chapter 5 heart last test
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heart last test
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Terms | Definitions |
|---|---|
 Chapter 5 cardiovascular systemcardiovascular functions (6) | • delivery of oxygen and other nutrients • removal of carbon dioxide and other metabolic waste • transport of hormones • thermal regulation • maintenance acid-base balance and overall body Fluid balance. • Immune functions |
| The anatomy of the heart | The anatomy of the heart There are four, chambers of the heart • the two top are the atrium • the bottom are the ventricles they are two pumps • the right pump are going to pump blood to the lungs the left pump are going to pump blood • to the rest of the body we have two major veins • the lower vein brings blood from the lower part of the body is called the in the inferior Vena cava • and the one come from the top is the superior vena cava • and they are going to transport the blood into the right atrium Then there are be of valve that is going to be left open called the tricuspid valve • then into the right ventricle • then it goes to the pulmonary valve(reminder Prof. About this mistake) • then by the pulmonary artery. It goes into the lungs • then it going to come back from the lungs by the pulmonary vein • into the left atrium • then it goes through the mitral valve • then into the left ventricle • then into the aortic valve • then into the aorta |
| another word for the heart is the? thickness varies according to what? Which ventricle is the most powerful? How does the size of the ventricle increase? | • myocardium • thickness varies according to the stress placed on the chamber walls • the left ventricle is the most powerful chamber and the largest chamber • with exercise training the size of the left ventricle increases |
| mechanisms for adaptations and cardiac performance with diseases are different from those observe with aerobic training | (basically the volume of the chamber will not change with aerobic type of training when a person have a disease where the heart is getting larger. It's generally restricting the volume in the chamber) (we can say they're both increasing in size, but no one is really Lowering the volume of the blood in the chamber) |
| similarites and defferences with cardiac and skeletal muscle | • similar to skeletal muscle. Both are striated and having myofibrils containing ACTING AND MYOSIN that participate in contraction and both are surrounded by sarcolemma differences • cardiac muscle are involuntary • cardiac muscle fibers are anatomically interconnected end to end by intercalated disc the disk have structures called the desmosomes which anchored the individual cells together, So they can't be pulled apart • disc also contains gap junctions which allows rapid transmission of the action potential that signals the heart to contract as one unit • contains only one fiber type symbol looks type I • highly oxidative • highly capillarized and have a large number of mitochondria • cardiac muscle contraction occurs by calcium induced calcium release (in other words, cardiac muscle requires extracellular calcium ions for the contraction to occur). The action potential spreads rapidly among the myocardial sarcolemma from cell to cell via gap junctions and also to the inside of the cell through the T tubules • upon stimulation calcium enters the cell by this receptor dihydropyridine receptor in the T tubules (this calcium serves as a trigger, what we are going to get from the T tubules. We will get that calcium that will be brought in from the extracellular fluid and that extra calcium is going to be important because it's going to help to trigger another type of receptor (dihydropyridine )that would release calcium from the sarcoplasmic reticulum, so it's actually calcium that is causing calcium be released) |
| Coronary circulation | • the heart receives blood via coronary arteries |
| Cardiac conduction system/sa node | Cardiac conduction system - unique ability to generate its own electrical signal, which is called auto conduction which allows it to the contract without any external stimulation sa node • the impulses for heart contraction is initiated in the SA node Sino atrial that is located in the upper posterior aspect of the right atrium cells spontaneous depolarized at a faster rate than the other myocardial cells(meaning other can beat on their own such as the ventricles but the sa node is the fastest) (meaning that this will set the pace, which is actually known as the cells pacemaker. It sets the rhythm and sets the pace of when the heart will be) • the SA node establish a rhythm called the sinus rhythm • impulses spread through both the atria and reaches the atrioventricular node which is located in the right atrial (the lower portion ) |
| AV node | • conducts the impulses from the atria into the ventricles • the impulse in delayed about 0.13 seconds as it passes through the AV node • and then it enters the AV bundle the delay allows blood from the atria to completely empty into the ventricle to maximize ventricular filling before the ventricle contracts |
| AV bundle/bundle of his | • travels along the ventricular septum and then sends right and left bundle branches into both ventricles. These branches sends the impulse towards the apex of the heart and then outward • each bundle branch subdivide into many smaller ones that spread throughout the entire ventricle wall and those are called the Purkinje fibers, they transmit the impulse through the ventricles approximately 6 times faster than throughout the rest of the cardiac conduction system |
| Extrinsic control on the heart activity. Although the heart initiates. It's own electrical impulses both the rate and effects can be altered under normal conditions. This is accomplished primarily through 3 extrinsic systems | • the parasympathetic nervous system. (Lower) • The sympathetic nervous system.(Higher) • And the endocrine(higher) |
| parasympathetic nervous system of extrinsic control of the heart at rest whic system predominates and what is vagal tone? | • the medulla located in the brainstem contains a group of neurons that forms the cardio inhibitory center arising from the center are parasympathetic fibers that reached the heart via the vagus nerve (cranial nerve number 10). These fibers innervate. The SA node and AV node. When this center is stimulated nerve impulses is transmitted, along the parasympathetic fibers cause the release of acetylcholine which causes hyperpolarization of these cells(hyperpolarization as in lack of action) • this decreases the rate of heartbeat and forced of contraction • at rest the parasympathetic system activity predominates in a state refered to as vagal tone • the vagus nerve has a depressant effect on the heart it slows impulses generation and conduction and thus decrease the heart rate a term referred to as bradycardia • bradycardia is termed as heart rate below 60 at rest |
| Blood pressure/ cardiac output/ pheripheral resistance | • blood pressure is = to cardiac output × pheripheral resistance • so if anyone of these goes up your blood pressure goes up • and vice versa. If one of these goes down your blood pressure goes down cardiac output = heart rate × stroke volume pheripheral resistance. • Is the dilation and the contraction of the smooth muscle in your arterial if you have receptors monitoring cardiac output going down they are going to send a message to the acceleratory that says increase cardiac output. Our blood pressure are going down cardio accelatory cardio inhibitatory |
| The sympathetic system | • With in the medulla of the brain we have to cardio accelatory • And rise our sympathetic fibers. They traveled down the track on the spinal cord • they passed outword in the cardio accelatory nerves • these are referred to as the preganglion nerves • then there are going to release norepinephrine on to the heart and they are going to innervate the AV and SA node and portions of the myocardi causing an increase of the rate of heartbeat and increase of the force of contraction |
| influence is of the endocrine system | • exerts its affect through the hormones epinephrine and epinephrine like the sympathetic nervous system. The hormone stimulates the heart to increase in fact release of this hormones is triggered by sympathetic stimulation during times of stress and their actions prolong the sympathetic response(the hormones last longer) |
| the electrocardiogram pwave, t wave, qrs wave, st segment from an EKG • you get what? | p wave • depolarizing QRS wave • ventricular depolarizing ST segment • repolarization of the ventricles T wave • repolarization of the ventricles from an EKG • you get the heart rate • the hearth rhythm • wheather the parts of the heart are receiving sufficient oxygen • and debth of the tissues |
| cardiac arrhythmias Bradycardia | • resting heart rate below 60 |
| Tachacardia | • resting heart rate above one hundred |
| premature ventricular contractions | • results in the feeling of skip or extra heart beat |
| ventricular Tachacardia | • is the real more consecutive PVCs |
| ventricular fibrillation | • is when contraction of the ventricle tissues is uncoordinated and can result in cardiac death. That is when it's Beating all over the place |
| Hypertrophic cardiomyopathy | • is a disorder of the heart, characterized by an increase thickness or hypertrophy of the walls of the left ventricle, the largest chamber • about half of the case of this disease is inherited • disease can present at any time in life • it is the leading cause of sudden death in athletes and young people |
| Marfan's syndrome | • is also an inherited disease results in abnormalities of connective tissues, especially in the Skelton, the eyes and the cardiovascular system. There is a weakening of the aorta,weaken valves • those with the syndrome tend to be tall with disproportional long arms and unusual long lower half of the body, very long fingers and toes and overly curved back bone ,a mouth or breastbone that either curves outward or inward, a backward curve of the leg, flat feet. • Other common visual signs are the leaneness ,small muscle mass, crowded teeth and nearsightedness |
| terminology of cardiac function cardiac cycle | • defined as the mechanical and electrical events that occur during one heartbeat • (so systole to systole) |
| Systole | • is the contraction phase during which the chambers expel blood and that is from the QRS to the T wave and that is where we are expelling the blood that is the contraction phase |
| Distole | • is the relaxation phase where the chambers are filled with blood • and this is from the T wave to the QRS |
| stroke volume | the volume of blood pumped out with each beat |
| end-diastolic volume | • volume of blood in the ventricle, just before contraction(diastolic is the relaxation phase. The ventricle is filled with blood) |
| End systolic volume | • the volume of blood in the ventricles. After we pump out the blood/contraction |
| stroke volume equals what? | stroke volume= end diastolic volume-end-systolic volume stroke volume = 100-40 = 60(s/v) |
| Ejection fraction | • the portion of the blood pumped out of the left ventricle with each beat • = s/v ÷ the end-diastolic volume • 60 ÷ 100 = 60% |
| cardiac output | • total volume of blood pumped by the ventricle per minute • cardiac output = heart rate times stroke volume |
| Blood pressure | • systolic pressure is the highest pressure with the heart contracts • diastolic is the lowest pressure when the heart is relaxed • blood pressure = 2 cardiac output × peripheral resistance if the heart rate goes down or stroke volume goes down vice versa. It's going to affect your blood pressure • constriction or dilation is going to affect your blood pressure • increase in the diameter of the arterials is also going to affect your blood pressure |
| what is general hemodynamics? in order for blood to flow in a vessel, they must be a what? blood will flow from the region of the vessel from what? what are the properits of the blood vessel? | • is the factors and forces that govern the flow of blood through blood vessels • in order for blood to flow in a vessel, they must be a pressure difference • from one end of the vessel to the other • blood will flow from the region of the vessel from high-pressure to the region of the vessel with low-pressure • alternatively, if there is no pressure difference across the vessel. There is no driving force and therefore no blood flow in the circulatory system. The mean arterial pressure in the aorta is approximately 100 mL of Mercury at rest and the pressure in the right atrium is very close to zero. Therefore the pressure difference across the entire circulatory system is about 100 mL of Mercury, on average the reason for the pressure defference from the arterial the venous circulation is that blood vessels themselves provide some resistance or appendence to blood flow (the arterials will always be slightly constricted) • the resistance that the vessels provide is largely dictated by the properties of the blood vessels and the blood itself. These properties includes the • length and radius of the blood vessels and the viscosity and thickness of the blood flowing through the blood vessels |
| resistance to blood flow | • changes in vascular resistance are largely due to changes in blood vessel radius or diameter • the viscosity of the blood and the length of the vessels do not change significantly under normal conditions. Therefore regulation of blood flow to organs is accomplished by small changes in blood vessels radius through vasoconstriction(decrease in blood flow) and vasodilation(increase in blood flow) • (when we start to exercise we want the blood that is going to the muscle to increase and the blood vessels that are going to the kidneys and digestive system. We wanted it shunted away and basically we do this by closing down, constricting and dilating) |
| intrinsic control of the blood flow | • refers to the ability of the local tissue vasodilate or vasoconstrictor the arterials that serve them and alter regional blood flow, depending on the immediate needs of those tissues. • With exercise. The increase metabolic demand of the exercising . Skeletal muscles, the arterioles undergo local mediate vasodilation, opening up to allow more blood to enter that highly active tissue(with exercise more dilation occurs and or constriction occurs to those tissues that are not needed) |
| there are essentially three types of intrinsic control of blood flow. | • The strongest stimulus for the release of local vasodilating chemicals is metabolic in particular, an increase for oxygen demand(so when those tissue need oxygen. The demand they will exert their affect and have the arterials dilate) • as the tissues oxygen use increases, available oxygen is diminished • local arterials vasodilate to allow more blood and thus more oxygen, to perfumes that area • other chemical changes that can stimulate increase blood flow are decreased in other nutrients and increase in byproducts (carbon dioxide, potassium, hydrogen, lactic acid) several dilating substances are can be produced. In The endothelial(the lining of the arterials) and initiate vasodilation in the smooth muscle. These substances include • nitric oxide • and endothelium derived hyperpolarized factor • (one a person is having some sort of, arterial disease or heart disease that is actually affecting that endothelium or arterial linining, which means it may not be producing these factors anymore, or only a little amount which means that they are not dilating. Accordingly, based on the conditions of the environment) pressure changes within the vessels themselves can also cause vasodilation and vasoconstriction. This is referred to as the myogenic response. The vascular smooth muscle contracts in response to an increase in pressure across the vessel wall and relaxes in response to a decrease in pressure across the vessels walls increase blood flow can either bring in needed substances such as oxygen, or clear out metabolical wastes such as carbon dioxide, or both |
| Extrinsic neural control of blood flow | • blood flow to all parts is regulated largely by the sympathetic nervous system(because we need blood pressure and we need a constant slightly vasoconstrictor blood vessels) (within the mudula We have to cardioacelator and we have to cardio inhibitory and now we have the vaso motor center) Vasomotor center • this center innovates the smooth muscles of the arterials under normal conditions the sympathetic nerves transmit impulses continuously to the blood vessels, keeping them moderately constricted to maintain adequate blood pressure and blood flow • this state of tonic vasoconstriction is referred to as vaso motor tone • when sympathetic stimulation increases, Further constrictions of the blood vessels are going to occur(so basically some areas will be decreased and constriction and some other areas will increase and allow more blood to be distributed elsewhere, such as the skeletal muscle) |
| Note | some sympathetic postganglionic fibers secrete acetylcholine. Most of them secrete norepinephrine. The postganglionic fibers of the sympathetic nervous system. However, some secrete acetylcholine • when stimulated by the vaso motor center . This fibers will cause vasodilation of the smooth muscle • acetylcholine will cause dilation and norepinephrine will cause constriction |
| there are two ways, where you can get dilation of the blood vessels. The first one is (test question) | 1. through the sympathetic nervous system where you have noraepinephrine being released constantly and when we want to cause more dilation the frequency will become less.(The sympathetic nervous system is responsible for maintaining a certain amount of constriction in your blood vessels by increasing the stimulus or decreasing the stimulus we will affect constriction or dilation through the frequency of that neural conduction 2. in addition, we have fibers releasing acetylcholine, and if those fibers are recruited, they will automatically cause dilation the sympathetic postganglion fibers secrete acetylcholine, and when stimulated by the vaso motor center . These fibers will cause vaso dialation of the smooth muscle |
| Integrative control of blood pressure blood pressure is normally maintained by reflexes from the autonomic nervous system specialize blood pressure sensors located the aortic arch and the carotid sinus arteries called | baroreceptors are sensitive to changes in arterial pressure(meaning that it is measuring the blood in the vessel. So if there's a lot of blood. We would get a little more stretching, not so much blood, not someone stretching) • they send information about the current blood pressure to the cardiovascular control center in the medulla where autonomic reflexes are initiated to respond to changes in blood pressure (for example, when the blood pressure is elevated the baroreceptors are stimulated by an increase stretch they relayed this information(the baroreceptors are located in the aortic arch and the carotid sinus) to the cardiovascular control center in the brain in a response to an increase in pressure. There is a reflex increase in vagal tone to decrease heart rate and decrease in sympathetic activity, which serves to normalize the blood pressure the Baroreceptors will be monitoring the blood pressure. It is too much of a stretch in the blood vessels that means that the blood pressure is too high and the information will be relayed to the cardiovascular control center in the brain in the cardio inhibitory center an a response will go back out to slow down the heart rate and decrease the blood pressure there is a case where we don't have any stretching going on the in formation is going to come in. That's the cardio accelatory center and is going to increase the heart rate and increase the blood pressure, heart is a factor when we want to increase and decrease our blood pressure blood pressure in response to a decrease in blood pressure • less stretch is sense by the baroreceptors and the response is to increase heart rate by vagal withdrawal and to increase sympathetic nervous activity, thus correcting the low blood pressure |
| sometimes when you're lying down and what happens when you get up too fast you get, a little dizzy. Why is that? | Because of the increase of blood pressure • also the baroreceptors sends impulses to the vaso motor centers that increase sympathetic stimulation to arterial and that results in vasoconstriction, so increase in the frequency will increase the constriction or decrease it will cause dilation the barrier receptors also send impulses to the vasomotor in response, the vasomotor center decrease sympathetic stimulation to arterials. Thus results in vasodilation in a response to a decrease in blood pressure stretch is sense by those baroreceptors , and to increase heart rate by vagal tone withdrawl and to increase the sympathetic activity and the result is constriction (remember, it is the sympathetic nervous system that continually sends the neural impulses to the smooth muscles in your arterials and they could speed that up. And you get more constriction and they could slow that down and you get more dilation) |
| return of blood to the heart the three factors that return blood back to the heart are | • vlaves in the veins.-Allows the blood to flow in only one direction • The muscle pump. - Mechanical: compressions of the veins from rytmic skeletal muscle contraction (when people stand at attention, sometimes those guys faint because they're standing still. But if they move around and they initiate the muscle pump the muscle pushing on the lower body, trying to push that blood back up to the heart also when people start exercise and the moving very fast. They need to slow down because when you exercising you have blood, especially in your lower extremity and then you stop, especially at a high cardiac output some of those blood will start to pool • The respiratory pump-that is our breathing in and out, that helps to actually move the blood back up to the heart |
| functions of the blood | • Transportation-delivery of nutrients removal of waste • temperature regulation-increase or decrease sweat evaporation • Acid-base balance pH |
| composition of whole blood | • 100% blood 55% of it in blood plasma • 45% are formed elements, which consists of 99% red blood cells, 1% white blood cells and platelets • within the plasma 99% of it are H2O (typically when people are exercising and they are sweating a lot. Most of the loss are coming from the plasma) |
| Hematocrit | • the ratio of the form elements to the total blood volume • White blood vessels are responsible for immune response • Blood platelets are cell fragments that help to coagulate in the blood • Red blood cells carry oxygen to tissues with the help from hemoglobin |
| Blood viscosity | • thickness of the blood • the more viscus the more resistance to flow • higher hematocrit results in higher viscosity |
| Higher brain centers | Higher brain centers. • Cerebral cortex. • Emotional factors, meaning that stress. Perhaps will be routed into this particular higher brain centers that will actually go into the muddula • motor cortex On the right-hand side, we have that is also the higher brain centers • hypothalamus • input from motor cortex • body temperature (meaning that if the body temperature goes up that the hypothalamus will send impulses to the cardioaccelatory center to get more cardiac output to try to decrease the temperature that is rising in the body on the left-hand side you have chemo receptors • when the partial pressure of carbon dioxide goes up and hydrogen goes up • and when the partial pressure of oxygen goes down • it leads to a general vasoconstriction • and all of that chemoreceptors is fed into the mudula affecting our vasomotor centers, which is the center that is called to be involved in our smooth muscles in our arterials on the right-hand side, we have systemic receptors • barroreceptors-that are found in the aorta and the carotid bodies response to our mean arterials pressure and it may lead to a increase in parasympathetic outflow a decrease in cardiac output or a decrease in sympathetic out low. It also has stretch receptors in the right atrium and it also has muscle receptors |
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