Great question! The terms cortex and medulla are used in anatomy to describe the outer and inner regions of organs — like the brain, kidneys, adrenal glands, lymph nodes, and more.
🧠 1. Brain
- Cortex = Outer layer of the brain (called the cerebral cortex)
- Handles higher functions: thinking, memory, language, decision-making.
- Medulla = Refers to the medulla oblongata, part of the brainstem
- Controls vital functions: breathing, heart rate, blood pressure.
⚙️ 2. Kidney
- Renal Cortex = Outer layer of the kidney
- Contains filtering units called nephrons.
- Renal Medulla = Inner region of the kidney
- Contains renal pyramids, helps concentrate urine.
💧 3. Adrenal Glands (sit above kidneys)
- Adrenal Cortex = Outer part
- Produces steroid hormones (like cortisol, aldosterone).
- Adrenal Medulla = Inner part
- Produces adrenaline and noradrenaline (fight-or-flight response).
🦠 4. Lymph Nodes
- Cortex = Outer part
- Contains B cells (immune cells).
- Medulla = Inner part
- Contains plasma cells and macrophages.
📌 Summary Table
| Organ | Cortex (Outer Part) | Medulla (Inner Part) |
|---|---|---|
| Brain | Thinking, memory (cerebral cortex) | Brainstem (medulla oblongata) – vital signs |
| Kidney | Filters blood (nephrons) | Concentrates urine (renal pyramids) |
| Adrenal Gland | Steroid hormones (cortisol, etc.) | Adrenaline (fight-or-flight) |
| Lymph Node | B cells (immune response) | Plasma cells, macrophages |
Human Body 