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Cysts
A cyst is a closed Wikt:sac, sac, having a distinct Cell envelope, envelope and cell division, division compared with the nearby Biological tissue, tissue. Hence, it is a cluster of Cell (biology), cells that have grouped together to form a sac (like the manner in which water molecules group together to form a bubble); however, the distinguishing aspect of a cyst is that the cells forming the "shell" of such a sac are distinctly abnormal (in both appearance and behaviour) when compared with all surrounding cells for that given location. A cyst may contain air, fluids, or semi-solid material. A collection of pus is called an abscess, not a cyst. Once formed, a cyst may resolve on its own. When a cyst fails to resolve, it may need to be removed surgically, but that would depend upon its type and location. Cancer-related cysts are formed as a defense mechanism for the body following the development of mutations that lead to an uncontrolled cellular division. Once that mutation has o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ovarian Cyst
An ovarian cyst is a fluid-filled sac within the ovary. They usually cause no symptoms, but occasionally they may produce bloating, lower abdominal pain, or lower back pain. The majority of cysts are harmless. If the cyst either #Cyst rupture, breaks open or causes ovarian torsion, twisting of the ovary, it may cause severe pain. This may result in vomiting or Lightheadedness, feeling faint, and even cause headaches. Most ovarian cysts are related to ovulation, being either follicular cyst of ovary, follicular cysts or corpus luteum cysts. Other types include Endometrioma, cysts due to endometriosis, dermoid cysts, and cystadenomas. Many small cysts occur in both ovaries in polycystic ovary syndrome (PCOS). Pelvic inflammatory disease may also result in cysts. Rarely, cysts may be a form of ovarian cancer. Diagnosis is undertaken by pelvic examination with a pelvic ultrasound or other testing used to gather further details. Often, cysts are simply observed over time. If they c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pseudocyst
Pseudocysts are like cysts, but lack epithelial or endothelial cells. Initial management consists of general supportive care. Symptoms and complications caused by pseudocysts require surgery. Computed tomography (CT) scans are used for initial imaging of cysts, and endoscopic ultrasounds are used in differentiating between cysts and pseudocysts. Endoscopic drainage is a popular and effective method of treating pseudocysts. This is not to be confused with the so-called "pseudocystic appearance", mainly radiographically, of other lesions, such as Stafne static bone cyst and aneurysmal bone cyst of the jaws. Signs and symptoms Pseudocysts are often asymptomatic. Symptoms are more common in larger pseudocysts, though the size and time present usually are poor indicators of potential complications. Pancreatic pseudocysts may cause abdominal pain, nausea and vomiting, a bloated feeling, and trouble eating or digesting food. They also may become infected, rupture, or block part of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nabothian Cyst
A nabothian cyst (or nabothian follicle) is a mucus-filled cyst on the surface of the cervix. They are most often caused when stratified squamous epithelium of the ectocervix (portion nearest to the vagina) grows over the simple columnar epithelium of the endocervix (portion nearest to the uterus). This tissue growth can block the cervical crypts (subdermal pockets usually 2–10 mm in diameter), trapping cervical mucus inside the crypts. Presentation Nabothian cysts appear most often as firm bumps on the cervix's surface. A woman may notice the cyst when inserting a diaphragm or cervical cap, or when checking the cervix as part of fertility awareness. A health care provider may notice the cysts during a pelvic exam. Nabothian cysts are also incidentally found during MRI imaging. During the healing process of chronic cervicitis, squamous epithelium of ectocervix proliferates and enter the cervical canal (endocervix), covering and obstructing the columnar epithelium of end ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bronchogenic Cyst
Bronchogenic cysts are small, solitary cysts or sinuses, most typically located in the region of the suprasternal notch or behind the manubrium. Clinical features These cysts are mostly found in young adults and are rare in infancy. The usual symptoms are the result of compression by the cyst, e.g., difficulty breathing or swallowing, cough, and chest pain. Malignant degeneration has been reported in these cysts on rare occasions. Bronchogenic cysts are usually found in the middle mediastinum. Chest x-rays show a smooth density just in front of the trachea or main stem bronchi at the carinal level. When the cyst communicates with the tracheobronchial tree, the air-fluid level may be seen within the cyst. CT scanning is useful in localizing these cysts. Pathology Bronchogenic cysts are formed in the 6th week of gestation from an abnormal budding of the tracheal diverticulum. They are lined by respiratory type (ciliated) epithelium, which is characterized by cilia. Histologically t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neoplasm
A neoplasm () is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists in growing abnormally, even if the original trigger is removed. This abnormal growth usually forms a mass, which may be called a tumour or tumor.'' ICD-10 classifies neoplasms into four main groups: benign neoplasms, in situ neoplasms, malignant neoplasms, and neoplasms of uncertain or unknown behavior. Malignant neoplasms are also simply known as cancers and are the focus of oncology. Prior to the abnormal growth of tissue, such as neoplasia, cells often undergo an abnormal pattern of growth, such as metaplasia or dysplasia. However, metaplasia or dysplasia does not always progress to neoplasia and can occur in other conditions as well. The word neoplasm is from Ancient Greek 'new' and 'formation, creation'. Types A neoplasm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dysplasia
Dysplasia is any of various types of abnormal growth or development of cells (microscopic scale) or organs (macroscopic scale), and the abnormal histology or anatomical structure(s) resulting from such growth. Dysplasias on a mainly microscopic scale include epithelial dysplasia and fibrous dysplasia of bone. Dysplasias on a mainly macroscopic scale include hip dysplasia, myelodysplastic syndrome, and multicystic dysplastic kidney. In one of the modern histopathological senses of the term, dysplasia is sometimes differentiated from other categories of tissue change including hyperplasia, metaplasia, and neoplasia, and dysplasias are thus generally not cancerous. An exception is that the myelodysplasias include a range of benign, precancerous, and cancerous forms. Various other dysplasias tend to be precancerous. The word's meanings thus cover a spectrum of histopathological variations. Microscopic scale Epithelial dysplasia Epithelial dysplasia consists of an expa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cell Envelope
The cell envelope comprises the inner cell membrane and the cell wall of a bacterium. In Gram-negative bacteria an bacterial outer membrane, outer membrane is also included. This envelope is not present in the Mollicutes where the cell wall is absent. Bacterial cell envelopes fall into two major categories: a Gram-positive type which stains purple during Gram staining and a Gram-negative type which stains pink during Gram staining. Either type may have an enclosing bacterial capsule, capsule of polysaccharides for extra protection. As a group these are known as polysaccharide encapsulated bacteria. Function As in other organisms, the bacterial cell wall provides structural integrity to the cell. In prokaryotes, the primary function of the cell wall is to protect the cell from internal turgor pressure caused by the much higher concentrations of proteins and other molecules inside the cell compared to its external environment. The bacterial cell wall differs from that of all other or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mediastinal
The mediastinum (from ;: mediastina) is the central compartment of the thoracic cavity. Surrounded by loose connective tissue, it is a region that contains vital organs and structures within the thorax, mainly the heart and its vessels, the esophagus, the trachea, the vagus, phrenic and cardiac nerves, the thoracic duct, the thymus and the lymph nodes of the central chest. Anatomy The mediastinum lies within the thorax and is enclosed on the right and left by pleurae. It is surrounded by the chest wall in front, the lungs to the sides and the spine at the back. It extends from the sternum in front to the vertebral column behind. It contains all the organs of the thorax except the lungs. It is continuous with the loose connective tissue of the neck. The mediastinum can be divided into an upper (or superior) and lower (or inferior) part: * The superior mediastinum starts at the superior thoracic aperture and ends at the thoracic plane. * The inferior mediastinum from this ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brainstem
The brainstem (or brain stem) is the posterior stalk-like part of the brain that connects the cerebrum with the spinal cord. In the human brain the brainstem is composed of the midbrain, the pons, and the medulla oblongata. The midbrain is continuous with the thalamus of the diencephalon through the tentorial notch, and sometimes the diencephalon is included in the brainstem. The brainstem is very small, making up around only 2.6 percent of the brain's total weight. It has the critical roles of regulating heart and respiratory system, respiratory function, helping to control heart rate and breathing rate. It also provides the main motor and sensory nerve supply to the face and neck via the cranial nerves. Ten pairs of cranial nerves come from the brainstem. Other roles include the regulation of the central nervous system and the body's sleep cycle. It is also of prime importance in the conveyance of motor and sensory pathways from the rest of the brain to the body, and from the b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spinal Cord
The spinal cord is a long, thin, tubular structure made up of nervous tissue that extends from the medulla oblongata in the lower brainstem to the lumbar region of the vertebral column (backbone) of vertebrate animals. The center of the spinal cord is hollow and contains a structure called the central canal, which contains cerebrospinal fluid. The spinal cord is also covered by meninges and enclosed by the neural arches. Together, the brain and spinal cord make up the central nervous system. In humans, the spinal cord is a continuation of the brainstem and anatomically begins at the occipital bone, passing out of the foramen magnum and then enters the spinal canal at the beginning of the cervical vertebrae. The spinal cord extends down to between the first and second lumbar vertebrae, where it tapers to become the cauda equina. The enclosing bony vertebral column protects the relatively shorter spinal cord. It is around long in adult men and around long in adult women. The diam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
