BIO 256 Exam 3 (100 out of 100) Chamberlain (Questions and Answers ) Already GRADED A.

BIO 256 Exam 3 (100 out of 100) Chamberlain (Questions and Answers ) Already GRADED A. An elaborate network of membranes in skeletal muscle cells that function in calcium storage is the _____ -sarcoplasmic reticulum The muscle cell plasma membrane is called a _____ -sarcolemma A motor neuron and the myofibers it innervates is known as a _____ -motor unit Muscle tone is _____ -a state of sustained partial contraction of muscles In an isotonic contraction, muscles _____ -stay the same length Which of the following periods is when a muscle is temporarily unable to respond to stimuli? -refractory period Glucose delivered to a recovering myofiber is used to _____ -reestablish glycogen stores Which of the following is a protective function of blood? -prevention of blood loss Oxygen is transported by red blood cells, it is carried by _____ -attaching to the iron ion in heme The process of forming new red blood cells is called _____ -erythropoiesis When red blood cells wear out, the iron hemoglobin is saved and recycled. The remainder of the heme is _____ -excreted as bile pigments (bilirubin) Which of the following is characteristics of all leukocytes? -they are nucleated A person with chronic leukemia is _____ likely to suffer a bacterial infection in/on their body more If cardiac muscle is deprived of its normal blood supply, damage would primarily result from _____ -lack of oxygen in myofibers Which component of the intrinsic autorhythmicity system of the heart functions to assure that the ventricles contract after the atria? -atrioventricular node Initiation of a normal heart beat is the responsibility of the _____ -sinoatrial node Input from the sympathetic nervous system causes the heart rate to _____ -increase Which component of an electrocardiogram indicates electrical activity associated with ventricular depolarization? -QRS complex Heart sounds other than those caused by closing of valves are called _____ -murmurs During the period of ventricular filing, _____ -blood flows from the atria and through the open atrioventricular valves Select the correct statement about cardiac output -a slow heart rate increases and diastolic volume, stroke volume, and force of contraction Negative chronotropic factors are _____ -factors that decrease heart rate Angina pectoris is _____ -pain accompanying myocardial ischemia The lymphatic vessels _____ return fluid escaping the circulatory system to veins above the heart Which is the best definition of blood pressure? -force per unit area exerted on the wall of a blood vessel When you go from sitting or lying down to standing too quickly, you feel dizzy. The drop in blood pressure stimulates vasoconstriction and increases heart rate to compensate. This is called _____ -baroreceptor reflex Which of the following blood pressure readings would be indicative of hyperextension? -170/80 in a 50-year-old man Which is NOT a possible result of chronic hypertensions? -obesity The velocity of blood flow _____ -is slowest in the capillaries because the total cross-sectional area is the greatest If capillary hydrostatic pressure equals 30 mmHg, capillary colloid osmotic pressure equals 26 mmHg, interstitial fluid osmotic pressure equals 5 mmHg, and interstitial hydrostatic pressure equals 2 mmHG, the net filtration pressure with be _____ - +7 mmHG On an EKG, the _____ wave represents atrial depolarization, while the _____ wave represents ventricular depolarization P, QRS Gas exchange occurs in _____ -capillaries Each muscle fiber is stimulated by a nerve ending known as a _____ -motor end plate A motor unit is _____ -a motor neuron and myofibers it stimulates The neurotransmitter used at a motor end plate is _____ -acetylcholine A motor neuron and the myofibers it innervate is known a _____ -motor unit Which blood protein(s) regulates osmotic pressure, pulling water into the blood? -albumin The function of hemoglobin is to _____ -carry oxygen Which of the following is NOT required for erythropoiesis? -production of vacuoles If a person has hepatitis, the liver may not convert bile pigments normally or transport them appropriately to the gall bladder. Thus, pigments accumulate in the blood; this is called jaundice. Which bile pigment would you expect to be in highest concentration in the blood of a person with this condition? -bilirubin All of the following can be expected with polycythemia except _____ -low blood viscosity Which of the following is a precursor of a basophil? -myeloblast Damage to the _____ is referred to as heart block -atrioventricular node The second heart sound (dub of lub-dub) is caused by the _____ -closure of the semilunar valves During the period of ventricular filling, _____ -blood flows from the atria and through the open atrioventricular valves The Frank-Starling law of the heart states that the heart contracts less forcefully when it fills with more blood -false Which of the following does NOT influence heart rate? -skin color Which blood vessels play the most important role for local regulation of capillary blood pressure? -arterioles Select the correct statement about factors that influence blood pressure -excess red cell production would cause a blood pressure increase The influence of blood vessel diameter on peripheral resistance is _____ -significant because resistance goes up when the diameter goes down Which is NOT a vital sign used to assess the cardiovascular system? -serum cholesterol Heguy became excited when he saw Shegal, so he developed _____. However, Shegal found Heguy boring, so she developed _____ -tachycardia, bradycardia Smooth muscle is significantly different from striated muscle in several ways. Which of the following is true? -smooth muscle can shorten and stretch more than striated muscle The normal neutrophil percentage of white blood cells is _____ -above 50% Cardiac ischemia can result in _____ -a myocardial infarction Which provides a positive chronotropic effect on the heart? -norepinephrine The effect of endurance-type athletic training may be to lower the resting heart rate. This phenomenon _____ -is caused by hypertrophy of the heart muscle Which is NOT directly involved in maintaining your blood pressure? -the thymus Which will increase blood pressure? -antidiuretic hormone Blood pressure peaks each day (assuming awakening in the morning, and going to sleep at night) -in the morning Cerebral blood flow is regulated by _____ -intrinsic autoregulatory mechanisms Select the correct statement about the movement of materials at the capillary level -carbon dioxide moves from its production site into the interstitial fluids and capillaries Which of the following are composed of myosin? -thick filaments Each muscle fiber is stimulated by a nerve ending known as a(n) -motor end plate After nervous stimulation of the muscle cell has ceased, the acetylcholine _____ -is destroyed by acetyl choline esterase Rigor mortis occurs because _____ -ATP required to detach myosin from actin molecules is depleted The number of muscle fibers in a contracted state in an otherwise relaxed muscle is known as its _____ -muscle tone In an isometric contraction, muscles _____ -stay the same length The buffy coat of centrifuged blood consists mainly of _____ -white blood cells and platelets Which of the following is a precursor of a monocyte? -monoblast The most abundant human leukocytes are the _____ -neutrophils Acute leukemia is more common in _____ persons; chronic leukemia is more common in _____ persons -younger, older During a normal cardiac cycle, the atria contract when they are directly stimulated by the _____ -sinoatrial node The time from when the ventricular contractile myofibers are depolarized until they depolarize is represented by the _____ S~T segment Normal heart sounds are caused by which of the following events? -closure of the heart valves The dicrotic notch refers to the _____ -brief rise in aortic pressure caused by backflow of blood rebounding off the aortic semilunar valve An increase in venous return most directly affects _____ -stroke volume Normal cardiac out is about _____ L/min -5.2 Angine pectoris is _____ -pain accompanying myocardial ischemia Which is NOT a possible result of chronic hypertension? -obesity Which of the following is likely during vigorous exercise? -capillaries of the active muscles will be engorged with blood Which ion is NOT directly involved in a muscle action potential? -Cl` A muscle cell undergoing tripe is exhibiting _____ summation -temporal In muscle action potential, the wave of positive mV charge travels through the _____ to the sarcoplasm from the sarcolemma -t tubules The warm up period required of athletes in order to bring their muscles to peak performance is called _____ -treppe A motor neuron and the myofibers it innervates is known as a(n) _____ -motor unit Immediately following the arrival of the stimulus at a skeletal muscle cell there is a short period called the _____ period during which calcium ions are released from the terminal cisterae -latent Oxygen is stored in myofibers on/in _____ -myoglobin Which of the following is true about blood plasma? -it is about 90% water What organ in the body regulates erythrocyte production? -kidney When erythrocytes are worn and tattered, the some of the hemoglobin molecule is recycled. Transferrin assists in this by _____ -transferring the iron to the red bone marrow where it can be reused Which would be associated with prematurely ruptured erythrocytes? -hemolytic anemia Which of the following is a precursor of a lymphocyte? -lymphoblast Cancer of the lymphoblasts developing quickly in a young child would be called _____ -acute lymphocytic leukemia The cardiac muscle contraction occurs when _____ -Ca++ enters the myofibers through slow channels The effect of endurance type athletic training may be to lower the resting heart rate. This phenomenon _____ -is caused by hypertrophy of the heart muscle When you go from sitting or lying down to standing too quickly, you feel dizzy. The drop in blood pressure stimulates vasoconstriction and increased heart rate to compensate. This is called the _____ -baroreceptor reflex Hemorrhage with a large loss of blood causes _____ -a lowering of blood pressure due to change in cardiac output Which of the following blood pressure readings would be indicative of hypertension? -170/80 in a 50 year old man Acute hypotension may be the result of _____