Hand,throax and back

The hand is composed of many different bones, muscles, and ligaments that allow for a large amount of movement and dexterity. There are 3 major types of bones in the hand itself, including:

Phalanges. The 14 bones that are found in the fingers of each hand and also in the toes of each foot. Each finger has 3 phalanges (the distal, middle, and proximal); the thumb only has 2.

Metacarpal bones. The 5 bones that compose the middle part of the hand.

Carpal bones. The 8 bones that create the wrist. The 2 rows of carpal bones are connected to 2 bones of the arm--the ulna bone and the radius bone.

Numerous muscles, ligaments, tendons, and sheaths can be found within the hand. The muscles are the structures that can contract, allowing movement of the bones in the hand. The ligaments are fibrous tissues that help bind together the joints in the hand. The sheaths are tubular structures that surround part of the fingers. The tendons connect muscles in the arm or hand to the bone to allow movement.

In addition, there are arteries, veins and nerves within the hand that provide blood flow and sensation to the hand and fingers.

We move forward to the Chest or throax

The thorax is the area of the body situated between the neck and the abdomen. The thorax itself can be split up into various areas that contain important structures.

The thorax is bound by bony structures including the 12 pairs of ribs and thoracic vertebrae, whilst also being supported by many ligaments and muscles.

The muscles of the thorax are also important for the vital actions of breathing and muscles that attach to the thoracic wall may also contribute to the general movement of the trunk, upper limbs and the neck.

The thoracic cavity is home to many vital organs, notably the lungs/pleurae and the heart, but also includes the thymus gland and the breasts. As the heart is found here, the great vessels associated with it are also found – including the pulmonary arteries/veins, the superior vena cava and the aorta (as well as some of its proximal branches).

In this section, learn more about the areas of the thorax, bones of the thorax, muscles of the thorax, organs of the thorax and the vasculature of the thorax.

Structure and function

front of the fourth rib or a little below; vertically it lies a little external to a line drawn down from the middle of the clavicle; in the female it is not so constant. A little below it the lower limit of the great pectoral muscle is seen running upward and outward to the axilla; in the female this is obscured by the breast, which extends from the second to the sixth rib vertically and from the edge of the sternum to the mid-axillary line laterally. The female nipple is surrounded for half an inch by a more or less pigmented disc, the areola. The apex of a normal heart is in the fifth left intercostal space, three and a half inches from the mid-line.

Clinical significance

pains differently for the same condition. Only a patient truly knows if the symptoms are mild or serious.

Chest pain may be a symptom of myocardial infarctions ('heart attack'). If this condition is present in the body, discomfort will be felt in the chest that is similar to a heavy weight placed on the body. Sweating, shortness of breath, lightheadedness, and irregular heartbeat may also be experienced. If a heart attack occurs, the bulk of the damage is caused during the first six hours, so getting the proper treatment as quickly as possible is important. Some people, especially those who are elderly or have diabetes, may not have typical chest pain but may have many of the other symptoms of a heart attack. It is important that these patients and their caregivers have a good understanding of heart attack symptoms.

lung injury.The size of the pneumothorax changes as air or gas builds up, so a medical procedure can release the pressure with a needle. If it is untreated, blood flow can be interrupted and cause a drop in blood pressure known as tension pneumothorax. It is possible for smaller cases to clear up on their own. Symptoms of this condition are often felt only on one side of the lung or as a shortness of breath.

in tetrapods

In mammals, the thorax is the region of the body formed by the sternum, the thoracic vertebrae, and the ribs. It extends from the neck to the diaphragm, and does not include the upper limbs. The heart and the lungs reside in the thoracic cavity, as well as many blood vessels. The inner organs are protected by the rib cage and the sternum. Thoracic vertebrae are also distinguished in birds, but not in reptiles.

The Back

The back is the body region between the neck and the gluteal regions. It comprises the vertebral column (spine) and two compartments of back muscles; extrinsic and intrinsic. The back functions are many, such as to house and protect the spinal cord, hold the body and head upright, and adjust the movements of the upper and lower limbs. The backBones

The vertebral column (spine) is the bony core of the back. It is formed by a chain of 33 interconnected vertebrae and their intervening joints. It forms the axial skeleton together with the skull and rib cage. Numerous muscles, ligaments and tendons support the spine, providing it with flexibility and a great range of motion.

The vertebral column is formed by a series of vertically aligned vertebrae. Vertebral alignment produces 4 curvatures of the vertebral column; cervical lordosis, thoracic kyphosis, lumbar lordosis and sacral kyphosis. Lordoses are concave posteriorly, while kyphoses are concave anteriorly. Located centrally within the vertebral column is the vertebral foramen (spinal canal), through which the spinal cord passes.

Vertebra

Vertebrae are the structural constituents of the spine. There are 33 vertebrae in total; seven cervical vertebrae in the neck, twelve thoracic vertebrae in the torso and five lumbar vertebrae in the lower back. Five sacral and 3-5 coccygeal vertebrae are fused into the sacrum and coccyx bones, respectively.

Each typical vertebra consists of a body, an arch and three processes that stem from the arch (spinous, transverse and articular). The vertebral body is the main weight bearing structure of the spine, while the arch and processes provide numerous muscle and ligament attachment points. The arch is connected to the body by bony pedicles, together these structures bound the Vetebral foreman.

The superior and inferior margins of each pedicle are convex toward its midline, forming superior and inferior vertebral notches. Notches of adjacent vertebrae bound the intervertebral foramen, providing an outlet for the spinal nerves and vessels.

Although having the same parts, the vertebral groups are distinct from each other in terms of their appearance. This is all related to their function.For example, cervical vertebrae have the widest vertebral foramen and the smallest bodies, while lumbar vertebrae have the largest bodies and a very narrow vertebral canal. This is because the lumbar vertebrae bear much more weight than the cervical. Vertebrae also differ in the appearance of their processes and other anatomical features.

Vertebral joint

Adjacent vertebrae are connected by two intervertebral joints:

Intervertebral discs - fibrocartilaginous joints (symphysis) interposed between the vertebral bodies.

Zygapophyseal joints - (z joints or facet joints) formed by the superior and inferior articular processes of adjacent vertebrae.

The column joins with the skull superiorly at the two craniovertebral joints; atlantooccipital and atlantoaxial joints. The former is between the occipital bone and atlas (C1 vertebra), while the latter is between the atlas and axis (C1 and C2 vertebrae). Inferiorly, the vertebral column articulates with the pelvis at sacroiliac joints.

Costovertebral joints anchor the ribs to the thoracic cage through articulations between each rib and its adjacent vertebral bodies and the intervening disc while at T1, T10-T12 levels the articulation is with a single vertebra. Costotransverse joints is the articulation between the rib neck and tubercle with the adjacent vertebral transverse process. This joint is present only at T1-T10 levels.

Muscles of the back act upon these joints producing the movements of the spine. The movements of the spine are flexion, extension, lateral flexion (sidebending) and rotation. Ligaments of the vertebral column support its joints and stabilize them during spinal movements. The anterior and posterior longitudinal ligaments (ALL, PLL) extended along the entire length of the spine, primarily supporting the intervertebral joints. Accessory ligaments also support the spine, these are the ligamenta flava, interspinous, supraspinous, nuchal and intertransverse ligaments. Other specialised ligaments are involved in supporting the atlantooccipital and atlantoaxial joints.