Question

When harmful bacteria enter the body through a cut, the immune system must act quickly to protect health. Different types of cells sendand receive messages that help coordinate the defense. These signals allow the body to detect the problem, call for reinforcements, and organize a response that eliminates the threat while keeping the system balanced.

Place the steps of cell communication during an immune response in the correct order.

Number Sequence Immune Response Description
1 Response area
2 Response area
3 Response area
4 Response area
5 Response area
6 Response area
7 Response area

Answer 1

1. Resident innate cells (macrophages/dendritic cells) at the cut detect bacteria via pattern receptors.
2. Those cells release signaling molecules (cytokines and chemokines) that announce the infection.
3. Signals (and histamine from mast cells) cause local blood vessels to dilate and become more permeable (inflammation).
4. Chemokines recruit neutrophils and monocytes from the blood into the tissue.
5. Recruited phagocytes (especially neutrophils, then macrophages) ingest and kill bacteria.
6. Dendritic cells carry bacterial antigens to lymph nodes and present them to helper T cells, activating the adaptive response.
7. Activated helper T cells stimulate B cells to make specific antibodies and coordinate effector T cells; after the threat is cleared, regulatory signals resolve inflammation and restore tissue homeostasis.