In a multicellular organism, an organ is a collection of tissues joined in a structural unit to serve a common function. In the hierarchy of life, an organ lies between tissue and an organ system. Tissues are formed from same type cells to act together in a function. Tissues of different types combine to form an organ which has a specific function. The intestinal wall for example is formed by epithelial tissue and smooth muscle tissue. Two or more organs working together in the execution of a specific body function form an organ system, also called a biological system or body system.
Parinaud's syndrome is a constellation of neurological signs indicating injury to the dorsal midbrain. More specifically, compression of the vertical gaze center at the rostral interstitial nucleus of medial longitudinal fasciculus (riMLF).
Lobar pneumonia is a form of pneumonia characterized by inflammatory exudate within the intra-alveolar space resulting in consolidation that affects a large and continuous area of the lobe of a lung.
In the anatomy of the human digestive tract, there are two colic flexures, or curvatures in the transverse colon. The right colic flexure is also known as the hepatic flexure, and the left colic flexure is also known as the splenic flexure. Note that "right" refers to the patient's anatomical right, which may be depicted on the left of a diagram.
The uncus is an anterior extremity of the parahippocampal gyrus. It is separated from the apex of the temporal lobe by a slight fissure called the incisura temporalis.
Pneumatosis intestinalis is pneumatosis of an intestine, that is, gas cysts in the bowel wall. As a radiological sign it is highly suggestive for necrotizing enterocolitis. This is in contrast to gas in the intestinal lumen. In newborns, pneumatosis intestinalis is considered diagnostic for necrotizing enterocolitis, and the gas is produced by bacteria in the bowel wall. The pathogenesis of pneumatosis intestinalis is poorly understood and is likely multifactorial. PI itself is not a disease, but rather a clinical sign. In some cases, PI is an incidental finding, whereas in others, it portends a life-threatening intra-abdominal condition.
The costoclavicular ligament, also known as the rhomboid ligament or Halsted's ligament, is a ligament of the shoulder girdle. It is short, flat, and rhomboid in form. It is the major stabilizing factor of the sternoclavicular joint and is the axis of movement of the joint, especially during elevation of the clavicle.
The esophageal veins drain blood from the esophagus to the azygos vein, in the thorax, and to the inferior thyroid vein in the neck. It also drains, although with less significance, to the hemiazygos vein, posterior intercostal vein and bronchial veins.
A portacaval anastomosis or portocaval anastomosis is a specific type of circulatory anastomosis that occurs between the veins of the portal circulation and the vena cava, thus forming one of the principal types of portasystemic anastomosis or portosystemic anastomosis, as it connects the portal circulation to the systemic circulation, providing an alternative pathway for the blood. When there is a blockage of the portal system, portocaval anastomosis enables the blood to still reach the systemic venous circulation. The inferior end of the esophagus and the superior part of the rectum are potential sites of a harmful portocaval anastomosis.
A radiologic sign is an objective indication of some medical fact that is detected by a physician during radiologic examination with medical imaging.
A flexion teardrop fracture is a fracture of the anteroinferior aspect of a cervical vertebral body due to flexion of the spine along with vertical axial compression. The fracture continues sagittally through the vertebral body, and is associated with deformity of the body and subluxation or dislocation of the facet joints at the injured level. A flexion teardrop fracture is usually associated with a spinal cord injury, often a result of displacement of the posterior portion of the vertebral body into the spinal canal.
Radiopaedia is a wiki-based international collaborative educational web resource containing a radiology encyclopedia and imaging case repository. It is currently the largest freely available radiology related resource in the world with more than 50,000 patient cases and over 16,000 reference articles on radiology-related topics. The open edit nature of articles allows radiologists, radiology trainees, radiographers, sonographers, and other healthcare professionals interested in medical imaging to refine most content through time. An editorial board peer reviews all contributions.
A Sertoli cell tumour, also Sertoli cell tumor, is a sex cord–gonadal stromal tumour of Sertoli cells. They can occur in the testis or ovary. They are very rare and generally peak between the ages of 35 and 50. They are typically well-differentiated and may be misdiagnosed as seminomas as they often appear very similar.
Adenocarcinoma of the lung is the most common type of lung cancer, and like other forms of lung cancer, it is characterized by distinct cellular and molecular features. It is classified as one of several non-small cell lung cancers (NSCLC), to distinguish it from small cell lung cancer which has a different behavior and prognosis. Lung adenocarcinoma is further classified into several subtypes and variants. The signs and symptoms of this specific type of lung cancer are similar to other forms of lung cancer, and patients most commonly complain of persistent cough and shortness of breath.
Pneumatosis is the abnormal presence of air or other gas within tissues.
Trethowan's sign is when Klein's line does not intersect the lateral part of the superior femoral epiphysis on an AP radiograph of the pelvis.
Emphysema is any air-filled enlargement in the body's tissues. Most commonly emphysema refers to the enlargement of air spaces (alveoli) in the lungs, and is also known as pulmonary emphysema.
Right heart strain is a medical finding of right ventricular dysfunction where the heart muscle of the right ventricle (RV) is deformed. Right heart strain can be caused by pulmonary hypertension, pulmonary embolism, RV infarction, chronic lung disease, pulmonic stenosis, bronchospasm, and pneumothorax.
An MRI pulse sequence in magnetic resonance imaging (MRI) is a particular setting of pulse sequences and pulsed field gradients, resulting in a particular image appearance.
