The dog is thinking about how to fight the intruder
Bark=Helper T Cells
WOOF WOOF
The fox is sick with a virus and he is hungry and wants to eat the chickens. The fox is like a pathogen. Pathogens are bacteria, viruses, or microorganisms that cause disease. The chickens are the cells and the coop is the protective wall, like skin. Skin is the first line of defense but there are other ways to get in like our nose, mouth, or eyes.
WOOF WOOF
Bird=B Cells
If he breathes on them the chicken might catch the virus and if he can attack the chickens they might die. Luckily the chickens have protectors.The dog is like the macrophages that help protect the chickens. Macrophages are white blood cells that help fight infections and signal other immune system cells to help fight.
The dog has other animals that can help fight off the fox. The dog starts to fight with the fox and he barks for help. The bark is like the Helper T cells. Helper T cells alert other T and B cells to make responses.
The bark calls on the porcupine and bird. The porcupine is first up and he tries to shoot the fox with his quills to kill him. The porcupine is like the Killer T cells. While the porcupine is fighting the Bird is working on a strategy in case the porcupine is unsuccessful. The Bird is like the B cells. Killer T cells kill cancer, infected and damaged cells. B Cells help make antibodies.
Porcupine=Killer T
The porcupine misses the fox so the Bird comes on the attack. The bird drops eggs on the fox. The eggs are like Plasma Cells. Plasma cells create antibodies.
Eggs=Plasma Cells
Inside the eggs are snakes that attack the fox and kill him. The snakes are like Antibodies. Antibodies are proteins that grow from fighting viruses. They remember the infected or bad cells that they have. killed before so if they return they can fight them right away. All of the protectors working together eventually kill the Fox.