Light enters through the cornea, which is the first step in refraction. The iris then modulates the amount of the light that enters the eye. The light then passes through the pupil, which regulates light entry into the inner eye and brings objects into focus. Light then then passes through the lens which focuses the light on the retina (made of rods and cones). The retina turns light into nerve impulses and sends it to the brain through the optic nerve.
2. Explain static and dynamic equilibrium. 6 points static equilibrium - The special sense which interprets the position of the head when not moving, allowing the CNS to maintain stability and posture. These levels are detected by mechanoreceptors in the vestibule of …show more content…
The mechanoreceptors for dynamic equilibrium reside in the semicircular canals. These mechanoreceptors help tell the brain whether or not a person has their balance during body movements or if their body is in motion.
3. Explain the meaning of an “odor snapshot” and its relevance to human beings. 4 points.
When the olfactory receptors located on the cilia are stimulated by chemicals dissolved in the mucus, they transmit impulses along the olfactory filaments, which comprise the olfactory nerve; this nerve conducts the impulses o the olfactory cortex of the brain. An "odor snapshot" is made in the olfactory cortex, which then becomes part of our long-term memory. The olfactory pathways are closely tied to the limbic system, the emotional-visceral part of the brain. Odors elicit strong emotional responses.
4. Explain the various processes of food propulsion. 6 points.
Propulsion is the process that moves food through the alimentary canal, and includes swallowing and peristalsis, which Its function is to squeeze food from one organ to the