SLCC Physiology Exam 1 Essay Questions
With Complete Solutions
Give an example of positive feedback & label the receptor, integrating center, and effector.
Child birth. During labor, the cervix begins to stretch and receptor cells send signals to the
brain (sensors). The signals are received in the hypothalamus (integrating center) which then
releases oxytocin. Oxytocin makes contractions speed up and become more intense (effectors).
The increase in contractions cause more oxytocin to be released and the cycle goes on until the
baby is born. The birth ends the release of oxytocin and ends the positive feedback mechanism.
Define passive energy It needs a concentration gradient. It does not require energy input.
It goes from higher to lower energy.
Define active energy It involves a pump (a protein) that moves something against it's
gradient. It requires energy to work. It goes from low to high concentration.
Simple diffusion Type of passive transport, doesn't require energy. Unassisted passage of
small, hydrophobic, nonpolar molecules from high to low concentration.
With Complete Solutions
Give an example of positive feedback & label the receptor, integrating center, and effector.
Child birth. During labor, the cervix begins to stretch and receptor cells send signals to the
brain (sensors). The signals are received in the hypothalamus (integrating center) which then
releases oxytocin. Oxytocin makes contractions speed up and become more intense (effectors).
The increase in contractions cause more oxytocin to be released and the cycle goes on until the
baby is born. The birth ends the release of oxytocin and ends the positive feedback mechanism.
Define passive energy It needs a concentration gradient. It does not require energy input.
It goes from higher to lower energy.
Define active energy It involves a pump (a protein) that moves something against it's
gradient. It requires energy to work. It goes from low to high concentration.
Simple diffusion Type of passive transport, doesn't require energy. Unassisted passage of
small, hydrophobic, nonpolar molecules from high to low concentration.
