NATS 1675 Lecture Notes - Lecture 20: Benign Tumor, Petri Dish, Contact Inhibition

• School: York University
• Department: Natural Science
• Course: NATS 1675
• Professor: Robert Crippen

Document Summary

The word means crab it suggests that, like the claws of a crab, cells from a malignant (cancerous) growth spread out in all directions. Contact inhibition fails to occur in cancer cells. In normal tissues, cells stop di(cid:448)idi(cid:374)g (cid:449)he(cid:374) the(cid:455) a(cid:396)e (cid:862)pa(cid:272)ked(cid:863) tightl(cid:455) togethe(cid:396). I(cid:374) (cid:272)o(cid:374)t(cid:396)ast, (cid:272)a(cid:374)(cid:272)e(cid:396) (cid:272)ells (cid:272)o(cid:374)ti(cid:374)ue to divide uncontrollably. Excessive cell division may also produce a benign growth, in which cells are contained within a single encapsulated mass called a benign tumour. They only cause limited damage in the area of the tumour. Cells break out of the capsule (or even lack a capsule) and invade other tissues. A cancerous growth often undergoes metastasis where the cells break away and migrate/travel to other sites in the body via the blood or lymph systems. You(cid:396) te(cid:454)t defi(cid:374)es (cid:272)a(cid:374)(cid:272)e(cid:396) as (cid:862)a ge(cid:374)eti(cid:272) disease (cid:396)e(cid:395)ui(cid:396)i(cid:374)g a se(cid:396)ies of (cid:373)utatio(cid:374)s ea(cid:272)h propelling cells towards development of a tumor, an abnormal mass of cells.