See anatomic Table of Bones in the Appendices for regional and alphabetical listings of bones, and see color plates 1 and 2. Collectively they form the skeletal system, a structure bound together by ligaments at the joints and set in motion by the muscles, which are secured to the bones by means of tendons. Myostatin Mutation Associated with Gross Muscle Hypertrophy in a Child. Markus Schuelke, M.D., Kathryn R. Wagner, M.D., Ph.D., Leslie.Bones, ligaments, muscles, and tendons are the tissues of the body responsible for supporting and moving the body. Some bones have a chiefly protective function. An example is the skull, which encloses the brain, the back of the eyeball, and the inner ear. Some, such as the pelvis, are mainly supporting structures. What is antagonist and agonist muscle? See my list of Antagonistic muscle groups and help your workout by knowing more about Skeletal Muscles and Antagonistic pairs. Free Newsletters Need help achieving your fitness goals? The Muscle & Fitness newsletter will provide you with the best workouts, meal plans and supplement advice to.
Other bones, such as the jaw and the bones of the fingers, are concerned chiefly with movement. The bone marrow in the center manufactures blood cells. The bones themselves act as a storehouse of calcium, which must be maintained at a certain level in the blood for the body's normal chemical functioning. Structure and Composition. Bone is not uniform in structure but is composed of several layers of different materials. The outermost layer, the periosteum, is a thin, tough membrane of fibrous tissue. It gives support to the tendons that secure the muscle to the bone and also serves as a protective sheath. This membrane encloses all bones completely except at the joints where there is a layer of cartilage. Beneath the periosteum lie the dense, hard layers of bone tissue called compact bone. Its composition is fibrous rather than solid and it gives bone its resiliency. Encased within these layers is the tissue that makes up most of the volume of bone, called cancellous or spongy bone because it contains little hollows like those of a sponge. The innermost portion of the bone is a hollow cavity containing marrow. Blood vessels course through every layer of bone, carrying nutritive elements, oxygen, and other products. Bone tissue also contains a large number of nerves. The basic chemical in bone, which gives bone its hardness and strength, is calcium phosphate. Cartilage forms the major part of bone in the very young; this accounts for the great flexibility and resiliency of the infant skeleton. Gradually, calcium phosphate collects in the cartilage, and it becomes harder and more brittle. Some of the cartilage cells break loose, so that channels develop in the bone shaft. Blood vessels enter the channels, bearing with them small cells of connective tissue, some of which become osteoblasts, cells that form true bone. The osteoblasts enter the hardened cartilage, forming layers of hard, firm bone. Other cells, called osteoclasts, work to tear down old or excess bone structure, allowing the osteoblasts to rebuild with new bone. This renewal continues throughout life, although it slows down with age. Cartilage formation and the subsequent replacement of cartilage by hard material is the mechanism by which bones grow in size. During the period of bone growth, cartilage grows over the hardened portion of bone. In time, this layer of cartilage hardens as calcium phosphate is added, and a fresh layer grows over it, and it too hardens. The process continues until the body reaches full growth. Long bones grow in length because of special cross- sectional layers of cartilage located near the flared ends of the bone. These harden and new cartilage is produced by the same process as previously described. In these diseases there is softening of the bones, due to inadequate concentration of calcium or phosphorus in the body. The usual cause is deficiency of vitamin D, which is required for utilization of calcium and phosphorus by the body. In osteitis fibrosa cystica, bone is replaced by fibrous tissue because of abnormal calcium metabolism. The condition usually is due to overactivity of the parathyroid glands. Although it is not common, it may occur in any of the bones of the body, and at any age. Some authorities also include the maxilla, zygomatic bone, and palatine bone. See anatomic Table of Bones in the Appendices. See anatomic Table of Bones in the Appendices. Some authorities include the lacrimal bones, nasal bones, inferior nasal concha, and vomer and exclude the hyoid bone. See anatomic Table of Bones in the Appendices. See anatomic Table of Bones in the Appendices. See anatomic Table of Bones in the Appendices. See anatomic Table of Bones in the Appendices. Called also lingual bone. See anatomic Table of Bones in the Appendices. See anatomic Table of Bones in the Appendices. See anatomic Table of Bones in the Appendices. Called also wormian bone. See anatomic Table of Bones in the Appendices. See anatomic Table of Bones in the Appendices. The fibers are impregnated with inorganic components, including crystals of calcium phosphate, such that using X- ray defraction, they are seen to be organized in a hydroxyapatite pattern (calcium phosphate is 8. A bone is enveloped by a fibrous membrane, periosteum, that covers the bone's entire surface except for the articular cartilage. Beneath the periosteum is a dense layer, compact bone, and beneath that a cancellous layer, spongy bone. The core of a long bone is filled with marrow. It is divided anatomically into four parts: the mastoid, petrous, squamous, and tympanic parts. It consists of a dense organic matrix and an inorganic, mineral component. There are more than 2. Bones(used with a sing. Vulgar Slang The penis. Vulgar Slang To have sexual intercourse with. Used especially of a man. Vulgar Slang To have sexual intercourse. Etymology: AS, ban. It is composed of compact osseous tissue surrounding spongy cancellous tissue permeated by many blood vessels and nerves and enclosed in membranous periosteum. Also called (Latin) os. See also connective tissue. See Basisphenoid bone, Blue bone, Carpal bone, Cancellous bone, Compact bone, Cuboid bone, Cuneiform bone, Disappearing bone, Dumbbell bone, Endochondral bone, Facial bone, Frontal bone, Funny bone, Halbard bone, Hetereotopic bone, Hungry bone, Hyoid bone, Innominate bone, Lacrimal bone, Membranous bone, Moth- eaten bone, Nasal bone, Navicular bone, Peppermint stick candy bone, Ping pong bone, Red bone, Rider's bone, Shooter bone, Spongy bone, Wormian bone, Woven bone, Zygomatic bon. A hard connective tissue consisting of cells embedded in a matrix of mineralized ground substance and collagen fibers. The fibers are impregnated with a form of calcium phosphate similar to hydroxyapatite as well as with substantial quantities of carbonate, citrate, sodium, and magnesium; by weight, bone is composed of 7. A portion of osseous tissue of definite shape and size, forming a part of the animal skeleton; in human adults there are approximately 2. A bone is enveloped by a fibrous membrane, periosteum, that covers the bone's entire surface except for the articular cartilage. Beneath the periosteum is a denselayer, compact bone, and beneath that a cancellous layer, spongy bone. The core of a long bone is filled with marrow. Osseous tissue, a specialized form of dense connective tissue consisting of bone cells (osteocytes) embedded in a nonliving matrix. Bone matrix is made of calcium carbonate, calcium phosphate, and collagen fibers. A unit of the skeleton; the human skeleton has 2. Bones surround and protect some vital organs, and give points of attachment for the muscles, serving as levers and making movement possible. In the embryo, the bones of the skull are first made of fibrous connective tissue, which is gradually replaced by bone matrix. The remainder of the skeleton is first made of hyaline cartilage, which is also replaced by bone matrix, beginning during the third month of gestation. The outer surface of a bone is compact bone, and the inner more porous portion is cancellous (spongy) bone. The shafts of long bones are made of compact bone that surrounds a marrow canal. Compact bone is made of haversian systems, which are precise arrangements of osteocytes, blood vessels, and lymphatics within the bony matrix. All of these contribute to the maintenance and repair of bone. The periosteum is the fibrous connective tissue membrane that covers a bone. It has blood vessels that enter the bone, and it provides a site of attachment for tendons and ligaments. Bones are classified according to shape as long, short, flat, or irregular. See: illustration; skeleton for names of principal bones alveolar bone. The bony tissue or process of the maxilla or mandible that supports the teeth. Synonym: alveolar processbasioccipital bone. The basilar process of the occipital bone. Synonym: spongy bonecarpal bone. One of the eight wrist bones, which are aligned in two rows. The proximal row contains (from the thumb to the little finger) the scaphoid, lunate, triquetral, and pisiform bones. The distal row contains (from thumb to little finger) the trapezium, trapezoid, capitate, and hamate bones. Synonym: endochondral bonecavalry bone. Rider's bone. collar bone. Clavicle. compact bone. The hard, dense bone made of haversian systems that forms the surface layer of all bones and the shafts of long bones, in contrast to spongy bone that forms the bulk of the short, flat, and irregular bones and the ends of long bones. It subsequently fuses with the pubis. See: ear for illus. Cartilage bone. ethmoid bone. A complex thin- walled bone, roughly cuboidal in shape, located in the middle of the skull above the nasal cavities and below the anterior fossa of the cranial cavity. Its flat upper surface is the cribriform plate, which forms much of the roof of the nasal cavities; its upper surface has a midline bony keel that projects up into the cranial cavity and on both sides of which are perforated valleys through which the olfactory nerves project up from the olfactory epithelium. In the midline under the cribriform plate is a mirror- image (to the crista galli) keel, the perpendicular plate, which projects down between the nasal cavities as part of the bony nasal septum. While the showoff muscles get all the acclaim, they'd be nothing without the supporting cast of smaller stabilizers and assisting muscles. Ignore them, experts say—and you'll eventually pay the price. Wondering if your'e guilty? Here, experts discuss the most neglected muscles, why they're important, and how to strengthen them for an even, injury- free physique. Rotator cuff. Why it's important: Deltoids the size of grapefruits won't do you much good if you tear your rotator cuff, which is a group of four muscles that literally form a “cuff” to stabilize the shoulder joint. Injure it, and you’ll restrict your range of motion, making overhead movements painful. You typically only see people doing these exercises after they're injured. Bend right arm at a 4. Next, stand with your right side towards the door hinge. With your right arm bent at a 4. Repeat 1. 0 to 1. Start with a light resistance, then work your way up. Erector spinae. Why it's important: You probably work your upper back and traps for that wide expanse, but you're likely neglecting the very muscles that keep you upright. The erector spinae is actually a bundle of muscles and tendons that extend throughout the lower, mid and upper back. Place your hands behind your head with elbows out to the sides. Slowly raise your torso (don’t swing) just until your body forms a straight line, with ears, shoulders, hips, knees and ankles in line. Slowly return back to start. Do three sets of 1. Gluteus medius and minimus. Why they're important: Few muscles get as much attention as the gluteus maximus, yet it could not reach its full potential without these two lesser- known helpers, which serve to stabilize the pelvis—especially when standing on one leg, says Guy Andrews, MA, C. S. C. S., executive director of Exercise. Etc. com. Plus, when they're toned they lift up the glutes. Stand in a wide sports stance, knees slightly bent, toes pointed straight ahead and hands on hips or out in front. Step out to the side and continue walking sideways for 8- 1. Perform 2- 3 sets, 2- 3 times a week. Tibialis anterior. Why it's important: Have you ever suffered from shin splints? If so, listen up: Failing to strengthen this vital muscle—which runs along the bottom part of your leg, next to your shin bone—plays a huge role in forming a healthy gait, and can increase your risk of getting those nagging lower- leg pains. To increase the challenge, you can balance a small dumbbell (5 lbs) on your foot for added resistance. Or you can also sit on a high chair or bench, with enough room for your feet to dangle, and do the same exercise with a dumbbell between them. Obliques. Why they're important: All the crunches in the world won't get you six- pack abs without working these puppies. The obliques include the external and internal obliques, which cross diagonally from the bottom of your rib cage to your pubic area. Problem is, most people believe they're strengthening them by doing side bends—but they won't work. Lie on your back with your legs extended, feet about 1. Rotate your right elbow toward your left knee, keeping your opposite elbow on the ground and your opposite leg straight. Exhale as you rotate, thinking about your ribs squeezing toward your hips, then straighten your leg back to the start position. Pause, then repeat the motion to the opposite side. Do 8- 1. 0 reps 2- 3 times a week. Hamstrings. Why they're important: Sure all those squats, dead lifts and lunges indirectly hit the hamstrings—but not enough. So what’s the big deal? Any imbalance of opposing muscle groups, like big quads and weak hamstrings, can cause unequal pull on the joint. And in this particular case, that sets the stage for knee injuries. Lie on the floor with your heels on top of the ball, toes up toward the ceiling, and legs slightly bent. Lift the hips by pushing down on the ball with your heels, then roll the ball towards you by pulling your heels towards your seat, kneecaps pointed towards the ceiling. Keeping the hips off the ground, roll the ball back out to the starting position and repeat. Do 8- 1. 0 reps 2- 3 times a week. Forearm extensors. Why they're important: Since these muscles are responsible for gripping heavy things, like dumbbells and barbells, weak ones my hamper your ability to train larger muscles and weaken your entire workout—not to mention your tennis backhand. Or try this: Tie a light weight to the end of a rope, then tie the rope around a piece of broom handle or a wooden dowel. Stand with arms extended in front of you and roll the weight up and then down by rotating the broom towards you and away from you.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. Archives
November 2017
Categories |