Cells and control study guide

The human brain is a complex organ responsible for controlling all bodily functions, processing information, and enabling thought, emotion, and memory. It is broadly divided into several key regions, each with specialised roles. The cerebral hemispheres are the largest part of the brain and are responsible for higher-level functions like conscious thought, voluntary movement, language, and sensory processing. The cerebellum, located at the back of the brain beneath the cerebral hemispheres, is crucial for coordinating fine motor skills, balance, and posture. The medulla oblongata, part of the brainstem, controls essential involuntary processes necessary for survival, such as breathing, heart rate, and blood pressure. These regions work together in a highly integrated manner to ensure the body functions correctly and to allow for complex behaviours and cognitive abilities.

Cancer arises from changes within cells that lead to their uncontrolled division. Normally, cell division is a tightly regulated process, ensuring that cells grow, divide, and die in an organised manner. This regulation is crucial for the healthy functioning of tissues and organs. However, if a cell accumulates certain genetic mutations, its control mechanisms can be disrupted. These mutations can cause the cell to ignore signals that would normally stop division or initiate programmed cell death. As a result, these altered cells begin to divide without restraint, forming a mass of cells known as a tumour. Tumours can be benign (non-cancerous) or malignant (cancerous). Malignant tumours have the ability to invade surrounding tissues and spread to other parts of the body, a process called metastasis, making them particularly dangerous.