Avid Medico

Brain tumors Brain tumors are abnormal growths or masses of cells in the brain or surrounding tissues. They can be either benign (non-cancerous) or malignant (cancerous) , and can originate from the brain itself (primary brain tumors) or from other parts of the body that have spread to the brain (secondary or metastatic brain tumors). Benign brain tumors There are many different types of benign brain tumors, each with their own characteristics and treatment options. Some of the most common types include: 1. Meningiomas : These tumors originate in the meninges, the protective layers of tissue that surround the brain and spinal cord. They are usually slow-growing and do not spread to other parts of the body. Symptoms may include headaches, seizures, and vision problems. 2. Pituitary adenomas: These tumors arise from the pituitary gland, which is located at the base of the brain. They can cause hormonal imbalances and symptoms such as headaches, vision problems, and fatigue. 3. Acous...

Intracranial lesions Intracranial lesions refer to abnormal growths or changes in the tissues within the skull or brain. These lesions can be benign or malignant and can occur in different parts of the brain, including the cerebrum, cerebellum, brainstem, and spinal cord. There are various types of intracranial lesions, including tumors, hematomas, aneurysms, abscesses, and stroke. Let's take a closer look at each of these types of lesions and their symptoms. 1. Tumors : These are abnormal growths that can be either benign or malignant. Brain tumors can develop from the brain itself, the meninges (the membranes that cover the brain), or from other parts of the body that have spread to the brain. Symptoms of brain tumors can include headaches, seizures, weakness or numbness in limbs, difficulty speaking or understanding language, changes in vision or hearing, or changes in mood or behavior. 2. Hematomas : These are collections of blood that accumulate in the brain or between the br...

  What is TB (Tuberculosis) Tuberculosis (TB) is a potentially serious bacterial infection that primarily affects the lungs, although it can also affect other parts of the body such as the kidneys, spine, and brain. The bacteria that cause tuberculosis is called Mycobacterium tuberculosis. How does TB spread? TB is spread through the air when an infected person coughs, sneezes, or talks, and another person inhales the bacteria. It is important to note that not everyone who is infected with TB will develop active tuberculosis, as the bacteria can remain dormant in the body for years without causing any symptoms. Signs and symptoms of TB Symptoms of TB may include a persistent cough, coughing up blood or phlegm, chest pain, weakness, fatigue, weight loss, fever, and night sweats. In some cases, tuberculosis can also cause other complications such as meningitis, which affects the brain and spinal cord, and bone or joint infections. The signs and symptoms of TB can vary depending on th...

IRREVERSIBLE CELL INJURY, MECHANISM AND MORPHOLOGY IRREVERSIBLE CELL INJURY: Persistence of ischaemia or hypoxia results in irreversible damage to the structure and function of the cell (cell death). Th e stage at which this point of no return or irreversibility is reached from reversible cell injury is unclear but the sequence of events is a continuation of reversibly injured cell. Two essential phenomena always distinguish irreversible from reversible cell injury   Inability of the cell to reverse mitochondrial dysfunction on re-perfusion or re-oxygenation.   Disturbance in cell membrane function in general, and in plasma membrane in particular. SEQUENCE OF CHANGES IN IRREVERSIBLE CELL INJURY 1. Calcium influx : Mitochondrial damage As a result of continued hypoxia, a large cytosolic influx of calcium ions occurs, especially after reperfusion of irreversibly injured cell. Excess intracellular calcium collects in the mitochondria disabling its function. Morphological chang...

  REVERSIBLE CELL INJURY, MECHANISM AND MORPHOLOGY REVERSIBLE CELL INJURY: If the ischaemia or hypoxia is of short duration, the effects may be reversible on rapid restoration of circulation e.g. in coronary artery occlusion, myocardial contractility, metabolism and ultra structure are reversed if the circulation is quickly restored. Th e sequential biochemical and ultra structural changes in reversible cell injury are as under: 1. Decreased generation of cellular ATP : Damage by ischaemia from interruption versus hypoxia from other causes. All living cells require continuous supply of oxygen to produce ATP which is essentially required for a variety of cellular functions (e.g. membrane trans port, protein synthesis, lipid synthesis and phospholipid metabolism). ATP in human cell is derived from 2 sources: a) Firstly, by aerobic respiration or oxidative phosphorylation (which requires oxygen) in the mitochondria. b) Secondly, cells may subsequently switch over to anaerobic glycoly...

  CELL INJURY Cell injury is defined as the effect of a variety of stresses due to etiologic agents a cell encounters resulting in changes in its internal and external environment. In general, cells of the body have inbuilt mechanism to deal with changes in environment to an extent.  The cellular response to stress may vary and depends upon following two variables:  i) Host factors i.e. the type of cell and tissue involved.  ii) Factors pertaining to injurious agent i.e. extent and type of cell injury. CAUSES OF CELL INJURY A. Genetic Causes Genetic abnormalities may result in a defect as severe as the congenital malformations associated with Down syndrome, caused by a chromosomal anomaly, or as subtle as the decreased life span of red blood cells caused by a single amino acid substitution in hemoglobin in sickle cell anemia. Genetic defects may cause cell injury because of deficiency of functional proteins, such as enzyme defects in inborn errors of metabolism, o...