File Name: ross and wilson anatomy and physiology .zip
The musculoskeletal system consists of the bones of the skeleton, their joints and the skeletal voluntary muscles that move the body.
The musculoskeletal system consists of the bones of the skeleton, their joints and the skeletal voluntary muscles that move the body. The characteristics and properties of joints, and of bone and muscle tissue, are discussed in this chapter. The illnesses section at the end of the chapter describes some disorders of bone, muscle and joints.
Although bones are often thought to be static or permanent, they are highly vascular living structures that are continuously being remodelled. These consist of a shaft and two extremities. As the name suggests, these bones are longer than they are wide. Examples include the femur, tibia and fibula. These have a diaphysis or shaft and two epiphyses or extremities Fig. The diaphysis is composed of compact bone with a central medullary canal, containing fatty yellow bone marrow. Thickening of a bone occurs by the deposition of new bone tissue under the periosteum.
Figure The outer layer is tough and fibrous, and protects the bone underneath. The inner layer contains osteoblasts and osteoclasts, the cells responsible for bone production and breakdown see below , and is important in repair and remodelling of the bone.
The periosteum covers the whole bone except within joint cavities, allows attachments of tendons and is continuous with the joint capsule. Blood supply to the shaft of the bone derives from one or more nutrient arteries; the epiphyses have their own blood supply, although in the mature bone the capillary networks arising from the two are heavily interconnected. The sensory supply usually enters the bone at the same site as the nutrient artery, and branches extensively throughout the bone.
Bone injury is, therefore, usually very painful. These have a relatively thin outer layer of compact bone with spongy bone inside containing red bone marrow Fig.
They are enclosed by periosteum except the inner layer of the cranial bones where it is replaced by dura mater. Bone is a strong and durable type of connective tissue. This inorganic matrix gives bone great hardness, but on its own would be brittle and prone to shattering. Collagen is very strong and gives bone slight flexibility. Osteoclasts break down bone. They are large, multinucleate cells made from the fusion of up to 20 monocytes p. A fine balance of osteoblast and osteoclast activity maintains normal bone structure and functions.
These bone-forming cells secrete both the organic and inorganic components of bone. They are present:. As bone develops, osteoblasts become trapped within the newly formed bone. They stop forming new bone at this stage and are called osteocytes. These are the mature bone cells that monitor and maintain bone tissue, and are nourished by tissue fluid in the canaliculi that radiate from the central canals. Their function is resorption of bone to maintain the optimum shape.
This takes place at bone surfaces:. Osteons tend to be aligned the same way that force is applied to the bone, so for example in the femur thigh bone , they run from one epiphysis to the other.
This gives the bone great strength. To the naked eye, spongy bone looks like a honeycomb. Osteocytes are nourished by interstitial fluid seeping into the bone through the tiny canaliculi. The spaces between the trabeculae contain red bone marrow. In addition, spongy bone is lighter than compact bone, reducing the weight of the skeleton. Microscopic structure of spongy bone. Development of bone tissue. During the process of bone development, osteoblasts secrete osteoid, which gradually replaces the initial model; then this osteoid is progressively calcified, also by osteoblast action.
As the bone grows, the osteoblasts become trapped in the matrix of their own making and become osteocytes. This is accompanied by development of a bone collar at about 8 weeks of gestation. Later the blood supply develops and bone tissue replaces cartilage as osteoblasts secrete osteoid components in the shaft. The bone lengthens as ossification continues and spreads to the epiphyses. Around birth, secondary centres of ossification develop in the epiphyses, and the medullary canal forms when osteoclasts break down the central bone tissue in the middle of the shaft.
This cartilage is then turned to bone. As long as cartilage production matches the rate of ossification, the bone continues to lengthen. At puberty, under the influence of sex hormones, the epiphyseal plate growth slows down, and is overtaken by bone deposition. Once the whole epiphyseal plate is turned to bone, no further lengthening of the bone is possible. Rising levels of these hormones are responsible for the growth spurt of puberty, but later stimulate closure of the epiphyseal plates Fig.
Oestrogens are responsible for the wider female pelvis that develops during puberty, and for maintaining bone mass in the adult female. Calcitonin increases calcium uptake into bone, and parathormone decreases it. Although the length and shape of bones does not normally change after ossification is complete, bone tissue is continually being remodelled and replaced when damaged. Osteoblasts continue to lay down osteoid and osteoclasts reabsorb it. The rate in different bones varies, e. Although bone growth lengthways permanently ceases once the epiphyseal plates have ossified, thickening of bone is possible throughout life.
This involves the laying down of new osteons at the periphery of the bone through the action of osteoblasts in the inner layer of the periosteum. Weight-bearing exercise stimulates thickening of bone, strengthening it and making it less liable to fracture.
Lack of exercise reverses these changes, leading to lighter, weaker bones. Healthy bone tissue requires adequate dietary calcium and vitamins A, C and D. Calcium, and smaller amounts of other minerals such as phosphate, iron and manganese, is essential for adequate mineralisation of bone. Vitamin A is needed for osteoblast activity. Vitamin C is used in collagen synthesis, and vitamin D is required for calcium and phosphate absorption from the intestinal tract. Most bones have rough surfaces, raised protuberances and ridges that give attachment to muscle tendons and ligaments.
These are not included in the following descriptions of individual bones unless they are of particular note, but many are marked on illustrations. Roughened bony projections, usually for attachment of muscles or ligaments. The different names are used according to the size of the projection. Trochanters are the largest and tubercles the smallest. Healing of bone. Following a fracture, the broken ends of bone are joined by the deposition of new bone.
This occurs in several stages Fig. A haematoma collection of clotted blood forms between the ends of bone and in surrounding soft tissues. There follows development of acute inflammation and accumulation of inflammatory exudate, containing macrophages that phagocytose the haematoma and small fragments of bone without blood supply this takes about 5 days. Fibroblasts migrate to the site; granulation tissue and new capillaries develop. Over the next few weeks, the callus matures, and the cartilage is gradually replaced with new bone.
Reshaping of the bone continues and gradually the medullary canal is reopened through the callus in weeks or months. In time the bone heals completely with the callus tissue completely replaced with mature compact bone. Often the bone is thicker and stronger at the repair site than originally, and a second fracture is more likely to occur at a different site.
Splinters of dead bone sequestrae and soft tissue fragments not removed by phagocytosis delay healing. This delays growth of granulation tissue and new blood vessels. Hypoxia also reduces the number of osteoblasts and increases the number of chondrocytes that develop from their common parent cells.
This may lead to cartilaginous union of the fracture, which results in a weaker repair. The most vulnerable sites, because of their normally poor blood supply, are the neck of femur, the scaphoid and the shaft of tibia. This may result in the formation of a large and irregular callus that heals slowly and often results in permanent disability.
Continuous movement results in fibrosis of the granulation tissue followed by fibrous union of the fracture. Pathogens enter through broken skin, although they may occasionally be blood-borne. Healing will not occur until the infection resolves.
Emboli consisting of fat from the marrow in the medullary canal may enter the circulation through torn veins. They are most likely to lodge in the lungs and block blood flow through the pulmonary capillaries. Axial skeleton in gold, appendicular skeleton in brown. Anterior view. Lateral view. Together the bones forming these structures constitute the central bony core of the body, the axis. Skull Figs The skull rests on the upper end of the vertebral column and its bony structure is divided into two parts: the cranium and the face.
The cranium is formed by a number of flat and irregular bones that provide a bony protection for the brain. The periosteum lining the inner surface of the skull bones forms the outer layer of dura mater.
In the mature skull the joints sutures between the bones are immovable fibrous.
The glossary has been expanded, as have the online access, learning outcomes and normal values tables. This book is excellent value for money. Ross and Wilson has been a core text for students of anatomy and physiology for over 50 years. This latest edition continues to be aimed at healthcare professionals including nurses, students of nursing, the allied health professions and complementary therapies, paramedics and ambulance technicians, many of whom have found previous editions invaluable. It retains the straightforward approach to the description of body systems and how they work.
One of the world's most popular textbooks of anatomy and physiology, it introduces the structure and functions of the human body and the effects of disease or illness on normal body function. More than any other text Ross and Wilson uses easy-to-understand, straightforward language, enhanced by colour illustrations and a huge range of interactive online activities, to make learning more visual and engaging. Students and physicians have been using anatomy and physiology texts by Ross and Wilson for more than 50 years. This latest 12th edition is an excellent opportunity. Illustrations have been revised, with new vivid electron micrographs and images that vibrantly carry learning to life. This describes the anatomy and roles of the body and the symptoms of the illness, with immersive multimedia exercises, animations and research aids to facilitate the learning process.
Key Features Get this from a library! In preparing this edition, we have. Ross and Wilson has been a core text for students of anatomy and physiology for almost 40 years.
Human anatomy is the science which deals with the structure of the human body. However, the two words, anatomy and dissection, are not synonymous. Dissection is a mere technique, whereas anatomy is a wide field of study. Gross or macroscopic anatomy: The study of anatomical features visible to the naked eye, such as internal organs and external features. Surface Anatomy: The study of anatomical landmarks that can be identified by observing the surface of the body. Sometimes called superficial anatomy. Microscopic anatomy: The study of minute anatomical structures on a microscopic scale, including cells cytology and tissues histology.
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