Midterm 2Name: __________________________Biology 449 - Animal Physiology Fall 2008Midterm 2 Fill in your scantron form as follows:- Write and bubble in your name in the upper left (last name first).- Sign your form on the upper right. By so doing you verify that you are abiding by Creighton’s policy on academic honesty.Multiple choice: As always, choose the best answer for each multiple-choice question. Answer on your scantron form. Each question is worth 3 points.1. A chemical messenger would be classified as a paracrine agent if it a. reached a target cell via the bloodstream.b. reached a target cell solely by diffusion.c. affected the cell that released it.d. was released by a modified neuron.e. was a modified form of cholesterol.2. Epinephrine is secreted by which of the following glands?a. Adrenal cortexb. Adrenal medullac. Anterior pituitaryd. Gonadse. Two of the above.3. Which of the following is/are steroid hormones? a. Growth hormoneb. Insulin-like growth factor I (IGF-I)c. Prolactind. Sex hormonese. Thyroid hormones4. The release of hormones from the anterior pituitary is controlled largely by the release of hormones from the hypothalamus. For which of the following hormones is release directly inhibited by a hormone released from the hypothalamus?a. follicle-stimulating hormone.b. growth hormone.c. luteinizing hormone. d. prolactin.e. Two of the above.1f. Which of the following shows a correct hormonal pathway? g. Thyroid stimulating hormone → thyrotropin releasing hormone → thyroid hormonesh. Thyroid stimulating hormone → thyroid hormones → thyrotropin releasing hormone i. Thyrotropin releasing hormone → thyroid stimulating hormone → thyroid hormonesj. Thyrotropin releasing hormone → thyroid hormones → thyroid stimulating hormone k. Thyroid hormones → thyroid stimulating hormone → thyrotropin releasing hormone5. An individual is found to have lower than normal levels of adrenocorticotropic hormone and corticotropin releasing hormone, and higher than normal levels of cortisol. Which of the following would explain this pattern?a. An autoimmune disease that causes antibodies to inhibit activation of receptors for adrenocorticotropic hormone.b. An autoimmune disease that causes antibodies to permanently activate receptors for adrenocorticotropic hormone.c. A tumor in the adrenal cortex that causes it to hypersecrete cortisol.d. High levels of stress.e. Two of the above.6. One of the primary mechanisms by which the thyroid hormone pathway increases metabolic rate is a. increased insertion of Na+/K+-ATPase into cell membranes.b. increased shivering.c. increased fatigue.d. increased growth.e. increased breakdown of proteins.7. Recall the relationship between the length of a sacromere and the force produced by the sarcomere during contraction. The reason the force eventually reaches zero as the sarcomere gets longer is thata. the thin filaments encounter the “bald spot” on the thick filament.b. the thin filaments start overlapping each other.c. the thick filaments are being compressed by the Z-line of the sarcomere.d. the thin and thick filaments no longer overlap.e. there is insufficient ATP to activate all the exposed myosin heads.8. The effect of increased Ca2+ levels on troponin is to a. cause it to lyse into two different molecules.b. cause it to change conformation.c. cause its binding site for myosin to become active.d. cause it to energize myosin heads.e. cause it to attach to the Z-lines.29. Consider a muscle lifting two different weights isotonically. If we look at a contraction during which the muscle lifts the heavier weight, compared to one during which it lifts the lighter weight, the contraction for the heavier weight will showa. a slower shortening velocity, a shorter period of shortening, and less distance shortened.b. a slower shortening velocity, the same period of shortening, and less distance shortened.c. the same shortening velocity, a shorter period of shortening, and less distance shortened.d. a slower shortening velocity, a longer period of shortening, and the same distance shortened.e. a faster shortening velocity, a shorter period of shortening, and the same distance shortened.10. The best definition for a “tetanic” contraction is one in whicha. the muscle cannot change its length.b. the muscle experiences a constant load.c. only some fibers in a muscle are activated.d. all the fibers in a muscle are activated.e. the muscle fibers show continuous action potentials.11. In a living vertebrate (as opposed to a laboratory preparation), the mechanism used to make awhole muscle produce a small amount of force (relative to its full potential) isa. a small number of slow oxidative fibers are each fully activated.b. a small number of fast glycolytic fibers are each fully activated.c. a large number of slow oxidative fibers are each partially activated.d. a large number of fast glycolytic fibers are each partially activated.e. all the fibers in the muscle are each partially activated.12. Blood pressure is normally lowest in which part of the systemic circuit?a. The arteriesb. The capillariesc. The venulesd. The veinse. Pressure is approximately equal in all these places.13. In a healthy mammalian heart, the heartbeat is initiated by action potentials in thea. atrial contractile muscle.b. atrioventricular node.c. sinoatrial node.d. venoatrial node.e. autonomic nervous system.3f. Which of the following statements about the systemic versus pulmonary circuits of the circulatory system is not true?g. Blood pressure is greater in the systemic circuit.h. Resistance is greater in the systemic circuit.i. Blood flow is greater through the systemic circuit.j. Two of the above are not true.k. a, b, and c are all true.14. Sitting in a hot bath tends to cause strong cutaneous vasodilation. Given this, which of the following statements is most likely correct, assuming no other changes in cardiovascular function occur?a. Blood flow to the skin will increase, blood pressure will increase, and blood flow to other tissues will increase.b. Blood flow to the skin will increase, blood pressure will increase, and blood flow to other tissues will decrease.c. Blood flow to the skin will increase, blood pressure will decrease, and blood flow to other tissues will decrease.d. Blood flow to the skin will decrease, blood pressure will increase, and blood flow to other tissues will increase.e. Blood flow to the skin will decrease, blood pressure