BIOL 251 1st EditionExam # 1 Study Guide Lectures: 11-17-Muscles respond to electrical signals to convert ___chemical________ energy into mechanical energy that can act on the environment. There are three types of muscle; the type that is striated and controlled by the autonomic nervous system is called ___cardiac_________ muscle. -How many motor neurons innervate a single skeletal muscle fiber?oOne -A single skeletal muscle is composed of many muscle fibers; each muscle fiber is composed of many __myofibrils__________, which in turn is composed primarily of _thick_________ filaments and ___thin________ filaments. -One source of ATP for muscle contraction is oxidative phosphorylation; what are the other 2 sources of ATP for muscle contraction?oglycolysis and creatine phosphate -The time between the initiation of the action potential and the onset of contraction in a skeletal muscle is called the _latent______________ period. -Which two skeletal muscle fiber types are able to interconvert over time, given proper trainingoFast oxidative and fast glycolytic -Identify whether the following structures or events occur in skeletal muscle, smooth muscle, or both.oCa++ activates contraction ____both________________otroponin ___skeletal______________________omuscle fiber extends full length of muscle cell ___skeletal_________________ouse ATP for contraction __both_________________ -In smooth muscle Ca++ binds to _calmodulin____________ to initiate contractions. -When an action potential reaches a contractile cardiac cell, __Na+_______rushes into the cell, causing a rapid depolarization. When the membrane potential reaches about 30 mV, __Ca++___ slowly enters the cell, which, in combination with the inactivation of __K+____ channels, cause a plateau phase in the action potential. -Which electrical events in the heart cause the following parts of an ECG?oP wave __atrial depolarization___________________oQRS complex__ventricular depolarization__________________-During the ST interval in a normal ECG, the ventricles are in _systole________; at this time, atrialpressure is _less________ than ventricular pressure, so the AV valves are __closed______________. -Calculate the stroke volume of a person with a heart rate of 60 beats per minute and a cardiac output of 4800 mls per min (include units in your answer).o80 mls/beat -The parasympathetic system tends to decrease heart rate by decreasing ___heart rate_____ andby increasing _AV nodal delay_____ . -Identify whether the following factors need to be minimized or maximized for the most effective capillary exchange:osurface area __max_____________odiffusion distance _min_______________otime for exchange ____max_____________ -Bulk flow is most important for odistributing ECF between plasma and interstial fluid -90% of your blood plasma is composed of ___water___________. -Name one plasma protein __ albumin, globulins, or fibrinogen ______________ -The packed cell volume after blood has been centrifuged is called ___hematocrit___. -If the radius of a blood vessel is doubled, how will the flow rate change, and by how much?oincrease by a factor of 16 -What is a motor unit?oA motor neuron and all the muscle fibers it innervates -Place the sequence of a skeletal muscle contraction in order: 1. Ca++ binds to troponin2. End plate potential becomes action potential on surface of membrane3. Tropomyosin moves aside4. Actin binds to myosin5. Action potential moves into t tubules 6. Ca++ released from SR 7. Cross bridge cycling occurs 8. Ca++ pumped into SR-2, 5, 6, 1, 3, 4, 7, 8 -Which of the following does NOT occur during the oxygen debt recovery from exercise A. Production of ATP from creatine phosphateA. Replenishment of glycogen storesB. Metabolism of lactic acidC. Recovery from high levels of epi D. Recovery from elevated chemical reactions -The binding of what molecule causes thick filaments to release thin filaments in skeletal muscle?oATP -In smooth muscle, calcium activates what molecule to initiate muscle contraction?oCalmodulin -Which type(s) of muscle have z lines oSkeletal, cardiac contractile, cardiac autorhythmic -What type of muscle can generate action potentials myogenically oSingle unit smooth, cardiac autorhythmic -In an ECG, the P wave is caused by "blank", the QRS complex is caused by "blank" and the T waveis caused by "blank"oAtrial depolarization, ventricular depolarization, ventricular repolarization -End diastolic volume is 150 ml/beat, end systolic volume is 80 ml/beat, and heart rate is 70 beats/min. What is cardiac output?o4900 -During the ST interval, why is the aortic valve open?oBecause pressure is higher in the ventricle than in the aorta -Blood is flowing from the ventricle into the aorta during oThe S-T interval -Diffusion in the capillaries is facilitated by oThin capillary walls -The most important function of the lymph system is oTo return cardiovascular system excess fluid filtered out of capillaries -Red blood cells contain