Содержание
- 2. Teeth are hard, bony structures that grow from the jawbone. Humans and other animals use their
- 3. Humans grow two sets of teeth during their lives. The first set has 20 teeth baby
- 4. Humans, same as the rest of the mammals, are heterodont animals, meaning that they have several
- 5. Types of teeth Human teeth belong to four distinct types each having a typical appearance and
- 6. Incisors Incisors (Cutting teeth) are the teeth at the center of the dental arch. There are
- 7. Canines (cuspids) Canines (also called eye teeth or cuspids) are the teeth located next to the
- 8. Premolars (bicuspids) Premolars (also called bicuspids) are the teeth located after the canines towards the back
- 9. Molars Molars are the teeth located at the back of the dental arch. Adult humans have
- 10. Molars perform most of the chewing, by crushing and finalizing grinding before swallowing the food. The
- 12. Sequence of Tenses The tense of a verb in the subordinate clause changes in accordance with
- 13. If the verb in the principal clause is in the present or the future tense, the
- 14. If the tense in the principal clause is in the past tense, the tense in the
- 15. If the principal clause is in the future tense, we do not use future tense in
- 16. Direct and indirect speech Direct speech– Direct speech is the original or actual words of the
- 17. There are four basic rules to change a direct speech into indirect speech. 1. Reporting verb
- 19. Скачать презентацию
Слайд 2Teeth are hard, bony structures that grow from the jawbone. Humans and other
Teeth are hard, bony structures that grow from the jawbone. Humans and other
Слайд 3Humans grow two sets of teeth during their lives. The first set has
Humans grow two sets of teeth during their lives. The first set has
Слайд 4Humans, same as the rest of the mammals, are heterodont animals, meaning that
Humans, same as the rest of the mammals, are heterodont animals, meaning that
Permanent human teeth come in four different types: incisors, canines, premolars, and
molars.
Слайд 5Types of teeth
Human teeth belong to four distinct types each having a typical
Types of teeth
Human teeth belong to four distinct types each having a typical
As a species, humans are omnivorous eating both meats and plants, so they need different types of teeth to handle both types of food. Generally, carnivorous animals need sharp teeth to pierce and tear meat, while herbivorous animals need flat teeth to crush and grind plants. Humans, as omnivorous, must have at least these 2 types of teeth. Through evolution humans have developed 4 different main teeth types:
Слайд 6Incisors
Incisors (Cutting teeth) are the teeth at the center of the dental arch.
Incisors
Incisors (Cutting teeth) are the teeth at the center of the dental arch.
Incisors are flat and board, shaped like a shovel with a narrow straight cutting edge that enables them to cut food. The main functions of an incisor in the mastication process are biting, cutting of food into chewable pieces and moving it inwards the mouth.
All eight incisors have a single root and almost the same shape, but their size may differ slightly with the upper incisors usually larger, and especially the central ones.
Слайд 7Canines (cuspids)
Canines (also called eye teeth or cuspids) are the teeth located next
Canines (cuspids)
Canines (also called eye teeth or cuspids) are the teeth located next
They have a sharp pointed edge that is used to rip and tear tough foods such as meat. In humans canine teeth have the same height as the rest of the teeth but in other animals they are longer and used to bite and kill prey. Canines have a single but long root that can reach up to 3 cm providing the stability required for their function.
They are the longest and most stable human teeth.
Слайд 8Premolars (bicuspids)
Premolars (also called bicuspids) are the teeth located after the canines towards
Premolars (bicuspids)
Premolars (also called bicuspids) are the teeth located after the canines towards
The morphology of premolars is a combination between canines and molars. They are also known as bicuspids, because usually they have at least two cusps on their upper side. Premolars have a broader surface for chewing and grinding, but they also have some sharp points for piercing and ripping at the edge of the cusps. Their major role is to begin the crushing of foods before they are transferred to the molars for the final grinding. The upper jaw first premolars have two roots, while the upper
second ones and all the lower jaw premolars have only one root.
Слайд 9Molars
Molars are the teeth located at the back of the dental arch. Adult
Molars
Molars are the teeth located at the back of the dental arch. Adult
seventh, and eighth teeth from the midline.
Слайд 10Molars perform most of the chewing, by crushing and finalizing grinding before swallowing
Molars perform most of the chewing, by crushing and finalizing grinding before swallowing
The first and second molars have a similar shape with premolars, but they are larger (with the first molar larger than the second one). The mandibular first molars (the one at the lower jaw) are usually the largest teeth of the human mouth. They have a more flattened surface with four to five cusps, and two to three roots.
The morphology and size of third molars (wisdom teeth) may vary significantly but they are usually smaller than the other molars. In some cases they fail to erupt properly in the mouth, either remaining trapped inside the jaw bone (impacted wisdom teeth), or erupting partially causing a painful condition known as pericoronitis.
Слайд 12Sequence of Tenses
The tense of a verb in the subordinate clause changes in
Sequence of Tenses
The tense of a verb in the subordinate clause changes in
Слайд 13If the verb in the principal clause is in the present or the
If the verb in the principal clause is in the present or the
He says that the tooth aches.
He says that the tooth ached.
He says that the tooth will ache.
He will say that the tooth aches.
He will say that the tooth ached.
He will say that the tooth will ache.
Слайд 14If the tense in the principal clause is in the past tense, the
If the tense in the principal clause is in the past tense, the
He said that he would go to the clinic.
He told me that he had been ill.
I knew that he would not recover.
We noticed that the blood had stopped.
We use may in the subordinate clause when the main clause is in the present tense. We use might in the subordinate clause when the main clause is in the past tense.
I study that I may pass examination in biochemistry.
I will study that I may pass examination in biochemistry.
I studied that I might pass examination in biochemistry.
Слайд 15If the principal clause is in the future tense, we do not use
If the principal clause is in the future tense, we do not use
I will call you when the doctor have free time. (NOT I will call you when the doctor will have free time.)
I shall wait until the doctor call me. (NOT I shall wait until the doctor will call me.)
Expressions such as as if, if only, it is time and wish that are usually followed by past tenses.
I wish I went to the dentist a bit earlier.
He talks as if the effect of lidocaine passed.
Слайд 16Direct and indirect speech
Direct speech– Direct speech is the original or actual words
Direct and indirect speech
Direct speech– Direct speech is the original or actual words
Indirect speech– In Indirect speech, the original or actual words of the speaker that are changed in our own manner and the statement is not in inverted commas.
Слайд 17There are four basic rules to change a
direct speech into indirect speech.
1.
There are four basic rules to change a
direct speech into indirect speech.
1.
2. Remove the inverted commas, replace them with an appropriate conjunction.
3. Change the pronoun according to reporting speech.
4. Change the adverbs of the Direct speech.