Answer:
The nervous system responds rapidly to stimuli by sending electrical action potentials along neurons, which in turn transmit these action potentials to their target cells using neurotransmitters, the chemical messenger of the nervous system.
Explanation:
Answer:
Option C, epiglottis
Explanation:
Epiglottis is a flap structure located at the larynx opening which is a separator between the upper and lower respiratory tract.
The upper part of the respiratory tract consists of Nostrils, Nasal Cavities, Pharynx, Epiglottis, and the Larynx.
After the Larynx, the upper respiratory tracts connects the trachea from where the lower respiratory tract starts. The lower respiratory tract consists of Trachea, Bronchi, Bronchioles, and the Lungs.
Hence, option C is the correct.
The change from a high to a low pitch is a phenomenon known as the Doppler Effect or the Doppler shift. Sounds come in waves and are known as sound waves.
The Doppler Shift or effect is relevant to the location of the person who is hearing the sound. When a person is moving closer to the source of the sound, the wavelengths become shorter and they become low pitch; but when the person moves away from the source of the sound, the wavelengths become longer and become high-pitched.