Q&A Hero

Q: Matching Questions The pumps that actively transport calcium back into the _______ are called Ca2+ -ATPase pumps. A. transverse tubules B. sarcoplasmic reticulum C. neuromuscular junction D. None apply.

Q: Matching Questions When a muscle is stimulated to contract, calcium release channels in the SR will release Ca2+ by A. active transport. B. facilitated diffusion. C. passive diffusion. D. exocytosis.

Q: Matching Questions What structures carry the action potentials into the interior of the muscle to cause muscle contraction? A. T tubules B. terminal cisternae C. sarcoplasmic reticula D. ryanodine receptors

Q: Matching Questions The process by which action potentials cause muscle contraction is A. the sliding filament theory. B. excitation-contraction coupling. C. the electromechanical release mechanism. D. Both excitation-contraction coupling and the electromechanical release mechanism.

Q: Matching Questions Which of the following is NOT true of the relaxation of a muscle fiber? A. ATP is needed to fuel the calcium pumps B. calcium release channels close C. the action potential must continue D. Ca2+ moves from the sarcoplasm to the sarcoplasmic reticula

Q: Matching Questions What is the role of ATP in muscle contraction and relaxation? A. It is hydrolyzed from the myosin head to attach to actin. B. It causes myosin head to detach from actin. C. It powers the Ca2+ pumps to return Ca2+ to the SR. D. All apply.

Q: Summation occurs in muscle cells when stimulus frequency increases to produce a greater force contraction.

Q: Matching Questions Which of the following is needed for the myosin head to undergo a power stroke? A. release of Pi B. binding of ATP to the head C. splitting of ATP into ADP and Pi D. addition of Ca2+ to the head

Q: Matching Questions What enzyme is needed to start the cross bridging process? A. creatine phosphatase B. kinase C. myosin ATPase D. Ca2+ATPase

Q: Matching Questions During skeletal muscle contraction, adjacent _________ are pulled closer together as the _______ between them shorten. A. A bands; I bands B. I bands; A bands C. Z disks; A bands D. Z disks; M lines

Q: Matching Questions ________ is characterized by continued attachment of myosin heads to actin filaments due to a lack of ATP. A. Tetanus B. Rigor mortis C. Flaccid paralysis D. Treppe

Q: Matching Questions During skeletal muscle contraction, A. the H band increases in size. B. Ca2+ associates with tropomyosin. C. myosin heads interact with tropomyosin. D. thin filaments slide across thick filaments.

Q: Matching Questions Which of the following molecules is NOT part of the thin filament? A. actin B. titin C. troponin D. tropomyosin

Q: Matching Questions Which molecule blocks the myosin head from binding to actin in a relaxed muscle? A. tropomyosin B. troponin C. calcium D. titin

Q: Matching Questions Which of the following does NOT occur during the cross bridge cycle? A. a second ATP binding causes cross bridges to release. B. ADP is released at the end of the power stroke. C. energized myosin heads bind troponin. D. ATP hydrolysis allows for cross bridge formation.

Q: Ca2+ must bind to tropomyosin so that the myosin binding sites on actin will be accessible to the myosin.

Q: Matching Questions The _________ complex contains three proteins designated as the I, T, and C types. A. actin B. myosin C. tropomyosin D. troponin

Q: Matching Questions The movement of the troponin-tropomyosin complex requires A. ATP. B. Ca2+. C. acetylcholine. D. Na+.

Q: The thick filament is split by a Z disc.

Q: During skeletal muscle contraction the A band decreases in size.

Q: Cross-bridge formation occurs when myosin heads attach to actin molecules located in the thin filaments.

Q: Myosin will not bind to actin unless ADP is bound to the myosin head.

Q: Matching Questions Myosin contains binding sites for ______________ and _____________. A. sodium, calcium. B. troponin, ATP. C. ATP, actin. D. actin, calcium.

Q: Matching Questions What muscle structural and functional unit runs from Z disc to Z disc? A. A band B. I band C. sarcomere D. myofibril

Q: Matching Questions The thick filament is also called the A. A band. B. I band. C. H band. D. M line.

Q: Matching Questions What protein primarily makes up the thick filament? A. actin B. myosin C. titin D. troponin

Q: Matching Questions What protein primarily makes up the thin filament? A. actin B. myosin C. titin D. Z-discs

Q: Matching Questions What is the lighter area in the center of the A-band called? A. M-line B. titin C. Z-disc D. H band

Q: Longer, stronger muscles have motor units with very few fibers.

Q: Matching Questions Somatic motor neurons release the neurotransmitter _________ at the neuromuscular junction. A. dopamine B. acetylcholine C. norepinephrine D. serotonin

Q: Matching Questions Each somatic motor neuron with all the muscle fibers it innervates is a A. fascicle. B. varicosity. C. motor unit. D. sarcolemma.

Q: Thin filaments are composed of myosin and tropomyosin.

Q: Sarcomeres contain elastic titin filaments which help the muscles return to their resting length during muscle relaxation.

Q: Matching Questions Subunits of skeletal muscle cells that are composed of sarcomeres are called A. myofibrils. B. myofilaments. C. sarcolemmas. D. transverse tubules.

Q: Matching Questions What structure is composed of protein filaments and is located in the center of the thick filaments? A. Z disk B. titin C. M line D. actin

Q: Matching Questions What structure runs the length of the sarcomere and contributes to the elastic recoil in muscle? A. Z disk B. titin C. M line D. actin

Q: Aspirin reduces inflammation by A. inhibiting the COX1 isoenzyme. B. inhibiting the COX2 isoenzyme. C. inhibiting the COX3 isoenzyme. D. increasing production on PGI2 and PGE2.

Q: Drugs that are useful for treating asthma are A. COX-2 inhibitors. B. anti-leukotrienes. C. COX-3 inhibitors. D. COX-1 inhibitors.

Q: Motor unit recruitment allows for _________ contraction strength. increased B. decreased C. no change in

Q: ______________ are derived from the precursor arachidonic acid. A. Thyroid hormones B. Adrenal medulla hormones C. Glucocorticoids D. Prostaglandins and leukotrienes

Q: The same prostaglandin may produce different effects in different tissues.

Q: Prostaglandins are eicosanoids derived from the fatty acid A. palmitic acid. B. linolenic acid. C. linoleic acid. D. arachidonic acid.

Q: Stomach irritation by NSAIDs like aspirin is believed to be the result of A. inhibition of PGI2 and PGE2. B. secretion of PGI2 and PGE2. C. inhibition of thromboxane A2. D. None apply.

Q: _____________ inhibits COX3 in the brain which results in pain and fever reduction. A. Acetaminophen (Tylenol) B. Aspirin C. Ibuprofen (Motrin) D. All apply.

Q: Which of the following statements about prostaglandins is true? A. Prostaglandin synthesis is blocked by the actions of caffeine. B. Prostaglandins inhibit inflammation. C. Prostaglandins may contribute to asthma. D. Thromboxane A2 induces vasodilation.

Q: All of the following are considered nonsteroidal anti-inflammatory drugs EXCEPT A. aspirin. B. celecoxib (Celebrex). C. acetaminophen (Tylenol). D. rofecoxib (Vioxx).

Q: Progesterone is secreted primarily from the corpus luteum.

Q: Male secondary sex characteristics would not develop in boys in which the ____________ cells did not secrete testosterone. A. seminiferous tubule B. interstitial C. Leydig D. Both interstitial and Leydig are correct

Q: A deficiency of dietary cholesterol would decrease the production of A. glucagon. B. atrial natriuretic hormone. C. melatonin D. estradiol-17b.

Q: The placental hormone with actions similar to both growth hormone and prolactin is A. chorionic somatomammotropin. B. chorionic gonadotropin. C. placental prolactin. D. placental lactogen.

Q: After menopause, the principal estrogen is estrone that is produced by the adrenal cortex.

Q: Molecules that are produced within one tissue but regulate a different tissue of the same organ are called A. autocrine regulators. B. endocrine regulators. C. paracrine regulators. D. exocrine regulators.

Q: ____________ regulators mediate the function of the cells in which they are synthesized. A. Autocrine regulators B. Endocrine regulator. C. Paracrine regulators. D. Exocrine regulators.

Q: Skin wound healing would be slowed due to a lack of ____________ growth factors. A. nerve B. endothelin C. epidermal D. platelet

Q: Blood vessel diameter is regulated by all of the following EXCEPT A. nitric oxide. B. bradykinin. C. endothelin. D. platelet-derived growth factor.

Q: Which of the following is NOT a role of glucagon in blood glucose homeostasis? A. raises blood glucose levels B. stimulates glycogenolysis and gluconeogenesis in the liver C. promotes lipolysis and ketogenesis D. promotes the movement of glucose out of skeletal muscle cells

Q: What hormone(s) is/are released when blood glucose levels decrease? A. insulin B. glucagon C. glucocorticoids D. both glucagon and glucocorticoids

Q: Pineal gland production of melatonin is stimulated by the _______________ of the hypothalamus. A. supraoptic nuclei B. paraventricular nuclei C. suprachiasmatic nucleus D. None apply.

Q: Cycles of physiological activity that follow a 24-hour pattern are called A. circadian rhythms. B. biomemetic rhythms. C. psychological rhythms. D. cerebral rhythms.

Q: Purported beneficial effects of melatonin include all of the following EXCEPT A. limiting the effects of jet lag. B. treating insomnia. C. preventing oxidative damage to cells. D. increasing weight loss.

Q: Melatonin is secreted by the pineal gland due to parasympathetic stimulation.

Q: Daylight causes stimulation of the pineal gland to release melatonin.

Q: What is needed to control secretion of melatonin from the pineal gland? A. sympathetic stimulation from the suprachiasmatic nucleus of the hypothalamus B. activation of melanopsin from ganglion cells of the retina C. sunlight or lack of sunlight D. All apply.

Q: Melatonin has an extremely important role in the onset of human puberty.

Q: The stomach and small intestines release hormones to help coordinate activities with the autonomic nervous system for digestion.

Q: Diabetes mellitus occurs due to lack of liver beta-cell function.

Q: The pancreas secretes hormones involved in regulation of A. blood glucose. B. the stress response. C. metabolic rate. D. growth and reproduction.

Q: Destruction of the pancreatic beta-cells would result in A. Cushing's disease. B. Grave's disease. C. diabetes mellitus. D. diabetes insipidus.

Q: Which of the following is NOT an effect of glucagon secretion? A. lipolysis B. ketogenesis C. glycogenesis D. glycogenolysis

Q: Insulin and glucagon are antagonistic hormones.

Q: What are the carrier proteins for glucose diffusion into cells? A. insulin B. GLUT4 C. GLUT2 D. glucagon

Q: Calcitonin and PTH are antagonistic hormones.

Q: Which of the following is NOT true of calcitonin? A. It is made by follicle cells of the thyroid. B. Inhibits loss of calcium by bones. C. It lowers blood calcium levels. D. All apply.

Q: Which of the following is true of parathyroid hormone function? A. It causes the kidneys to reabsorb calcium. B. It causes the dissolution of calcium phophate from bones. C. It increases blood calcium levels. D. All apply.

Q: ___________________ can form a goiter due to the presence of autoantibodies that exert TSH-like effects on the thyroid. A. Grave's disease B. Myxedema C. Cretinism D. Cushing's disease

Q: A child with ____________ would be lethargic, shorter than average, have mental retardation, and a low body temperature. A. Grave's disease B. cretinism C. dwarfism D. Addison's disease

Q: Which of the following is an effect of hyperthyroidism? A. accelerated growth B. rapid pulse C. increased plasma T4 levels D. All apply.

Q: An individual with bulging eyes may A. be secreting inadequate thyroid hormone. B. be secreting excessive thyroid hormone. C. be secreting inadequate cortisol. D. be secreting excessive cortisol.

Q: What element is necessary for production of thyroxine? A. sodium B. calcium C. iodine D. chlorine

Q: What amino acid of the protein colloid in thryoid follicles does iodine bind to? A. threonine B. serine C. tyrosine D. alanine