Unit 5 digestive system

Vocabulary list to text a

abomasum n	[ˌæbəˈmeɪsəm]	сычуг
absorption n	[ əbˈzɔːp.ʃən ]	поглощение
avian	[ ˈeɪvɪən ]	птичий
belch up v	[ beltʃ ]	отрыгаться
break down v	[ breɪk ]	расщеплять
сecum n	[ˈsiːkəm]	слепая кишка
сhew v	[ tʃuː]	жевать
concentrate n	[ ˈkɒnsntreɪt]	концентрированный (богатый питательными веществами) корм
crop n	[ krɒp]	зоб
сud n	[kʌd]	жвачка
digestion n	[ daɪˈdʒestʃən ]	пищеварение
esophagus n	[ ɪˈsɒfəɡəs ]	пищевод
feedstuff n	[ ˈfiːdstʌf ]	корм
fermentation n	[ fɜːmenˈteɪʃn ]	брожение
forage n	[ ˈfɒrɪdʒ ]	фураж, грубые корма
gizzard n	[ ˈgɪzəd ]	желудок (мускульный)
hydrochloric acid	[ haɪdrəˈklɒrɪk  ˈæsɪd ]]	соляная кислота
monogastric adj	[ˈmɒnəʊ ˈɡæstrɪk ]	однокамерный
omasum  n	[ əˈmeɪsəm]	книжка
pouch n	[ paʊtʃ ]	мешок
proventriculus n	[ˌprəʊvenˈtrɪkjuləs]	преджелудок, железистый желудок
pseudo-ruminant adj	[ sjuːdəʊ  ˈruː.mɪ.nənt]	псевдо-жвачное (животное)
reticulum n	[ rɪˈtɪkjuləm ]	сетка (второй отдел желудка жвачного)
roughage n	[ ˈrʌfɪdʒ ]	грубая пища
rumen n	[ ˈruːmɪn ]	рубец
ruminant adj	[ˈruː.mɪ.nənt]	жвачное (животное)
species n	[ˈspiː.ʃiːz ]	вид
stomach	[ ˈstʌmək ]	желудок

Text a types of animal digestive systems

Read the text to find out about a) the types of the digestive system and their characteristic features. Complete the table below.

Digestion is the process of breaking down feed into simple substances that can be absorbed by the body. Absorption is the process of taking the digested parts of the feed into the bloodstream.

The digestive system consists of the parts of the body involved in chewing and digesting feed. This system also moves the digested feed through the animal’s body and absorbs the products of digestion. Different species of animals are better able to digest certain types of feeds than others. This difference occurs because of the various types of digestive systems found in animals. There are four basic types of digestive systems: monogastric, avian, ruminant, and pseudo-ruminant.

A monogastric digestive system has one simple stomach. The stomach secretes acid, resulting in a low pH¹. The low pH destroys most bacteria and begins to break down the feed materials. Animals with this type of digestive system are better adapted to eat rations high in concentrates. Concentrates are highly digestible feedstuffs that are high in energy and low in fiber. Examples of monogastric animals are hogs, cats, dogs, and humans.

The avian digestive system is found in poultry. This system differs greatly from any other type. Since poultry do not have teeth, there is no chewing. Poultry break their feed into pieces small enough to swallow by pecking with their beaks or scratching with their feet. Feed enters the mouth, travels to the esophagus, and empties directly into the crop. The crop is where the food is stored and soaked. Food then moves from the crop to the proventriculus. The proventriculus is the stomach in a bird, where gastric enzymes and hydrochloric acid are secreted. From the proventriculus, the food makes its way to the gizzard. The gizzard is a very muscular organ, which normally contains grit or stones that function like teeth to grind the food. The food then moves from the gizzard to the small intestine and then to the large intestine. The nondigestible food components then travel into the cloaca. Uriс acid is also emptied into the cloaca. The material is then passed out of the body through the vent. Digestion in the avian system is very rapid.

F ig.1

The ruminant digestive system is found in cattle, sheep, goats, and deer. Ruminant animals eat feed rations that are high in roughages and low in concentrates. Ruminants are different from monogastric animals in that they swallow their food in large quantities with little chewing. Later they will ruminate, or belch up the feed, chew, and swallow it again. The ruminant digestive system has a large stomach divided into four compartments - the rumen, the reticulum, the omasum, and the abomasum.

Rumen. The first and largest section of the stomach is the rumen. In the rumen, solid feed is mixed and partially broken down. The rumen contains millions of bacteria and other microbes that promote fermentation, which breaks down roughages. The rumen also contains microorganisms that synthesize amino acids and B-complex vitamins. Amino acids are the building blocks of proteins and are essential for the growth and maintenance of cells.

Reticulum. The reticulum is the second segment of the stomach. The reticulum is a small pouch on the side of the rumen that traps foreign materials, such as wire, nails, and so forth. Since ruminants do not chew their food before swallowing, they can occasionally swallow foreign objects.

Omasum. The omasum is the third compartment of the stomach. The omasum produces a grinding action on the feed and removes some of the water from the feed. Hydrochloric acid and digestive enzymes are mixed with feed in the omasum.

Abomasum. The abomasum is the fourth compartment of the stomach. The abomasum is also referred to as the true stomach because it is similar to the stomach in monogastric animals.

Fig.2

A pseudo-ruminant is an animal that eats large amounts of roughage but does not have a stomach with several compartments. The digestive system does some of the same functions as those of ruminants. For example, in the horse, the cecum ferments forages. An animal with a pseudo-ruminant digestive system can utilize large amounts of roughages because of the greatly enlarged cecum and large intestine, which provide areas for microbial digestion of fiber. Pseudo-ruminants often eat forages as well as grains and other concentrated feeds. Besides horses, examples of pseudo-ruminants are rabbits, guinea pigs, and hamsters.

Notes

1. Low pH- низкий уровень кислотности

Type of of digestive systems	Animals	Physiological characteristics	Food they eat
monogastric
avian
ruminant
pseudo-ruminant

Exercise 1. Expand the given statements using the information from the text.

1. Different species of animals are better able to digest certain types of feeds than others. 2. A monogastric digestive system has one simple stomach. 3. The avian digestive system is found in poultry. 4. The proventriculus is the stomach in a bird. 5. The cloaca is an all-purpose exit. 6. Cud chewing in ruminants is a complex process. 7. The ruminant digestive system has a large stomach divided into four compartments. 8. An animal with a pseudo-ruminant digestive system can utilize large amounts of roughages.

Exercise 2. Find the English equivalents to the words with Latin origin.

gastric food pipe to ruminate guts esophagus pouch avian to chew intestine bird adj compartment stomach adj

Exercise 3. a) Find the antonyms.

monogastric to construct to destroy                          to synthesize                           to absorb                           to differ              to be similar slow to break polygastric rapid to secrete

b) Fill in the gaps with the words from the table above.

1. Digestion in the avian system is very … . 2. Ruminants are different from … animals in that they swallow their food in large quantities with little chewing. 3. Microbes promote fermentation which … roughages. 4. The avian digestive system … greatly from any other type. 5. Simple substances can be …-ed by the body.

Exercise 4. Translate the derivatives. Make up your own sentences with some of these words.

1. Rumen, ruminant, rumination, to ruminate. 2. To absorb, absorption, absorbent, absorbable, absorbability. 3. To digest, digestive, digest, nondigestible. 4. Ferment, to ferment, fermentation, fermenting, fermented.

Exercise 5. Complete the following sentences. Choose the ending according to the text.

1. Digestion is the process of … 2. Absorption is … . 3. The digestive system consists of the parts of the body involved in … . 4. There are four basic types of digestive systems: … . 5. A monogastric digestive system has … . 6. Concentrates are … . 7. The avian digestive system is found in … . 8. The crop is… . 9. The proventriculus is … . 10. The gizzard is… . 11. The ruminant digestive system is found in … . 12. Ruminants are different from monogastric animals in … . 13. The rumen is… . 14. The reticulum is … . 15. The omasum is … . 16. The abomasum is… .

Exercise 6. Translate the following words and phrases into English.

Пищеварительный тракт; книжка; пища, богатая питательными веществами; желудок; всасывать воду; соляная кислота; пищеварительные ферменты; жевать; расщеплять; птичий; зоб; неперевариваемый; отрыгаться; грубая пища; увеличенная в размере слепая кишка; микробное переваривание волокон; сычуг; сетка; железистый желудок птиц; мускульный желудок птиц.

Exercise 7. Give the English equivalents of the Russian words in brackets.

1. Cows are (жвачные) animals. It means they have more than one (отдел желудка). 2. The ruminant animals (глотать) their food (не жуя) it at first. 3. (Неперевариваемые) food components then travel into the cloaca. 4. The avian (зоб) is where the food is stored and soaked. 5. The first and largest section of the ruminant (желудок) is (рубец). 6. (Соляная кислота) and digestive (ферменты) are mixed with feed in the omasum. 7. Animals with this type of digestive system are better adapted to eat rations high in (богатая питательными веществами пища). 8. The digestive system consists of the parts of the body involved in (пережевывание и переваривание) feed.

Exercise 8. Fill in the gaps with an appropriate word given below.

Rumen Microorganisms

Ruminants rely on microorganisms for the digestion of … . The rumen microorganisms are very diverse and consist of … … …. Bacteria are the most numerous rumen microorganisms, at approximately one billion bacteria per milliliter of rumen fluid. Bacteria are responsible for most feed … in the rumen. They break down cellulose to form volatile fatty acids¹ (VFAs). The VFAs provide the ruminant with 60 to 80 percent of its … needs. Protozoa are typically responsible for about 25 percent of the fiber digestion in the rumen, even though a ruminant can survive without any protozoa in the rumen. Fungi contribute up to 8 percent of the total rumen… . Fungi are responsible for the digestion of cellulose² and lignin³ in more resistant …, such as barley straw.

(microorganisms; bacteria, protozoa, and fungi⁴; roughages; forages; energy; digestion)

Notes 1. Volatile fatty acids - летучие жирные кислоты 2. Cellulose - клетчатка 3. Lignin - лигнин - сложное полимерное соединение, содержащееся в клетках сосудистых растений 4. Fungi - грибы

Exercise 9.Translate the following sentences into English.

1. Расщепление питательных веществ происходит в пищеварительной системе. 2. По характеру пищеварения животных подразделяют на несколько типов. Первый тип — животные с однокамерным желудком. 3. Жвачные животные имеют четырехкамерный желудок. Значительная часть корма переваривается без участия пищеварительных ферментов. 4. У свиней желудочного сока выделяется больше при приеме концентратов. 5.  Корм из рубца отрыгивается в ротовую полость, пережевывается, смешивается со слюной и вновь проглатывается. 6. Желудок у птиц состоит из двух частей: так называемого железистого желудка и мышечного желудка. 7. В слепых отростках происходят процессы брожения, которые способствуют усвоению клетчатки.

Exercise 10. Test yourself by answering the following questions to see how much you remember and understand. 1. Name the four basic types of digestive systems. 2. What type of feedstuff is high in energy and low in fiber? 3. What type of feedstuff is low in energy and high in fiber? 4. Name three examples of monogastric animals. 5. How do poultry break their food into smaller pieces? 6. List the four compartments of the ruminant stomach. 7. Name three examples of ruminant animals. 8. What is the most prevalent microorganism found in the rumen? 9. Name three examples of pseudo-ruminant animals.