Our ears have an outer ear, middle ear, and inner ear. All of these sections play a role in allowing us to hear sound. The outer ear consists of the ear canal and the ear drum. The middle ear houses three tiny bones called the hammer, anvil, and the stirrup. On the other side of the bones there is a membrane called the oval window. The inner ear holds semicircular tubes and the cochlea. The cochlea is a bony tube shaped like a snail. This tube allows you to hear sounds. Inside the cochlea contains hair cells with sensory hairs. The cells are linked to larger bundles of nerves that carry signals to the brain. When sound waves enter our ears, they hit the eardrum which vibrates it. The eardrum further vibrates the hammer, anvil, and stirrup. The stirrup vibrations cause the oval window to vibrate which causes the fluid in the cochlea to vibrate. The fluid bends the hair cells which then send signals to the brain through the auditory nerve. The brain receives the signals and processes the information that allows people to hear sounds. All of the parts of the ear are held responsible for people to …show more content…
Extra glucose is produced. Mental alertness increases and your pupils dilate. Adrenal glands release the hormone epinephrine into the bloodstream (Macaulay, 198). Adrenaline (epinephrine) increases the amount of sugar into your blood, increases your heart rate, and raises your blood pressure. After all of these changes have been made to your body, you are now ready to fight or flee. The prefrontal cortex is aware of the threat and now has to decide what to do (Macaulay,