HUMAN  PHYSIOLOGY 

William Harvey is considered the founder of modern physiology in 1578 – 1657 .
Johannes muller is main contribution to physiology was to make it a comparative science, and differences among species of animals in 1801 – 1858 .
The human physiology deals with the following topics :

Digestion and absorption .

Digestion : it is the process of conversion of complex food into simple absorption forms is called digestion .
Absorption : it is the process by which nutrients pass from alimentary canal into the blood and lymph through the mucous membrane .
Food : food is one of the basic requirement of all living beings and the major components of food is carbohydrates, proteins and fat .
Food provides energy and organic materials for growth and repair tissues or cells .
Vitamins and minerals is Small quantities in food .
Carbohydrates, proteins, and fat is large quantities in food .
Organic nutrients : Carbohydrates, proteins, vitamins, and fat .
Inorganic nutrients : minerals and water .

                                                         Human digestive system 





Human digestive system consists of two main parts :
  1. Alimentary canal .
  2. digestive glands .
1. Alimentary canal :
Anterior opening of alimentary canal is mouth and the posterior part is anus .
Mouth :  human mouth have a vestibule, tongue, teeth, palate, etc. 
a. Vestibule : The vestibule is a slit-like space bounded by lip and teeth .
b.  Oral cavity (buccal cavity) : it is inner portion of mouth which has following parts :
c.  Palate : The roof of the oral cavity ( buccal cavity ) is called palate
   Palate are two types : hard palate and soft palate .
   Hard palate : anterior part of the palate is known as hard palate and hard palate have a transverse rugae .
   Soft palate : posterior part of the palate is known as soft palate and also uvula is a part of soft palate . the uvula help in the close the nasal passage at the time of swallowing .

Tongue ( Linguae ): the human tongue is attach to the floor of the mouth by a fold is called lingua   frenulum . the inverted V – shape part is sulcus terminalis divide the tongue has two parts 1. anterior part is oral part and 2. posterior part is pharyngeal part . and the sulcus terminalis projects backward and a small median pit is called Foramen caecum .  
Tongue have a four types of papillae on the upper surface :
              I.      Vallate papillae ( circumvallate papillae ) : largest size papillae and they have about 8-12 in number and each have 100 taste buds .
           II.      Filliform papillae : smallest size papillae and most numerous of the four types .these papillae contain tactile ( touch ) receptor but not any taste buds .
         III.      Fungiform papillae : medium size papillae less numerous and they are most numerous at the tip of the tongue .  Fungiform papillae have 5 taste buds .
        IV.      Foliate papillae : they are not develop in human tongue and these taste buds degenerate in early childhood . they are leaf like and 4-5 vertical folds .



Human tongue has a four types of taste buds :
           I.      Sweet
           II.      Salt
           III.      Sour
          IV.      Bitter
Functions of tongue :
           I.      Help in swallowing the food .
           II.      Help in speech and talking .
          III.      Helps in chewing the food .
         IV.      It acts as a brush of teeth .
         V.      It is an organ of taste .
        VI.      Help in detect the taste of food .
       VII.      Dog tongue : help in regulation of body temperature .
      VIII.      Frog tongue : help in prey capturing .


Teeth :
Teeth is a living structure .
False teeth are develop from ectoderm .eg. Tadpole larva in frog .
True teeth are develop from mesoderm + ectoderm .eg. fish, amphibians, reptiles, mammals, etc
On the basis of function and shape of teeth :
           I.      Homodont : The all teeth are same structure and function .
           II.      Heterodont : The all teeth are different structure and function .
On the basis of attachment of teeth :
            I.      Acrodont : teeth are attached to the free surface of jaw .eg. shark, frog
           II.      Pleurodont : teeth are attached to the inner side of jaw .eg. Lizard
          III.      Thecodont : teeth are embedded in the jaw .eg.crocodiles, mammals .
On the basis of replacement of teeth :
            I.      Monophyodont : teeth are appeared one time in a life .eg. whale
           II.      Diphyodont : teeth are appeared two time in a life .eg. humans
          III.      Polyphyodont : teeth are appeared many times in a life .eg. fishes, amphibians, etc 
Human teeth :

Heterodont , thecodont , diphyodont .
The milk or deciduous ( temporary teeth ) are 20 teeth ( diphyodont )
The permanent teeth are 12 teeth ( 8- premolar , 4- molar )( monophyodont )
The all teeth are appeared in 18- 25 year of age .
Dental formula :
In child : milk teeth are 20 in numbers ( 8 - incisors, 4 – canine, premolar are absent , 8- molar  )
In adult : permanent teeth are 32 in number ( 8- incisors, 4- canine, 8- premolar, 12- molar )
The third molar teeth are Wisdom teeth .
In child : 2102 / 2102 × 2 = 20 teeth
In 17 year : 2122 / 2122 × 2 = 28 teeth
In adult : 2123 / 2123 × 2 = 32 teeth
 In rabbit : 2033 / 1023 × 2 = 28 teeth
In rat : 1003 / 1003 × 2 =16 teeth
In dog : 3142 / 3142 × 2 = 42 teeth
In pig and horse : 3143 / 3143 × 2 = 44 teeth
In tiger : the pre molar teeth are very sharp are called carnassial teeth .
Human teeth are heterodont and functions of teeth :
Incisors : cutting
Canine : tearing
Pre molar : chewing
Molar : chewing
Types of roots :
Upper jaw : incisors has one root, canine has one root, first premolar has two root and second premolar has one root, molar has three roots .
Lower jaw : incisors has one root, canine has one root, premolar has one root and molar has two roots .
Structure of teeth :
The tooth consists of three parts :
            I.      Crown ( above the root )
           II.      Neck  ( surrounded by gums )
          III.      Root  ( embedded in the gums )
Enamel : it is a hardest part of the body ( enamel forming ameloblast  ).
Dentine : it is cover by enamel part and dentine has a pulp cavity and root canal . (dentine forming odntoblasts )
Pulp cavity has a nerves, vien, artery, etc .
Cement : it is present between the gums and root of teeth . and fixes the tooth .
Periodontal ligament is made up of collagen fibre and cover by the cement .


                   


                         

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