Answer:
Medulla
Explanation:
It is given that, During times of stress, Yanira notices that her heart pounds a little faster than normal.
The medulla is responsible for her increased heart rate. The medulla controls involuntary actions. For example, blinking of eyes, heartbeat, etc. It is is a part of hindbrain.
Human brain consists of three part of brain i.e. forebrain, midbrain and hindbrain.
The largest part of the brain is cerebrum. It controls the voluntary action i.e. emotions, control of movement.
Others parts of the human brain are pons, cerebellum etc.
