Which of the Following Hormones Is a Peptide Hormone

Name______

ID#______

Zoology 242

Mid-Term Exam 2

March 9, 2017

Instructor: Dr. Cheryl Schmitt

BE SURE TO READ THE FOLLOWING INSTRUCTIONS CAREFULLY BEFORE BEGINNING THE EXAM.

a) Please write your name on the top of this page and on the optical score sheet (Last name first on this one please).

b) Use a pencil to shade in your answers to the multiple-choice questions (1-32).

c) This exam contains 12 pages and consists of 33 multiple-choice questions and 7 short answer questions. Make sure that you have a complete exam.

d) You have until the end of the class period to write the exam. I will ask for the exams to be returned at 3:20 p.m.

The exam is out of 60 possible marks (plus 1 bonus point) and is worth 22% of your final grade.

τ = RmCm

λ = √ Rm/ Ri

Ri = 1/h

Rm = 1/ 2 r h

V = I.R

1 2 Multiple choice questions. Fill in the letter of the best answer on your scanning sheet. Use a pencil. (30 marks)

Use the following figure of to answer questions 1 through 3.

1) During the part of the voltage trace indicated by “X”, the voltage gated sodium channels are: A) open and allowing Na+ to move into the cell. B) open and allowing Na+ to move out of the cell. C) closed and no Na+ can move across the plasma membrane. D) open and allowing both Na+ and K+ to move into the cell. E) Inactivated.

2) During the part of the voltage trace indicated by “Y”: A) the plasma membrane is depolarized because K+ is moving out of the cell. B) both K+ and Na+ are moving across the plasma membrane. C) the resistance of the plasma membrane is very high. D) Na+ channels are inactivated. E) Both A and C are correct.

3) The part of the voltage trace indicated by “Z”: A) represents the absolute refractory period. B) represents the relative refractory period. C) shows that the cell is hyperpolarized at this time. D) is called membrane depolarization. E) Both B and C are correct.

4) The autonomic nervous system can be differentiated into three branches. Which of the following is NOT one of them? A) enteric/celiac B) sympathetic C) somatic D) parasympathetic E) Actually, the autonomic system is made up of FOUR functional branches, all of which are listed above.

5) In the sympathetic and parasympathetic nervous systems the preganglionic neuron releases the neurotransmitter:

3 A) acetylcholine B) nicotine C) glycine D) epinephrine E) norepinephrine

6) Saltatory conduction of an action potential: A) occurs in squid neurons. B) results from higher than normal salt concentration. C) refers to “leaping” of an action potential from one node of Ranvier to the next. D) is a passive electrical property of cells. E) is of little importance for conduction in neural axons.

7) An adaptation that would result in an increase in action potential conduction velocity would be: A) decreased axon diameter. B) myelination of the axon. C) fewer voltage-gated sodium channels in the internodes. D) shorter internodes. E) more than one of the above is a good answer.

8) Which of the following is NOT an advantage of a chemical synapse relative to an electrical synapse? A) Signals travel in one direction through a chemical synapse. B) A chemical synapse is faster. C) The signal through a chemical synapse can be amplified. D) A chemical synapse can be more highly regulated. E) Chemical synapses can be strengthened or weakened by synaptic plasticity.

9) The size of the postsynaptic potential (PSP) generated in a muscle cell depends upon the: A) total amount of neurotransmitter released from the motor neuron. B) number of vesicles that undergo exocytosis and release neurotransmitter. C) number of neurotransmitter receptors on the postsynaptic cell. D) number of ion channels that are opened. E) all of the above.

Questions10-11 relate to Long-Term Potentiation (LTP) in the rat hippocampus.

10) Long-Term Potentiation (LTP) A) is a neural adaptation the allows for a rapid conduction of action potentials. B) is a long-lasting enhancement of synaptic activity. C) is a passive electrical property of neurons. D) occurs as a result of a strong hyperpolarizing event in the post-synaptic cell. E) All of the above are true of LTP.

11) Which of the following signals are important for LTP to occur? A) Strong hyperpolarization of the post-synaptic cell. B) Release of Mg2+ from NMDA receptors. C) Release of Mg2+ from AMPA receptors. D) rapid inward movement of Cl- into the cell. E) Rapid outward movement of Ca2+ out of the cell.

12) In the example of the gill withdraw reflex of Aplysia, sensitization results from: A) a reduction in available neurotransmitter. 4 B) EPSPs (depolarization) in the presynaptic cell of the reflex arc. C) blockage of Ca2+ influx into axon terminal of the presynaptic cell. D) greater Ca2+ influx into the axon terminal of the presynaptic cell. E) more endocytosis from the presynaptic cell.

5 Consider a neuron with the following characteristics then answer the following question.

ENa+ = +50 mV EK+ = -85 mV

13) Which of the following would you expect to be true about this neuron? A) Na+ concentration is higher outside the cell than inside the cell. B) K+ concentration is higher outside the cell than inside the cell. C) An action potential generated in this neuron would reach +60 mV at its peak. D) The resting membrane potential of this neuron is -85 mV. E) The resting membrane potential of this neuron is about -18 mV.

The following graph illustrates the responses of two different stretch receptors. These are afferent cells that are part of a local reflex circuit. Answer Question 14 based on the graph.

14) Receptor A: A) has a lower threshold for detection than Receptor B. B) has a narrower dynamic range compared to Receptor B. C) reaches its maximum response at a lower stretch intensity than Receptor B. D) exhibits range fractionation. E) is capable of producing much greater electrical events compared to Receptor B.

15) The part(s) of the eye that refract and focus light on the fovea is/are: A) aqueous humor B) lens C) cornea D) A and C E) B and C

16) Which of the following is true regarding retinal organization in mammalian eyes: A) the retina is inverted with the photoreceptor cells at the back. B) the rods show convergence with multiple rods being part of a single ganglion receptive field. C) the cones show divergence with a single cone activating multiple ganglion cells. D) A and B are true. E) A and C are true.

17) Which taste receptor does not use a G-protein-coupled receptor for activation? A) bitter B) sweet C) salty D) umami E) tequila

18) The detection of odorants occurs when organic molecules bind to receptors on the cell membrane, activating a G protein that ultimately causes _____. A) cation (Na+, Ca2+) channels to open. B) sodium channels to close. C) potassium channels to open. D) chloride channels to close. E) potassium channels to close.

Based on the figure below, answer questions 19 and 20.

6 19) What is the best term to describe the type of muscle contraction seen in the figure? A) Isotonic eccentric B) Isotonic concentric C) Isometric D) Painful E) There are no words to describe this picture.

20) Look at the picture again :) Which of the following statements is false regarding this type of muscle contraction? A) Calcium is being released from organelles in this individual’s muscle cells. B) Muscle tension is generated during this type of contraction. C) ATP is being used by this individual’s muscle cells. D) This individual is doing a lot of work. E) Antagonistic muscle pairs are being used.

7 21) The speed of muscle contraction is limited by: A) the number of myofibers present. B) the type of metabolism used by the muscle cells. C) the ATPase activity of the myosin head. D) the type of actin filaments. E) the type of troponin present.

22) Generally speaking, the muscles of a sprinter will use______to generate ATP whereas those of a marathon runner will use ______to generate ATP. A) aerobic metabolism; anaerobic metabolism. B) anaerobic metabolism; aerobic metabolism. C) lipid; creatine phosphate. D) glucose; creatine phosphate. E) lipid; glucose.

23) Which of the following statements about fast glycolytic (FG) muscle fibers is true? A) FG fibers have a lot of myoglobin B) The myosin filaments of FG muscles have a very low rate of ATPase activity C) FG fibers generate ATP primarily through anaerobic metabolism D) Only birds have FG muscle fibers E) None of the above statements are true

24) The “length-tension relationship” as it relates to muscle contraction means: A) there is an ideal length for muscle contraction. B) the speed of muscle contraction decreases with the tension generated. C) less contractile tension can be generated when the muscle is stretched out. D) that muscle contraction performs work. E) Both A and C are true

25) Consider the role of calcium in skeletal muscle contraction. Which of the following statements is false? A) calcium is released from the SR only when an action potential travels down the T tubule. B) calcium is the physiological regulator of muscle contraction. C) calcium binds to Tn-I to reposition tryopmyosin. D) CaATPase actively pumps calcium in the SR after when there is no more stimulation of the muscle. E) ALL of these answers are correct, not false statements.

26) When calculating the resting membrane potential of a cell A) you would use the Nernst Equation. B) you would need to know the ion concentrations on the inside and outside of the cell. C) the voltage threshold for action potentials must be known. D) the types of voltage-sensitive channels must be known. E) the type of cell must be known.

27) Smooth and striated muscle share some common features, including A) organization of filaments into sarcomeres. B) the use of actin and myosin for contraction. C) dependence on T-tubules for spread of depolarization. D) the use of gap junctions to spread electrical signals to neighboring cells. E) the use of epinephrine to signal muscle contraction.

8 Use the following information to answer questions 28 to 32.

A neurobiologist was interested in measuring the synaptic events in the jumping reflex of a predatory spider. From the central ganglia (brain) of the spider she identified and isolated a group of synapses that connect three interneurons to a single motor neuron (MN), which is in turn connected to a leg muscle. She set up electrodes to depolarize the interneurons (by injecting a current) and then measure the change in electrical potential in the motor neuron dendrites. She also determined the reversal potential for each synapse. Answer the questions based on the data she collected in the table below. Note: Resting membrane potential (Vm) of the motor neuron is -70 mV.

Interneuron Measured Reversal(Equilibrium) stimulated PSP (mV) Potential = Pot (mV) A -30 +90 B -58 +30 C -85 -90 A+B -18 Not measured A+C -45 Not measured

28) Which of the synapses generates an excitatory post-synaptic potential (EPSP) in the motor neuron? A) A B) B C) C D) Neurons A and B both generate EPSPs E) all of the interneurons generate EPSPs

29) Which of the following techniques was likely used to determine the reversal potential in the motor neuron dendrite? A) patch –clamp B) voltage-clamp C) long term potentiation D) facilitation E) habituation

30) Consider the following statements. Based on the data in the table, which could be true about the post- synaptic response? i) Interneuron A activates a metabotropic receptor which causes an inhibitory post-synaptic potential (IPSP). ii) Interneuron A activates an ionotropic receptor which is a sodium channel. iii) Interneuron A activates an ionotropic receptor which is a potassium channel. iv) Interneuron B activates a metabotropic receptor which causes an IPSP. v) Interneuron B activates an ionotropic receptor which is both a sodium and potassium channel. vi) Interneuron C activates an ionotropic receptor which is a potassium channel. vii) Interneuron C activates an ionotropic receptor which is a sodium channel.

A) i, ii, vii B) ii, iv, vii C) ii only D) ii, v, vi E) iv, vi

9 31) Which of the following would be recorded in the post-synaptic cell when interneuron A is stimulated at the same time as interneurons B or C? A) amplification B) inhibition C) spatial summation D) temporal summation E) nothing

32) The threshold potential for firing an action potential in this motor neuron (MN) is -40 mV. The expected response in the attached muscle cell when interneuron(s) ______is(are) stimulated is______. A) A; a muscle contraction B) C; a muscle contraction C) B; a muscle contraction D) A and B; no muscle contraction E) A and C; muscle contraction

33) Which of the following statements about hormones is / are true? A) Insulin and epinephrine are both protein hormones. B) mineralocorticoids and glucocorticoids are hydrophilic hormones. C) the biogenic amine cortisol is an example of a hydrophilic hormone. D) The steroid hormones are hydrophobic and all are formed from cholesterol. E) I though you wouldn’t as a question about this, so who knows :)

Short Answer: Answer the following questions in the space provided.

1) Choose the correct words and fill in the blanks to complete the following statement: (2 marks)

Electrotonic spread is (INSTANTANEOUS / RELATIVELY SLOW) and accounts for electrical spread in the internodal area of a myelinated axon. (LIGAND GATED / VOLTAGE GATED) Na+ channels are brought to threshold in the ______during saltatory conduction. The NaKATPase (PASSIVELY / ACTIVELY) restores ions to the proper side of the membrane.

2) Briefly describe three purposes of ATP during vertebrate skeletal muscle contraction and relaxation. (3 marks)

10 3) Match the following phrases with the best term from the list below (6 marks).

_____blocks myosin-binding site on actin _____protein that changes shape allowing calcium out of the SR in muscle contraction _____prolonged, steady muscle contraction _____distance of a single cytoskeletal contraction _____all cytoskeletal components between two Z-discs _____calcium buffer protein _____ a vitamin A derivative in photosensitive cells _____ the type of modality that can be detected by a specific receptor _____a non-conscious modality _____ sense organ adaptation that prevents stimulus from irrelevant stimuli _____fast adapting receptors that often signal an off response _____repeated action potentials resulting in more ICF calcium and larger releases of neurotransmitter

a. opsin m. tonic receptors b. pH n. antifacilitation c. peripheral filter o. unitary displacement d. touch p. myosin e. facilitation q. parvalbumin f. light r. sarcoplasmic reticulum g. adequate stimulus s. dihydropyridine receptor (DHPR) h. retinal t. actin i. sarcomere u. troponin j. ryanodine receptor (RyR) v. tropomyosin k. facilitation w. myofibril l. phasic receptors x. tetanus y. z. aa. 4) What is presynaptic inhibition? Sketch the relationship of 3 neurons to show how it works. (2 mark) ab. ac. ad. ae. af. ag. ah. ai. aj. 11 ak. 5) The optic chiasma in humans is important for the way that visual images are integrated in the occipital cortex. al. CIRCLE the correct answer in the following questions/statements. (3 marks) am. an. a) Which fibers leaving the optic nerve cross sides in the chiasma? (NASAL FIBERS / TEMPORAL FIBERS) ao. ap. b) The right visual field from each eye is evaluated by the right occipital lobe of the brain (TRUE / FALSE) aq. ar. c) Binocular vision is possible in people because each eye evaluates a slightly different perspective giving us depth as. perception capabilities. (TRUE / FALSE) at. au. av. a) Label cells A, B, C, and D. (2 marks) aw. ax. b) Cells A, B, and C make up a “straight-through” pathway in the retina. This pathway is part of an “on-center” ganglion cell receptive field. Fill in the table below to indicate if the cell is hyperpolarized or depolarized when light strikes in the center of the “on-center” receptive field being considered. In the second column indicate whether or not the cell produces a true action potential. (2 marks) ay. az. ba bb. On- bc. Tr . Center ue C ap?

b be. bf. d. A b bh. bi. g. B bj bk. bl. . C bm.

12 bn. bo. bp. bq. br. bs. bt. bu. bv. bw. bx. by. bz. ca. cb. cc. cd. ce. cf. cg. ch. d) As a result of question c, how will this affect the polarity in: (1 mark) ci. cj. -Cell B: (HYPERPOLARIZED / DEPOLARIZED) ck. cl. -Cell C: (HYPERPOLARIZED / DEPOLARIZED) cm. cn. co. 7) Explain and show the sequence of events that result in photo-transduction of light to an electrical signal in a rod photoreceptor cell. (4 marks). cp. cq. First, light strikes the photoreceptor  cr. cs. ct. cu. cv. cw. cx. cy. cz. da. db. dc. dd. de. **Bonus**: What causes rigor mortis? (1 mark) df. dg. dh. di. dj. dk. dl. dm. dn. 13 do. dp. dq. Score

dr. Multiple ds. /33 Choice dt. Short Answer du. /27 (plus bonus question) dv. Total dw./60 dx. dy. dz. ea. eb. ec. ed. ee. ef. eg.