Term
| Name the 2 kinds of cardiac muscle cells |
|
Definition
| Conduction Cells 1% and Contraction Cells 99% |
|
|
Term
| What are the 5 parts of the conduction system? |
|
Definition
1. Sinoatrial node
2. Atrioventricular node
3. Atrioventricular Bundle of His
4. Bundle branches
5. Conduction myofibers (purkinje) |
|
|
Term
| Which part of the conduction system leads to atrial depolarization and contraction? |
|
Definition
| Spread of depolarization from SA node to AV node |
|
|
Term
| Which part of hte conduction system leads most of ventricular depolarization and contraction? |
|
Definition
|
|
Term
Depolarization in the "pacemaker potential" consists of 2 phases; slow depolarization and fast depolarization.
What causes the slow depolarizatoin? |
|
Definition
| There is a special channel that responds to hyperpolarization; this channel is permeable to both Na+ and K+, but since the gradient is greater for Na+ entry, Na+ floods in and depolarization occurs |
|
|
Term
| What causes the fast depolarization? |
|
Definition
| When depolarization reaches treshold (-40 mV), voltage-gated Ca channels open and calcium floods in |
|
|
Term
Repolarization of a contractile cardiac muscle cell consists of 3 phases: rapid initial repolarization slow (plateau) repolarization, and rapid final repolarization
What causes the rapid initial repolarization? |
|
Definition
| Initial rapid reversal in polarity (K+ out) |
|
|
Term
| What causes the slow (plateau) repolarization? |
|
Definition
| Slow Calcium in offsets Potassium moving out |
|
|
Term
| What causes the rapid final repolarization? |
|
Definition
| Rapid Potassium out (many voltage gated K+ channels open) |
|
|
Term
True or False
Cardiac muscle cell contraction is similar to skeletal muscle cell contraction in that both involvte excitation/contraction coupling, cross bridge cycling between actin and myosin and the sliding filament mechanism? |
|
Definition
|
|
Term
| Why is wave summation and tetany not possible in cardiac muscle like it is in skeletal muscle? |
|
Definition
| Because long refractory period occurs in conjuction with prolonged plateau phase; ensures alternate periods of contraction and relaxation which are essential for pumping blood |
|
|
Term
| What is the cardiac cycle? |
|
Definition
| Events that take place during one heart beat |
|
|
Term
True or fasle
At no time during the cardiac cycle should all 4 chambers be in systole |
|
Definition
|
|
Term
True or False
At no time during the cardiac cycle should all 4 chambers be in diastole? |
|
Definition
|
|
Term
| Explain isovolumetric ventricular contraction |
|
Definition
| Ventricular volume does not chanbe because semilunar and AV vavles are closed (no blood can go out); ventricular pressure has to exceed arterial pressure before semilunar valve opens and ventricular volume decreases due to ejection |
|
|
Term
| Explain isovolumetric ventricular relaxation |
|
Definition
| Ventricular volume does not change because the semilunar and AV valves are closed (no blood can come in); atrial pressure from fillasing has to exceed ventricular pressure before AV valve opens and ventricular volume increases due to filling |
|
|
Term
| Explain why the dicrotic notch occurs |
|
Definition
| There is an increase in arterial pressure when the semilunar valve closes |
|
|
Term
| What makes S1 the first heart sound? |
|
Definition
|
|
Term
| What makes S2 the second heart sound? |
|
Definition
|
|
Term
|
Definition
| the amount of blood ejected from the left ventricle in one minute |
|
|
Term
|
Definition
| the amount of blood ejected from the left ventricle in one beat |
|
|
Term
| What is the formula for determing CO? |
|
Definition
|
|
Term
| What is the formula for determing SV? |
|
Definition
|
|
Term
| Name 3 major ways stroke volume can be regulated? |
|
Definition
1. EDV (preload)
2. afterload
3 contractility |
|
|
Term
|
Definition
| EDV (volume in ventricle at end of diastole |
|
|
Term
| What does the Frank Starling Mechanism state? |
|
Definition
| Incfreased EDV increases stretch which increases contraction strength which inreases SV |
|
|
Term
| Is the Frank-Starling mechanism an intrinsic or extrinsic control mechanism? |
|
Definition
| Intrinsic (it occurs even if the heart is removed from the body |
|
|
Term
| Name 4 ways to increase venous return and therefore increase EDV? |
|
Definition
1. skeletal muscle pump and vein valves
2. respiratory activity
3. vasoconstriction by ANS
4. blood volume (controlled by hormones such as ADH, aldosterone, angiotensin II) |
|
|
Term
| What is the effect of excercise on SV? (consider venous return, EDV, and contraction strength) |
|
Definition
| skeletal muscle contraction squeezes on veins forcing blood toward heart and inreasing venous return. Frank - Starling mechanism: inreased EDV increases stretch which increases contraction strenght (contractility ) increases Stroke volume which decreases HR (heart does not have to work so hard) |
|
|
Term
| Describe the effect of respiratory activity on venous return? |
|
Definition
| diaphragm contraction forces diaphragm down which increaes pressure in abdominal cavity and decreases pressure in thoracic cavity; blood flows from high to low pressure towards the heart. |
|
|
Term
| Increased peripheral resistance increases or decreases blood pressure? |
|
Definition
|
|
Term
|
Definition
| Arterial pressure determines SV; blood can only be ejected from ventricle when ventricular pressure exceeds arterial pressure; ifarterial pressure is high, then SV will be decreased. So, arterial pressure presents an impedance to the ejection of blood from the ventricle (called an afterload) |
|
|
Term
| How does increased peripheral resistance effect Stroke Volume? |
|
Definition
| IPR increases BP wich increases afterload which decreases SV |
|
|
Term
| Explain the mechanism of how NE increase contractility? |
|
Definition
| NE activates a G protein mechanism that opens Calcium channels (more calcium in the sarcoplasmic reticulum enhances interaction between myosin and actin) |
|
|
Term
| What is the effect of slower HR on EDV and why does this occur? |
|
Definition
| Slower HR increases filling time for ventricle which increases EDV (preload) and increases stretch which increaes contractility and increases Stroke Volume |
|
|
Term
| Name 2 hormones that have an effect on HR. What are the effects and what glands secrete these hormones? |
|
Definition
Epinephrine - produced by adrenal MEDULLA; increases HR like NE
Thyroid hormone - produced by thyroid gland; inreaess NE/E effects |
|
|
Term
| Name the 3 routes by which substances pass between the blood and interstitial fluid? |
|
Definition
1. through clefts between endothelial cells
2. through fenestration (pores) in endothelial cells
3. through plasma membrane and cytoplasm of endothelial cells |
|
|
Term
| List the 3 mechanisms by which substances pass between the blood and interstitial fluid? which is the most important? |
|
Definition
1. Passive diffusion - MOST IMPORTANT; substances move from high concentration to low concentratoin
2. transcytosis - endothelial cells pick up droplets of fluid from one side of the plasma membrane (pinocytosis) and transport them via vesicles across the cell and discharge the fluid on the ot her side of exocytosis
3. filtration/reabsorption - capillaries filter plasma at the arteriole end of the capillary bed and reabsorb it at the venule end of the capillary bed. |
|
|
Term
| Capillaries filter plasma at what end of the bed? |
|
Definition
|
|
Term
| capillaries reabsorb plasma at what end of the capillary bed? |
|
Definition
|
|
Term
| What is the "pushing out" force? |
|
Definition
|
|
Term
| What is the "pulling in " force? |
|
Definition
|
|
Term
| Specifically, filtration pressure is what kind of pressure and where does it come from? |
|
Definition
| filtration is HYDROSTATIC pressure and comes from the left ventricle |
|
|
Term
What is the avg hydrostatic pressure at the arterial side of the capillary?
What is the avg at the venous side? |
|
Definition
35 mgHg at arterial
20 mgHg at venous |
|
|
Term
| Reabsorption is what kind of pressure? |
|
Definition
|
|
Term
| Where does reabsorption / osmotic pressure come from? |
|
Definition
| Proteins taht are too large to be filtered stay in the capillaries; this high solute concentration in the capillaries draws the water back in at the venous end of the capillary bed. |
|
|
Term
| What "osmotically active" protein is found in plasma but not in interstitial fluid? |
|
Definition
|
|
Term
| What is the function of albumin in the plasma? |
|
Definition
| Albumin is osmotically active; it is responsibel for the osmotic pressure that reabsorbs water at teh venule end of the capillary bed. |
|
|
Term
What is the avg osmotic pressure at the arterial end?
What is the avg osmotic pressure at the venous end? |
|
Definition
|
|
Term
| Osmolarity of blood describes the WHAT concentration? |
|
Definition
|
|
Term
| As water is reabsorbed, solute follows. What is this phenomenon called? |
|
Definition
|
|
Term
| Even through filtration pressure is higher than the reabsorption pressure, a lot more fluid doesn't leave the capillaries than reenters them. Why? |
|
Definition
| There is much more surface area at teh venule end of the capillary bed |
|
|
Term
| What results in more surface area at the venous end of the capillary bed than the arterial end? |
|
Definition
1. more capillary branches at the venule end of the bed than at the arteriole end.
2. Capillaries are larger in diameter at the venule end of the bed than at the arteriole end. |
|
|
Term
| What is the effect on blood pressure if blood osmalarity is too high? |
|
Definition
| Increases blood pressure since too much ISF is reabsorbed - inreases blood volume, which increases blood pressure. |
|
|
Term
| What is the effect on blood pressure if blood osmalarity is too low? |
|
Definition
| Decreases blood pressure sine there is insufficient ISF reabsorbed which decreaes blood volume and thus decreases blood pressure |
|
|
Term
| Why is hemoglobin packaged in rbc instead of being free in the plasma? |
|
Definition
| Hemoglobin would inrease blood osmolarity if it was not packaged inside a rbc; this would inreasse blood pressure. |
|
|
Term
| consider true and shunt capillaries in capillar beds. Which one is referred to as the "straight shot" capillary? |
|
Definition
|
|
Term
| If ANS cannot control capillary diamter (radius) then how does the body control blood flow through a cap. bed? |
|
Definition
| constrictoin/ dlation of precapillary sphincters regualted blood flow through capillary beds. |
|
|
Term
| Constriction of precapillary sphincters closes woff which type of cap. bed? |
|
Definition
|
|
Term
| Describe a situation when true cap. beds might be bypassed? |
|
Definition
1. digestive system capillaries during stress when sympathetic divsion overrides the parasympathetic divsion.
2. When the hypothalamus is inducing a fever, blood flow to the skin in restricted so that heat is not given off to the environment. |
|
|
Term
|
Definition
| Blood pressure is the force blood exerts agaisnt the blood vessel wall |
|
|
Term
| What are Korotkoff sounds? |
|
Definition
| sound of blood agaisnt arterial wall when vessel is partially occluded by BP cuff? |
|
|
Term
| Why is a BP cuff used to take BP? |
|
Definition
| to occlude an artery; initially cuff completely closes off vessel. but then pressure is released so that vessels open up (Korotkoff sounds are heart - begining sounds indicate systolic pressure) as one continues to release pressure in cuff and cuff pressure drops below diastolic pressure, sounds are no longer heart |
|
|
Term
| What happens to Korotkoff sounds when the cuff pressure drops below diastolic pressure? |
|
Definition
|
|
Term
| What is the formula for determining pulse pressure? |
|
Definition
PP = SP - DP
difference between systolic pressure and diastolic pressure |
|
|
Term
|
Definition
| Mean Arterial Pressure - it is themean pressure you would obtain if you took measurements at several interavals trhoguhout a cardiac cyclike (like every 0.1 sec) |
|
|
Term
| What is the formula for MAP? |
|
Definition
|
|
Term
| What would be an avg value for MAP in blood vessels at heart level? |
|
Definition
|
|
Term
| Why does MAP have such a funky formula (geometric mean) why cant we just find the arithmetic mean? |
|
Definition
| At lower heart rates, MAP is not the avg between SP and DP - the curve is spread out; the area under the curve is much greater for SP than DP; simply averaging the two would giv you a MAP that is too high |
|
|
Term
| At high heart rates what happens to MAP? |
|
Definition
| at high heart rates MAP is more closely approximated by the arithmetic mean of systolic and diastolic pressure because of the change in shape of the arterail pressure graph - in thsi case the graph becomes more NARROW |
|
|
Term
| What phase makes arteries expand and absorb some of the force of the ejected blood? |
|
Definition
|
|
Term
| At what fase do arteriaes recoil exerting pressure on the blood? |
|
Definition
|
|
Term
| What is the #1 way blood flow is controlled? |
|
Definition
| Blood vessel diameter (radius |
|
|
Term
| What does vasocontriction do to blood flow? |
|
Definition
|
|
Term
| What is the layer in the blood vessel controlled by ANS? |
|
Definition
|
|
Term
| What is peripheral resistance? |
|
Definition
| The opposition to blood flow resulting from friction developed as blood flows through a blood vessel. The smaller the blood vessel the higher the peripheral resistance |
|
|
Term
| Which vessels are the major resistance vessels? |
|
Definition
|
|
Term
| What does inreased peripheralresistance do to blood flow? |
|
Definition
|
|
Term
| What does inreased peripheral resistance do to stroke volume? |
|
Definition
|
|
Term
| Name 3 factors regulating blood flow? |
|
Definition
1. Vessel diameter (radius)
2. Blood viscosity
3. Blood vessel length |
|
|
Term
| Veins have a higher complicance than arteries. What does thi smean? |
|
Definition
| less muscualr walls than arteries; blood causes more distenstion (expansion) in veins than in arteries |
|
|
Term
| How much of the blood is foundin the veins? |
|
Definition
|
|
Term
| 6 factors that effect venous return? |
|
Definition
1. skeletal muscle pump
2. venous valves
3 respiratory activity
4. cardiac suction
5. vasoconstriction
6. blood volume - influenced by thirst center in hypothalamus, urine volume (hrmones ADH and aldosterone) and distribution of water between plasma and interstital fluid |
|
|
Term
| Explain how the skeletal muscle pump increases venous return. |
|
Definition
| skeletal muscle squeezes on veins during contraction, and due to vein valves. Blood is forced toward the heart (increases EDV or preload) |
|
|
Term
| How does cardiac suction increase venous return? |
|
Definition
| When the heart is in diastole pressure falls just below that in the veins so that blood moves toward the heart |
|
|
Term
| Name 2 hormones that decrease urine volume, increasing blood volume, Include the glands that produce them. |
|
Definition
1. Aldosterone - produced by the adrenal cortex.
2. ADH produced by the hypothalamus and stored in the posterior pituitary. |
|
|
Term
| What is reactive hyperemia? |
|
Definition
| Increased metabolism increases oxygen need and increases buildup of waste therefore hypoxia and decrease in pH and vasodilation of blood vessels to inrease blood flow. |
|
|
Term
| Is reactive hyperemia an example of instrinsic or extrinsic regulation? |
|
Definition
|
|
Term
| Explain the action of intrinsic myogenic control of blood vessel diamter in organs such as the brain? |
|
Definition
| Occurs in some organs, such as the brain; a decrease in arterial pressure causes cerebral vessels to dilate so that adequate rates of blood flow can be maintanied despite the decreased pressure. |
|
|
Term
Baroreceptor, Chemoreflex, Medullary Ischemic reflex?
Similar to golgi tendon organ? |
|
Definition
|
|
Term
Baroreceptor, Chemoreflex, Medullary Ischemic reflex?
Receptor in artery that monitors blood chemistry? |
|
Definition
|
|
Term
Baroreceptor, Chemoreflex, Medullary Ischemic reflex?
Initiated by hypothalamus? |
|
Definition
| Medullary Ischemic Reflex |
|
|
Term
Baroreceptor, Chemoreflex, Medullary Ischemic reflex?
Stretch receptor in artery? |
|
Definition
|
|
Term
Baroreceptor, Chemoreflex, Medullary Ischemic reflex?
Response to a drop in brain perfusion? |
|
Definition
| Medullary ischemic reflex |
|
|
Term
| What hormone is produced by juxtaglomerular apparatus in the kidney? |
|
Definition
|
|
Term
| What hormone is produced by heart; alosterone antagonist; increases sodium secretion in kidneys |
|
Definition
| Atrial Natrieretic peptide |
|
|
Term
| What hormone is another name is vasopressin? |
|
Definition
|
|
Term
| What hormone isproduced by the adrenal medulla? |
|
Definition
|
|
Term
| What hormone is produced by the adrenal cortex under the influence of the anterior pituitary gland? |
|
Definition
|
|
Term
| What hormone is causes the kidneys to reabsorb salt ; water follow thus decreasing urine volune and increasing blood volume and increasing blood pressure? |
|
Definition
|
|
Term
| What hormone isproduced by the hypothalamus; targets kidneys (increases reabsorption of water) turns off sweat glands to retain water, and results in vasoconstriction; all to increase blood volume and blood pressure? |
|
Definition
|
|
Term
| What hormone produceses by basophils; results in vasodilation as part of inflammatory resposne? |
|
Definition
|
|
Term
| What hormone isconverted from renin; vasocontstriction, activates thirst center in hypothalamus increasse aldosterone production? |
|
Definition
|
|
Term
| Name the 2 primary determinants of MAP? |
|
Definition
1. Cardiac Output
2. Total peripheral resistance.
MAP = CO X total peripheral resistance. |
|
|
Term
|
Definition
| Liquid, cell free portion of the blood |
|
|
Term
|
Definition
| plasma that is depleted of its clotting factors |
|
|
Term
| What are 2 advantages to rbc's lacking a nucleus? |
|
Definition
1. It gives them their shape (biconcave disc) which allows them to flex as they pass through capillaries and allows more surface area for gas exchange.
2. It allows them to carry more hemoglobin |
|
|
Term
| What is a disadvantage to rbc's lacking a nucleus? |
|
Definition
| They have no genetic material (DNA) to direct protein synthesis - they cannot make new proteins so they only last around 120 days |
|
|
Term
| What is an advantage to rbc's lacking mitochondria? |
|
Definition
| They do not use any oxygen they are carrying for their aerobic respiration (ATP production); mitochondria are the site for the electro transport system (where lots of ATP are produced) |
|
|
Term
| Describe the hemoglobin molecule |
|
Definition
| The hemoglobin molecule consists of 4 identical proteins called globins and four nonprotein pigments called hemes (each contains an iron atom) |
|
|
Term
| How many oxygen molecules can a hemoglobin molecule carry at once? |
|
Definition
| 4; each iron binds to an oxygen molecule |
|
|
Term
| The kidneys have hormonal control over hematopoiesis through the production of what hormone? |
|
Definition
|
|
Term
| Specifically, what is the target of this hormone? |
|
Definition
| Bone marrow; it increases hematopoiesis |
|
|
Term
| What may account for a higher hematocrit in males? |
|
Definition
|
|
Term
|
Definition
| They have no DNA to direct protein synthesis, so nothing can be repaired in the cell; for example their plasma membranes get damaged due to friction against the walls of the small diameter capillaries |
|
|
Term
|
Definition
|
|
Term
| Where is the rbc graveyard? |
|
Definition
| spleen msotly and back up is the liver |
|
|
Term
| What is recycled after rbc destruction? |
|
Definition
| The iron in the hemoglobin |
|
|
Term
| What is leftover and how does the body rid itself of this compound? |
|
Definition
| Heme is degraded into a greenish yellow pigment (biliverdin) and then converted to bilirubin by the liver; bilirubin is a component of bile produced by the liver. Bile is used in the small intestine for the emulsification of fats, absorption of fat soluble vitamins etc. So it leaves the body in the feces. |
|
|
Term
| How can a baby get hemolytic disease of the newborn? |
|
Definition
| If the mother is Rh negative and the father is Rh positive there is a chance th ebaby will be Rh positive; Once sensitized from a previous pregnancy, the mother's Ab will cross the placenta and harm the baby |
|
|
Term
How is hemolytic disease of the newborn prevented?
Rhogam (anti Rh antibodies) is administered to Rh negative mothers who have Rh positive partners, to block this reaction |
|
Definition
|
|
Term
| What are 2 important consequences of Transfusion reactions? |
|
Definition
1. The donor's red blood cells are attacked by the recipients antibodies causing clumping or agglutination of rbcs. This leads to clogging of small blood vessels through the body.
2. Red blood cells are lysed releasing their hemoglobin in the blood stream (hemolysis). Circulating hemoglobin passes into kidney tubules and can block the tubules, causing renal shutdown. If complete renal failure occurs, the person may die |
|
|
Term
| What kind of anemia decreases hemoglobin concnetration due to a B12 deficiency? |
|
Definition
|
|
Term
| What kind of anemia results from insufficient numbers of rbcs due to blood loss? |
|
Definition
|
|
Term
| What kind of anemia is insufficient numbers of rbc's due to bone marrow cancer? |
|
Definition
|
|
Term
| What kind of anemia is a genetic disease which causes change in structure of hemoglobin molecule; causes a change in shape of rbc's? |
|
Definition
|
|
Term
| What kind of blood condition causes an excess of rbcs which increases blood viscosity? |
|
Definition
|
|
Term
| Explain the structure of a platelet? |
|
Definition
| Large cells called megakaryocytes shed fragments of their cytoplasm and each fragment becomes enclosed by a piece of the cell's membrane |
|
|
Term
| What do you call the mechanism of blood clotting? |
|
Definition
|
|
Term
| What is the normal platelet count? |
|
Definition
|
|
Term
| What organs remove old platelets from circulation? |
|
Definition
| Macrophages (wbc's) in the spleen and liver remove platelets after 4 - 10 days. |
|
|
Term
| List and explain the 4 major phases involved in hemostasis? |
|
Definition
1. Vascular spasms - immediate response to blood vessel injury is vasoconstriction; fxn: reduce blood loss through hemorraging.
2. Platelet plug formation - plateles swell and form spiky processes; they also become " sticky" and adhere to the exposed area and to each other; the release of different chemiacls attracts great numbers of platelets to the area; platelet plugs are loosely knit.
3. Coagulation - blood becomes gel like; a plasma protein called prothrombin is converted into the enzyme thrombin; the enzyme thrombin catalyzes the joining of plasma fibrinogen molecules into a fibrin mesh, which traps blood cells and seals the hole.
4. Clot removal - clot is later dissolved. |
|
|
Term
| Describe the coagulation phase of hemostasis |
|
Definition
| Prothrombin is converted into the Enzyme thrombin. Thrombin catalyzes the joining of fibrinogen molecules into a mesh, which traps cells and seals the hole |
|
|
Term
| Which anticoagulant is found in spoiled sweet clover, and interferes with vitamin K function? |
|
Definition
|
|
Term
| which anticoagulant is produced by bacteria? |
|
Definition
|
|
Term
| Which anticoagulant is derived from wbc's found in beef lungs and hog intestines; activates antithrombin? |
|
Definition
|
|
Term
| which anticoagulant is produced by leeches; blocks thrombin by binding to it? |
|
Definition
|
|
Term
| Which anticoagulant prevents platelets from sticking together by inhibiting prostaglandin production? |
|
Definition
|
|
Term
| How would you reverse the warfarin effect? |
|
Definition
| megadoses of Vit. K to overwhelm the drug |
|
|
Term
| Why is hemoglobin protein packaged in a rbc instead of being free in the plasma? |
|
Definition
| Free hemoglobin in the plasma would increase the osmolarity of the blood, increasing osmotic pressure (reabsorption pressure); this would cause high blood pressure and would also interfere with hydrostatic (filtration pressure) |
|
|
Term
True or False
If a patient has A+ blood she is able to receive one transfusion of B+ blood without a transfusion reaction occurring? |
|
Definition
| False; she has preformed anti-B (antibody against B) |
|
|
Term
True or False
If a patient has A- blood she is able to receive one transfusion of A+ blood without a transfusion reaction occurring? |
|
Definition
| True, one has to be sensitized to the Rh factor (no preformed Ab) |
|
|
Term
|
Definition
| Blood flow to organs can be adjusted to meet metabolic needs |
|
|
Term
|
Definition
| Most common; abundant in skin and muscles; called continuous, but have small gaps or clefts between the endothelial cells (large enough to allow limited passage of fluids and small solutes) |
|
|
Term
|
Definition
| found in small intestine, endocrine glands, kidneyds; endothelial cells have large fenestrations (pores) more permeable than continuous capillaries |
|
|
Term
| Sinusoid (leaky capillaries) |
|
Definition
| Found in liver, bone marrow, lymphoid tissues, some endocrine glands; these capillaries have large clefts and fenestrations; allow alrge molecules (proteins) and even blood cells to pass out of hte vessel; blood moves sluggishly thorugh sinusoids allowing blood to be processed and modified. |
|
|
Term
| What are the 3 routes that substances pass between blood and interstital fluid? |
|
Definition
1. through intercellular clefts between endothelial cells
2. through fenestrations (pores)
3. through the endothelial cell plasma membrane and cytoplasm |
|
|
Term
| myogenic control - reactive hyperemia |
|
Definition
| Occurs in some organs, such as the brain; a decrease in arterial pressure causes cerebral vessels to dilate so that adequate reates of blood flow can be maintained despite the decreased pressure |
|
|
Term
| Tell me about Aldosterone |
|
Definition
| Produced by the adrenal cortex; causes kidney tubules cells to reabsorb Na+; sine water follows Na+, water is also reabsorbed and returned to the blood which increases blood volume and increases blood pressure; urine volume is subsequently decreased |
|
|
Term
| Atrial natriuretic peptide |
|
Definition
| Produced by atria; aldosterone antagonist; increases sodium secretion by kidneys so that salt is passed in the urine and water is not reabsorbed; increases urine volume and decreases blood volume, decreasing blood pressure |
|
|
Term
|
Definition
| Produced by basophils and other whit blood cells; results in vasodilation (part of inflammatory response) |
|
|
Term
| Tell me about ADH / Vasopressin |
|
Definition
| Produced by the hypothalamus; stored and released by the posterior pituitary; increases blood pressure; 3 targets include (1) kidneys (causes them to reabsorb water and return it to the blood) 2. Sweat glands (turns them off) and 3. smooth muscle of tunica media which creates vasoconstriction. |
|
|
Term
| Tell me about Angiotensin II (AG-II) |
|
Definition
| Renin released from Juxtaglomerular cells of kidney acts on Angiotensinogen which turns into angiotensin I which turns into Angiotensin II; a potent vasoconstrictor, activates thirst center in hypothalamus and increases aldosterone production by adrenal cortex. |
|
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Term
| What is the resistance equatio? |
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Definition
eight X viscosity X length
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pie times radius to the fourth power |
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Term
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Definition
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Term
| Blood flow to indiviaul tissues is regulated by selecteive vasoconstriction and vasodilation of which vessels? |
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Definition
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Term
| What is hyperemia? How does active hyperemia differ from reactive hyperemia? |
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Definition
| Hyperemia is a localized region of increased blood flow. In active hyperemia, the increased blood flow is in response to an increase in metabolism. Reacive hypermia is an increase in flow that follows a period of decreased blood flow. |
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Term
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Definition
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Term
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Definition
| Time during which ventricles are contracting and emptying |
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Term
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Definition
| Time during which ventricles are relaxing and filling |
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