Exercise 17. Find the information about the skeleton of different vertebrates. Prepare a short talk
UNIT 3
THE MUSCLES
VOCABULARY LIST TO TEXT A
| bind v | [ baɪnd] | связать |
| bowel n | [ baʊəl ] | кишечник |
| bundle n | [ ˈbʌndl̩] | пучок |
| continence n | [ ˈkɒntɪnəns] | регуляция мочеиспускания |
| contraction n | [ kənˈtrækʃən] | сокращение |
| extend v | [ ɪkˈstend] | разгибать |
| fascia( -ae) n | [ˈfeɪʃɪə] [ ] | фасция |
| flex v | [ˈfleks] | сгибать |
| net n | [ net] | сеть |
| propel v | [ prəˈpel] | продвигать |
| posture n | [ ˈpɒs.tʃər ] | осанка |
| striated adj | [ straɪˈeɪtɪd] | поперечно-полосатые |
| striation n | [ straɪˈeɪʃn] | бороздчатость |
| voluntary adj | [ˈvɒləntəri] | произвольный |
TEXT A
TYPES OF MUSCLES
Read the text to find out about a) the functions of muscles; b) the groups of muscles. Complete the table.
Muscle is a soft tissue in the body of humans and animals. Its main purpose is to produce force and motion. Muscles are responsible for maintaining posture, physical movement (sitting, walking, eating, etc.), and movement of internal organs (such as keeping the heart pumping to circulate blood and moving food through the digestive system).
The word muscle is derived from the Latin term musculus, meaning "little mouse". This Latin term could be due to the shape of some muscles or because muscles contracting under the skin can look like a mouse moving under a rug.
Tendons connect soft contracting muscles to hard bones.
Muscles can be under voluntary or involuntary control. Voluntary muscles, such as those found in the arms and legs, can be controlled by thought. Involuntary muscles are those that are automatically controlled by the nervous system and cannot be moved at will.
There are three main types of muscular tissue that we identify and classify on the basis of structure and functions:
1) smooth or visceral muscle,
2) striated or skeletal muscle,
3) cardiac muscle.
Smooth (visceral) muscle can contract slowly and do so without the intervention of the will (involuntary muscles). They make up the walls of the internal organs such as those of the blood vessels, the digestive tract, and the bladder. Smooth muscles maintain continence of the bladder and propel food through the bowel. Smooth muscle tissues consist of long cells. Smooth muscle fibers are bound into bundles by connective tissue, which contains blood vessels and nerves.
Striated muscles are most necessary for manipulation of the bones of the skeleton. Skeleton muscles are voluntary muscles. They are involved with such activities as walking, eating, tail motion and eye movement. Striated muscle tissue consists of large fibers in the form of bundles. Each individual muscle is composed of many cells held together by connective tissue. Skeletal muscles attach to bones by means of connective tissue tendons, which are elastic and strong. When muscles contract, they pull on the tendons, which then pull on the bones and cause the limbs to move. Each muscle fiber receives its own nerve impulses, which trigger various motions. Voluntary muscles can contract and pull, but they cannot push, so they must work in pairs that flex and extend. Muscles receive a generous blood supply from neighboring blood vessels. A rich capillary (the smallest of all blood vessels) distribution helps to deliver oxygen to muscles.
Cardiac (heart) muscle is a cross between the previous two. A characteristic feature of cardiac muscle is that fibers have neither a beginning nor an end. The heart is simply a huge net of muscles in which all elements are continuous with each other. Cardiac muscles have the force of contraction of skeletal muscle. Cardiac muscle is under complete involuntary control. In that, it resembles visceral muscles.
Exercise 1. Expand the given statements using the information from the text.
1. The main purpose of the muscle is to produce force and motion.
2. Muscles can be under voluntary or involuntary control.
3. Smooth muscle is found in the walls of many organs.
4. Skeletal muscles are complex in structure.
5. Cardiac (heart) muscle is a cross between the striated and smooth muscle.
6. Muscles receive a generous blood supply.
7. Skeletal muscles attach to bones by means of connective tissue tendons.