Space Radiation Biology for “Living in Space”

Table 4

Classification of tissues based on their radiosensitivity.

Frequency of cell division	Tissue	Radiosensitivity
++	Lymphoid tissue, hematopoietic tissue (bone marrow), testicular epithelium, follicular epithelium, and intestinal epithelium	Extremely high
+	Oropharyngeal oral epithelium, skin epidermis, hair follicle epithelium, sebaceous gland epithelium, bladder epithelium, esophageal epithelium, lens epithelium, gastric gland epithelium, and ureteral epithelium	High
+/–	Connective tissue, small vessel tissue, and growing cartilage/bone tissue	Intermediate
–	Mature cartilage/bone tissue, mucous serous epithelium, sweat gland epithelium, nasopharyngeal epithelium, lung epithelium, renal epithelium, liver epithelium, pancreatic epithelium, pituitary epithelium, thyroid epithelium, and adrenal epithelium	Low
– –	Nerve tissue and muscle tissue	Extremely low