BISC306 Test 2 Review
Place the structures in order according to the path of blood circulation through the heart.
Systemic venous circulation 1. venae cavae 2. right atrium 3. right ventricle 4. pulmonary artery 5. lungs 6. pulmonary vein 7. left atrium 8. left ventricle 9. aorta Systemic arterial circulation
Which of the following statements regarding the cardiac cycle is correct?
The atrioventricular valves are open during mid-to-late diastole
When do the first and second heart sounds occur, in relation to an ECG?
The first heart sound occurs right after the R wave, and the second heart sound occurs right after the T wave
Which statement accurately describes the mechanism of the length-tension relationship? - The muscle generates the greatest amount of tension when it is stretched, because the thin filaments have the longest distance to travel. - The muscle generates the greatest amount of tension when it begins its contraction from resting length, because the thin filaments do not have very far to travel. - The muscle generates the greatest amount of tension when it begins its contraction from resting length, because the thin filaments can travel a great distance. - The muscle generates the greatest amount of tension when it is shortened, because the thin filaments do not have very far to travel
The muscle generates the greatest amount of tension when it begins its contraction from resting length, because the thin filaments can travel a great distance.
The circulatory system of mammals is arranged in two separate circuits, the pulmonary circuit, and the systemic circuit. In this double circulation system, blood is pumped through the heart twice. Identify the route of blood transport in the pulmonary circuit and the systemic circuit. - The pulmonary circuit transports blood to and from the body, and the systemic circuit transports blood to and from the lungs - The pulmonary circuit transports blood to and from the lungs, and the systemic circuit transports blood to and from the kidneys - The pulmonary circuit transports blood to and from the lungs, and the systemic circuit transports blood to and from the body - The pulmonary circuit transports blood to and from the brain, and the systemic circuit transports blood to and from the body
The pulmonary circuit transports blood to and from the lungs, and the systemic circuit transports blood to and from the body
Considering the structure and function of the human heart, why are the walls of the ventricles much thicker than the walls of the atria? - Ventricles are more susceptible to myocarditis, or inflammation of the myocardium, which leads to the thickening of the walls over time - Because the ventricles are larger chambers, they have more fat lining the walls to provide insulation and structural support. - The atria expel blood over a greater distance and therefore have a lesser pericardium layer for superior flexibility in contraction. - The ventricles expel blood over a greater distance and therefore have a larger myocardium layer for increased strength. - The ventricle walls contain more nervous tissue in the form of the sinoatrial node, which acts as the pacemaker of the heart
The ventricles expel blood over a greater distance and therefore have a larger myocardium layer for increased strength.
What is the function of heart valves? - Valves allow ions to pass between cardiomyocytes - Valves ensure that blood moves in one direction through the heart - Valves separate oxygenated blood from deoxygenated blood - Valves contain receptors that detect and maintain blood pressure
Valves ensure that blood moves in one direction through the heart
With regard to normal muscle physiology, what is complete tetanus? - maintenance of low-level muscle contractions - a continuous, fused contraction of the muscle - the result of fewer calcium ions in the sarcoplasm - a single, isolated muscle contraction
a continuous, fused contraction of the muscle
Which change is associated with an increase in vagal stimulation of the heart? - an increase in cardiac output - an increase in heart contractility - a decrease in heart rate - a decrease in parasympathetic tone
a decrease in heart rate
What is heart block? - a coronary artery blockage due to fatty deposits - a blood clot in the heart - a disrupted signal transmission in the heart - a series of rapid and irregular heart contractions
a disrupted signal transmission in the heart
Select the description of a neuromuscular junction. - a site where a motor neuron meets a muscle fiber - a site where muscle fibers meet to form a tendon - a site where one neuron transmits a signal to another neuron - a site a sensory neuron meets the epidermis of the skin
a site where a motor neuron meets a muscle fiber
What is a capacitance vessel? - a vessel that is highly elastic, which tolerates large changes in blood pressure - a vessel that is fenestrated, which allows the quick diffusion of nutrients out of blood - a vessel that is distensible, which accommodates a large percentage of blood volume - a vessel that is contractile, which propels and distributes blood to peripheral tissue
a vessel that is distensible, which accommodates a large percentage of blood volume
Extensibility
ability to lengthen and stretch
Elasticity
ability to regain shape after stretching or constricting
Excitability
ability to respond to a stimulus
Contractility
ability to shorten and generate force
Which enzyme is responsible for degrading the neurotransmitter that remains in the synaptic cleft after a muscle contraction? - glutamate decarboxylase - acetylcholinesterase - cysteine protease - alcohol dehydrogenase
acetylcholinesterase
What is bradycardia? - an abnormal stretching of the ventricles - a series of rapid, irregular heart contractions - an abnormally low heart rate - a heart rate above 100 beats per min
an abnormally low heart rate
What is hyperplasia? - a developmental abnormality involving changes in cell size, shape, and appearance - the reversible transformation of a differentiated cell type to another cell type - an increase in cell size within an organ or tissue - an increase in the number of normal cells within an organ or tissue
an increase in the number of normal cells within an organ or tissue
What is the Frank-Starling law of the heart? - a decrease in end diastolic volume results in an increase in stroke volume - an increase in heart rate results in an increase in stroke volume - an increase in ventricular filling results in an increase in stroke volume - end systolic volume minus end diastolic volume equals stroke volume
an increase in ventricular filling results in an increase in stroke volume
What causes the dicrotic notch in a graph of aortic pressure? - atria contracting - aortic valve closing - bicuspid valve closing - pulmonary valve closing
aortic valve closing
Ventricular contraction
begins just after the Q (of QRS)
Which of the following is greater? - blood pressure when parasympathetic stimulation to the heart increases - blood pressure when sympathetic stimulation to the heart increases
blood pressure when sympathetic stimulation to the heart increases
The plateau of the action potential in cardiac ventricular cells results from the opening of voltage-gated slow ______ channels in the plasma membrane of the cell.
calcium
In which region of the vasculature is blood flow velocity the slowest? - veins - superior vena cava - capillaries - pulmonary arteries - arterioles
capillaries
What is the term for a network of fine branching blood vessels that are found between arterioles and venules? - metarteriole - fenestrated capillaries - capillary bed - sinusoid
capillary bed
In an isotonic contraction, the muscle ________. - changes in length and moves the "load" - rapidly resynthesizes creatine phosphate and ATP - does not change in length but increases tension - the muscle does not tire as easily
changes in length and moves the "load"
What is atrophy? - programmed cell death - increased cell number - decreased cell size - increased cell size
decreased cell size
As blood moves from the arterial end to the venous end of a capillary, net filtration pressure:
decreases, as blood hydrostatic pressure decreases
Which microscopic structure is found in smooth muscle cells but not in skeletal muscle cells? - Z disc - dense body - sarcomere - myosin filament
dense body
When blood is centrifuged and its components separate, the bottom of the tube holds the:
erythrocytes
What is edema? - inflammation of tissues due to an infection - fluid loss from tissues due to dehydration - excess fluid buildup in a tissue compartment - excess cell growth in a tissue compartment
excess fluid buildup in a tissue compartment
The thin filament is an ATPase - true - false
false
Which of the following changes would most increase the resistance to blood flow in a blood vessel?
halving the diameter of the vessel
Which of the blood components is responsible for carrying the majority of oxygen found in blood? - prothrombin - hemoglobin - neutrophils - platelets
hemoglobin
Curare is an inhibitor of acetylcholine receptors at the motor end plate. This would result in - inability of the muscle fiber to respond to nervous stimulation - more acetylcholinesterase production - sustained contraction of the muscle - increased stimulation of the muscle - lack of calcium uptake by the muscle fiber
inability of the muscle fiber to respond to nervous stimulation
Which of the following is not a usual result of resistance exercise? - increase in the number of muscle cells - increase in the efficiency of the respiratory system - increase in the number of myofibrils within the muscle cells - increase in the efficiency of the circulatory system
increase in the number of muscle cells
If the pressure gradient in a blood vessel is increased while resistance remains unchanged, how is blood flow affected? - decreased - no change - cannot determine - increased
increased
Define cardiac arrhythmia - irregular contraction pattern of the heart - heart beating in sinus rhythm - abnormally slow heart rate - normal impulse conduction in the heart
irregular contraction pattern of the heart
The force per unit area that blood places on the inside wall of a blood vessel
is called the blood pressure
Events of excitation contraction coupling, such as the release of calcium from intracellular stores, occur during the _______ period of a muscle twitch. - latent - relaxation - contraction
latent
Choose the best definition of plasma. - endocrine hormones carried by the blood - liquid matrix of blood - blood proteins that aid in clotting - cells that carry oxygen-binding hemoglobin
liquid matrix of blood
Skeletal muscles are almost never completely relaxed. Even when a skeletal muscle is not fully contracting or moving, the nervous system automatically stimulates different groups of motor units, which creates a small degree of contraction. What is the name of this mechanism? - muscle tension - muscle tone - isometric contraction - concentric contraction
muscle tone
Which layer of the heart is responsible for making the heart beat? - pericardium - endocardium - epicardium - myocardium
myocardium
Muscle contraction is caused by - filaments lengthening of the sarcomere - actin filaments pulling on myosin filaments - the shortening of each myosin filament - myosin heads pulling actin filaments closer
myosin heads pulling actin filaments closer
Normally, the hydrostatic pressure difference between capillary fluid and interstitial fluid favors movement of fluid ________ the capillary. The osmotic pressure difference between capillary fluid and interstitial fluid favors movement of fluid ______ the capillary.
out of, into
Which of the structures regulates the flow of blood through capillary beds? - intercellular clefts - precapillary sphincters - arteriovenous anastomoses - varicose veins
precapillary sphincters
Capillary reabsorption is the movement of fluid from the interstitial space into the capillary lumen (into the blood plasma). What is the driving force for this inward movement? - pressure exerted by proteins suspended in interstitial fluid - force exerted by interstitial fluid on the outside of capillaries - force exerted by blood plasma on the capillary walls - pressure exerted by proteins suspended in blood plasma
pressure exerted by proteins suspended in blood plasma
The aortic valve
prevents the backflow of blood into the left ventricle during ventricular diastole
What is fibrillation? - faster-than-normal heart rate - premature contraction of the ventricles - rapid, uncoordinated contractions of cardiac muscle - blood regurgitation through the atrioventricular valve
rapid, uncoordinated contractions of cardiac muscle
How does visceral smooth muscle ultimately respond to stretch? - generating tension concentrically - relaxing - contracting - resisting the stretch
relaxing
Which fibers dominate many of the back and calf muscles that contract almost continually to maintain posture? - fast, glycolytic fibers - fast, oxidative fibers - slow, oxidative fibers - slow, glycolytic fibers
slow, oxidative fibers
Match a functional description to each component of thin filaments found in cardiac and skeletal muscle. - Actin - Tropomyosin - Troponin
- Actin: a structural protein that binds the thick filament during the cross-bridge cycle - Tropomyosin: a regulatory protein that blocks the thick filament binding sites - Troponin: a regulatory protein that binds calcium, causing a conformational change
Match each definition to the appropriate term. - Blood flow - Blood pressure - Resistance
- Blood flow: the volume of blood that passes through the body in a set amount of time - Blood pressure: the force blood exerts on blood vessel walls - Resistance: the force that opposes blood flow
Classify the given muscle properties as pertaining to cardiac, skeletal, or smooth muscle.
- Cardiac muscle: has striations and a moderately regular structure, is autorhythmic, is found in the heart - Skeletal muscle: has striations and a highly regular structure, must be stimulated by nerves, attaches bones to one another - Smooth muscle: has no striations, can be autorhythmic or activated by nerves, is found in the digestive tract
Which are characteristics of type O blood? (select all that apply) - Has anti-A antibodies - Has surface antigen B on its erythrocytes - Has anti-B antibodies - Has surface antigen A on its erythrocytes - Has surface antigen O on its erythrocytes
- Has anti-A antibodies - Has anti-B antibodies - Has surface antigen O on its erythrocytes
Match the descriptions with the appropriate kind of skeletal muscle contraction. - Isotonic - Isometric - Concentric - Eccentric
- Isotonic: peak muscle tension does not equal load, muscle length changes - Isometric: peak muscle tension never exceeds load, muscle length remains constant - Concentric: peak muscle tension exceeds load, muscle shortens - Eccentric: peak muscle tension less than load, muscle lengthens
Select the functions of blood - It produces hormones that coordinate body activities - It collects metabolic waste from the body - It delivers oxygen and nutrients to the body - It generates cholesterol to aid cell membrane production in the body
- It collects metabolic waste from the body - It delivers oxygen and nutrients to the body
Categorize each valve of the heart as being either atrioventricular or semilunar and left or right. - Mitral valve - Tricuspid valve - Aortic valve - Pulmonary valve
- Mitral valve: left, atrioventricular - Tricuspid valve: right, atrioventricular - Aortic valve: left, semilunar - Pulmonary valve: right, semilunar
Match each definition to the appropriate muscle component. - Muscle fiber - Myofibril - Myofilament
- Muscle fiber: an individual muscle cell - Myofibril: an organelle that contains sarcomeres - Myofilament: may contain either actin or myosin
Match each definition to the appropriate term. Nor all definitions will be used. - Preload - Afterload - Venous return
- Preload: extent of cardiac muscle cell stretch before a contraction - Afterload: amount of pressure a ventricle must produce to eject blood - Venous return: amount of blood returning to the heart Not used: - amount of blood in a ventricle during diastole
Classify statements as features of either the pulmonary circulation or the systemic circulation.
- Pulmonary circulation: relatively low blood pressure, arterial blood is deoxygenated, relatively high amount of CO2 in arterial blood - Systemic circulation: relatively high blood pressure, venous blood is deoxygenated, relatively high amount of CO2 in venous blood
Identify which chamber of the heart performs each function.
- Right atrium: receives oxygen-poor blood from body - Right ventricle: pumps oxygen-poor blood to lungs - Left atrium: receives oxygen-rich blood from lungs - Left ventricle: pumps oxygen-rich blood to body
Match each description to the appropriate microscopic feature of skeletal muscles: - Sarcoplasm - Sarcolemma - Sarcoplasmic reticulum
- Sarcoplasm: cytoplasm of muscle fiber - Sarcolemma: plasma membrane of muscle fiber - Sarcoplasmic reticulum: smooth endoplasmic reticulum of muscle fiber
Classify each of the structures as containing primarily smooth, skeletal, or cardiac muscles. - Smooth muscle - Skeletal muscle - Cardiac muscle
- Smooth muscle: vein, intestine - Skeletal muscle: forearm, thigh - Cardiac muscle: heart
Match each definition to the corresponding term. - Systolic pressure -Diastolic Pressure - Pulse pressure
- Systolic pressure: arterial blood pressure during contraction of the ventricles - Diastolic pressure: arterial blood pressure during relaxation of the ventricles - Pulse pressure: the difference in blood pressure between ventricular contraction and relaxation
Which statements describe the action potential in cardiomyocytes (heart muscle cells)? - The absolute refractory period can last for about 200 ms - Depolarization stimulates voltage-gated, slow calcium channels to open - Repolarization occurs immediately after the initial depolarization - Rapid sodium influx causes the membrane to rapidly depolarize
- The absolute refractory period can last for about 200 ms - Depolarization stimulates voltage-gated, slow calcium channels to open - Rapid sodium influx causes the membrane to rapidly depolarize
Which of the following defines vasodilation? - a decrease in the diameter of the lumen of a blood vessel, causing an increase in blood pressure - an increase in sympathetic stimulation that causes the smooth muscles of a blood vessel to relax - an increase in the diameter of the lumen of a blood vessel due to the relaxation of the muscles of the vessel walls - widening of a blood vessel lumen due to smooth muscle relaxation, causing an increase in blood pressure
- an increase in the diameter of the lumen of a blood vessel due to the relaxation of the muscles of the vessel walls
Select the statements that describe the anatomical location of the heart. - inferior to the diaphragm - inferior to the lungs - anterior to the vertebral column - superior to the diaphragm
- anterior to the vertebral column - superior to the diaphragm
Which characteristics pertain to mammalian red blood cells? - biconcave to increase surface area - lack nucleus - five major types - aid in clotting blood - generate ATP anaerobically
- biconcave to increase surface area - lack nucleus - generate ATP anaerobically
Muscle cells store only enough ATP to complete a few contractions. After using up the readily available ATP, muscle cells can form additional ATP from which of the choices? - creatine phosphate - cellular respiration - glycolysis - dephosphorylation - the Calvin cycle
- creatine phosphate - cellular respiration - glycolysis
What are the effects of the baroreceptor reflex? - decreased stroke volume - vasoconstriction - vasodilation - increased heart rate
- decreased stroke volume - vasodilation
Which statements describe intercalated discs? - intercalated discs prevent direct communication between cells - intercalated discs allow synchronized contraction of cardiac muscle cells - intercalated discs contain desmosomes - intercalated discs occur in smooth muscle - intercalated discs are found between cardiomyocytes
- intercalated discs allow synchronized contraction of cardiac muscle cells - intercalated discs contain desmosomes - intercalated discs are found between cardiomyocytes
Which of these problems can cause a heart murmur? - abnormally fast heart rate - malformed heart valve cusps - premature atrial contraction - defective papillary muscles
- malformed heart valve cusps - defective papillary muscles
Which statements are true of the arteriole and venule ends of a capillary bed? - fluid moves into the capillary bed at the arteriole end - osmotic pressure at the arteriole end and the venule end are equal - net filtration pressure is higher at the arterial end than it is at the venule end - fluid moves into the capillary bed at the venule end - osmotic pressure is higher at the venule end than it is at the arteriole end
- osmotic pressure at the arteriole end and the venule end are equal - net filtration pressure is higher at the arterial end than it is at the venule end - fluid moves into the capillary bed at the venule end
Which of the actions are functions of skeletal muscle? - regulating blood vessel diameter - producing movement - pumping blood through the heart - helping to stabilize joints
- producing movement - helping to stabilize joints
Select the descriptions that refer to the physical characteristics of blood. - salty and slightly metallic in taste - amounts to approximately 4-6 liters per person - slightly acidic - red in color when well oxygenated and blue after delivering oxygen to the tissues - bright red in color when well oxygenated and dark red after delivering oxygen to the tissues
- salty and slightly metallic in taste - amounts to approximately 4-6 liters per person - bright red in color when well oxygenated and dark red after delivering oxygen to the tissues
Classify each characteristic based on whether it describes slow oxidative, fast oxidative, or fast glycolytic muscle fibers. - slow oxidative fibers - fast oxidative fibers - fast glycolytic fibers
- slow oxidative fibers: primarily use oxygen to produce ATP and have a slow contraction speed, red, low glycogen and high myoglobin stores - fast oxidative fibers: red or pink, intermediate glycogen and high myoglobin stores, primarily use oxygen to produce ATP and have a fast contraction speed - fast glycolytic fibers: high glycogen and low myoglobin stores, primarily do not use oxygen to produce ATP and have a fast contraction speed, white
Categorize the exercises according to whether they utilize isotonic or isometric contractions. -Isotonic contraction - Isometric contraction
-Isotonic contraction: pull-up, deadlift - Isometric contraction: static lunge, plank position
Place the events of excitation-contraction coupling in the sequence they occur
1. An action potential is produced in the sarcolemma 2. The action potential enters the T Tubules 3. Calcium channels in the sarcoplasmic reticulum open 4. Calcium ions flow into the sarcoplasm 5. Calcium ions bind to troponin 6. Troponin changes shape 7. Tropomyosin moves 8. Active sites are exposed on the thin filament 9. The thin and thick filaments bind
Arrange the events that take place when a motor neuron's action potential triggers a muscle contraction in sequential order, from the top down.
1. The motor neuron's action potential arrives at the neuromuscular junction 2. Acetylcholine arrives at the muscle fiber's plasma membrane, which causes the membrane to depolarize 3. The transverse (T) tubules carry the action potential throughout the muscle fiber 4. The sarcoplasmic reticulum becomes more permeable in response to the action potential, causing a release of calcium ions. 5. When the tropomyosin shifts position as calcium ions bind to troponin, actin binding sites are exposed 6. Myosin cross-bridges attach to actin fibers 7. Sarcomeres within the muscle fibers contract
Put these phases of the cardiac cycle in the correct order
1. beginning of atrial systole 2. completion of ventricular filling 3. beginning of ventricular systole 4. closure of the AV valves 5. isovolumic contraction 6. opening of the semilunar valves 7. ventricular ejection 8. ventricular relaxation
What is a normal value for systolic pressure in a healthy adult? - 111 mmHg - 72 mmHg - 156 mmHg - 39 mmHg - 25 mmHg
111 mmHg
Suppose a vessel has a blood flow rate of 19 mL/min and the pressure in the vessel drops by 39 mmHg. What is the resistance in the vessel?
2.05 mmHg * min/mL
The tube represents a centrifuged sample of blood. Use the scale provided to estimate the hematocrit value.
20%
Calculate the cardiac reserve for someone whose resting heart rate (HR) is 65 bpm and resting stroke volume (SV) is 71 mL and whose maximal HR is 179 bpm and maximal SV is 183 mL.
28.142 L/min
Suppose that an athlete has a strove volume of 80.0 mL/beat and a heart rate of 50.0 beats/min. Calculate the athlete's cardiac output.
4 L/min
If someone's blood pressure were listed as 125/75 mmHg, then their pulse pressure would be: (in mmHg)
50
If someone's blood pressure were listed as 110/65 mmHg, then their mean arterial pressure (MAP) would be: (in mmHg)
80
Suppose a person's blood pressure is 122/77 mmHg. Calculate the mean arterial pressure (MAP) for this person.
92 mmHg
Which interval would not shrink during shortening of the muscle? - A Band - I band - H Zone
A Band
Suppose that a potential blood donor has type B+ blood. Classify the recipient's blood types as compatible or incompatible
Able to receive type B+ blood: - type B+ - type AB+ Unable to receive type B+: - type A+ - type O- - type B-
Indicate whether each characteristic describes arteries or veins.
Arteries - thick walls - high elasticity - transport oxygenated blood in systemic circulation Veins - transport deoxygenated blood in systemic circulation - one-way valves - walls with little elastic tissue - low elasticity
Indicate whether each characteristic describes arteries, veins, or capillaries.
Arteries - thick, elastic walls - transport oxygenated blood in systemic circulation Veins - transport deoxygenated blood in systemic circulation - one-way valves regulate blood flow - think, fibrous, and inelastic walls Capillaries - thin, permeable walls - sphincters regulate blood flow - exchange nutrients between blood and tissues
Why would calcium deficiency limit muscle contractions? - Calcium forms cross-bridges, which connect thick filaments to thin filaments during contraction - Calcium binds to the troponin-tropomyosin complex, exposing actin's myosin-binding sites - Calcium hydrolyzes ATP, releasing energy to pull the thin filaments past the thick filaments - Calcium is released from motor neurons, stimulating an action potential in the muscle fiber
Calcium binds to the troponin-tropomyosin complex, exposing actin's myosin-binding sites
There are four pressures that influence the bulk flow of fluid across capillary walls. Match each definition to the correct pressure.
Capillary hydrostatic pressure - the force of fluid in the blood pushing against the inner capillary wall Interstitial fluid hydrostatic pressure - the force of interstitial fluid pushing against the outer capillary wall Capillary colloid osmotic pressure - the force caused by large nondiffusible molecules in the blood Interstitial fluid colloid osmotic pressure - the force caused by large nondiffusible molecules in the interstitial fluid
Give the correct sequence of events following the depolarization of transverse tubules in excitation-contraction coupling in cardiac muscle?
Depolarization of Transverse Tubules 1. Calcium ion influx through sarcolemma 2. Calcium release into sarcoplasm 3. Actin and myosin attach 4. Thin myofilaments slide toward the middle of sarcomeres
Place the structures of the intrinsic conduction system in the order in which electrical impulses pass through them.
First 1. sinoatrial node 2. atrioventricular node 3. atrioventricular bundle 4. bundle branches 5. subendocardial conducting network (Purkinje fibers) Last
A list of some of the blood vessels of the systemic circuit is provided. Arrange them in order from highest to lowest blood pressure
Highest blood pressure 1. aorta 2. small arteries 3. arterioles 4. capillaries 5. venules 6. large veins 7. inferior vena cava Lowest blood pressure
Place the scenarios in order from the highest pressure to the lowest pressure.
Highest pressure 1. left ventricle during systole 2. right ventricle during systole 3. right atrium during systole 4. right ventricle during diastole Lowest pressure
Classify the factors based on whether they cause cardiac output to increase or decrease.
Increase - increased epinephrine levels - increased blood carbon dioxide levels - increased thyroid hormone levels - nicotine - sympathetic stimulation Decrease - beta blockers - increased blood oxygen levels - vagal stimulation - parasympathetic stimulation
Classify each factor according to whether it increases or decreases the resistance in a blood vessel.
Increases resistance - turbulent blood flow - a constricted blood vessel Decreases resistance - low blood viscosity - a shorter blood vessel
Which statement accurately describes the respiratory pump? - Inhalation constricts the thoracic veins, which increases venous return - Inhalation increases the thoracic cavity space, which increases the pressure - Inhalation increases pericardial pressure, which decreases venous return - Inhalation decreases thoracic pressure, which increases venous return
Inhalation decreases thoracic pressure, which increases venous return
Place the mechanical events of the cardiac cycle in order from the start of an initial atrial systole to the start of the next atrial systole.
Initial atrial systole 1. atrial ejection 2. start of atrial diastole and ventricular systole 3. isovolumetric contraction 4. ventricular ejection 5. start of ventricular diastole 6. isovolumetric relaxation Next atrial systole
One of the primary functions of blood is to transport carbon dioxide from the tissues to the lungs. Arrange the methods of transportation in order from the method that transports the largest amount of carbon dioxide to the method that transports the smallest amount of carbon dioxide.
Largest amount 1. dissolved as bicarbonate ions 2. bound to hemoglobin 3. dissolved as carbon dioxide Smallest amount
Place the events of a sinoatrial node cell generating a pacemaker potential in order. Start when the membrane potential is most negative (-60 mV), and end when the membrane potential becomes most negative again, immediately prior to the next pacemaker potential.
Membrane potential is -60 mV 1. Voltage-gated sodium channels open 2. The membrane slowly depolarizes 3. Voltage-gated calcium channels open 4. The membrane quickly depolarizes 5. Voltage-gated potassium channels open 6. The membrane repolarizes Membrane potential returns to -60 mV
Select the statement that describes recruitment in muscle contraction. - Neurotransmitters from the synaptic terminal of a motor neuron stimulate an action potential in the muscle fiber - The contraction of muscle fibers in one muscle stimulates the contraction of antagonistic muscles in a related muscle group - An increasing number of motor neurons are connected to the muscle fiber as a muscle grows and becomes stronger - More motor neurons and larger motor units are activated to stimulate a greater number of muscle fibers for a stronger muscle contraction
More motor neurons and larger motor units are activated to stimulate a greater number of muscle fibers for a stronger muscle contraction
Arrange the components of blood in order of relative abundance.
Most abundant 1. plasma 2. red blood cells 3. buffy coat Least abundant
Place the muscle fiber types in order from most fatigable to least fatigable.
Most fatigable - fast glycolytic fiber - fast oxidative fiber - slow oxidative fiber Least fatigable
Place the layers of the pericardium in order from the most superficial layer to the deepest layer.
Most superficial 1. fibrous pericardium 2. parietal serous pericardium 3. pericardial cavity 4. visceral serous pericardium Deepest
Which statement best describes the sliding filament model of contraction? - A bands binding to I bands through cross bridges causes thin filaments to slide past thick filaments - Tropomyosin binding to troponin through cross bridges causes thin filaments to slide past thick filaments - Myosin binding to actin through cross bridges causes thin filaments to slide past thick filaments - Myofibrils binding to sarcomeres through cross bridges causes thin filaments to slide past thick filaments
Myosin binding to actin through cross bridges causes thin filaments to slide past thick filaments
Give the formula for net filtration pressure: HP = hydrostatic pressure COP = colloid osmotic pressure b = blood if = interstitial fluid
NFP = (HPb - HPif) - (COPb - COPif)
Classify statements as features of either the pulmonary circulation or the systemic circulation.
Pulmonary circulation - relatively low blood pressure - arterial blood is deoxygenated - relatively low amount of CO2 in venous blood Systemic circulation - relatively high blood pressure - arterial blood is oxygenated - relatively high amount of CO2 in venous blood
Place the events of a cardiac action potential in order, starting with the resting state.
Resting state 1. Rapid depolarization occurs as sodium channels open 2. Repolarization begins as sodium channels close 3. Repolarization slows as calcium channels open 4. Rapid repolarization occurs as calcium channels close. Resting state
What is tachycardia? - tachycardia is an interruption of action potentials in the heart - tachycardia is a heart sound caused by a valvular stenosis - tachycardia is a resting heart rate of more than 100 beats per minute - tachycardia is a persistent, abnormally slow heart rate
tachycardia is a resting heart rate of more than 100 beats per minute
During which phase of the ECG is the ventricular pressure highest? - the P wave - the T wave - the Q-T interval - the QRS complex
the Q-T interval
Which statement most accurately describes hematocrit? - the volume of plasma in a blood sample - a blood disorder - the fraction of red blood cells in a blood sample - the molecule in red blood cells that transports oxygen
the fraction of red blood cells in a blood sample
If the membranes of the cardiac muscle cells in the SA node become more permeable to potassium ions,
the heart rate will decrease
The power stroke begins when - the inorganic phosphate and ADP are released from the myosin - the actin is attached to the myosin head - the actin is released by the myosin head - the ATP is hydrolyzed by the myosin head
the inorganic phosphate and ADP are released from the myosin
What is autoregulation? - a positive feedback system that amplifies a change to the normal state within a tissue or organ - the intrinsic ability of an organ or tissue to adjust blood flow according to its needs - the intrinsic regulatory mechanism of the body that controls hormone release - the ability of the body to regulate its internal conditions despite changes to the external conditions
the intrinsic ability of an organ or tissue to adjust blood flow according to its needs
Cardiac output is equal to
the product of heart rate and stroke volume
What is hematopoiesis (hemopoiesis)? - the storage of fat - the breakdown of red blood cells - the production of blood cells - the release of minerals from bone
the production of blood cells
What does autorhythmicity (automaticity) mean? - the irregular, uncoordinated contraction of cardiac muscle - the spread of a depolarization wave throughout cardiac muscle - the stability of the cell membrane potential of contractile cardiac muscle - the spontaneous, regular depolarization and contraction of cardiac muscle
the spontaneous, regular depolarization and contraction of cardiac muscle
What does autorhythmicity (automaticity) mean? - the spread of a depolarization wave throughout cardiac muscle - the irregular, uncoordinated contraction of cardiac muscle - the stability of the cell membrane potential of contractile cardiac muscle - the spontaneous, regular depolarization and contraction of cardiac muscle
the spontaneous, regular depolarization and contraction of cardiac muscle
Severe bleeding can decrease the body's blood pressure. What mechanism causes an increase in the body's blood pressure in response to an injury? - the sympathetic nervous system causes a widening of blood vessels. - the sympathetic nervous system causes vasoconstriction - the parasympathetic nervous system causes vasoconstriction - the parasympathetic nervous system causes a widening of blood vessels
the sympathetic nervous system causes vasoconstriction
Which structure prevents blood from flowing backward in veins? - valves - venules - the tunica externa - sinuses
valves
Which factor has the greatest influence on resistance to blood flow? - blood viscosity - blood pressure - vessel diameter - vessel length
vessel diameter
What causes the heart sounds? - impact of the walls of the heart against each other during a contraction - blood flow into the ventricles following opening of the atrioventricular valves - impact of the heart valve leaflets on each other after the leaflets close - vibrations due to turbulence in blood flow following the closure of heart valves
vibrations due to turbulence in blood flow following the closure of heart valves
In which situation would the stroke volume be the greatest?
when venous return is increased
Muscles used for delicate, finely controlled movements have smaller motor units than more coarsely controlled muscles. - false - true
true
Place the steps of smooth muscle contraction in order from contraction initiation to relaxation
1. Contraction initiation 2. Smooth muscle is stimulated by an autonomic motor neuron 3. Calcium ions enter the sarcoplasm 4. Calcium ions bind calmodulin 5. Myosin light chain kinase phosphorylates myosin. 6. Actin-myosin crossbridges form 7. Contraction cycles occur 8. Myosin light chain phosphatase dephosphorylates myosin 9. Relaxation Not used: - Calcium ions bind troponin - Smooth muscle is stimulated by a somatic motor neuron
How would a decrease in venous return alter stroke volume? - stroke volume changes only when venous return increases - venous return does not affect stroke volume - stroke volume increases - stroke volume decreases
stroke volume decreases
Atherosclerosis (fat build-up in artery walls, which narrows the arteries) involves a:
sustained increase in resistance that leads to increases in arterial pressure to maintain adequate blood flow
Suppose a heart has two chambers that are connected to one another. The blood pressure in chamber A is 50 mmHg, and the blood pressure in chamber B is 50 mmHg. There is no valve in this scenario. In which direction will blood flow? - from chamber B to chamber A - there is no way to know - from chamber A to chamber B - there is no net blood movement
there is no net blood movement
What is the function of elastic arteries? - to constrict and aid in the regulation of blood flow to specific tissues - to act as a reservoir for blood returning to the heart from the capillaries - to connect muscular arteries to capillary beds and maintain capillary pressure - to help maintain relatively constant blood pressure as the heart beats
to help maintain relatively constant blood pressure as the heart beats
What is the function of arterioles? - to collect blood from capillary beds and feed into venous return - to receive blood from the heart as it is pumped out of the ventricles - to regulate blood flow to capillaries - to provide a large surface area for the diffusion of substances
to regulate blood flow to capillaries
Cardiac muscle cannot undergo tetanus because its absolute refractory period lasts almost as long as the muscle twitch. - true - false
true