oppurtunities

ADVANTAGES AND DISADVANTAGES OF MECHANIZATION

ADVANTAGES AND DISADVANTAGES OF MECHANIZATION farm mechanization ensures that all farm operation are done and completed within a given per...

popular post of all time

TYPES OF DENTITION


DENTITION

The mammalian teeth
What is dentition?
Dentition refers to the number, arrangement and conformation of teeth in an organism.

TYPES OF DENTITION

There are two major types of dentition. They are
1. Homodont dentition and
2. Heterodont dentition

i. Homodont dentition: in this type of dentition, the organism possesses or have the same types or sets of teeth. In this types of dentition, there are no specialized set of teeth for a particular type of function. All the teeth of a typical homodont dentition are of the same sizes, shape and functions. Typical examples of homodont dentition is found in the reptiles, amphibians and fishes
ii. Heterodont dentition: in this type of dentition, the organism has teeth different sizes, shapes and functions. Examples organisms having the heterodont dentition are mammals like rabbits, man, dogs, lions, cattle and pigs.
Mammals generally has four types or set of teeth. These are
i. Incisors
ii. Canines,
iii. Premolars and
iv. Molars
The type of teeth possessed by an animal depends on the types food it eats.
Mammals have two sets of teeth, they are milk teeth and permanent teeth.








1.Milk teeth:
this the set of teeth possessed by young ones that in the case of humans, the children. It is made up of incisors, canines and premolars and the molars are absent. It is common in children and infants and numbers around 20. It will later fall off to be replaced by the permanent teeth.
2.

Permanent teeth:

this is the sets of teeth possessed by adults and are usually four groups consisting of the incisors, canines, premolars and molars. The permanent teeth stays till old age and may number up to 32 for a full grown adult human

TYPES OF TEETH

There are four types of teeth in mammals. These are incisors, canines, premolars and molars.
i. Incisors: these are located in the front of the jaw. They are flat, chisel shaped and sharp edge used in cutting and holding on the prey so that they cannot escape.
ii. Canines: these set of teeth are found next to the incisors. They are sharp and pointed at the tips. Canines are used for tearing flesh and bones in the case of carnivores
iii. Premolars: premolars are located at the back of the jaw following the canines. They have flat ridged surfaces or cusps used for grinding and chewing of foods
iv. Molars: molars are located at the extreme back of the jaws. They are closely packed with ridged surfaces. They are used for chewing and grinding of food

The structure of a tooth

A typical tooth such as the canine or incisor is made up of three parts or regions which are the crown, the neck and the root
1. The Crown: the crown is the parts of the tooth which above the gum
2. The Root: the root is the part of the tooth that is embedded in the socket of the gum
3. The Neck: this is the narrow junction between the crown and the root







Incisors and canines have one root each while the premolars and molars have two or three roots each
Starting with the external parts, then tooth consists of enamel which is manufactured by special cells of the gum. Enamel is a very hard, non-living substance containing calcium salts. The enamel protects the dentine and pulp cavity and form an efficient hard biting surface.
Below the enamel, the dentine is located. The dentine is a bony-like material which contains the pulp cells thereby making it alive.
At the centre of the tooth is pulp cavity which is made of connective tissues, sensory nerves and blood capillaries.
The blood capillaries of the pulp are important in the transportation of oxygen and digested food substances. Due to the presence of sensory nerves endings, the tooth is able to respond to heat, cold and pain.
At the root region, the tooth is not covered by enamel but by a bone-like material called cement.
The tooth is embedded in the jaw bone of maxilla (upper jaw) and the mandible (lower jaw). A fibrous tissue called periodontal membrane fixes the tooth into the jaw bone.


DENTAL FORMULA

Meaning of dental formula
What is the dental formula?
The dental formula refers to the numbers and types of teeth present in the mouth of an animal. The number and type of teeth present in the mouth of a mammal or animal is a reflection of special adaptation of mammalian teeth for feeding.

The adaptation of mammalian teeth for feeding


Incisors

– The four front teeth in both the upper and lower jaws are called incisors. Their primary function is to cut food. The two incisors on either side of the midline are known as central incisors. The two adjacent teeth to the central incisors are known as the lateral incisors. Incisors have a single root and a sharp incised edge.

Canines

– There are four canines in the oral cavity. Two in the maxillary arch and two in the mandibular area. They are behind and adjacent to the lateral incisors. Their main function is to tear food. They have a single, pointed cusp and a single root. They have the longest root of any tooth. They also serve to form the corners of the mouth.

Premolars (Bicuspids)

– These teeth are located behind and adjacent to the canines and are designed to crush food. There are eight premolars in the oral cavity. There are two in each quadrant of the mouth. The one closest to the midline is the first premolar and the one farthest from the midline is the second premolar. These teeth can have 3-4 cusps. The maxillary first premolar has two roots, and the remaining premolars have a single root. There are no premolars in the primary dentition.

Molars

– The most posterior teeth in the mouth are the molars. They have broader and flatter surfaces with 4-5 cusps. They are designed to grind food. Molars typically have two roots, although the maxillary first molar (behind the second premolar) has three roots. There are 12 molars in the permanent dentition with three in each quadrant of the mouth. They are named starting with closest to the midline as first molars, second molars and third molars. Although, some people do not fully develop the third molars. Third molars are often referred to as wisdom teeth. The primary dentition only contains eight molars.











1.

The human teeth


The dental formula of man is as follows
I= ,c= ,p= ,m= total=32



Man is an omnivore, i.e. it feeds on both flesh and vegetables and the total number of teeth in the mouth is 32, which is also adapted to its type of diet.
i. Incisors: incisors are broad and sharp for cutting food
ii. Canines: canines are bluntly pointed and are used for gripping and tearing food
iii. Premolars: premolars and molars have strong cusps for chewing and grinding of food


2.

The teeth of dogs

I= ,c= ,p= ,m= total=42
Dog is a carnivorous animal, which means it feeds on flesh hence it has 42 in number and are adapted to the kind of food its eat. So here is the arrangement of the teeth in the mouth of a dog
i. INCISORS: the incisors of carnivores are very small and pointed. They are mainly used for cutting and tearing off flesh from bones.
ii. Canines: the canines of a typical carnivore are long, a little curved, large and pointed. The canine is used for attack and defense as well as for seizing prey, and tearing off flesh from the bones
iii. Premolars: premolars and molars are broad and thick. The last premolar in the upper jaw and the first molar ion the lower jaw are large and modified to form CARNASSIAL TEETH. The possess sharp cutting edges which are used to cut up meat and tear it away from bones. They are also used for cracking bones. Premolars and molars are cusped, blunt with flat surfaces used mainly for cutting and grinding


3.

The teeth of Rabbit


The dental formula of rabbit is
I= ,c= ,p= ,m= total=28

The rabbit is a herbivorous animal, that is to say it feeds on vegetables mainly hence its teeth is 28 in number, and is adapted for the kind of food it eats.

i. The incisors of a rabbit are flat with sharp cutting edges for cutting vegetables or grasses.
ii. The canines are practically absent in rabbit. So the space created by the absence of canines in rabbit is called DIASTEMA. The DIASTEMA allows the manipulation of grasses in the mouth.
iii. The premolars and molars of the rabbit are large, closely packed and have large ridge surface area cutting and grinding of food


don't forget to use the comment box and leave a message or suggestion and we will get back to you within seconds.

You can read some of most interesting topics below

Agricultural biology topics
1. ENVIRONMENTAL FACTORS AFFECTING AGRICULTURAL PRODUCTION
2. DISEASES
3. 52. SOIL MICRO-ORGANISMS
4. ORGANIC MANURING
5. FARM YARD MANURE
6. HUMUS
7. COMPOST
8. CROP ROTATION
9. GRAZING AND OVER GRAZING
10. IRRIGATION AND DRAINAGE
11. IRRIGATION SYSTEMS
12. ORGANIC MANURING
13. FARM YARD MANURE
14. HUMUS
15. COMPOST
16. CROP ROTATION
17. GRAZING AND OVER GRAZING
18. IRRIGATION AND DRAINAGE
19. IRRIGATION SYSTEMS
20. INCUBATORS
21. MILKING MACHINE
22. SIMPLE FARM TOOLS
23. AGRICULTURAL MECHANIZATION
24. THE CONCEPT OF MECHANIZATION
25. PROBLEMS OF MECHANIZATION
26. SURVEYING AND PLANNING OF FARMSTEAD
27. IMPORTANCE OF FARM SURVEY
28. SURVEY EQUIPMENT
29. PRINCIPLES OF FARM OUTLAY
30. SUMMARY OF FARM SURVEYING
31. CROP HUSBANDRY PRACTICES
32. PESTS AND DISEASE OF MAIZE- ZEA MAYS
33. CULTIVATION OF MAIZE CROP
34. OIL PALM
35. USES OF PALM OIL
36. MAINTENANCE OF PALM PLANTATION
37. COCOA
38.
39. PROCESSES IN COCOA CULTIVATION
HOLING AND LINING
40. YAM
41. LAND PREPARATION FOR YAM
42. DEPT OF PLANTING
43. SPACING OF YAM
44. PLANTING DEPT OF YAM
45. STORAGE OF YAM
46. STAKING OF YAM
47. HARVESTING OF YAM
48. COWPEA
JUTE
49. FORAGE CROP AND PASTURE
50. FORAGE GRASSES
51. SILAGE
52. PASTURE
53. TYPES OF PASTURE
COMMON GRASSES AND LEGUMES
54. GRASSES
55. LEGUMES
56. ESTABLISHMENT OF PASTURES
57. 201. FORAGE PRESERVATION
58. HAY SILAGE
59. FORESTRY IMPORTANCE OF FORESTRY 206. FOREST MANAGEMENT FOREST REGULATION DEFORESTATION AFFORESTATION
60. DISEASES AND PESTS OF CROPS
61. MAIZE SMUT
62. RICE BLAST
63. MAIZE RUST
64. LEAF SPOT OF GROUNDNUT
65. COW-PEA MOSAIC
66. COCOA BLACK POD DISEASE
67. COFFEE RUST
68. CASSAVA BACTERIA BLIGHT
69. BLACK ARM BACTERIA BLIGHT OF COTTON
70. TOMATO ROOT KNOT
71. DAMPING-OFF OF TOMATO
72. ONION DOWNY MILDEW
73. STORED PRODUCE MOULD
74. PESTS OF CROPS
75. STEM BORERS
76. ARMY WORM

77. COCOA MIRIDS(CAPSIDS)
78. APHIDS
79. WHITE FLY SEED BUGS
80. CASSAVA CULTIVATION
81. CASSAVA MEALYBUGS
82. VARIEGATED GRASSHOPPER
83. GREEN SPIDER MITE
84. COTTON STAINER
85. COTTON
86. PESTS OF VEGETABLES
87. GRASSHOPPER





88. THRIPS
89. LEAF ROLLER
90. BEAN BEETLE
91. RICE WEEVILS
92. . PROBLEMS WITH PESTS CONTROL
93. CROP IMPROVEMENT
94. PROCESS OF CROP IMPROVEMENT METHODS OF CROP IMPROVEMENT
95. HYBRIDIZATION OF CROPS
96. ANIMAL PRODUCTION
97. THE DIGESTIVE SYSTEM OF ANIMALS
98. THE LARGE AND SMALL INTESTINE
99. RUMINANT ANIMALS
100. THE NERVOUS SYSTEM
101. THE NEURONS
102. A SYNAPSE ACTION IMPULSE REFLEX ACTION VOLUNTARY ACTION
103. THE CENTRAL NERVOUS SYSTEM
104. PERIPHERAL NERVOUS SYSTEM
105. THE REPRODUCTIVE SYSTEM MALE AND FEMALE REPRODUCTIVE SYSTEM
106. REPRODUCTIVE SYSTEM OF BIRDS
107. THE CIRCULATORY SYSTEM
108. THE PULMONARY CIRCULATION
109. THE HEART
110. THE RESPIRATORY SYSTEM
111. THE TRACHEA INSPIRATION THE EXPIRATION THE DIAPHRAGM
112. HEAT PERIODS OESTROUS CYCLE
113. MATING
114. PARTURITION
115. MAMMARY GLAND
116. LACTATION
117. EGG FORMATION IN POULTRY
118. LIVESTOCK MANAGEMENT
119. MANAGEMENT OF GOATS
120. REPRODUCTION IN GOAT
121. POULTRY
122. POULTRY MANAGEMENT
123. BATTERY CAGE SYSTEM
124. INTENSIVE SYSTEM
125. . SEMI-INTENSIVE EXTENSIVE SYSTEM

PROODING AND REARING IN POULTRY
126. POULTRY SANITATION

127. ANIMAL NUTRITION
128. RATION
129. CONCENTRATE
130. ROUGHAGE
131. NUTRIENT SOURCES AND FUNCTIONS
132. CARBOHYDRATES
133. PROTEIN FATS
134. MINERALS
135. VITAMINS
136. FEEDING MECHANISMS IN HOLOZOIC ORGANISMS
137. TYPES OF DIETS
138. FATTENING OR FINISHING DIETS
139. LAYER DIETS
140. BALANCED DIETS
141. LACTATION DIETS
142. MALNUTRITION
143. DISEASE, CAUSES, SYMPTOM CORRECTION
144. RANGE MANAGEMENT AND IMPROVEMENT
145. LIVESTOCK DISEASES
146. VIRAL DISEASES
147. RINDER PESTS
148. NEWCASTLE DISEASE
149. BACTERIA DISEASES
150. ANTHRAX
151. BRUCELLOSIS
152. TUBERCULOSIS
153. FUNGAL DISEASES


154. PROTOZOAN DISEASES
155. TRYPONOSOMIASIS
156. COCCIDIOSIS
157. RED WATER FEVER(PIROPLASMOSIS)
158. ENDO PARASITES
159. TAPE WORM
160. ROUND WORM OF PIGS
161. LIVER FLUKE
162. ECTO PARASITES
163. TICK
164. LICE