What cell type is the most radiosensitive?
Rapidly proliferating non-differentiated cells are the most radiosensitive. Well known representatives of this class of cells are the stem cells of the hematopoietic tissues and the cells of the intestinal crypts. The differentiated fixed postmitotic cells are the most radioresistant.
What do you call the most sensitive cells quizlet?
The MOST sensitive cells in the human body are in the : Brain. The oropharynx is also known as: The mouth. You just studied 39 terms!
Which of the following organ is highly sensitive?
Q. Which of the following organ / tissue of human body is most sensitive to intake of lead? Notes: Brain is the most sensitive part in human body with respect to lead poisoning.
Which human organ is highly radiosensitive?
From these discussions we can conclude that Bone marrow is the most radiosensitive tissue of the body.
Which Tumours are radiosensitive?
Embryonal tumors, as well as tumors composed of rapidly growing cells, are sensitive to radiotherapy. Lymphoid cells are particularly susceptible to radiation. On the contrary, neurosarcoma, glioma and melanoma are radioresistant.
Are oxygenated cells sensitive to radiation?
cells are less sensitive to radiation than well oxygenated cells, they may gain enhanced radiation sensitivity following reoxygenation.
Which of the following cells are considered less sensitive to radiation?
Amongst the body cells, the most sensitive are spermatogonia and erythroblasts, epidermal stem cells, gastrointestinal stem cells. The least sensitive are nerve cells and muscle fibers.
Does radiation affect oxygen?
The best known explanation of the oxygen effect is the oxygen fixation hypothesis developed by Alexander in 1962, which posited that radiation-induced non-restorable or “fixed” nuclear DNA lesions are lethal to cells in the presence of diatomic oxygen.
Can radiation affect oxygen levels?
Recently published reviews suggest that acute radiation-induced oxidative stress and inflammation generate chronic reactive oxygen species that may ultimately result in late radiation-induced brain injury, including cognitive impairment (10–12).
Does radiation require oxygen?
Supplying Oxygen to Boost Radiation Therapy But many tumors are resistant to the cell-killing effects of radiation. Much of this resistance is caused by the low levels of oxygen often found in tumors: oxygen is required for radiation therapy to generate the molecules, called free radicals, that kill cancer cells.
Why are hypoxic cells resistant to radiotherapy?
In radiotherapy, the primary mechanism is the creation of reactive oxygen species; hypoxic tumors are therefore radiation resistant. A number of chemotherapeutic drugs have been shown to be less effective when exposed to a hypoxic environment which can lead to further disease progression.
Does radiation cause hypoxia?
Tumor Hypoxia: Impact on Radiation Therapy and Molecular Pathways. Tumor hypoxia is a common feature of the microenvironment in solid tumors, primarily due to an inadequate, and heterogeneous vascular network. It is associated with resistance to radiotherapy and results in a poorer clinical outcome.
Is radiation a treatment?
Radiation therapy (also called radiotherapy) is a cancer treatment that uses high doses of radiation to kill cancer cells and shrink tumors. At low doses, radiation is used in x-rays to see inside your body, as with x-rays of your teeth or broken bones.
What is hypoxic tumor?
Tumor hypoxia is the situation where tumor cells have been deprived of oxygen. As a tumor grows, it rapidly outgrows its blood supply, leaving portions of the tumor with regions where the oxygen concentration is significantly lower than in healthy tissues.
Which of the following hormones is expressed in response to hypoxia?
The glycoprotein hormone erythropoietin (EPO) counteracts tissue hypoxia by increasing the systemic oxygen-carrying capacity. It induces augmentation of red blood cell mass by stimulating the formation and differentiation of erythroid precursor cells in the bone marrow.
What hormones might be released due to the lack of oxygen?
Vasopressin, a powerful antidiuretic hormone involved in salt and water homeostasis, is released in response to acute hypoxia.
Which hormone is released in response to hypocalcemia?
Low calcium levels in the blood stimulate parathyroid hormone secretion, whereas high calcium levels in the blood prevent the release of parathyroid hormone.