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AV valves are attached to the chordate tendinae (heart strings), which anchor the valves to the papilla muscles of the heart, and enable them to open and close with the contraction and relaxation of the heart.
have sarcomeres - look striated, & largest t-tubules
smaller sarcoplasmic reticulum, ca to trigger is extracellular TOO
tons of mitochondria bc so much energy use
long refeactory period for action potential (cant fire again until the twitch is over pretty much) skeletal muscles can have additive APs leading to tetanus - max muscle tension built
spread through atrial cells, depolarizing but block to ventricle
conducting system routes info.
internodal pathways are faster, conduct SA node to AV node where they can be tnsmit to ventricles.
slows the signal, lets atria finish contraction before vents contract
route signal sthrough bundle branches and perkinje fibers to apex of heart
Vs contract from apex toward base so pump to arteries
measure ht electrical activity. strong enough can measure on skin above it
p: atrial de
qrs: v depolarization
t: v repolarization
water and ions, aminos, nitrogenous waste, proteins (albumin, globulin, fibrinogen), glucose, lipids
chunk of megakaryocytes (multinucleate cells, break off peices - platelets)
secretes substance from cell act on distant target, can be considered a hormone.
4 proteins (2 alpha 2 beta), contain porforin rings which contain iron
epicardium (outer) which prevents excess expansion/ movement,
myocardium (middle layer) initiates contractions
endocardium (inner layer) lines cavities and valves
valves seperate atria from ventricles, ensure direction of flow, prevent exit of blood from ventricles on contraction. r and left heart seperated by septum. upper are atria, lower ventrucles
semi lunar valves (pulmonary and aortic) separate ventricles from feeder vessels (pulmonary artery and aorta)
exit from theventricles is controlled by semilunar valves,
atria and ventricles are separated by atrioventricular (AV) valves,
The atria do not have inlet valves,
The mitral/bicuspid valve is on the left side of the heart, and the tricuspid valve is on the right side of the heart.
finger-like projections from the wall of the ventricles, connect the chordae tendonaea (heart strings) to the cusps of the atrioventricular valves. This connection prevents the valve from inverting under pressure.
describes ventricular contraction, when blood is pumped from the heart into circulation.
describes ventricular relaxation, when blood moves from the atria to the ventricles, and the ventricles fill in preparation for systole.
The outer layer of the pericardium is the fibrous pericardium, comprised of dense connective tissue, which protects the heart, anchors it to the surrounding walls, and prevents it from overfilling.
The inner layer of the pericardium, the serous pericardium, is further divided into two layers, an outer parietal layer and an inner visceral layer.
thin layer of connective tissue and fat, and serves as an additional layer of protection for the heart, under the pericardium.
muscle tissue of the heart, composed of cardiac muscle cells called cardiomyocytes, which contract like other muscle cells, but also conduct electricity to coordinate contraction.
composed of endothelial cells and lines the inner surface of the heart.
line blood vessels and the inside of the heart; they provide a barrier and filtration system for blood and the nutrients, waste, and cells it carries, as well as a smooth surface for flow.
the superior and inferior vena cava, the pulmonary artery, the pulmonary vein, and the aorta.
adapted to be highly resistant to fatigue.
It has a large number of mitochondria, enabling continuous aerobic respiration,
numerous specialized oxygen-storing pigments called myoglobins.
Cardiac muscle also has a large blood supply relative to its size, which provides a continuous stream of nutrients and oxygen.
Norepinephrine can stimulate vasoconstriction or vasodilation. The majority constricts in response and is secreted by the body to increase blood pressure
coronary circulation, elicits vasodilation,
its the beta-adrenergic receptors. alpha-receptors, elicit very little constriction in the coronary circulation.
A small globular protein, containing a heme group, that carries oxygen to muscles. sometimes talked about as an oxygen storing pigment
When the pressure in the left ventricle drops to below the pressure in the left atrium, the mitral valve opens, and the left ventricle fills with blood that was accumulating in the left atrium.
Systole, is initiated sinoatrial node. These cells are activated spontaneously by depolarization of their membranes beyond a certain threshold for excitation.
Voltage-gated calcium channels on the cell membrane open and allow calcium ions to pass through, into the sarcoplasm. Some calcium ions bind to receptors on the SR causing an influx of calcium ions into the sarcoplasm.
A specialized connection between cells that allows for intercellular communication, or the transfer of low molecular-weight substances. spreads action potentials in the heart vua passage of sodium ions
phosphorylates calcium ion channels in sarcolemma (the membrane of a muscle fiber cell), so Ca influx is increased. cause more Ca receptors of SR activated, so larger flow of Ca into sarcoplasm. More troponin will be bound and more myosin binding sites cleared [of tropomyosin] so that more myosin heads can be recruited for the contraction and a greater force and speed of contraction results
epresents the rapid depolarization of the left and right ventricles. The QRS complex has a larger amplitude than the P wave because the ventricles have more muscle mass than the atria.
repolarization of the ventricles. The atria repolarize while the ventricles are depolarizing, so the large QRS complex blocks the reading.
The first heart tone "lub," or S1, is caused by the closure of the mitral and tricuspid atrioventricular valves at the beginning of ventricular systole.
The second heart tone "dub," or S2 ( a combination of A2 and P2), is caused by the closure of the aortic valve and pulmonic valve at the end of ventricular systole.
involves calculating the oxygen consumed over a given period of time from measurement of the oxygen concentration of the venous blood and the arterial blood. Q can be calculated from these measurements.
Sx:: pleuritic chest pain, relieved by sitting up and leaning forward.
The classic hallmark of pericarditis is a friction rub auscultated on the cardiovascular examination usually on the lower left sternal border.
Pericarditis may progress to cardiac effusion and then to cardiac tamponade
Common causes inc myocardial infarction and other forms of ischemic heart disease, htn, valvular heart disease, and cardiomyopathy.
occurs when the heart is unable to pump sufficiently to maintain blood flow to meet the needs of the body
sx: tiredness, & leg swelling, SOB worse with exercise, when lying & @ night
compensatory mechanism when the terminally differentiated heart muscle fibers increase in size in an attempt to improve contractility.
may contribute to the increased stiffness and decreased ability to relax during diastole. Ventricular hypertrophy will also contribute to the enlargement and spherical shape of the failing heart and may reduce stroke volume due to mechanical and contractile inefficiency.
to the kidneys stimulates the release of renin – an enzyme that catalyzes the production of the potent vasopressor angiotensin .Angiotensin and its metabolites cause further vasoconstriction, and stimulate increased secretion of the steroid aldosterone from the adrenal glands. This promotes salt and fluid retention at the kidneys, also increasing the blood volume.
links to the nucleus tractus solitarius - increases symp, release catecholamines into the blood stream.
Binding to alpha-1 receptors results in arterial vasoconstriction. beta-1 receptors in the myocardium increase heart rate & contractions more forceful, an attempt to increase cardiac output. However, this also increases the amount of work the heart has to perform.
All of the cells in the heart have ability to initiate an action potential; only some of these cells are designed to -found in the conduction system of the heart and inc SA node, AV node, Bundle of His, & Purkinje fibers. sinoatrial node is a single specialized location in the atriuma faster pacemaker and is usually responsible for setting the heart rate & initiating each heart beat.
The thick outer (tunica adventitia or tunica externa) made of connective tissue.
The middle layer (tunica media) thicker& more contractile tissue in arteries. circularly arranged elastic fiber, connective tissue
Tunica intima. single layer of simple squamous endothelium stuck in place by matrix.
An artery with a large number of collagen and elastin filaments, giving it the ability to stretch in response to each pulse. generally largest/ closest to heart. lots of collagen and elastin in the tunica media. give rise to muscular arteries
Medium-sized arteries that draw blood from an elastic artery and branch into "resistance vessels" including small arteries and arterioles. distribute blood to resistance arteries
occur normally in the body in the circulatory system, serving as backup routes for blood to flow if one link is blocked or otherwise compromised. if from trauma is usually called a fistula
. Capillaries do not function on their own. The "capillary bed" is an interweaving network of capillaries supplying an organ. The more metabolically active the cells, the more capillaries they will require to supply nutrients and carry away waste products.
They are continuous in the sense that the endothelial cells provide an uninterrupted lining, and only allow small molecules, like water and ions to diffuse through tight junctions which leave gaps of unjoined membrane called intercellular clefts.
have pores in the endothelial cells (60-80 nm in diameter) that are spanned by a diaphragm of radially oriented fibrils and allow small molecules and limited amounts of protein to diffuse.
a special type of fenestrated have larger openings in the endothelium. allow red and white blood cells & serum proteins to pass aided by a discontinuous basal lamina.
primarily located in marrow, lymph nodes, & adrenal gland. Some do not have the tight junctions called discontinuous sinusoidal capillaries (in the liver and spleen where greater movement is necessary)
thick outermost layer of a vein is made of connective tissue, called the tunica adventitia or tunica externa. Below the tissues are thin bands of smooth muscle called the tunica media. The interior is lined with endothelial cells called the tunica intima.
small blood vessels in micro circ that connect the capillary beds to the veins
specialized post-capillary venous swellings characterized by plump endothelial cells as opposed to the usual thinner endothelial cells found in regular venules. HEVs are found in all secondary lymphoid organs except the spleen, where blood exits through open arterioles and enter the red pulp.
resistance to flow must be overcome to push blood through. resistance of peripheral is the systemic vascular resistance (SVR), resistance of the vasculature of the lungs is the pulmonary vascular resistance (PVR).
When bv constrict, flow is restricted thus, retaining heat or increasing vascular resistance.Cutaneously, this makes the skin turn paler bc less blood reaches the surface
oncotic pressure in capillaries is gen by high quantities of albumin.
if plasma proteins are reduced, reduction in oncotic pressure and an increase in filtration across the capillary, resulting in excess fluid buildup in the tissues (edema).
Systemic blood pressure refers to the pressure exerted on blood vessels in systemic circulation, and is often measured using the arterial pressure, or pressure exerted upon arteries during heart contractions.
Blood pressure (BP), sometimes referred to as arterial blood pressure, is the pressure exerted by circulating blood upon the walls of blood vessels, and is one of the principal vital signs.
work by detecting how stretched a bvs.
send to medulla oblongata where raise or lower blood pressure via the autonomic nervous system
Normal: systolic 90-119 mmHg and normal diastolic 60-79 mmHg,
Prehypertensive: 120-139 mmHg systolic and 80-89 mmHg diastolic,
Hypertensive: 140-159 mmHg systolic and 90-99 mmHg diastolic.
About 70 percent of pressure reductions in the vasculature occur in small arteries and arterioles. Thus, small arteries and arterioles are the main regulators of TPR.(total peripheral resistance) The significance of smooth muscles in the control TPR is major.
A network or interwoven mass, especially of nerves, blood vessels, or lymphatic vessels
system of veins comprising the hepatic portal vein and its tributaries. The liver consumes about 20% of the total body oxygen when at rest which is why the total liver blood flow is quite high.
Initial stage: the state of hypoperfusion causes hypoxia. lack of oxygen, so cells perform anaerobic respiration.
Compensatory: body employing physio mechs,
Progressive:compensatory mechs begin to fail.
Refractory: vital organs have failed. shock cant be reversed. Brain damage and cell death are occurring, death soon.
Supplying oxygen to tissues
Removing waste such as CO2, urea, & lactic acid
Immunne: inc circ WBC & antib's detect foreign
Messenger fctn, inc hormones & signal damage
Regulation of body pH & temperature
carried in blood in three different ways
70% to 80% converted to bicarbonate ions HCO3− by the enzyme carbonic anhydrase in the red blood cells,
5% – 10% is dissolved in the plasma,
5% – 10% is bound to hemoglobin as carbamino compounds.
no nucleus, biconcave shape, no dna or organelles, cant divide
life span 120 days
Oxygen binds the heme groups each hemoglobin can bind four oxygen molecules.
binding affinity cooperative. It is increased by the oxygen saturation of the molecule: binding of an initial oxygen molecule influences the shape of the other binding sites causing the binding of additional oxygen molecules to be more favorable.
A antigen on the surface of their RBCs, and blood serum containing IgM antibodies against the B antigen. Therefore, a group A individual can only receive blood from individuals of groups A or O (with A being preferable), and can donate blood to individuals of groups A or AB .
granulocytes: neutrophils, basophils, and eosinophils.
Agranulocytes: lymphocytes, monocytes and macrophages.
defend against bacterial or fungal infection and other very small inflammatory processes. They are usually the first responders to microbial infection; their activity and death in large numbers forms pus.
three types: B-lymphocytes, which produce antibodies in the humoral immune response, T-lymphocytes which participate in the cell-mediated immune response, and the null group which contains natural killer cells; cytotoxic cells that participate in the innate immune response.
present pieces of pathogens to T cells so that the pathogensmay be recognized again and killed, or so that an antibody response may be mounted.
monocytes that have migrated out of the blood stream and into the body tissues. They take up and destroy necrotic cell debris and foreign material including viruses, bacteria, and tattoo ink.
defend against bacterial or fungal infection as the most common first responders to microbial infection.
A large cell, found in bone marrow, responsible for the production of platelets.
growth factors significant role in the repair and regeneration of connective tissues.
secrete factors increase local platelet aggregation (thromboxane A), enhance vasoconstriction (serotonin), and promote blood coagulation (thromboplastin).
from mgeakaryocytes, 5–9 day span.
: (1) vascular spasm; (2) platelet plug formation; and (3) coagulation.
"molecular glue" during clot formation to stop blood flow.
dependent on the release of multiple coagulation factors from platelets trapped in the fibrin mesh of the clot. Factors released from the healthy endothelium result in shrinkage of the fibrin network and a gradual decrease in thrombus volume.
break down of a fibrin clot.Plasmin is the enzyme that breaks down fibrin. activated and regulated by multiple factors. inc T-PA
opposite of hemophilia is Factor V Leiden thrombophilia, a disorder of human factor V blood protein that causes a hypercoagulability disorder or overactive clotting resulting in dangerous blood clots.
In Factor V Leiden thrombophilia disorder, the Leiden variant of factor V cannot be inactivated by activated protein C, as it would be in a person with normal factor V, resulting in excess clotting.
red blood cells undergo a change in shape upon deoxygenation because of polymerization of the abnormal sickle hemoglobin.
condition in which there is a net increase in the total circulating erythrocyte (red blood cell)
cancer of the blood or bone marrow characterized by an abnormal proliferation of blood cells, usually white blood cells (leukocytes)
iron overload with hereditary cause or occurring due to a metabolic disorder.
Excessive iron deposition can lead to hepatic cirrhosis, hypopituitarism, cardiomyopathy, diabetes, arthritis, or hyperpigmentation
.DX serum ferritin, HFE gene; liver biopsy or MRI for iron deposition levels
Tx: bloodletting or chelation
anemia due to hemorrhage (excessive blood loss), hemolysis (blood cell destruction), or ineffective hematapoiesis (deficient red blood cell production). Symptoms of anemia include fatigue, malaise, heart enlargement, and impaired concentration.
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