Thoracic wall

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Thoracic wall
Scheme body cavities-en.svg
Body cavities
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A transverse section of the thorax, showing the contents of the middle and the posterior mediastinum.
Identifiers
MeSH D035441
Anatomical terminology

The thoracic wall or chest wall is the boundary of the thoracic cavity.

Thoracic cavity

The thoracic cavity is the chamber of the body of vertebrates that is protected by the thoracic wall. The central compartment of the thoracic cavity is the mediastinum. There are two openings of the thoracic cavity, a superior thoracic aperture known as the thoracic inlet and a lower inferior thoracic aperture known as the thoracic outlet.

Contents

Structure

The bony skeletal part of the thoracic wall is the rib cage, and the rest is made up of muscle, skin, and fasciae.

Bone rigid organs that constitute part of the endoskeleton of vertebrates

A bone is a rigid organ that constitutes part of the vertebrate skeleton. Bones protect the various organs of the body, produce red and white blood cells, store minerals, provide structure and support for the body, and enable mobility. Bones come in a variety of shapes and sizes and have a complex internal and external structure. They are lightweight yet strong and hard, and serve multiple functions.

The human skeleton is the internal framework of the body. It is composed of around 270 bones at birth – this total decreases to around 206 bones by adulthood after some bones get fused together. The bone mass in the skeleton reaches maximum density around age 21. The human skeleton can be divided into the axial skeleton and the appendicular skeleton. The axial skeleton is formed by the vertebral column, the rib cage, the skull and other associated bones. The appendicular skeleton, which is attached to the axial skeleton, is formed by the shoulder girdle, the pelvic girdle and the bones of the upper and lower limbs.

Rib cage arrangement of bones

The rib cage is the arrangement of ribs attached to the vertebral column and sternum in the thorax of most vertebrates, that encloses and protects the heart and lungs. In humans, the rib cage, also known as the thoracic cage, is a bony and cartilaginous structure which surrounds the thoracic cavity and supports the shoulder girdle to form the core part of the human skeleton. A typical human rib cage consists of 24 ribs in 12 pairs, the sternum and xiphoid process, the costal cartilages, and the 12 thoracic vertebrae.

The chest wall has 10 layers, namely skin, superficial fascia, deep fascia, serratus anterior, layer for ribs (containing intercostal muscles), and endothoracic fascia from superficial to deep. However, the muscular layers vary according to the region of the chest wall. For example, they may include muscles like pectoralis major or latissimus dorsi.

Function

Diving reflex

When not breathing for long and dangerous periods of time in cold water, a person's body undergoes great temporary changes to try to prevent death. It achieves this through the activation of the mammalian diving reflex, which has 3 main properties. Other than Bradycardia and Peripheral vasoconstriction, there is a blood shift which occurs only during very deep dives that affects the thoracic cavity (a chamber of the body protected by the thoracic wall.) When this happens, organ and circulatory walls allow plasma/water to pass freely throughout the thoracic cavity, so its pressure stays constant and the organs aren't crushed. In this stage, the lungs' alveoli fill up with blood plasma, which is reabsorbed when the organism leaves the pressurized environment. This stage of the diving reflex has been observed in humans (such as world champion freediver Martin Štěpánek) during extremely deep (over 90 metres or 300 ft) free dives.

Bradycardia Heart rate that is below the normal range

Bradycardia is a condition typically defined wherein an individual has a resting heart rate of under 60 beats per minute (BPM) in adults. Bradycardia typically does not cause symptoms until the rate drops below 50 BPM. When symptomatic, it may cause fatigue, weakness, dizziness, sweating, and at very low rates, fainting.

Clinical significance

Necrosis

In rare cases intentional or accidental trauma may lead to chest wall (thoracic wall) necrosis. [1]

Related Research Articles

Body cavity fluid-filled space in a multicellular organism

A body cavity is any fluid-filled space in a multicellular organism other than those of vessels. The human body cavity normally refers to the ventral body cavity, because it is by far the largest.

Perineum Region of the body including the perineal body and surrounding structures

The perineum is the space between the anus and scrotum in the male and between the anus and the vulva in the female. The perineum is the region of the body between the pubic symphysis and the coccyx, including the perineal body and surrounding structures. There is some variability in how the boundaries are defined. The perianal area is a subset of the perineum.

Thorax frontal part of an animals body, between its head and abdomen

The thorax or chest is a part of the anatomy of humans and various other animals located between the neck and the abdomen. The thorax includes the thoracic cavity and the thoracic wall. It contains organs including the heart, lungs, and thymus gland, as well as muscles and various other internal structures. Many diseases may affect the chest, and one of the most common symptoms is chest pain.

Subclavian artery major arteries of the upper thorax, below the clavicle

In human anatomy, the subclavian arteries are paired major arteries of the upper thorax, below the clavicle. They receive blood from the aortic arch. The left subclavian artery supplies blood to the left arm and the right subclavian artery supplies blood to the right arm, with some branches supplying the head and thorax. On the left side of the body, the subclavian comes directly off the aortic arch, while on the right side it arises from the relatively short brachiocephalic artery when it bifurcates into the subclavian and the right common carotid artery.

Thoracic diaphragm sheet of internal skeletal muscle

The thoracic diaphragm, or simply the diaphragm, is a sheet of internal skeletal muscle in humans and other mammals that extends across the bottom of the thoracic cavity. The diaphragm separates the thoracic cavity, containing the heart and lungs, from the abdominal cavity and performs an important function in respiration: as the diaphragm contracts, the volume of the thoracic cavity increases, a negative vacuum is created which draws air into the lungs.

Spermatic cord cord-like structure in males

The spermatic cord is the cord-like structure in males formed by the vas deferens and surrounding tissue that runs from the deep inguinal ring down to each testicle. Its not serosal covering, the tunica vaginalis, is an extension of the peritoneum that passes through the transversalis fascia. Each testus develops in the lower thoracic and upper lumber region and migrates into the scrotum.during its descent it carries along with it vas deferens, its vessels, nerves etc it is one on each side.

The diving reflex, also known as the diving response and mammalian diving reflex, is a set of physiological responses to immersion that overrides the basic homeostatic reflexes, and is found in all air-breathing vertebrates studied to date. It optimizes respiration by preferentially distributing oxygen stores to the heart and brain, enabling submersion for an extended time.

Intercostal muscle

Intercostal muscles are several groups of muscles that run between the ribs, and help form and move the chest wall. The intercostal muscles are mainly involved in the mechanical aspect of breathing. These muscles help expand and shrink the size of the chest cavity to facilitate breathing.

Fascia layer of fibrous connective tissue that surrounds muscles, blood vessels and nerves

A fascia is a band or sheet of connective tissue, primarily collagen, beneath the skin that attaches, stabilizes, encloses, and separates muscles and other internal organs. Fascia is classified by layer, as superficial fascia, deep fascia, and visceral or parietal fascia, or by its function and anatomical location.

Breast reduction

Reduction mammoplasty is the plastic surgery procedure for reducing the size of large breasts. In a breast reduction surgery for re-establishing a functional bust that is proportionate to the woman's body, the critical corrective consideration is the tissue viability of the nipple-areola complex (NAC), to ensure the functional sensitivity and lactational capability of the breasts. The indications for breast reduction surgery are three-fold — physical, aesthetic, and psychological — the restoration of the bust, of the woman's self-image, and of her mental health.

Rectus abdominis muscle paired muscle running vertically on each side of the anterior wall of the human (of some other mammals) abdomen

The rectus abdominis muscle, also known as the "abdominal muscle" or "abs", is a paired muscle running vertically on each side of the anterior wall of the human abdomen, as well as that of some other mammals. There are two parallel muscles, separated by a midline band of connective tissue called the linea alba. It extends from the pubic symphysis, pubic crest and pubic tubercle inferiorly, to the xiphoid process and costal cartilages of ribs V to VII superiorly. The proximal attachments are the pubic crest and the pubic symphysis. It attaches distally at the costal cartilages of ribs 5-7 and the xiphoid process of the sternum.

Abdominal internal oblique muscle

The internal oblique muscle is a muscle in the abdominal wall that lies below the external oblique and just above the transverse abdominal muscles.

Abdomen frontal part of the body between the thorax (chest) and pelvis

The abdomen constitutes the part of the body between the thorax (chest) and pelvis, in humans and in other vertebrates. The abdomen is the frontal part of the abdominal segment of the trunk, the dorsal part of this segment being the back of the abdomen. The region occupied by the abdomen is termed the abdominal cavity. In arthropods it is the posterior tagma of the body; it follows the thorax or cephalothorax. The abdomen stretches from the thorax at the thoracic diaphragm to the pelvis at the pelvic brim. The pelvic brim stretches from the lumbosacral joint to the pubic symphysis and is the edge of the pelvic inlet. The space above this inlet and under the thoracic diaphragm is termed the abdominal cavity. The boundary of the abdominal cavity is the abdominal wall in the front and the peritoneal surface at the rear.

Abdominal wall represents the boundaries of the abdominal cavity

In anatomy, the abdominal wall represents the boundaries of the abdominal cavity. The abdominal wall is split into the posterior (back), lateral (sides) and anterior (front) walls.

Fascia of Scarpa

The fascia of Scarpa is the deep membranous layer (stratum membranosum), of the superficial fascia of the abdomen. It is a layer of the anterior abdominal wall. It is found deep to the Fascia of Camper and superficial to the external oblique muscle.

Muscles of respiration

The muscles of respiration are those muscles that contribute to inhalation and exhalation, by aiding in the expansion and contraction of the thoracic cavity. The diaphragm and, to a lesser extent, the intercostal muscles drive respiration during quiet breathing. Additional 'accessory muscles of respiration' are typically only used under conditions of high metabolic demand or respiratory dysfunction. However, in instances where these accessory muscles become stiff and hard, expansion of the rib cage can be restricted. Maintenance of the elasticity of these muscles is crucial to the health of the respiratory system and to maximize its functional capabilities.

Outline of human anatomy Overview of and topical guide to human anatomy

The following outline is provided as an overview of and topical guide to human anatomy:

Subcutaneous emphysema

Subcutaneous emphysema is when gas or air is in the layer under the skin. Subcutaneous refers to the tissue beneath the skin, and emphysema refers to trapped air. Since the air generally comes from the chest cavity, subcutaneous emphysema usually occurs on the chest, neck and face, where it is able to travel from the chest cavity along the fascia. Subcutaneous emphysema has a characteristic crackling feel to the touch, a sensation that has been described as similar to touching Rice Krispies; this sensation of air under the skin is known as subcutaneous crepitation.

Pulmonary pleurae serous membrane that lines the wall of thoracic cavity and the surface of lung

The pulmonary pleurae are the two pleurae of the invaginated sac surrounding each lung and attaching to the thoracic cavity. The visceral pleura is the delicate serous membrane that covers the surface of each lung and dips into the fissures between the lobes. The parietal pleura is the outer membrane which is attached to the inner surface of the thoracic cavity. It also separates the pleural cavity from the mediastinum. The parietal pleura is innervated by the intercostal nerves and the phrenic nerve.

References

  1. Eskandarlou, M; Moaddab, AH (Aug 2010). "Chest wall necrosis and empyema resulting from attempting suicide by injection of petroleum into the pleural cavity". Emerg Med J. 27 (8): 616–8. doi:10.1136/emj.2009.073486. PMID   20558490.

Medical Subject Headings (MeSH) is a comprehensive controlled vocabulary for the purpose of indexing journal articles and books in the life sciences. It serves as a thesaurus that facilitates searching. Created and updated by the United States National Library of Medicine (NLM), it is used by the MEDLINE/PubMed article database and by NLM's catalog of book holdings. MeSH is also used by ClinicalTrials.gov registry to classify which diseases are studied by trials registered in ClinicalTrials.