Muscular and Endocrine Systems - Assignment Example

29 March Exam III: Muscular and Endocrine Systems B The absence of ducts. Explanation of incorrect answer: The type of hormone. Hormones from the endocrine glands can act over long distances as compared to hormones from the exocrine glands. Hormones are chemical substances that are secreted by specific organs and act on target organs. They are regulatory. Explanation for the correct answer: The absence of ducts. Endocrine glands secrete hormones into the blood. Ducts are delivery systems that are used to transport substances in the body (Olubummo, 2010). 2. B. Paracrine. Explanation of the incorrect answer: Endocrine. The hormones are secreted into the blood. The blood and tissue fluids carry them to the target cells they are to act on. Explanation of the correct answer: Paracrine. The hormones diffuse in the area around the secreting cells. They act upon nearby cells of a different cell type. An example is the release of neurotransmitters at synapses (Olubummo, 2010). 3. C. Cyclic hormone secretion: Explanation of the incorrect answer: acute hormone response occurs in immediately in response to stimuli. Acute means sudden and in high amounts. Explanation of correct answer: This is shown by the endometrium which undergoes cyclic changes due to certain hormones that control ovulation. It occurs timely (Olubummo, 2010). 6. B. By a second messenger: Explanation of the incorrect answer: The ligand enters the cell. When ligands bind to a receptor at the surface of the cell, they cause changes to the biochemical activities inside the cell. Explanation of the correct answer: A second messenger is a molecule which transmits signals obtained at the surface of the cell to the target area or molecule inside the cell. They also strengthen the signal’s strength (Olubummo, 2010). 7. A. The anterior pituitary: Explanation of the incorrect answer: The posterior pituitary arises from the neuroectoderm.It grows as an extension of the hypothalamus. Explanation of the correct answer: The anterior pituitary arises from the invagination of the oral ectoderm. On invagiation, it forms the Rathke’s pouch. The ectoderm is a primary germ cell layer that is found in the early phase of embryo growth. Rathke’s pouch is a cavity in the surface of the developing mouth that is found in front of the buccopharyngeal membrane (Olubummo, 2010). 8. D. The hypothalamus: Explanation of incorrect answer: the posterior pituitary. This is because the hormones secreted by the posterior pituitary are secreted by the hypothalamus and passed on through the pituitary stalk to the pituitary. Explanation of the correct answer: The hypothalamus is responsible for the synthesis and release of the hormones which act on the pituitary gland. This regulates the functioning of the master endocrine gland. 9. D. Hypothalamus: Explanation for the incorrect answer: They are made in the posterior pituitary gland as the pituitary gland releases hormones that act on different glands. Explanation for the correct answer: The hypothalamus. As stated in question 8, the hormones secreted by the hypothalamus move through the pituitary stalk to the pituitary gland where they are released into the blood (Olubummo, 2010). 10. C. Prolactin hormone: Explanation for the incorrect answer: Antidiuretic hormone is also known as vasopressin. It is produced in the hypothalamus, stored and released from the pituitary gland. It functions on the kidney by regulating the uptake and release of water in the kidney. Explanation for the correct answer: Prolactin hormone is a hormone of the anterior pituitary gland. It enables the release of milk from the mammary glands. It promotes lactation in response to a stimulus. The stimulus is normally mainly suckling (Olubummo, 2010). 13. E. Both a and c: Explanation for the incorrect answer: Oxytocin. This is a hormone secreted by the hypothalamus. It is stored and released by the posterior pituitary gland. It is involved in sexual reproduction mainly during child birth. Explanation for the correct answer: Both follicle stimulating hormone and luteinizing hormone are constituents of the protein family that makes up gonadotropins. Gonadotropins are hormones made up of proteins which are manufacture and secreted by cells called gonadotropes in the anterior pituitary gland. Gonadotrops control reproduction, sexual development and normal body growth (Olubummo, 2010). 14. A. Lower blood calcium levels: Explanation for the incorrect answer: Increase blood calcium levels. Bone deposition is the process by which bones are formed. It needs phosphate and calcium minerals. Explanation for the correct answer: Lower blood calcium levels. By decreasing osteoclastic activity, the process by which osteoclasts breakdown bone and release calcium into the blood is decreased. Instead, calcitonin increases bone deposition which involves bone formation. This process needs calcium hence there is uptake of calcium from the blood which lowers its levels in the blood (Olubummo, 2010). 15. A. Calcium is vital to neurotransmitter release: Explanation for the incorrect answer: Calcium is vital to neurotransmitter production. Calcium is not actually involved in the production of neurotransmitters, but it plays vital roles in their release. Explanation for correct answer: Calcium is important for neurotransmitter release. Nervousness is as a result of increase in neuromuscular excitability that is as a result of neurotransmitter release (Olubummo, 2010). 16. B. Lungs: Explanation for the incorrect answer: heart. The hormone estrogen is very important. It initiates the vital processes of fetal maturation. The organs such as liver and heart cannot mature without it. Explanation for correct answer: Lung. The maturation of lungs in the fetus is regulated by cortisol which is secreted by fetal adrenals. The maturation of the fetal lung is triggered by release of fetal lung surfactant which enhances lung maturation. This release of fetal lung surfactant is due to increase in cortisol production (Olubummo, 2010). 18. A. Prolonged anti – inflammatory response with white blood cell inhibition: Explanation for incorrect answer: long term anti – histamine response. Anti – histamine inhibits the histamine’s action. It does this through obstruction of histamine to attach to histamine receptors. Anti – histamine is used in the relieving of an allergy. Explanation for correct answer: Prolonged anti – inflammatory response with white blood cell inhibition. They hinder total inflammatory reactions to physical and infectious agents through the inhibition of inflammatory reactions like edema, movement of leukocytes to the specific region and phagocytic action (Olubummo, 2010). 19. C. Ability to shorten with force: Explanation for incorrect answer: Ability to stretch. This is what is termed as extensibility. It means that muscles can be stretched to their regular length when they are at rest or beyond to a certain extent. Explanation for correct answer: Contractility is the ability of muscles to contract with force. This is normally in response to a stimulus. It takes place through a sliding filament mechanism. The actin filaments slide inwards among the myosin filaments (Olubummo, 2010). 20. A. Striations in the membrane: Explanation for incorrect answer: Many mitochondria. Mitochondria are cell organelles that are involved in the production of energy in the cells. Muscle cells need this energy. Explanation for correct answer: Muscle fibers are formed from the fusion of myoblasts. This process is termed as myogenesis. Skeletal muscles are striated. They are voluntarily controlled (Olubummo, 2010). 21. D. Sequesters calcium: Explanation for incorrect answer: Protein production. It is the process by which new proteins are produced. The cell organelles that are involved in protein production are ribosomes. Explanation for correct answer: Sequesters calcium. The sarcoplasmic reticulum controls the quantity of calcium in the cells by storing and releasing it. This process instigates contraction of the muscle. In skeletal muscles, it controls the concentration of intracellular calcium (Olubummo, 2010). 22. C. Active, passive + active: Explanation for the incorrect answer: active, passive. In muscle function, contraction is active; however relaxation is not only passive. Explanation for correct answer: In muscle function, contraction is active as it involves the active sliding of actin and myosin past each other. Relaxation is both active and passive as the muscle returns to its normal length (Olubummo, 2010). 23. B. The ability to recoil is lost: Explanation of the incorrect answer: ability to stretch is increased. If elasticity is lost, then the ability to stretch cannot be increased as the muscle has to be elastic to stretch. Explanation for correct answer: The ability to recoil is lost. Muscles are passively elastic. This is very important to their functioning as it is the driving force behind their ability to recoil after actively contracting. They recoil back to their original resting length (Olubummo, 2010). 24. B. Increase in the contractile protein content: Explanation of the incorrect answer: All of the above. This answer cannot apply as connective tissue is not a constituent of muscle. It is a tissue that connects other tissues and organs of the body including the muscle itself. Explanation of the correct answer: Increase in contractile tissue. When a body builder works to increase the size of his muscles, muscles adapt by increasing the size and amount of contractile proteins that are comprised of the myofibrils in each muscle fiber (Olubummo, 2010). 25. a. Epymisium: Explanation of the incorrect answer: Endomysium. It surrounds each muscle fiber and is made up of dense meshwork of collagen fibrils. It also makes attachments to the basement membrane. Explanation for the correct answer: Epimysium. It is a tough coating which surrounds the whole muscle separating it from other muscles. It is made up of collagen fibers (Olubummo, 2010). 26. B. Tendon: Explanation of the incorrect answer: Ligament. This is a tissue that is made up of fibers. It connects a bone to a bone. Explanation for the correct answer: Tendon. This is a connective tissue. It connects muscle to bone. It is made up of collagen (Olubummo, 2010). 27. B. A – band: Explanation of the incorrect answer: Z – disk. It is located between the I bands. It is viewed as a sequence of dark lines Explanation for the correct answer: A – band. The A – band is found after the I – band. They are made up of the whole length of a thick filament which is mysosin (Olubummo, 2010). 28: B. Generation of an action potential: Explanation of the incorrect answer: fall in calcium levels. Calcium initiates muscle contraction by reacting with the controlling proteins. When calcium is not available, these proteins hinder the interaction of actin and myosin. Explanation of the correct answer: generation of an action potential. A stimulus causes the generation of an action potential in the muscle fiber which leads to muscle contraction. A pulse of calcium is released into the cytosol. This activates the sliding filament mechanism. A twitch is the result of a higher stimulus. It is a fast cycle of contraction and relaxation (Olubummo, 2010). 29. B. Isometric: Explanation of the incorrect answer: Isotonic. In this type of contraction, the tension in the muscle does not change but the length of the muscle change. Explanation for the incorrect answer: Isometric contraction. In this type, the muscle is activated. However, instead of being permitted to change in length, its length remains constant, it does not change (Olubummo, 2010). 32: B. It allows muscles to continue contracting when mitochondrial activity is limited: Explanation of the incorrect answer: It is more efficient than aerobic respiration. Aerobic respiration needs oxygen to generate energy. In aerobic respiration, glycolysis goes on with the kreb’s cycle and oxidative phosphorylation. This occurs in the mitochondria. In terms of the ATP net gain, it is more efficient than anaerobic metabolism. Explanation for the correct answer: it allows muscles to continue contracting when mitochondrial activity is limited. Mitochondrial activity needs oxygen to occur. Hence, in limited oxygen supply, anaerobic respiration occurs with glycolysis been the sole source of energy which allows muscles to continue contracting (Olubummo, 2010). 36. B. Alkalosis: Explanation of the incorrect answer: Acidosis. Acidosis is a result of increased acidic ions in the blood. Explanation for the correct answer: Alkalosis. Aldosterone homorne promotes the production of hydrogen ions in exchange for sodium ions. This regulates the acid/base concentration of blood plasma. Too much activity of aldosterone results in too much uptake of sodium ions into the blood plasma in exchange for the hydrogen ions, this leads to alkalosis which is the decrease in the concentration of hydrogen ions in the blood plasma (Olubummo, 2010). 37. D. Pubic and axillary hair growth and maintenance of the sex drive: Explanation of the incorrect answer: Pubic and axillary hair growth and sexual identity. It is true that adrenal androgens cause pubic and axillary hair growth during puberty in females. However, they do not give females their sexual identity. Explanation for the correct answer: Pubic and axillary hair growth and maintenance of the sex drive. In puberty, they promote growth of pubic and underarm hair. They are important in the production of estrogen and maintenance of sexual desire and satisfaction (Olubummo, 2010). 38: D. Number of fibers stimulated and the frequency of stimulus: Explanation of the incorrect answer: number of fibers stimulated. This alone cannot determine the amount of tension in the whole muscle as tension is as a result of several factors. Explanation for the correct answer: Number of fibers stimulated and frequency of stimulus. Muscle tension is the force which is as a result of muscular contractions. It is generated on formation of cross – bridges between the two proteins, actin and myosin each muscle fiber (Olubummo, 2010). 40. A. The one performing majority of the movement: Explanation of the incorrect answer: the one aiding in completing the movement. This means that this muscle does not take part in initiation of the movement. It just aids in completion of the movement. Hence, it only takes part in only a small part of the whole process. Explanation of the correct answer: The one performing majority of the movement. This muscle functions to generate, sustain and complete the movement. It functions directly to bring about this movement with the help of other muscles (Olubummo, 2010). Cardiovascular System 1. D. Deoxygenated blood flows through the arteries and oxygenated blood flows through the veins. Explanation of the incorrect answer: Oxygenated blood flows through both veins and arteries. This does not occur in any of the either of the circulation types. Explanation of the correct answer: Deoxygenated blood flows through the arteries, the pulmonary artery to the lungs, and then oxygenated blood flows back to the heart through the pulmonary vein (Johnson, Thomas and Bass, 2010). 2. C. They do not need to contract. Explanation of wrong answer: They never relax. In actual sense, atria are the upper chambers of the heart. They are the ones that receive blood from the body. They contract a little to force blood out into the ventricles so they do relax after the contraction. Explanation for the correct answer: They do not need to contract. This is so because there are valves which hold blood in them and prevent it from flowing into the ventricles. This builds up pressure which is enough to make blood flow into the ventricles once the valves open (Johnson, Thomas and Bass, 2010). 3. D. Superior, Inferior venacavae and coronary sinus. Explanation of the incorrect answer: Superior vena cava. It is a vein that carries deoxygenated blood to the right atrium. It has a wide diameter and is of short length. Explanation for the correct answer: The inferior, superior venacavae and coronary sinus. The inferior and superior venacavae are both large veins that return blood that is low in oxygen to the heart via the right atrium. The coronary sinus returns blood that is low in oxygen from the walls of the heart into the right atrium (Johnson, Thomas and Bass, 2010). 5. D. The right atrium receives deoxygenated blood while the left receives oxygenated blood. The right atrium receives deoxygenated blood from the body while the left atrium receives oxygenated blood from the lungs. Explanation of the incorrect answer: The right atrium does not receive oxygenated blood nor does the left receive deoxygenated blood (Johnson, Thomas and Bass, 2010). 6. C. They must contract to pump blood. This is because they pump blood out of the heart and into vessels that take blood to the lungs and the rest of the body. This requires pressure which is achieved through contracting. Explanation of the incorrect answer: They never contract is incorrect as they contract and relax with the help of the ventricular walls lining them (Johnson, Thomas and Bass, 2010). 7. D. They prevent back flow into the atrium. When the muscles of the ventricles contract to push blood out of the heart and into the vessels, the atrioventricular valves close to prevent blood from flowing back into the atrium. Explanation of the incorrect answer: Prevent leakage in the heart. The walls of lining the heart are the ones that prevent leakage. The valves control blood flow (Johnson, Thomas and Bass, 2010). 8. A. It is pumped into the coronary circuit by the left ventricle. Blood rich in oxygen is pumped into the aorta from the left ventricle. It is at this point that it enters the left and right major coronary arteries. Explanation for the incorrect answer: It is pumped into the coronary circuit by the right ventricle. Actually the right ventricle pumps deoxygenated blood, so it would not be source entry of blood into the coronary circuit (Johnson, Thomas and Bass, 2010). 9. A. Systole. It is in this phase that pressure is at its highest in the arteries as a result of the contraction of the ventricles. Explanation of the incorrect answer: S- phase is part f the cell cycle (Johnson, Thomas and Bass, 2010). 10. D. Both ventricles then both atria, the ventricles contract pumping blood into the arteries, and then the atria contract pumping blood into the ventricles. Explanation of the incorrect answer: right atrium, right ventricle, left atrium, left ventricle, it does not occur this way as the cardiac cycle occurs in two stages where there is contraction and relaxation (Johnson, Thomas and Bass, 2010). 11. A. Sino – atrial node. The sino – artrial node is a small group of cells positioned in the right atrium. It sends electrical impulses that spread through the atria walls causing contraction and blood flow into the ventricles. It sets the rhythm and rate of the heartbeat. Explanation of the incorrect answer: ventricular systole. During the ventricular systole, the cardiac ventricles contract pumping blood into the pulmonary artery and aorta (Johnson, Thomas and Bass, 2010). 12. C. It slows down and then returns to normal. This is because the atrioventricular node functions as a gate. It slows down the electrical impulse before it goes to the ventricles. Explanation of the incorrect answer: it is faster, the atrioventricular node does not make the heart rate faster (Johnson, Thomas and Bass, 2010). 13. A. The bundle of His, it is a connection of fibers which sends impulses to the walls of the ventricles and through the heart. Explanation of the incorrect answer: AV and SA node. They both work in coordination to transmit electrical impulses that are spread throughout the heart by the bundle of his (Johnson, Thomas and Bass, 2010). 14. B. Ventricular systole, it involves the contraction of the walls of the ventricles. It causes an increase in pressure in the ventricles. It is the beginning of the heart pulse. Explanation of the incorrect answer: ventricular diastole is the time when the ventricles are in the relaxation phase (Johnson, Thomas and Bass, 2010). 15. D. Ventricular diastole. This is the time when the ventricles are relaxing and recovering. It is represented by the T wave. Explanation of the incorrect answer: atrial systole: in this phase there is contraction of the atrium pumping a small quantity of blood into the ventricles (Johnson, Thomas and Bass, 2010). 17. D. Ectopic focus: It normally takes over when the sinoatrial node fails. It is a bundle of cells that is excitable. If the sino – atrial node is functioning, it usually generates premature beats of the heart. Explanation of the incorrect answer: secondary focus is not applicable in this case (Johnson, Thomas and Bass, 2010). 18. B. Closing of the semilunar valves, this sound, S2 is normally described as the “dub.” It is as a result of the two valves, pulmonary aortic valve, closing to prevent flow of blood backwards. Explanation of the incorrect answer: atrial contraction, atrial contraction causes the heart sound known as S4. The sound is as a result of ventricukar wall vibration as the atrial contracts (Johnson, Thomas and Bass, 2010). 19. D. Atrial contraction, the fourth heart sound, S4, is as a result of atrial contraction. Atrial contraction is as a result of the ventricular wall vibrating. It is normally observed during reduction of the ventricle compliance. Explanation of the wrong answer: turbulent flow into ventricles: On arterial contraction, the walls of the ventricles stiffen these results in an unusual turbulent flow due to the contraction of the atria which forces blood into the ventricles (Johnson, Thomas and Bass, 2010). 20. A. End diastolic volume, it is the quantity of the blood that is in the ventricle just before the systole and just after the ventricular diastole. Explanation of the incorrect answer: cardiac output, it is the blood volume pumped out of the heart/minute. It equals to the multiplication of the beats/minute and the stroke volume. 21. D. Stroke volume, it is the blood volume that is pumped from the ventricles per heart beat. It usually determines the cardiac output. Explanation of the incorrect answer: end diastolic volume is the blood volume that is in the ventricle when systole ends and at the start of diastole (Johnson, Thomas and Bass, 2010). 22. D. Cardiac output, it is the blood volume that is pumped by the ventricles per minute. In short, it is the volume pumped out of the heart per minute. Explanation of the incorrect answer: end systolic volume, it is the blood volume that is in the ventricle when systole ends and diastole starts. It represents the lowest blood volume that can be found in the ventricle (Johnson, Thomas and Bass, 2010). 23. B. It decreases. This is the formula for cardiac output. If the heart rate is decreased, then the multiplying factor shall be small. This means that the cardiac output given by the equation shall decrease. Explanation of the incorrect answer: Increases, it cannot increase if the heart rate decreases (Johnson, Thomas and Bass, 2010). 25. C. Arterioles and venules, the capillary beds are composed of numerous capillaries that deliver blood to certain body organs. The capillary beds connect venules and arterioles taking away deoxygenated blood and delivering oxygen rich blood to the organ. Explanation of the incorrect answer: arterioles and arteries, the arteries from the heart branch into small arteries which branch into smaller arteries known as arterioles (Johnson, Thomas and Bass, 2010). 26. B. To aid the skeletal muscle pump in returning blood up the lower extremity. This ensures that blood flows only in one direction back to the heart. Explanation of the incorrect answer: regulate blood pressure; regulation of the blood pressure is a collective function of various body organs including the brain (Johnson, Thomas and Bass, 2010). 27. B. Thrombophlebitis. It is caused by a blood clot. It is shown by inflammation of the veins and acute pain in the body part affected. Explanation of the incorrect answer: venous embolism. Defining an embolus, it is a clot that has broken away from the area of origin and moves through the vessel until it reaches a vessel where it is too big to pass through the vessel. In this case, it occurs in the vein hence venous embolism (Johnson, Thomas and Bass, 2010). 30. A. Increase. Sympathetic stimulation of the heart results in an increased heart rate and force of contraction of the heart. This in turn causes an increase in the pressure of blood flowing through the arteries hence increase in blood pressure. Explanation of the incorrect answer: Decrease, decrease in the heart rate is caused by parasympathetic stimulation which causes decrease in blood pressure (Johnson, Thomas and Bass, 2010). 31. B. Decrease. In normal cases, the function of ADH is to maintain water in the body. So when it is reduced in concentration, the amount of water retained in the body is minimal, this results in reduced blood pressure. Explanation of the incorrect answer: remain the same, if the concentration of ADH changes, then the amount of water retained in the body also changes so it cannot remain the same (Johnson, Thomas and Bass, 2010). 33. B. Decrease. Blood pressure is reduced as the blood flow through increased number of vessels. Explanation of the incorrect answer: increase, increase is as a result of reduced number of vessels to flow through (Johnson, Thomas and Bass, 2010). 34. Increase. The blood pressure increases as the vascular walls harden as a result of building up of plaque on the vascular walls. This causes narrowing of the blood vessels which increases the blood pressure. Explanation of the incorrect answer: decrease, decrease in blood pressure in association with the vascular walls occurs if they are smooth and thin (Johnson, Thomas and Bass, 2010). 36. A. He would need to increase the number. This is because the femoral artery is a large artery and blood pressure reduces as the size of the vessel increases. Explanation of the incorrect answer: he would need to decrease the number; this would result in lower blood pressure than normal as the blood pressure is already low (Johnson, Thomas and Bass, 2010). 37. A. There are few symptoms until damage is done. This because the blood vessels and the heart are able to keep up with the high blood pressure for a long time until the heart becomes large and weak to an extent of failure. Usually injury occurs to the blood vessels and body organs. Explanation of the incorrect answer: there are never any symptoms; the symptoms are normally there but not easily recognizable (Johnson, Thomas and Bass, 2010). 38. A. Closing of the AV valves, this sound is as a result of the immediate blocking of blood flow back into the atria by the AV valves. The AV valves consist of bicuspid and tricuspid valves. It occurs as systole is beginning. Explanation of the incorrect answer: atrial contraction: it is when there is contraction by the atrium forcing blood into the ventricles (Johnson, Thomas and Bass, 2010). 39. B. It decreases. If end diastolic volume reduces, then the stroke volume shall reduce. End diastolic volume is normally the volume of blood that is in ventricles just before the start of the ventricular systole. Explanation of the incorrect answer: Stays the same, it cannot stay the same as the equation is a computation involving subtraction from the end diastolic volume (Johnson, Thomas and Bass, 2010). 40. B. End systolic volume, this is the quantity of blood in the ventricles just after the ventricular systole. Explanation of the incorrect answer: stroke volume, stroke volume is determined by the subtraction of end systolic volume from the end diastolic volume (Johnson, Thomas and Bass, 2010). 41: Essay. Blood flow. Blood flows into the heart from the superior and inferior venacava delivering deoxygenated blood into the right atrium. Meanwhile, the pulmonary vein delivers oxygenated blood into the left atrium from the lungs. The tricuspid valve opens and blood flows into the right ventricle from the right atrium. The valve then shuts to hinder backflow of blood when the ventricle is full and the ventricular walls are contracting. Meanwhile on the left side, blood flows into the left ventricle from the left atrium through the biscuspid valve. The bicuspid valve also closes to hinder backflow of blood back into the atrium once the left ventricular walls begin contraction to push blood out of the heart. On the right side, blood is pumped out through the pulmonic valve to the pulmonary artery flowing for the lungs. Meanwhile, on the left side, blood is pumped out through the aortic valve to the aorta flowing for the body system (Johnson, Thomas and Bass, 2010). Works Cited Johnson, Robert, Alan Thoma and Paul Bass. The Cardiovascular Ssytem. 2nd ed. Churchill Livingstone Elsevier. Print. Olubummo, Adeyemi. Human Anatomy and Physiology. iUniverse, 2010. Print. Read More