Tuesday 2 June 2020

IDENTIFICATION TEST FOR ANIONS

IDENTIFICATION TEST FOR ANIONS

ACETATE ION       
             
1.     Adding oxalic acid to a concentrated sodium acetate solution produces acetic acid, which emits a strong smell of vinegar.

Acetate Oxalic acid acetic acid sodium Acetate

2.                When a drop of concentrated sulphuric acid and ethanol are added, the distinctive smell of an ester can be observed. This applies  to all carboxylates, but is particularly useful in this case because the two reactants, acetic acid and ethanol, have distinctive smells which are replaced completely by different smellof the ester; in this case, ethyl acetate, which smells not unlike glue or nail polish remover.


3.                To 3 ml of water/soda extract 0.25 ml lithium nitrate solution and 0.1ml of o.1N potassium iodide solution were added. After this, few drops of dilute ammonia solution was added and the resultant solution was heated. within a few minute blue colour is obtained.

4.                Equal volume of soda/water extract and pure calcium hydroxide is taken in a test tube. Heat the solution and pass the evolved vapours into a solution of 2,4 DNP hydrazine.


Friday 29 May 2020

arjuna bark | cardiotonics


      Arjuna




arjuna-bark,cardiotonics,BARK,arjuna
arjuna-bark, cardiotonics




Biological source -:


Arjuna is the dried bark of terminalia Arjuna

Family -:


Combretaceae.

Geographical occurrence -:


The plant is a large deciduous tree, reaching a height of 60 to 80 feet. It grows throughout India.

Collection -:


The bark is collected mostly from wild trees by making suitable incisions and dried.

Characters -:


1.     Arjuna bark occurs as flat or curved pieces of various sizes.
2.     The outer surface is ash coloured and smooth the inner surface is reddish in colour and striated.
3.     It breaks with a fibrous fracture.
4.     No odour but taste is astringent.

Constituents -:


1.     Tannins, mainly pyrocatechol tannins.
2.     Arjunetin, a glycoside which on hydrolysis yields glucose and Arjunic acid.
3.     Arjunollic acid, a trieterpene-saponin (it is responsible for diuretic effect).
4.     Large quantities of calcium salts and traces of aluminium and magnesium salts.

Uses -:


1. As a cardiotonic. It has a beneficial effect in ischemic heart diseases. 2. As a diuretic (this effect is caused by saponin).
3. As an astringent and febrifuge,

Adulterant -:


 The dried bark of terminalia tomentosa is sometimes used as an adulterant of arjuna bark.


Tuesday 26 May 2020

ASTRINGENTS | CATECHU | BLACK CATECHU



  ASTRINGENTS

          CATECHU

     BLACK CATECHU




acacia-catechu,astringent,acacia,catechu,catachu-nigrum
acacia catechu,astringent



Synonyms -: Catechu Nigrum, Cutch.

Source -: 
        Black catechu is a dried extract prepared from the heart wood of Acacia catechu Wild.

Family -: Leguminoseae


Geographical occurrence -: 
       The plant is a tree of medium size. It grows in India and Burma.

Preparation -:

1.     The trees arc felled the heart wood cut into pieces and boiled with water in earthen pots.
2.     The decoction is evaporated in an iron vessel to form a thick syrup. Because of iron in the vessel, catechu becomes black le colour.
3.     It is then poured on leaves or paper and allowed to solidify. Then it is cut into pieces and marketed.

Characters -:

1.       Black catechu occurs in the form of black or dark brown irregular masses or cubes.
2.       The outer surface is glossy and porous.
3.       Fracture is brittle and it breaks into a powdery mass.
4.       It has no odour. But taste is bitter initially, then tums sweet and finally astringent.

Constituents -:

1.       Tannins -: They are catechins and catechu tannic acid.
2.       Flavinoids : They are quercetin and its derivatives.

Identification tests -:

1. Black catechu is completely soluble in alcohol and hot water.

2. Addition of lime water to the aqueous extract produces a brown colour. This on standing produces a red precipitate.

3. Aqueous solution of black catechu produces a dark green colour with ferric chloride solution.

4. It produces a pink or red colour with vanillin hydrochloric acid

5. The tip of a match stick is smeared with a paste of black catechu, after dipping in concentrated hydrochloric acid; it is warmed near a flame. A purple colour is produced.

Gambir fluorescine test -:

 Powdered drug is boiled with alcohol and filtered. To the filtrate, sodium hydroxide solution is added followed by petroleum ether. The petroleum layer shows a green fluorscence only for pale catechu. This can distinguish from black catechu.

Uses -:

1.     Astringent in diarrhoea.
2.     For cleaning the mouth and gums,
3.     In dyeing and tanning industry.

Sunday 24 May 2020

Digestive System | anatomy of digestive system | physiology of digestive system | digestive system organ and function

               

   Digestive System


Points to study

1)           what is digestive system

2)           part of digestive system

3)           digestive system organs and function

4)           how does the digestive system work

5)           digestive system function

6)           digestive system process

7)           diagram of digestive system

8)           anatomy and physiology of digestive system

9)           anatomy of organs

10)      function of organs


 
Digestive-System,anatomy-of-digestive-system,organs-of-digestive-system
digestive-system,organs-digestive-system




The digestive system performs the following functions in our body.

1.    Converts the various food stuffs by chemical action into simpler forms which can be easily absorbed into blood. The absorbed material is utilized by the various tissues of the body according to their requirements.

2.  This is the pathway for the entry of vitamins, fluids and minerals into our body.

3.  The digestive system is also responsible for the excretion of residue and waste products.


The digestive tract begins at the mouth and ends at the rectum. There are certain accessory organs of digestion and they are the salivary grands, liver and pancreas. Digestive process in the body takes place in four stages:

1)        Ingestion, mastication and swallowing
2)        Digestion proper
3)        Absorption
4)        Excretion of the left out and waste products.

a)                      Ingestion or taking in of food and mastication are performed by the mouth and teeth. This is aided by the tongue. The pharynx and Oesophagus are concerned with swallowing.

b)                     Digestion proper although begins in the mouth, is mainly carried out in the stomach and upper part of the small intestine.

c)                      The absorption of the various food stuffs takes place mainly in the small intestine but it can also take place from other parts of the digestive tract depending on the nature and state of the substances concerned.

d)                     In the large intestine absorption of water and transit of the residue for excretion in the form of faeces takes place.


  ANATOMY OF DIGESTIVE ORGANS


It consists of the lips, mouth, pharynx, oesophagus, stomach, duodenum, jejunum, ileum (small intestine), caecum, appendix, colon and rectum. Out of this the lips, mouth, pharynx and oesophagus are concerned with the ingestion of food while the stomach, small and large intestine are concerned with digestion, absorption and excretion of food stuffs.
The process of digestion is aided by certain accessory organs of digestion namely the salivary glands, liver and pancreas, mainly by way of their secretions. The splitting up of the food into simpler forms involves a number of chemical processes which are performed by means of substances secreted by the glands of the alimentary tract and these are An enzyme is a substance which is secreted by the called enzymes.
glands of the digestive tract and has the ability of acting on a food stuff to convert it into a simple form suitable for absorption. Each enzyme, however, has a specific action i.e. it acts on one particular type of food stuff.

The first part of the digestive system to deal with the food stuffs is the mouth.

The digestive process which begins here is aided by the salivary secretion from the salivary glands. Mouth is the upper expanded portion of the alimentary canal. The interior of the mouth is lined by mucous membrane. At the floor of the mouth is the tongue.

Tongue -:


       is a muscular organ covered on its free surface by a special type of mucous surface. The mucous membrane of the mouth is smooth except that of the tongue. The mucous membrane of the tongue is rough and this is due to the numerous minute elevations called papillae.

       Microscopic examination of the mucous membrane from the sides of the tongue shows that it contains a number of specialized collections of epithelial cells called taste buds. The hind most part of the tongue is attached the hyoid bone. There are three types of papillae found on the tongue

1. Eight or nine large papillae arranged in a V-shaped manner the  base of the tongue. These are called the circumvallate papillae and contain numerous taste buds.

2. Fungiform or flattened papillae.

3. Filiform papillae which are small pointed elevations.

Teeth -:


      During the lifetime of an individual two sets of teeth make their appearance. The deciduous or temporary (milk) teeth and the permanent teeth. There are 32 permanent teeth 16 above and 16 below. Out of 16 teeth, four are incisors (2 on either side), 2 canines (I on either side), premolars on either side), and 6 molars (3 on either side).


Digestive-System,anatomy-of-digestive-system,organs-of-digestive-system,teeth
teeth,digestive-system


Functions of teeth -:


     The ingested food undergoes mastication and teeth is essential for this. Chewing or mastication is the process biting and grinding of food between the upper and lower teeth. This breaks up large food particles and mixes the food with salvia. Mastication is assisted by tongue and cheek. The muscles of mastication include the temporalis, masseter and the medial and lateral pterygoids.

Salivary Glands and Salivary Secretion -:


The three pairs of salivary glands are:
i)         Parotid
ii)       Submandibular or submaxillary
iii)     Sublingual

      The salivary glands are racemose (looks like a bunch of glands). Each gland consists of a large number of acini. Each acinus is lined by pyramidal shaped epithelial cells. The secretion of these glands, saliva enters the mouth by means of the ducts of the glands. Fine ductless which unite with similar ductless to form a bigger ductless. Similar bigger ductless unite and ultimately the main duct of the gland is formed.
    
      All these glands receive nerve supply from sympathetic and parasympathetic divisions of the autonomic nervous system. Parasympathetic innervation is more important than the other. Salivary glands contain either mucous or serous cells or both. Mucous cells contain mucinogen granules and serous cells zymogen granules.

Functions of Saliva -:


1)                     Its main function is to help digestion and to provide a protective secretion in the mouthy which keeps the mucous membranes moist and these aids in oral hygiene.

2)                     Lubricating the food in preparation for swallowing.

3)                     Saliva acts as solvent for the molecules which stimulate the taste buds and has cleansing action.

4)                     It helps in maintaining the oral pH and also helps in regulation of water balance.

Stomach -:
     
      Stomach acts as a receptacle for food. Here the food is stored where it is mixed with acid, mucous and pepsin and released at a controlled and steady rate into the duodenum. It is the most dialated portion of the digestive tract and lies under the diaphragm.


Digestive-System,anatomy-of-digestive-system,organs-of-digestive-system,stomach,
stomach,digestive-system


The stomach has three parts:


a. The fundus which is an upper portion ballooning towards the left;

b.The body which is the central portion; and

c. The pyloric portion (antrum), a relatively constricted portion at the terminal part with pylorous, just before the entrance into the duodenum. The structure of stomach

Its wall has four coats namely:

·     Serous
·     Muscular
·     Submucous
·      Mucous

     The muscular layer can be further differentiated into three layers. From outside to inwards, these are:

1. Longitudinal fibers
2. Circular fibers
3. Oblique fibers

    The peritoneum forms the outer covering of the stomach. The musculature is heavier in the pyloric portion than in the rest of the stomach. The circular muscle layer is thickened in the pyloric portion to form the pyloric sphincter.

    When the stomach is empty the mucous membrane is thrown into prominent folds called rugae. These become flattened when the stomach is full. The epithelium of the stomach is simple columnar. Gastric glands, densely packed numbering about 35 million open at the surface by way of gastric pits. The glands are branched tubular and penetrate the lamina propria all the way to the muscularis mucosae.

Functions of Stomach -:


1. Storage of food -: 


      When food enters stomach, it relaxes by a reflex process of receptive relaxation. This relaxation is aided by the movement of the pharynx and oesophagus. The food is stored here until it is emptied into the duodenum.

2. Gastric secretion -: 


     This is the secretion of the gastric glands present in the stomach, The gastric secretion contains enzymes (see Table 10.1) and mucus. Two other important components of the gastric juice are hydrochloric acid and pepsinogen.

3.Hydrochloric acid secretion -: 


     Hydrochloric acid is secreted by parietal cells of the gastric glands. It is concentrated enough to cause tissue damage, but in normal individuals the mucosa does not get damaged because of the surface membrane of the mucosal cells.

4.Pepsinogen secretion -:


       Chief cells of the gastric glands secrete pep- sinogens which are the precursors of the pepsins in the gastric juice.

5. Mixing of food with acid mucus and pepsin -: 


       Peristaltic contractions are responsible for the mixing of food with acid, mucus and pepsins.

6.Gastric emptying -: 


     Peristaltic contractions in the stomach, in addition to mixing of food is also responsible for the entry of food into the duodenum at a controlled rate, Peristaltic wave which may be upto 3 min are marked most in the distal half of the stomach. Pyloric sphincter has only a limited control in gastric emptying. of duodenum function as a unit and contract in a sequential manner. This allows the gastric contents to enter the duodenum in bits.

    The antrum, pylorus and upper part Gastric secretion and motility 
are regulated by neural and hormonal mechanisms.

Small Intestine -:


     This extends from the distal end of the pyloric sphincter to the cecum which is the first portion of the large intestine.
It is about 18 feet in length and is divided into three parts namely:-

1. Duodenum
2. Jejunum
3. Ileum.



Digestive-System,anatomy-of-digestive-system,organs-of-digestive-system,intestine,small-intestine
small-intestine,digestive-system


Duodenum -: 


It is the shortest, widest and most fixed portion of the small intestine. It is about 22 cm. in length.

Jejunum -: 


This is about two fifths of the small intestine.

Ileum -: 


This constitutes three fifths of the small intestine.
Both small and large intestine is anchored to the abdominal wall by folds of peritoneum called mesenteries.

Structure of Small Intestine -:


     The four layers typical of the gastro intestinal tract is present in the intestine also. However, there are certain specialized features particularly in the mucosa. The small intestine is concerned with absorption and hence this modification helps to increase the surface area. The following are seen:

1.                      Circular folds (Plicae circulares) -:  


     These are large permanent, transverse folds seen in the entire thickness of the mucosa containing a core of sub mucosa.

2.                      Villi -: 



Digestive-System,anatomy-of-digestive-system,organs-of-digestive-system,villi,villus,villi-digestive-system
villi,digestive-system,villus



      Villi are finger like projections of the mucosa into i lumen containing blood vessels and a centrally located lymphatic vessel (central lacteal).

3.                      Microvilli -: 


Digestive-System,anatomy-of-digestive-system,organs-of-digestive-system,micovilli,villi,villus
digestive-system,villi,microvilli



     There are many cylindrical processes on the free edges of the epithelial cells which give a striated or brush border Crypts of Lieberkuhn are the tubular glands found in the mucosa between the villi.

      In the duodenum there are small coiled glands which secrete mucous high in bicarbonate content. These are called Brunner's glands. Simple columnar epithelial cells are found lining the small intestine. Amidst the cells of the epithelium are found goblet cells which secret mucus.

Functions of Small Intestine -:


1)         Secretion of the small intestine contains many enzymes which help in digestion of various food stuffs. Pancreatic secretion is also poured into the small intestine along with bile secretion) this is also helpful in digestion.

2)       Most of the absorption takes place at the small intestinal mucosa)

3)       Various types of movements of the small intestine like peristalsis. segmenting contraction help in the mixing and churning of food materials before propelling it towards large intestine.

Large Intestine -:


     Large intestine is approximately five feet long and extends from the end of ileum to the anus and is divisible into:

              i.     Cecum;
            ii.     Colon;
         iii.     Rectum; and
          iv.     Anal canal


Digestive-System,anatomy-of-digestive-system,organs-of-digestive-system,large-intestine,intestine
large-intestine,intestine,digestive-system



It is different from the small intestine in the following ways:

1. It is wider than the small intestine.
2. Its mucosal surface has no villi.
3. In the cecum, colon and upper part of the rectum the glands present are of greater depth and more closely packed. This contains more of goblet cells.

Cecum -:


     This is the first portion of the large intestine. Attached to the base of cecum is a slender tube; the verniform (worm like) process or appendix. lleocaecal valve is present at the junction of ileum and cecum.

    Appendicitis or inflammation of the appendix occurs in both children and adults.
        

Ascending colon -:

  
      It extends upward from the cecum.

Transverse colon -: 

  
     This overlies the coils of the small intestine and Ascending colon crosses the abdominal cavity from right to left below the stomach.

Descending colon -: 

    
     This begins near the spleen passing downward on the left side of the abdomen to the iliac crest to become the sigmoid pelvic colon. This is so called because of its S-shaped course within the pelvic cavity.

Rectum -: 


     The pelvic colon passes into the rectum and lies on the anterior surface of the sacrum and coccyx. It terminates in the narrow anal canal which opens to the exterior at the anus.

Structure of the Large Intestine -:  


      Like the other parts of the gastro intestinal tract including small intestine, large intestine also has the four coats. The muscle layer has a characteristic feature. Longitudinal muscles do not form a continuous layer over the whole gut but are arranged in three separate bands taenia coli. These bands being shorter than the length of the large intestine the large intestine has a sacculated appearance.

Functions of the Large Intestine -:


1.                      It secretes the intestinal secretion which lubricates the faeces and facilitates their passage through the rectum and anus.
2.                      The bacteria present in the large intestine act on the various food materials which are left without digestion and absorption by the intestine.
3.                      Absorption of water, glucose and salt also takes place in the large intestine.
4.                      Excretion of excess calcium, iron and drugs of the heavy metal type takes place from the walls of the intestine,
5.                      Segmentation contraction of the large intestine helps in mixing the contents of the colon while peristaltic contraction propel the contents towards rectum.
6.                      A type of contraction called mass action contraction in which k there is simultaneous contraction over a large area of the intestine takes place in descending and sigmoid portions. This is helpful in defecation.

Liver -:


     The liver is the largest organ in the body and has a weight of 1275- 1550 gm. It is situated in the upper part of the abdominal cavity immediately below the diaphragm.

    It has an irregular shape. It may be conveniently divided into right and left lobes and has superior, inferior, anterior and posterior surfaces. Superior surface is in contact with the under surface of the diaphragm which separates it from the bases of the lungs. Inferior surface is concave and is related to other abdominal viscera.


Digestive-System,anatomy-of-digestive-system,organs-of-digestive-system,liver,digestive-system
liver,digestive-system


    
    Anterior surface is related to the abdominal wall in the midline. Posterior surface crosses the vertebral column in the middle and is also related to the aorta, inferior vana cava and lower end of the esophagus.
In the centre of the inferior surface is the hilum or gate of the liver. This is also called as portal fissure. This is the point of entry and exit for

(1)                  Portal vein
(2)                  Hepatic artery; and
(3)                  Bile ducts.

    The liver also has a fibrous capsule and the greater part of its surface is covered by peritoneum.

Structure of Liver -:


    A large number of lobules consisting of columns of liver cells constitute the liver. The liver cells of a lobule are arranged around a central vein in a radiating fashion. Each lobule has got a blood supply from hepatic artery, and portal vein. Bile secreted by the liver cells passes out through the bile ducts. Bile leaves the liver through the right and left hepatic ducts. These combine together to form the common hepatic duct. The hepatic duct is joined by the cystic duct from the gall bladder to form the common bile duct. The common bile duct joins the pancreatic duct to open into the duodenum at the duodenal papilla or ampulla of vater.

Functions of Liver -:


1)                     It produces bile. Bile mainly contains bile salts and bile pigments. Bile is responsible for the digestion and absorption of food.
2)                     It is concerned with the storage of glycogen.
3)                     Liver is concerned with the production of plasma proteins/(albu- min and globulin) which are essential for the body.
4)                     The breakdown of protein and the formation of urea.
5)                     Storage of Vitamin B12 and iron
6)                     Heat production.
7)                     Destruction of various toxic substances and drugs.
8)                     Desaturation of fats



Pancreas -:


    It is a large lobulated gland and resembles salivary glands in struc- Pancreas has a head, body and tail. Pancreas has two parts.
(1) Exocrine part
(2) Endocrine part



Digestive-System,anatomy-of-digestive-system,organs-of-digestive-system,pencreas,
pencreas,digestive-system


Exocrine part


      Pancreatic juice is secreted by the exocrine part. Pancreatic juice is alkaline and has a high bicarbonate content. Pancreatic juice also contains a large number of enzymes required for digestion. Pancreatic juice is secreted into the duodenum through the pancreatic duct.
Pancreatic juice is secreted by the exocrine part. This digestive juice contains many enzymes for digestion. Pancreatic duct empties its secretion into the duodenum.
      
      Pancreatic secretions is controlled by both neural and hormonal factors. Secretin and cholecystokinin-pancreozymin (CCK-Pz or CCK) are the two hormones controlling the secretion. Vagal stimulation also causes secretion of pancreatic juice.

Endocrine part -:


    The Islets of Langerhans, a collection of ovoid cells scattered throughout the pancreatic tissue (more cells in the tail region) forms the endocrine part of the pancreas. A or α cells secrete glucagon and B or B cells secrete insulin. The known effect of insulin is its hypoglycemic action. Insulin facilitates the entry of glucose into the cells except in brain. Glucagon on the other hand causes break down of glycogen glycogenolytic action.


Physiology of Digestion and Absorption -:


     The major foodstuffs are carbohydrates, proteins and fats. These are broken down by the enzymes present in the various digestive juices secreted by the different parts of the gastrointestinal tract. Digestion of the various foodstuffs can be described as follows:



Digestive-System,anatomy-of-digestive-system,organs-of-digestive-system,digestive-system
digestive-organs,digestive-system



 Digestion of carbohydrates -:


     The principal carbohydrates present in food is starch composed of glucose units. Others are sucrose, fructose and lactose. Digestion begins in the mouth with the enzymatic action of Ptyalin, salivary amylase. The enzymatic action of ptyalin continues in the stomach. All sugars are converted into simple monosaccharides by various enzymes (sucrase, maltase, lactase). In the small intestine en- cymes like pancreatic amylase, maltase, sucrase and lactase act up on the Starch and disaccharides respectively.

 Digestion of proteins -:


      The digestion of protein is initiated in the Momach by the action of pepsin of the gastric juice and proteins ure verted into peptones and polypeptides. Trypsin and chymotrypsin of the pancreatic juice also acts upon the proteins in the intestine and convert them into peptides and peptidases, split peptides into amino acids.

Digestion of fat -:


      Pancreatic lipase splits fat into monoglycerides, fatty acids and glycerol. Intestinal lipase also splits the fats.

Absorption -:


      The absorption of the digested food material occurs almost exclusively in the small intestine. However, some glucose, alco- hol and water are absorbed in the stomach. Significant amounts of water and salts are absorbed from large intestine. The following Table shows the site of absorption and the substances absorbed.

Mouth  

    normally no absorption but a few drugs may be absorbed into the blood through the mucous membrane in case it is allowed to dissolve under the tongue e.g. glycerol nitrate, isoprenaline.

Stomach


    Water; glucose; alcohol; and some drugs may also be absorbed.

Small Intestine

     Water; amino acids; simple sugars; short chain fatty acids; glycerol, vitamins and minerals; calcium

Large Intestine


Products of lipid digestion.