Unit 1

Pre-text assignments

1 Learn the key words:

ligament, cartilage, joint, framework, tendon, bone, lever, limb

2 Translate the following phrases:

a set of interrelated organs, specialized functions, protective shields, rigid structures, longitudinal axes, expanded ends, platelike structures

3 Choose the correct definition of the following terms:

1) bone a) an aggregate of cells together with their

intercellular substance

2) limb b) the point of contact between elements of the

skeleton

3) tissue c) the hard largely calcareous tissue

4) joint d) a leg or arm of a human being

Skeletal System

The human organism consists of several organ systems. Each system includes a set of interrelated organs that work together to provide specialized functions.

The organs of the skeletal and muscular systems function to support and move body parts.

The skeletal system consists of the bones as well as the ligaments and cartilages that bind the bones together at joints. These parts provide frameworks and protective shields for softer tissues, serve as attachments for muscles, and act together with muscles when body parts move. Tissues within bones also function to produce blood cells and store inorganic salts.

Bones

Bones are composed of several kinds of tissues, and thus they are the organs of the skeletal system.

Because bones are rigid structures, they provide support and protection for softer tissues, and they act together with skeletal muscles to make body movements possible. They also house the tissue that produces blood cells, and they store inorganic salts.

The shapes of individual bones are closely related to their functions. Projections provide places for the attachment of muscles, tendons, and ligaments; openings serve as passageways for blood vessels and nerves; and the ends of bones are modified to form joints with other bones.

Bones can be classified according to their shapes - long, short, flat, or irregular.

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.

Flat bones are platelike structures with broad surfaces, such as the ribs, scapulae, and bones of the skull.

Irregular bones have a variety of shapes and are usually connected to several other bones. Irregular bones include the vertebrae that comprise the backbone and many of the facial bones.

In addition to these four groups of bones, some authorities recognize a fifth group called the round or sesamoid bones. The bones of this group are usually small, and they often occur within tendons adjacent to joints, where the tendons undergo compression. The kneecap (patella) is an example of a very large sesamoid bone.

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.

Bones give shape to structures such as the head, face, thorax, and limbs. They also provide support and protection. For example, the bones of the feet, legs, pelvis, and backbone support the weight of the body. The bones of the skull protect the eyes, ears, and brain. Those of the rib cage and shoulder girdle protect the heart and lungs, while bones of the pelvic girdle protect the lower abdominal and internal reproductive organs.

Although the number of bones in a human skeleton is often reported to be 206, the actual number varies from person to person. Some people lack certain bones, while others have extra ones. For example, the flat bones of the skull usually grow together and become tightly joined along irregular lines called sutures. Occasionally extra bones called wormian or sutural bones develop in these sutures. Also, extra small, round sesamoid bones may develop in tendons, where they function to reduce friction in places where tendons pass over bony prominences.

Post-text assignments

1 List four groups of bones, based upon their shapes, name an example from each group.

2 Build medical terms. Choose them from the list below:

1 Abnormal condition of porous bones. 2 Inflammation of bone and bone marrow. 3 Dead bone tissue. 4 A disease in which there is enlargement of the bones of the head, hands and feet resulting from a tumor of the putuitary gland that causes overproduction of growth hormone. 5 An instrument for recording muscular contractions.

(a – ...graph; b – osteomyel...; c – ...porosis; d – sequestrum; e – ...megalia)

3 Match the descriptions and functions listed in column 1 with the bones listed in column II (Drawings 1, 2):

I II

1) coronoid process a) ethmoid bone

2) cribriform plate b) frontal bone

3) foramen magnum c) mandible

4) mastoid process d) maxillary bone

5) palatine process e) occipital bone

6) sella turcica f) temporal bone

7) supraorbital notch g) sphenoid bone

8) temporal process h) zygomatic bone

9) acromion process i) femur

10) deltoid tuberosity j) fibula

11) greater trochanter k) humerus

12) lateral malleolus l) radius

13) medial malleolus m) scapula

14) olecranon process n) sternum

15) radial tuberosity o) tibia

16) xiphoid process p) ulna

Unit 2

Pre-text assignments

1 Learn the key words and phrases:

joint, junction, lever system, to bend, to straighten, rigid structure, fibrous joints, cartilaginous joints, synovial joints, immovable, slightly movable, freely movable joints

2 Build medical terms:

1 Inflammation of joints. 2 Inflammation of bone and joints. 3 Abnormal condition of pus in a joint. 4 Any of various immovable articulations, or joints (as in suture joints of the skull). 5 A freely movable joint; any articulation, as of the hip, permitting free movement in any direction. 6 Neuralgic pain in a joint or joints.

(a – synarthr...; b – ...itis; c – ...arthritis; d – arthro...osis; e – dia…osis; f – arthr...ia)