BIOS 255 Anatomy and Physiology Comprehensive Exam with Verified Answers

What does a synergistic muscle do - ANS: also called fixators, act around a joint to help the action of an agonist muscle. (iliacus, psoas major, and rectus femoris) hamstring group - ANS: biceps femoris, semitendinosus, semimembranosus sodium-potassium ion - ANS: Neuron has a negative charge at rest. Slightly positive charge sodium ions on the outside. During the firing, sodium ions rush into the axon causing depolarization. Potassium ions rush out of the axon causing it to return to its resting state (negative charge) What is a graded potential? - ANS: changes in membrane potential that vary in size, as opposed to being all-or-none Phrenic nerve - ANS: Carries impulses to the diaphragm from the brain. function of cerebrospinal fluid - ANS: shock absorption, support weight of brain, nourishment and waste removal, Primary motor cortex - ANS: the section of the frontal lobe responsible for voluntary movement Anti-diuretic hormone (ADH) - ANS: A hormone produced by the pituitary gland when the body is dehydrated. It causes the kidneys to reabsorb more water into the blood making the urine more concentrated. Cranial nerves "wanders" - ANS: The Vagus Nerve sympathetic activation - ANS: occurs in anger or fear, leads to physiological arousal - increased vigilance, heart rate, and blood flow to the skeletal muscles, and decreased blood flow to the gastrointestinal system and skin (which is why arousal leads to cold hands and feet). Order of light passing through the eye - ANS: cornea, pupil, lens, vitreous humor, retina, optic nerve