Siddiq Publications
(vi) Gizzard or proventriculus: The posterior extension of the crop is called gizzard. It is a thick, muscular and triangular sac. Its wall is made up of tough, thick and circular muscles. The anterior part of the gizzard is called the armarium and the posterior part is the stomodium captica. Armarium wall folded longitudinally to form six leaf-like teeth. There is a pad-like layer behind the teeth. These leaves have fine bristles or hairs. Longitudinal folds contain bristles in deep pits. Gizzard teeth crush food. Bristle or Rome serves as strainer. Kapatika prevents reverse flow of food.

The tube extending from mouth to anus is called alimentary canal. The alimentary canal of the grasshopper is divided into three parts. Stomodium, mesenteron and proctodeum.
1. Stomodium: The part from the stomata to the gizzard is called the anterior alimentary canal. It consists of six parts. These are:
(i) Mukhashidra: The openings in front of the alimentary canal are called mukhashidras. Food enters through it
(ii) Oral cavity: The part enclosed by the oral cavity after the oral cavity is called oral cavity. Food is mixed with saliva in the mouth. It takes the food from the mouth to the pharynx.
(iii) Pharynx: The small, muscular, narrow and cylindrical part located behind the mouth is called pharynx. Through this, food enters the esophagus.
(iv) Esophagus: The narrow, long and cylindrical part after pharynx is called esophagus. It is covered by a thin wall. It transports the food to the crop.
(v) Croup: Esophagus swells to form a sac-like croup. It is thin walled. Food is temporarily stored in it. Food digestion starts from here. Dr. Siddiq Publications
(vi) Gizzard or proventriculus: The posterior extension of the crop is called gizzard. It is a thick, muscular and triangular sac. Its wall is made up of tough, thick and circular muscles. The anterior part of the gizzard is called the armarium and the posterior part is the stomodium captica. Armarium wall folded longitudinally to form six leaf-like teeth. There is a pad-like layer behind the teeth. These leaves have fine bristles or hairs. Longitudinal folds contain bristles in deep pits. Gizzard teeth crush food. Bristle or Rome serves as strainer. Kapatika prevents reverse flow of food.
2. Middle alimentary canal or mesenteron: The part from gizzard to proctodeum is called mesenteron. The junction of the gizzard and the mesentery is called the cardia. The mesentery is called the stomach. The anterior and posterior ends of the stomach have muscular rings or sphincters. It is short and syntactic. It arises from the endoderm and is covered by the peritrophic membrane. The peritrophic membrane prevents food from sticking to the intestinal wall. It protects the intestines from damage. At the junction of the anterior and middle alimentary canal are 6 pairs of hepatic or gastric sica. Hepatic caeca are long, hollow and twisted. Stomach holds food and digests food. Hepatic cica helps in food absorption. Dr. Siddiq Publications
3. Proctodaeum: The posterior part of the middle esophagus is the posterior esophagus. There are 10–15 Malpighian ducts at the junction of the middle and posterior alimentary canals. The posterior alimentary canal consists of four parts. Ileum, colon, rectum and anus. Dr. Siddiq Publications
(i) Ileum: Ileum is narrow, short and tube like part. Its inner wall is furrowed and folded. These folds act like eyelids. Ileum digests food and absorbs nutrients.
(ii) Colon: The long irregular portion next to the ileum is called the colon. The diameter of the colon is greater than that of the ileum. It absorbs food.
(iii) Colon: The most posterior part of alimentary canal is called colon. It is swollen and thick-walled. Its inner wall has 6 folds. These folds are called rectal papillae. It absorbs excess water, mineral salts, amino acids etc. from stool. It also stores the undigested part of the food.
(iv) Anus: The opening at the end of the rectum is called the anus. It removes waste food from the body.