- •Unit 1
- •Skeletal System
- •Bones
- •Long bones have long longitudinal axes and expanded ends. Examples are the arm and leg bones.
- •Short bones are somewhat cube like, with their lengths and widths roughly equal. The bones of the wrists and ankles are examples of this type.
- •Functions of Bones
- •Skeletal parts provide shape, support, and protection for body structures. They also act as levers that aid body movements, house tissues that produce blood cells and store various inorganic salts.
- •Joints of the Skeletal System
- •The Plan for Rendering the Text
- •Unit 3
- •1 Learn the key words and phrases:
- •2 Match the terms to following definitions:
- •the gap between the ends of the broken
- •bone
- •4) the remains of something broken
- •down or destroyed
- •5) a rigid dressing of gauze impregnated
- •with plaster of Paris for immobilizing a
- •diseased or broken part
- •Fractures
- •Repair of a Fracture
- •Meanwhile, phagocytic cells begin to remove the blood clot as well as any dead or damaged cells in the affected area. Osteoclasts also appear and resorb bone fragments, thus aiding in "cleaning up" debris.
- •Unit 5
- •Muscular System
- •Muscles, the organs of the muscular system, consist largely of cells that are specialized to undergo contractions. During these contractions, chemical energy from nutrients is converted into mechanical energy, or movement.
- •Atrophy and Hypertrophy of Skeletal Muscles
- •Pre-text assignments
- •Digestive System and Digestion
- •Unit 10
- •The Alimentary Canal
- •Unit 11
- •Stomach
- •Unit 12
- •Heart
- •Unit 19
- •Actions of the Heart
- •Unit 20
- •Blood Vessels
- •Unit 21
- •Paths of Circulation
contracted at will. It is found chiefly in internal organs, such as the intestine wall and the heart, whose function is automatic.
Unit 6
Pre-text assignments
1 Learn the key words and phrases:
disuse, enlarge, hypertrophy, atrophy, mitochondria, resist fatigue, fatigable fibers, filaments of actin and myosin, discontinued, reduction, capillary networks, motor neurons, reinnervate
2 Memorize the explanation to the terms: increase becoming greater in size, amount, etc. decrease becoming gradually less, smaller, etc.
Atrophy and Hypertrophy of Skeletal Muscles
Skeletal muscles are very responsive to use and disuse. For example, those that are forcefully exercised tend to enlarge. This phenomenon is called muscular hypertrophy. Conversely, a muscle that is not used undergoes atrophy – that is, it decreases in size and strength.
The way a muscle responds to use also depends on the type of exercise involved. For instance, when a muscle contracts relatively weakly, as during swimming and running, its slow, fatigue-resistant red fibers are most likely to be activated. As a result, these fibers develop more mitochondria, and more extensive capillary networks develop around the fibers. Such changes increase the fibers' abilities to resist fatigue during prolonged periods of exercise, although their sizes and strengths may remain unchanged.
Forceful exercise, such as weight lifting, in which a muscle exerts more than 75% of its maximum tension, involves the muscle's fast, fatigable white fibers. In response, existing muscle fibers develop new filaments of actin and myosin, and as their diameters increase, the whole muscle enlarges. However, no new muscle fibers are produced during hypertrophy.
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Since the strength of a contraction is directly related to the diameter of the muscle fibers, an enlarged muscle is capable of producing stronger contractions than before. However, such a change does not increase the muscle's ability to resist fatigue during activities such as running or swimming.
If exercise is discontinued, there is a reduction in the capillary networks and in the number of mitochondria within the muscle fibers. Also, the size of the actin and myosin filaments decreases, and the entire muscle atrophies. Such atrophy commonly occurs when limbs are immobilized by casts or when accidents or diseases interfere with motor nerve impulses. A muscle that cannot be exercised may decrease to less than one-half its usual size within a few months.
The fibers of muscles whose motor neurons are severed not only decrease in size, but also may become fragmented and, in time, be replaced by fat or fibrous connective tissue. However, if such a muscle is reinnervated within the first few months following an injury, its function may be restored. Meanwhile, atrophy may be delayed by treatments in which electrical stimulation is used to cause muscular contractions against loads.
Post-text assignments
1 Respond to the following tasks:
1Explain how muscles may become fatigued and how a person's physical condition may affect tolerance to fatigue.
2Explain the differerence between atrophy and hyperthrophy of skeletal muscles
2 Choose the proper term to the identification:
1 The way (route) of administration of drugs. 2 The science dealing with the effect of drugs on living organisms. 3 Conditions which ban (forbid) the use of a drug. 4 The science that deals with medicinal products of plant, animal, or mineral origin in their crude or unprepared state. 5 The branch of pharmacology that deals with the effect and the reactions of drugs within the body. 6 Pertaining to against pain.
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(a – contraindications; b – analgesic, analgetic; c – intramuscular; d – pharmacology; e – pharmacognosy; f – pharmacodynamics)
Key:
1 – c (intramuscular); 2 – d (pharmacology); 3 – a (contraindications); 4 – e (pharmacognosy); 5 – f (pharmacodynamics)
Unit 7
1 Match the muscles in column I with the descriptions and functions in column II (Drawings 3,4):
I 1) buccinator
2) epicranius
3) medial pterygoid
4) platysma
5) rhomboideus major
6) splenius capitis
7) temporalis
8) zygomaticus
I
9) biceps brachii
10) brachialis
11) deltoid
12) latissimus dorsi
13) pectoralis major
14) pronator teres |
n) rotates the arm medially |
15) teres minor |
o) strongest flexor of the elbow |
16) triceps brachii |
p) strongest supinator of the |
|
forearm |
I |
II |
17) biceps femoris |
q) inverts the foot |
18) external oblique |
r) a member of the quadriceps |
|
femoris group |
19) gastrocnemius |
s) a plantar flexor of the foot |
20) gluteus maximus |
t) compresses the contents of |
|
the abdominal cavity |
21) gluteus medius |
u) largest muscle in the body |
22) gracilis |
v) a hamstring muscle |
23) rectus femoris |
w) adducts the thigh |
24) tibialis anterior |
x) abducts the thigh |
2 Read the text and render its main idea:
ln the United States, approximately 3 million people present to emergency departments for treatment of traumatic facial injuries each year. Most of these injuries are relatively minor soft tissue injuries that simply require first aid care or primary closures. A small percentage of facial traumas (0.04-0.09%) require major repair with possible bony reconstruction. Motor vehicle accidents (MVAs) were the most frequent cause of facial injuries before 1970. In recent years, with the institution of state seat belt laws, the number of deaths from MVAs has declined along with the incidence of facial injuries, although the prevalence of facial trauma has remained fairly constant. This is due to the growing population and other human factors, such as on-the-job accidents, sports-related injuries, domestic interpersonal violence, self-inflicted wounds, and animal bites.
The mechanism of injury for facial trauma varies widely from one locality to the next, depending significantly upon the degree of urbanization, socioeconomic status of the population, and cultural background of each region. MVAs continue to be a primary contributor to significant facial injuries in rural areas. In contrast, in
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inner metropolitan areas, domestic violence is the leading cause of facial trauma despite a denser population, a difference that may be due to stricter enforcement of traffic laws.
Unit 8
Anatomical Terminology
Terms of relative position are used to describe the location of one body part with respect to another. They include the following:
1 Superior means a part is above another part, or closer to the head. (The thoracic cavity is superior to the abdominopelvic cavity).
2 Inferior means situated below another part, or toward the feet. (The neck is inferior to the head).
3 Anterior (or ventral) means toward the front. (The eyes are anterior to the brain).
4 Posterior (or dorsal) is the opposite of anterior; it means toward the back. (The pharynx is posterior to the oral cavity).
5 Medial relates to an imaginary midline dividing the body into equal right and left halves. A part is medial if it is closer to this line than another part. (The nose is medial to the eyes).
6 Lateral means toward the side with respect to the imaginary midline. (The ears are lateral to the eyes). Ipsilateral pertains to the same side (the spleen and the descending colon are ipsilateral), while contralateral refers to the opposite side (the spleen and the gallbladder are contralateral).
7 Proximal is used to describe a part that is closer to a point of attachment or closer to the trunk of the body than another part. (The elbow is proximal to the wrist).
8 Distal is the opposite of proximal. It means a particular body part is farther from the point of attachment or farther from the trunk than another part. (The fingers are distal to the wrist).
9 Superficial means situated near the surface. (The epidermis is the superficial layer of the skin). Peripheral also means outward or near the surface. It is used to describe the location of certain blood vessels
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