Brain injuries
…refer to physical damage to brain tissue and can be classified as:
- Traumatic Brain Injuries (TBIs): External force (blow, fall, crash). Severity ranges from mild concussion to severe injury with long-term effects.
- Non-traumatic (Acquired) Brain Injuries: Internal events such as stroke, tumor, anoxia/hypoxia, or infections.
Brain disorders
…affect brain structure or function and include neurological (e.g., epilepsy, Alzheimer’s, MS) and psychiatric (e.g., depression, schizophrenia, bipolar) conditions.
They may be congenital or arise from genetics, infection, autoimmunity, vascular issues, or environmental factors (trauma, substances).
Brain Anatomy
The Circle of Willis: A Critical Hub of Cerebral Circulation
The Circle of Willis is a ring-like arterial network at the brain’s base, connecting anterior (internal carotids) and posterior (vertebral/basilar) circulation. This creates collateral routes that can preserve perfusion if one segment is narrowed or blocked.
Components:
- Anterior cerebral arteries (left & right)
- Anterior communicating artery
- Internal carotid arteries (left & right)
- Posterior cerebral arteries (left & right)
- Posterior communicating arteries (left & right)
This redundancy is clinically important, but anatomical variations are common (often incomplete), influencing risk in stroke, aneurysm, and TIA. Understanding the Circle of Willis is foundational in neurology, neurosurgery, and vascular medicine.