| Question | Answer |
|---|
| Cardiac output = heart rate x ______ _______, which is based on the ______ of contraction. | |
| Cardiac output can only increase if ______ ______ also increases. | |
| An increase in the rate of force development can also be called an increase in __________, which depends on intracellular _______ concentration. | |
| Mechanisms for changing force of contraction are classified extrinsic or intrinsic, or __________ and __________. | |
| Which type of mechanism is always intrinsic? This mechanism changes the ________ of the contraction and total force developed, but not contractility. | |
| Are neural influences intrinsic or extrinsic? | |
| The cardiac excitation-contraction coupling mechanism: the cardiac action potential leads to the opening of __-type Ca channels and __-tubules during plateau. | |
| The small entry of extracellular Ca leads to a large Ca-induced Ca release from the ___________ _________, via the _________ receptor. | |
| The released Ca diffuses to contractile proteins and binds to ________ on thin filaments, leading to unmasking of ______-_______ cross-bridge sites, leading to contraction. | |
| Ca is taken back into the SR producing relaxation by an enzyme, SERCA. What does SERCA stand for? | |
| Ca is then pumped from the SR to extracellular space in diastole to keep balance in the process, mostly by the __-Ca exchanger, and some by membrane Ca-ATPase. | |
| Inotropic mechanism: increased intracellular Ca leads to more released from SR for excitation-contraction coupling, so more cross bridges can be formed, _______ contraction force. | |
| Sympathetic control can be an ________ influence on the heart, and produce a(n) ________ in contractility of the ventricles. | |
| Noradrenaline binds to a _____-1 receptor on the ventricular cell membrane, activating ______ _______ which converts intracellular ATP into _______ (the second messenger). | |
| The second messenger activates ______ _____ __ which phosphorylates _____-dependent Ca channels, _________ the time they spend in open state. | |
| Longer opening time leads to increased permeability, which allows more Ca to enter the cell during the ______ phase of the cardiac AP. | |
| Rate-induced regulation: lower heart rate leads to shorter diastole, so ____ Ca is pumped to the EC space and intracellular Ca _______. | |
| True/false - the vagus nerve cannot influence the force of contraction. | |
| Increased venous return leads to increased filling of the ventricle, which ______ the force of contraction. Does the contractility change? (Yes/No) | |
| Increased arterial pressure leads to an initial drop in _____ _______, which then ________ end-systolic and end-diastolic volume, leading to an increase in force of contraction. | |
| For striated muscle, there is an optimum length. If it is too long, there is an _______ of actin and myosin, while if it is too short then there is _______ of filaments. | |
| Cardiac muscle is normally at (below/around/above) optimum length, while skeletal muscle is at (below/around/above) optimum length. | |
| The cardiac function curve is a graphical representation of cardiac _____ __ _________ against ______ of ventricular muscle. | |
| Usually the y-axis is ______ ______ or stroke volume, while the x-axis is ______ ______ ________. | |
| A ___________ change leads to a shift in the curve while a __________ change means the heart operates at a new location on the curve (movement along the curve). | |
| | Question | Answer |
|---|
| Overfilling of the heart leads to a decline in force, a condition known as ________ _____ ______. | |
| Veins have a volume ________ function as they have high ________ and are easy to stretch - ___% of total blood volume is in the veins. | |
| Venous pressure is the pressure in _______ veins driving blood back to the heart, and has a value of around ___-___ mmHg. | |
| Central venous pressure is the pressure in the _____ _____, and has a value of around __-__ mmHg (similar to ____ ______ pressure). | |
| Mean circulatory filling pressure is pressure in circulation when flow is equal to _____. It is also the __-intercept on the vascular function curve. | |
| Venous return is directly proportional to the pressure gradient between the ______ and the _____ ______. | |
| The vascular function curve plots ______ _____ against _____ ______ _______. | |
| For RAP below zero, the vascular function curve levels off as the decreased ______ counteracts the increased ______ _______. | |
| Pressure in any vessel depends on the ______ of blood inside it, and its ________. | |
| Sympathetic nerve activity leads to smooth muscle ________, ________ in venous compliance, ________ in venous pressure and therefore increase in venous return. | |
| The above mechanism corresponds to a shift (inward/outward) of the vascular function curve. | |
| Increase in blood volume leads to increased venous volume and therefore an increase in venous _______, (increasing/decreasing) venous return. | |
| Increase in peripheral resistance means more blood pools (centrally/peripherally) which means that pressure is higher (centrally/peripherally). | |
| Increase in peripheral resistance ________ venous pressure and venous return. MCFP is (unchanged/increased/decreased). | |
| Rhythmic skeletal muscle contractions and compression of veins leads to an _____ in venous pressure and pumps blood back to the heart. | |
| Maintained skeletal muscle contraction is equivalent to an increase in _______ ________. | |
| On inspiration, thoracic volume (increases/decreases) compared to abdominal and therefore the pressure gradient between abdominal and thoracic pressure is (less/more). | |
| Upright posture leads to an increase in gravitational pressure on blood in lower limbs. Is the pressure gradient changed? (Yes/No) | |
| However, higher gravitational pressure leads to increased _______ pressure, and (less/more) pooling of blood in the lower limbs, _________ venous return. | |
| The decreased venous return leads to less stroke volume and cardiac output, so systolic BP ________. This is detected by _________ which lead to a reflex increase in _______ ______ | |
| By this mechanism, diastolic BP is (higher/normal/lower) and mean blood pressure is (higher/normal/lower). | |
| The heart must be operating at the _________ of the cardiac and vascular function curves. | |
| Which of the following changes would affect both the cardiac and vascular function curves: increased blood volume, increased contractility or increased total peripheral resistance? | |
| The two main mechanisms by which substances cross the capillary wall are _______ and ______. | |
| The amount of diffusion of a substance that takes place depends only on its _________ gradient across the capillary wall and the ______ ____ available. | |
| | Question | Answer |
|---|
| Lipid soluble substances have a (large/small) surface area available for diffusion; water soluble substances: (large/small), and respiratory gases: (large/small). | |
| Filtration is passive: net driving force = algebraic sum of the ________ and ______ forces across the capillary wall. | |
| Filtration forces try to move water (into/out of) the capillary into interstitial spaces. Absorption forces do the opposite. | |
| Oncotic pressure is the _______ osmotic pressure - osmotic pressure created by _____ molecules which themselves (can/cannot) diffuse. | |
| The main filtration force is ________ _________ pressure. This depends on blood volume, which depends on arterial + venous pressures and ratio of post: pre capillary resistance. | |
| Increase in arterial pressure leads to an _______ in capillary blood volume, leading to an _______ in capillary hydrostatic pressure. | |
| Increase in venous pressure leads to an _______ in capillary blood volume, leading to an _______ in capillary hydrostatic pressure. | |
| The ratio determines how much blood is retained in the capillary. If precapillary resistance increases there is (more/less) retained. | |
| If postcapillary resistance increases there is (more/less) retained, leading to a (higher/lower) capillary hydrostatic pressure. | |
| In human skin, the level of Pc is around ___ mmHg at the arterial end and ___-___ mmHg at the venous end. | |
| Interstitial fluid hydrostatic pressure opposes ________, but its value is low - it is (positive/negative) __-__mmHg in brain or kidney. | |
| Interstitial fluid hydrostatic pressure is (positive/negative) in subcutaneous tissues or muscle, around ___-___mmHg. | |
| The negative pressure probably involves removal of fluid from interstital space, which is achieved through __________ of fluid, or via the _________. | |
| Capillary oncotic pressure arises from the plasma proteins (65% ______, 15% ________, 20% lots of other stuff) and its value is about ___mmHg. | |
| If there is starvation or nephrosis, there is a decrease in plasma proteins, leading to a decrease in _______ pressure. Filtration exceeds reabsorption, presenting as ______. | |
| Interstitial fluid oncotic pressure arises because of the escape of a little plasma _______. Its value ranges from ___ to __ mmHg. | |
| Starling's hypothesis for interstital fluid formation: at the arterial end of the capillary net ________ occurs, while at the venous end net ________ occurs. Overall it is balanced | |
| The idealized balance only occurs in some tissues (e.g. _____ ____), while in some only filtration occurs (e.g. ____ ________) and in some only absorption occurs (e.g. ____) | |
| Fill in increases or decreases for all (?): Congestive heart failure --> right atrial pressure (?) --> venous return (?) --> venous pressure (?) --> venous pressure (?) | |
| Right heart failure will lead to (systemic/pulmonary) oedema while left heart failure leads to the opposite. | |
| Lymph vessels commence from blind ends in the __________ spaces, and consist of a series of '_______' separated by _____. | |
| Lymph flow is around __-__L a day. | |
| When the chamber contracts pressure rises to around ___mmHg while when it is not contracting the pressure is around __mmHg. | |
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