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Flashcards in PHYS 1 MIDTERM 1 Deck (500):
1

What is Physiology?

The study of living function.

2

About how many cell do humans have?

75 Trillion

3

What is Homeostasis?

Maintenance of constant conditions within the body.

4

What does it mean to function as an automaton?

The vast Majority of operations are carried out by automatic control systems.

5

Physiology sometimes is thought of as the study of _______ systems.

Control

6

What is the more typical approach to control systems?

Negative feedback

7

Negative feedback involves what type of a response?

Negative

8

The negative feedback consists of what?

A sensor and an output system.

9

Negative feedback is like what system in a house?

The furnace. It is an on/off system

10

Homeostasis is a _____ balanced state of self-regulation.

Dynamically

11

For negative feedback the degree of effectiveness of the control is a function of what?

The "Gain" of the feedback system.

12

Negative feedback system leads to what?

Homeostatic stability.

13

How common is positive feedback and it leads to what?

Uncommon and leads to instability.

14

Positive feedback involves what type of response?

In the Positive or same direction.

15

Positive feedback leads to what?

a vicious cycle that circles until death.

16

When is positive feedback helpful?

in short-term situations like blood clotting and action potentials.

17

What does thrombocytopenia mean?

Low levels of platelets.

18

Idiopathic thrombocytopenia purpura is what type of disorder?

One of decreased platelet numbers. normal platelet numbers 200,000-400,000 down to 50,000 or less.

19

what are the 2 versions of idiopathic thrombocytopenia purpura?

Childhood version that seems to self-resolve Adult version needs ongoing therapy.

20

What are the signs of idiopathic thrombocytopenia purpura?

easy bleeding micro-bleeds easy brusing nosebleeds

21

What are the laboratory findings of idiopathic thrombocytopenia purpura?

Prolonged bleeding times anemia may develop deficient clot retraction.

22

What type of fluid is blood?

A transportation fluid.

23

What color is oxygenated and deoxygenated blood?

oxygenated = brighter red deoxygenated = darker red

24

What is the specific gravity of blood?

1.050 g/ml

25

What is the ph and temperature of blood?

ph= 7.4 temp = 37 c or 98.6 f

26

How much more viscous is blood than water?

3-5 times more.

27

How much blood does the average person have?

5 liters 7.75% of body weight.

28

What % of blood is Plasma, WBC with platelets, and RBC?

Plasma= 55% WBC with platelets= very little RBC= 45 %

29

What is the thin veneer in the middle of a test tube of seperated blood called and made of?

Buffy coat made of Leukocytes and platelets.

30

The erythrocytes make up 45 % of the blood in a test tube and the volume of rbc in blood is known as?

Hematocrit

31

What are the specific values for Hematocrit?

5,000,000 +- 500,000 per mm3

32

A decreased hematocrit is indicative of what?

Anemia

33

You are considered anemic with a hematocrit count of how low?

4 million of lower

34

An increased hematocrit is indicative of what?

Polycythemia.

35

What is polycythemia?

A high amount of RBC.

36

What is the hematocrit count for polycythemia?

6 million or more.

37

Extreme polycythemia can result in what?

An interrupted blood flow to microvasculature.

38

Each RBC is packed with what, and what will it do?

Hemoglobin carries o2

39

How much hemoglobin is contained in 100 ml of blood?

15 grams

40

Each RBC contains how much hemoglobin?

250 million

41

How much o2 can each rbc carry?

about 1 billion.

42

How many liters of o2 are found in the entire blood?

1 liter.

43

Total RBC numbers is a function of what?

Oxygen Content.

44

What is erythropoiesis?

Making of RBC in Bone marrow.

45

What controls the amount of RBC made?

A hormone called Erythropoietin aka epo

46

Where is erythropoietin primarily produced at?

Kidneys.

47

When will erythropoietin be made?

When blood oxygen is low the oxygen in the kidneys will be low and this signals the kidneys to make more erythropoitin.

48

Erythropoietin is an example of what type of feedback to maintain homeostasis?

Negative feedback.

49

What is physiologic polycythemia?

An increase in RBC in people who live in high altitudes.

50

What is hemoglobin made of?

It is a protein made of amino acids and Iron.

51

What is needed to make erythropoietin?

Vitamin b12 and folic acid.

52

How long will RBC last in the blood?

120 days.

53

Without centrifuging blood just letting the RBC seperate out from the plasma and the WBC what would this process be called?

Erythrocyte sedimentation rate.

54

What is a normal erythrocyte sedimentation rate?

5 mm/hour

55

What would an increased erythrocyte sedimentation rate mean?

It is elevated during infection, cases of arthritis and inflammatory diseases.

56

Why will the erythrocyte sedimentation rate increase during infections?

Tissues release acute phase reactant proteins that stick on RBC and allow them to clump together and this increases the rate of sedimentation.

57

What besides water is the major component of Plasma?

Plasma Proteins.

58

What plasma protein helps with pressure of capillaries? And how? What is this called?

Albumins. The fluid will want to come inside the capillaries to establish an equillibruim with the albumins. Called Plasma colloidal osmotic pressure.

59

Plasma proteins are involved in what?

Carriers, defense, clotting/coagulation.

60

Name the 3 broad groups of Plasma proteins? List them in the order of smalles to largest.

Albumins, Glogulins, and Fibrinogens.

61

Nearly all the plasma proteins are made where?

In the liver.

62

What Plasma proteins help as a carrier function? what will they specifically bind?

Albumins. Fatty acids. Globulin

63

What are the 3 types of globulin?

alpha= a globulin Beta = b globulin gama = y globulin

64

List the 3 groups of plasma proteins starting with the least commn and ending with the most common.

Fibrinogen, Globulins, Albumins

65

Alpha a globulin does what?

Transports or carries: proteins, lipids (HDL), Steroid-binding proteins, and clotting factors.

66

Beta B globulin does what?

Transports or carries: Lipids (LDL), and Iron.

67

Beta B globulin carries iron as what?

Transferrin.

68

Gama Y globulin does what?

it is a family of various antibodies.

69

What is fibrinogens main purpose?

Precursor to a clot.

70

clotting is a function of what?

plasma proteins.

71

Fibrinogen is a precursor to what?

Fibrin.

72

What is fibrin?

A molecule that can polymerize to form an insoluble mesh used to minimize blood loss.

73

Fibrin does what to blood?

Coagulates it (turns from liquid to solid) aka clotting.

74

What happens to Fibrinogen to make a clott?

Fibrinogen ---------> Fibrin Monomer--------> Cross-linking fibrin Ca2+ Fibrin stabalizing and Thrombin Factor

75

What does hemostasis mean?

Blood same. This is the ability to maintain blood volume.

76

What 3 mechanisms help with hemostasis?

1. Vascular constriction. 2. Platelet 3. Clot formation.

77

What induces vasoconstriction?

Trauma to a vessels wall. This trauma releases a local vasoconstrictive factor from smaller vessels like endothelin-1.

78

How do platelets stimulate vasoconstriction?

They release thromboxane A2 and serotnin.

79

What will promote platelet aggregation to help make a platelet plug?

Thromboxane and thrombin.

80

While forming a platelet plug thrombin functions through what system?

IP3/DG

81

Platelets are small fragments from where?

Bone marrow megakaryocytes.

82

What do Platelets have inside of them?

NO nucleus, but they have various organelles. They are also covered with lots of receptors.

83

What are the three processes a platelet goes throught when contacting a damaged vessel wall?

1. Adherence 2. Aggregation 3. Secretion.

84

What makes a platelet adhere to a damaged vessel wall?

Contact with damaged endothelia and contact with tissue proteins including collagen.

85

Simultaneous aggregation of platelets form what?

A Platelet plug

86

What are platelet plugs used for that clots are not?

Platelet plugs are useful in routine daily injuries that produce tiny holes in vessels.

87

Aspirin can effect platelets how?

It can inhibit platelet aggregation.

88

During normal hemostasis which pathway is used?

Both intrinsic and extrinsic pathways.

89

What are the major players in blood clotting besides factors?

Thrombin is the major player, but ca2+ and platelet phospholipids are also important.

90

What is calcium chelation?

A way to keep blood from clotting in a test-tube because it removes calcium and this stalls many clotting reactions.

91

What is the primary activation for the intrinsic pathway in blood clotting?

contact with collagen or trauma to the blood.

92

What is the primary activation for the extrinsic pathway of blood clotting?

Release of tissue factors.

93

How long will blood clotting take?

1-6 minutes.

94

What makes the blood clotting system turn from positive feedback to negative feedback?

Anti-clotting mechanisms.

95

What specifically happens to Fibrinogen to make it fibrin?

Clipping off parts of Fibrinogen.

96

What is needed to change fibrinogen to fibrin?

ca2+ and thrombin.

97

What is needed to make thrombin?

You start with prothrombin and you need ca2+ and prothrombin activator. Then you get thrombin.

98

Prothrombin activator is a complex substance made of several molecules, but mostly what?

Factor X.

99

What has to happen to factor X for it to help make Prothrombin?

factor X ---------------> Factor Xa (a signals that it is the activated form) ca2+

100

What ways can prothrombin be activated?

Intrinsic pathway and Extrinsic pathway.

101

The intrinsic pathway used to activate prothrombin requires what factors?

IX, and VIIIa.

102

Which pathway is faster at activating prothrombin intrinsic or extrinsic?

Extrinsic pathway is the quickest.

103

Which pathway is most effective at activating prothrombin?

Intrinsic pathway because it is amplified.

104

which factors are required to use the extrinsic pathway?

VII, III

105

The bl0od clotting system is an example of what type of feedback?

Positive.

106

How is the endothelial lining of vessels engineered to act as a anti-clotting mechanism?

They are smooth simple squamous cells that are coated with glycocalyx which tends to repel clotting factors.

107

A formed clot will minimize blood flow to the area and how will this be an anti-clotting factor?

This will minimize the amount of clotting factors that can come into the area.

108

How will thrombin help with anti-clotting?

It will activate an alpha a globulin (plasma protein) called antithrombin III which will bind to thrombin and inactivate it in a delayed way that takes longer than clotting.

109

What will help antithrombin III destroy or inhibit thrombin? Where will it come from?

Heparin that comes from mast cells.

110

What is fibrinolysis?

Plasminogen is an inactive protease (a group of enzymes that degradates proteins) that will destroy fibrin when activated and this happens as fibrin is forming.

111

What is the active form of plasminogen and how is it activated?

Plasmin and it is activated by tpa

112

What is tpa? And where will it come from?

Tissue plasminogen activator. It is released from injured tissues a day or so later.

113

tPA has been commercially sold as a drug that is used for?

Acute heart attacks and strokes, but must be infused very soon after injury to be helpful.

114

What vitamin is required for synthesis of several clotting factors?

Vintamin K

115

How is Vitamin K made?

By bacterial flora in the Intestine

116

What does coumarin do?

It is a competitive inhibitor for vitamin K sites in Hepatocytes. It is wrongly called a blood thinner it wont thin blood but it will minimize dangerous clotting in patients.

117

What results from a lack of factor VIII?

Hemophilia A and lots of uncontrolled bleeding.

118

What are 2 thromboembolitic conditions.

1. Thrombus 2. Embolism.

119

An abnormal clot that forms in vessels is called what?

A thrombus.

120

What is an embolism?

A thrombus that breaks away and freely float in vessel.

121

Generally how will thromboembolic conditions arise?

From roughened endothelia or in area where blood moves slowly.

122

why is the platelet count down in Idiopathic thrombocytopenia pruprua?

They are destroyed and removed from the blood in the spleen.

123

What does idiopathic mean and why is idiopathic thrombocytopenia purpura idiopathic?

Unknown and the root cause of this disease is still unknown.

124

Why will people with idiopathic thrombocytopenia purpura have increased bleeding times?

Because they need platelets to participate in clotting pathways.

125

Why will people with Idiopathic thrombocytopenia Purpura bruse easy?

With low platelets they cant fix routine micro holes in the vessels and this leads to bleeding from membranes and dermal microvasculature.

126

What form of Idiopathic thrombocytopenia Purpura is more serious the childhood or adult form? And why?

Adult. Because of autoimmunity.

127

What are some treatment for idiopathic thrombocytopenia purpura?

Some receive a splenectomy. Some receive platlets. Some get corticosteroids.

128

How many children will show a functional murmur at some point in time?

80%

129

How can you tell someone has a functional murmur?

Listen for a sound that can be heard during the ejection of blood from a normal heart. A noise between the lub and dub of the heart.

130

What specifically will the sound of a functional murmur sound like?

short and twangy low-pitched sound.

131

A functional murmur will often be seen with what other conditions?

Anxiety, stress, fever, anemia, hyperthyroidism, or pregnancy.

132

What is the physics formula for flow?

Q=delta P/R Q= flow Delta P = pressure differential R= vascular resistance.

133

What happens to Q (flow) if R (vascular resistance) is increased?

IT goes down.

134

How can we solve for R (vasculature resistance)?

R= 8nL/pi r^4 n= viscosity L= length r= radius

135

viscosity of blood is just a function of what?

Hematocrit (a measure of what percentage of blood is RBC).

136

What is more viscous plasma or water and why?

Plasma because of proteins.

137

What is the formula for blood flow after we take out all the factors that can't be changed?

Q = r^4

138

What is the single greatest determinant of blood flow through a vessel?

The diameter (or Radius).

139

Doubleing the diameter of a blood vessel will increase its flow by how much and why?

16 fold because the formula Q=r^4 and the radius is raised to the fourth power.

140

The normal result of blood flow moving through vessels takes what kind of profile?

a Parabolic velocity profile.

141

If a barrier was removed from a blood vessel what blood will travel the fastest and why?

The blood in the middle because there is not drag from the walls.

142

What is the name of the flow when blood moves faster in the middle and slower as we move towards the walls?

Laminar flow.

143

What are the qualities of laminar flowing fluids?

Very efficient, smooth, and quiet.

144

What happens when the streamlines of flowing blood are disturbed?

We get turbulent flow.

145

What are the qualities of turbulent flow?

Inefficient, rough, and noisy.

146

Noise from turbulent flow in vessels and in valves is known as what?

Vessels = bruit valves = murmur

147

Turbulent flow typically happens when?

With obstructions and high velocity.

148

Obstructions will disturb laminar streamlines into what?

Eddy currents.

149

What is stenosis and what will it cause?

A narrowing and it causes the velocity to increase and the total flow to decrease.

150

When we increase the diameter of a blood vessel what happens to flow and what happens to pressure of the blood upstream?

The flow will increase, but the pressure upstream will decrease as more blood is flowing through.

151

What other agents will help convert or activate plasminogen besides tPA?

Tissue lysosomes.

152

What is Reynolds number?

The point when turbulence happens.

153

What is the destabilizing factor in reynolds number?

Velocity.

154

How will shear force effect blood flow?

Normaly it is minimal, but with turbulence (exceeding reynolds number) it causes clotting and additional injury.

155

What is carotid artery stenosis? what will it cause? how common is it?

The carotid artery becomes occluded by fatty plaque. It can cause a ischemic stroke common in aging process

156

During carotid artery stenosis what is reynolds number like?

It is exceeded and turbulence happens.

157

What are korotkoff sounds?

Normal arterial noises heard during routine assessment of blood pressure using the ausculatory method and using a sphygmomanometer and a stethoscope.

158

What is auscultation?

Listening to beats with the stethoscope.

159

What is compliance when talking about blood vessels?

Intravascular pressure that stretches blood vessels in proportion to their ability to absorb more blood.

160

How is compliance numerically defined?

a change in volume per a change in pressure: Compliance= delta V/delta p

161

What is more compliant an artery or a vein?

Arteries are not very compliant Veins are very compliant.

162

What type of stimulation can modify the performance of vessel systems?

Sympathetic stimulation

163

What percentage of our blood is found in Veins/venules, and arteries/arterioles?

Veins/venules= 64% or about 2/3 artery/arterioles= 15%

164

What is the aorta used for?

Pulse dampening and distribution.

165

What are large arteries used for?

Pulse dampening and distribution.

166

What are small arteries used for?

Distribution and resistance.

167

What are arterioles used for?

Distribution and resistance.

168

What are capillaries used for?

Nutrient and waste exchange.

169

What are venules used for?

limited exchange and collection. Also some capacitance (blood storage).

170

What are Veins used for?

Capacitance

171

What is the Vena cava used for?

collection of blood sent into the heart.

172

What does it mean for a vascular compartment to be variably compliant?

Due to the capacity of the vascular system's smooth muscle cells to relax if exposed to sustained stretching forces the vessel can be enlarged if chronically overloaded with blood and this is a DELAYED COMPLIANCE.

173

Can delayed compliance also constrict vessels to increase pressure?

Yes.

174

What is the major determinant of flow?

Q=R^4

175

What causes the noise heard in a functional murmur?

due to the powerful ejections of blood from the left ventricle this can cause the blood to exceede reynolds number and become turbulent in the aortic arch.

176

Why is a functional murmur termed functional?

because it is of physciological and not anatomical origin.

177

What phase of heart contraction is the functional murmur heard?

Systole phase.

178

What causes contact dermatitis? What will contact dermatitis cause?

Contact with an external agent. It causes a localized inflammation response in the integument.

179

What are the 2 types of contact dermatitis? Which one is more common?

1. Irritant (80%) 2. Allergic (20%)

180

What are the clinical features of contact dermatitis?

within minutes of exposure the skin becomes itchy, red and may blister.

181

How long will contact dermatitis last?

it disappears within a few days to weeks and blisters dry up.

182

What type of cells are the capillary beds made of?

Metabolizing cells.

183

Most blood vessles have _____ muscle around them in the form of a ______ _______.

Smooth, Tunica media.

184

What are the regulators of microvasculature (controlling the entry into capillaries)?

Arterioles

185

How is vascular smooth muscle innervated?

sympathetic branch of the autonomic nervous system.

186

Decreasing the radius of a blood vessel will do what to blood? This is aka?

decrease flow aka vasoconstriction

187

Increasing the radius of the blood vessels will do what to blood flow and it is aka?

It will increae flow and it is aka vasodilation.

188

What type of contractions will smooth muscle have?

slow sustained tonic contractions.

189

What is vascular smooth muscle like?

It is composed of small spindle shaped cells that lack the regulatory protein troponin. The actin and myosin are poorly organized. they can maintain a good slow level contracted state.

190

Is calcium needed for vascular smooth muscle to contract?

Yes. also needs atp.

191

What 3 ways can vascular smooth muscle tone be modified?

1. Mechanical stimulation 2. Electrical stimulation 3. Chemical stimulation

192

How is mechanical stimulation of vascular smooth muscle tone accomplished?

Rapid expansion of a vessel causes depolarization of the vascular smooth muscle (passive stretching lead to a contraction).

193

Why is the mechanical stimulation of vascular smooth muscle often described as autoregulation?

Because it stabilizes the flow.

194

Is the mechanical stimulation of vascular smooth muscle a slow or fast reaction?

Fast.

195

If flow is increased in a vascular blood vessel what will mechanical stimulation do to it?

It will cause vasoconstriction and decrease the flow.

196

What happens to a vascular blood vessel with mechanical stimulation if the blood flow is decreased?

It causes vasodilation and increases flow.

197

How will mechanical stimulation of vascular blood vessels be effected by sustained force?

It may do the oppostie due to the slow delayed compliance.

198

What do endothelial cells of blood vessels do with increased shear stress?

They secrete nitric oxide.

199

What will nitric oxide do to vascular smooth muscle?

Causes Vasodilation.

200

How will electrical stimulation of vascular smooth muscle work?

It will open voltage-dependent ca2+ channels and start an action potential in a neighboring smooth muscle cell.

201

How will the chemical stimulation of vascular smooth muscle cause a contraction or vasoconstriction?

The chemicals traveling from far or near will use the standard signal transduction pathway to increase intracellular ca2+ and elicit contraction.

202

Name the chemicals that are given that will cause vascular smooth muscle to contract?

norepineprine angiotensin II Vasopressin, Endothelin-1 Serotonin thromboxane a2

203

How will chemical stimulation cause vascular smooth muscle to relax or to vasodialate?

They cause a relaxation by inhibiting the contractile machinery.

204

Name the given chemicals that will chemicaly stimulate vascular blood vessels to vasodialate?

Nitric oxide prostacyclin local metabolites.

205

What will vascular smooth muscle need to respond to chemical stimulations?

Receptors or nothing will happen.

206

What are adrenergic receptors used to bind?

norepinephrine and epinephrine.

207

What specific adrenergic receptor is sensitive to norepinephrine? This receptor is released from what?This reaction will cause what?

alpha1 receptor axons of sympathetic fibers vasoconstriction

208

What will Beta2 receptors cause?

Vasodilation

209

What is an alpha blockade?

it uses alpha adrenergic blockers that are specific to alpha1 receptors to manage blood pressure in hypertensive patients this causes widespread vasodilation.

210

What will endothelin-1 receptors and Angiotensin-2 receptors cause to happen when they get the proper chemical stimulant?

They cause vasoconstriction.

211

What chemical is cholinergic receptors sensitive to? What will this cause.?

acetylcholine causes vasodilation

212

Are the same receptors in different areas of the body equally receptive?

no cerebral vascular smooth muscle is not nearly as responsive as GI vascular smooth muscle.

213

Nitric oxide is secreted due to shear forces of the arterial walls and how else?

It is released by endothelial cells after shear force is excerted on them and when endothelial cells have hormones and paracrine compounds stiumlate them. Both ways nitric oxide is released and causes vasodiliation.

214

How will nitric oxide cause vasodiliation?

It acts as a paracrine agent and causes intracellular levels of ca2+ to drop.

215

How will prostacyclin specifically effect vascular smooth muscles?

When signaled to do so by blood borne agents endothelial cells will release prostacyclin(a hormone and paracrine agent) and this causes vasodilation working through the G-protein singal transduction system.

216

What is a vascular spasm?

A rapid and profound vasoconstriciton with endothelial injury. When the endothlia is damaged it loses it's ability to secrete nitric oxide and loses its ability to balance diameter and the diameter shifts towards vasoconstriction.

217

What is the purpose of nitroglycerin & amyl nitrite when talking about vascular vessels?

It is an organic nitrate drug that can cause profound vasodilation. They just serve as an extra source of nitric oxide. Used with chest pain to allow vasodilation and let more blood flow to the heart.

218

What will the production of H+ and co2 made in tissue cause to happen in vascular vessles?

It inhibits the ability of vascular smooth muscle to contract and this induces a local vasodilation.

219

What are the 2 broad sources of chemical agents that effect vascular smooth muscle?

Intrinsic- local control Extrinsic- Humoral or nervous control.

220

Generally intrinsic control causes what? Generally extrinsic control causes what?

Intrinsic- vasodilation Extrinsic- Vasoconstriction

221

Which control intrinsic or extrinsic is more rapid and more important?

Intrinsic

222

Intrinsic control usually comes from where?

Local paracrine agents from tissue.

223

When is the extrinsic control most important?

During critical periods.

224

What makes extrinsic control more potent?

Receptors Non essential tissues can have lots of receptors and be very vasoconstricted Under these circumstances extrinsic control cna overide intrinsic control.

225

Increased metabolism will do what to blood flow?

Increase it.

226

Decreased metabolism will do what to blood flow?

Decrease it.

227

Why will increased metabolism increase blood flow?

due to the production of tissue metabolites (waste) that needs to be removed. NOT due to oxygen demand.

228

What is active hyperemia?

Increased blood flow from activity/metablism.

229

With increased blood flow the tissue produces a reddening color called what?

Rubor.

230

What is the major metabolic waste from tissues or cells?

H+ This comes from co2 + h2o--> h2co3- + H+ so co2 is part of this process and is also a metablic waste.

231

Besides H+ and Co2 what are some metabolic waste from tissues or cells?

Adenosine Potassium ion Lactic acid

232

What is the primary control for setting tissue blood flow in the body and what is it like?

Local control and it is automatic and tissue centered.

233

Since all tissues are crying out I want blood, but they all cant get what they want and some become deprived of nutrients and this is called?

Ischemia.

234

When tissues are ischemic they are not getting enough blood and are deprived of oxygen and accumulate deoxygenated blood and get a blue color called?

Cyanosis.

235

Ischemia will produce what in affected tissues?

Pain.

236

Since automatic control of blood flow could lead to chaos how will body wide order be controled?

Nervous control.

237

What is bradykinin?

Damaged blood that causes vasodilation.

238

What type of chemical stimulant is histamine on vascular vessels? Where will it come from?

vasodilation comes from mast cells.

239

What is reactive hyperemia?

After a tissue is ischemic it has had no blood for a while and when blood is restored blood will flow there in a massive way that nearly matches the amount of blood that would have been delivered there the whole time it is blocked. Lots of blood will flow here until complete restoration of oxygen levels and all metabolites are gone.

240

Extrinsic control of the vascular sytem involves what?

The Central nervous system.

241

What type of axons innervate vascular smooth muscle?

Autonomic axons.

242

where do the autonomic axons come from that innervate the vascular smooth muscle?

The spinal sympathetic chain.

243

the axons that terminate on vascular smooth muscle will secrete what? what will it do?

They Secrete norepinephrine that lands on alpha1 adrenergic receptors and cause vasoconstriction.

244

what is vasomotor tone?

A steady low-level activity of autonomic nerves that produces a background tone(a vasoconstiction tone) in the peripheral vasculature.

245

How will most systemic blood vessels get innervated?

By spinal sympathetic chain axons NOT paraysmpathetic innervation.

246

Overall what effect will the autonomic nervous system have on blood vessels, blood pressure, and blood volume?

Blood vessels will vasoconstrict Blood pressure will rise Blood volume available to be used will increase, but actual volume remains the same.

247

Name another type of extrinsic control of vasculature besides autonomic control?

Hormonal systems.

248

where is the adrenal medulla found at and what will it do?

it is located above the kidneys. It is an extrinsic control of vasculature.

249

what will the adrenal medulla release and what will this do?

Epinephrine 80% and norepinephrine 20% This will cause vasoconstriction.

250

What will cause the adrenal medulla to release it's hormones (epinephrine and norepinephrine)?

Sympathetic nervous system axons that originally are in the medulla of the brain.

251

After the adrenal medulla relase epinephrine and norepinephrine where will it go?

It goes to alpha1 adrenergic receptors on vascular smooth muscle and this causes vasoconstriction.

252

When wil the adrenal medulla release it's hormones?

After sympathetic nervous system tells it to, and this is probably a steady background release rate.

253

How fast and how powerful are the hormones released by the adrenal medulla on vasculature smooth muscle?

It is powerful, but slow.

254

How is the kidney involved in extrinsic control of the vascular smooth muscle?

The renal cortex relases renin.

255

What will renin released from the renal cortex do?

It causes the formation of angiotensin II.

256

What will angiotensin II do?

It will go to angiotensin II receptors on vascular smooth muscle and causes endothelin-1 production to result in vasoconstriction.

257

When will the renal cortex release renin?

This is probably a steady background release rate .

258

How powerful and how quick is the effect of renin on the vascular smooth muscle?

It is powerful and slow.

259

What will the posterior pituitary gland do to effect vascular smooth muscle?

It will release vasopressin.

260

What will vasopressin do?

It effects blood vessels and renal collecting ducts.

261

Where will vasopressin go?

It goes to vasopressin receptors at many locations.

262

How will vasopressin effect vascular smooth muscle and how will it effect collecting ducts of the kidneys?

It will cause vasoconstricion of the vascular smooth muscle. It will cause more aquaporins in cells and this results in retention of water.

263

When will the posterior pituitary gland release vasopressin?

This is also a steady background release rate.

264

How powerful and how fast are the effects of vasopressin?

Powerful and slow.

265

How will hormones effect the extrinsic control of blood vessels, blood pressure, and available blood volume?

Blood vessels will vasoconstrict Blood pressure will go up available blood volume will increase.

266

What is contact dermatitis?

Dermal inflammation due to exposure to an irritant or allergent.

267

How will harsh chemicals cause irritation?

They cause local mast cell degranulatoin.

268

How will allergents cause contact dermatitis?

Langerhans cells of the epidermis alert the rest of the immune system and the sensitization process begins.

269

In all cases of contact dermatitis what is released?

Histamine

270

What will histamine do to the arteriols and the capillaries?

It will promote vasodilation and capillaries will be leaky.

271

How long after contact to irritant in contact dermatitis until the skin becomes itchy and red? Why?

minutes, because histamine must change vessels and it takes a short while to leak enough fluid out to accumulate faster than it can be removed.

272

Congestive heart failure is a condition wherein what happens?

The heart fails to adequately pump blood.

273

How long will it usually take to develop congestive heart failure?

It is a gradual disease.

274

What are 2 subforms of congestive heart failure?

systolic and diastolic.

275

How common is congestive heart failure?

Common in older people. over 50 -1% over 75 -5%

276

Name 3 clinical findings of congestive heart failure?

1. Dyspnea= A breathing Hunger. 2. peripheral edema= swelling in peripheral 3. fatigue

277

What are 2 laboratory findings in congestive heart failure?

1. Enlarged heart 2. Low ejection fraction

278

what are cardiac muscle cells like?

Small striated muscle cells anchored by intercalated disks.

279

What will intercalated disks act as?

A point of low electrical resistance.

280

What is functional syncytium?

Allowing the impulse/ action potential to propagate from cell to cell.

281

The heart is a demanding tissue that requires what?

An extensive capillary density within its endomysium to deliver a steady supply of oxygen.

282

What will happen to the cardiac muscle cells with even a slight reduction of oxygen?

Ishcemia, and cells will not be able to maintain its polarized state and will reach its action potential causing it to fire this will cause other cells to fire due to syncytium. Then everything fires out of control.

283

What happens to heart cells when they die?

They can't regenerate.

284

Can cardiac cells grow?

They can't regenerate or reproduce, but they can hypertrophy.

285

What are purkinje cells of the heart?

Special cells that have abandoned much of their myofiberillar appartus for rapid impulse conduction/propagation. They help get the depolarization stimulus everywhere at the right time.

286

What is the action potential of cariac cells like?

The action potential is very long (not the contraction, but the action potential)

287

When will a contraction of cardiac muscle occur in relationship to the action potential?

It comes shortly after depolarization not right away.

288

What are the 3 phases of cardiac muscle action potential?

1. Depolarization 2. Plateau 3. Repolarization.

289

How will cardiac muscle depolarization occur?

Rapid influx of na+ voltage gates that open Ca2+ channels.

290

What is the caridac muscle like during the plateau of an action potential?

cells are resistant to stimulation and can't contract called ABSOLUTE REFRACTORY PERIOD.

291

What is the repolarization phase of the cardiac muscle action potential like?

K+ is relocated to the interior and the cells are in a RELATIVE REFRACTORY PERIOD.

292

what is the end ot the relative refractory period called? And what is it like.

Supranormal excitability period. Where stimulation easily causes another depolarization.

293

What is digoxin?

A poison from foxglove leaves that binds sodium/potassium exchange pumps in cardiac muscles and inhibits them this leads to intracellular levels of na2+ increasing and the ca2+ levels will increase and the heart will have a stronger beat and can cause congestive heart failure.

294

What will happen to a cardiac muscle cell when the cell is lengthened during the relaxation?

It tends to produce a stronger contraction in the next cycle.

295

What type of stess is the heart responsive to?

Chronic stress.

296

What will chronic stress do to the heart?

Cause it to work harder and this leads to very serious hypertrophy.

297

Is the action potential of all cardiac muscle cells the same?

No it is variable.

298

What is the time like that sino-atrial nodal cardiac muscle cells spend depolarizing and repolarizing?

THey are slow to depolarize(send contraction) and quick to repolarize(get ready to contract).

299

What will regular cardiac muscle cells do/show before repolarization?

They have a broad plateau phase.

300

Why will different cardiac muscle cells have variable action potentials?

Due to different inoic gating systems.

301

What will the plateua phase before repolarization do in cardiac muscle?

It sets limits on the number of beats per minute.

302

What is auto-rhythmicity?

Spontaneous action potentials (cardiac cells can spontaneously create action potentials)

303

How will cardiac muscle cells create auto-rhythmicity?

They have naturally leaky membranes that allow ions to move intracellularly.

304

What type of cardiac muscle cells have the fastest cycle of polariztion and repolarization?

SA node (sino-atrial node). Even though the action potential isn't as fast in the depolarization phase.

305

Cardiac muscle cells are complexly covered with what? And this will lead to what?

Receptors. That make cells sensitive to hormones and neurotransmitters.

306

Name the 2 groups of receptors found on cardiac muscle cells?

1. Adrenergic receptors 2. Cholinergic receptors

307

What is the primary type of adrenergic receptor found on cardiac muscle cells? What are these receptors sensitive to and where will this come from?

Beta1 receptors They are sensitive to norepinephrine released from the axons of the sympathetic fibers.

308

What wil norepinephrine do to cardiac muscle cells once it comes in contact with the beta1 receptors(from the adrenergic receptor group)?

Increase the excitability and strength and rate of contractions by hypo-polarizing the plasma membrane of the cell.

309

What is the major cholinergic receptor and what is it sensitive to and where will it come from?

Ach "muscarinic" receptors sensitive to acetylcholine. Acetylcholine is released from parasympathetic fiber axons.

310

What will acetylcholine released from parasympathetic fiber axons do to cardiac muscle cells when it contacts cholinergic receptors(from the cholinergic receptors)?

Decrease the excitability and strenght and rate of contraction by hyperpolarizing the membranes.

311

What are the main pumps of the heart?

The venticles.

312

What type of pump are the atria?

Priming pumps.

313

What is the valve of the heart that is between the right atrium and the right ventricle?

Right Atrioventricular valve aka Tricuspid.

314

What is the name of the valve between the left atrium and left ventricle?

Left atrioventricular valve aka mitral.

315

What are the right and left valves that leave the venticles?

Right and left semilunar valves Right aka pulmonic left aka aortic

316

What is the shape of the right ventricle?

Crescentic or "c" shaped.

317

What will the high pressure pump aka the left ventricle look like?

Cylindrical.

318

What are the 2 circulatory systems of blood flow?

1. Systemic circulation= extensive body wide. 2. Pulmonary circulation= small and goes to lungs.

319

What are the names for the contraction and relaxation periods of the heart?

Contraction= systole relaxation= diastole

320

What is the cardiac cycle?

The full action of the heart per beat.

321

What are the 6 parts to the cardiac cycle?

1. Ventricular pressure 2. Aortic pressure 3. Ventricular volume 4. Electrocardiogram 5. Phonocardiogram 6. Atrial pressure.

322

How will blood flow into the ventricles at rest?

75% comes from normal blood flow through the veins. 25% is done by systolic atrial contractions

323

Since only 25% of blood in ventricles comes from atrial contractions what is the purpose of the atrium?

Maximizes the efficiency of each ventricluar beat.

324

What is isovolumetric relaxation?

A very brief period of no filling of the ventricle during diastole.

325

What is rapid inflow?

It is 1/3 of the time of blood inflowing and filling the ventricles where 75% of the blood is passively brought in.

326

What is diastasis?

1/3 of the time for filling the ventricles where minimal filling happens.

327

What is the atrial systole phase?

1/3 of the time for filling the ventricles where the atria actively fill the last 25% of the ventricals.

328

What are the valves doing during isovolumetric contraction?

The valves are closed.

329

When will the isovolumetric contraction take place?

During the systole phase at the begining.

330

What happens after isovolumetric contractions of the systole phase?

Ejection of blood.

331

What is the end-diastolic volume measuring and what is the number?

Volume of blood in the ventricle at the end of diastolic phase. about 130ml.

332

What is end-systolic volume measuring and what is the number?

It measures the volume of blood in the ventricle at the end of systole about 60ml

333

What is the stroke volume measuring and what is the normal number.

It is the volume of blood that the heart ejected so take the end-diastolic volume and minus the end-systolic volume and we get the stroke volume normal is about 70ml.

334

What will the ejection fraction measure and what is the normal number and when will it be a problem?

stroke volume divided by end-diastolic volume which is a percentage of blood volume ejected and should normaly be 50% problems if it is less than 40%.

335

What part of the electrocardiogram is systole slightly preceded by?

QRS complex.

336

What will the QRS complex do?

It causes the Ventricles to contract. Then ejection happens.

337

What is the T wave?

The part of the electrocardiogram where the ventricle cells repolarized near the end of ejection.

338

What is a P wave?

A P wave causes atrial systolic filling not just blood gussing into the ventricles.

339

What happens to ventricular pressure at the onset of systole and why?

It skyrockets because of the imediate closure of the mitral valve.

340

What is the period of isovolumetric contraction?

The volume of blood will stay the same because the mitral and aortic valves are both closed and ventricular pressure increases because no blood can get out and the ventricle is contracting.

341

When will the peroid of ejection begin?

As the pressure inside the ventricle exceeds the pressure in the aorta then the aortic valve will open and ejection happens.

342

What happens during the period of ejection?

The aortic and ventricular pressure both increase until they reach a peak and then they both start to drop.

343

What happens when the aortic and ventricular pressures fall during the period of ejection?

The Ventricular pressure will fall below the aortic and this will cause the aortic valve to close.

344

What happens after the aortic valve closes?

Isovolumetric relazation because both mitral and aortic valves are closed this allows aortic pressure to remain almost the same and ventricular pressure to fall off to zero.

345

What is the ventricular pressure like during filling of the ventricle?

It remains at essentialy zero and rises briefly during atrial systol filling.

346

What is the normal systolic pressure and what is it?

It is about 120 mm Hg and it is the peak aortic pressure derived from systole.

347

What is diastolic pressure and what is the normal pressure?

It is the lowest aortic pressure found at the end of diastole and it is normaly about 80 mm Hg

348

What could make the Diastolic pressure lower?

Lower heart rates because the aortic pressure would have more time to drop.

349

What is the Dicrotic notch?

It is a small increase in aortic pressure due to elastic recoil following the aortic valve closure.

350

What causes heart noise?

Valve action most likely valves closing.

351

What causes S1 and S2 and what sounds will they make?

S1- Closure of the AV valve and makes the Lub sound S2- Closure of the semilunar valves makes a dub sound

352

What is heart auscultation?

Listening to the heart.

353

What 2 things can cause valvular abnormalities in general?

1. Stenosis- difficulty pushing blood through. 2. Insufficiency- valve fails to prevent backflow.

354

What is Aortic Stenosis? What will it cause and it is known as what?

Difficulty pushing blood through the aortic valve. This creates a loud murmur heard during left ventricular ejection. Can be heard by standing by someone and is called a Thrill.

355

What is aortic insufficiency?

The aortic valve fails to prevent backflow into left ventricle a murmur is heard during diastole.

356

What is mitral stenosis?

Difficulty pushing blood through the mitral valve creates a murmur during second half of diastole.

357

What is mitral insufficiency?

Mitral valve fails to prevent blood to backflow into the left atrium and creates a murmur heard throughout systole.

358

What is chamber dilation?

When the heart has vascular abnormalities it works harder to maintain the net stroke volume and this causes hypertrophy and can overload the heart and this leads to chamber dilation and failure.

359

What is cardiac output?

Combine the stroke volume(volume of blood pumped inot aortic arch each beat) and multiply it by the heart rate (beats per min.) This gives us the volume of blood pumped into the aortic arch per minute.

360

What is the normal cardiac output?

5000 ml/minute

361

Cardiac input can rise from the normal 5L/min to what?

Up to 30L/min

362

What are 2 basic regulations of cardiac output?

1. Intrinsic autoregulation 2. Reflex (extrinsic) control

363

What is the mechanism for intrinsic autoregulation of cardiac output?

Frank-starling mechanism or Law of the heart.

364

What is Frank-starling mechanism or law of the heart?

When Diastolic filing goes up the chamber is stretched and this will increase the end diastolic volume this will increase the strength of contraction and this decreases the end systolic volume and this will increase the stroke volume.

365

According to intrinsic autoregulation of cardiac output what happens when venous return to the heart is increased?

Increase cardiac output in other words put more blood in more comes out.

366

since the heart pumps all the blood that comes to it, it will be described as what type of pump?

A permissive pump.

367

What is most important in regulating cardiac output?

The peripheral factors that affect returining blood flow.

368

What is preload?

An incoming force that creats a tensile load on the chamber muscle prior to contraction

369

What are the limits to increasing cardiac output with just the intrinsic autoregulation? What happens after the top?

it tops out at about 15 L/min. Performance will decline.

370

What else will happen when the right atrium stretches besides frank-starling mechanism?

The SA node is stretched and this will increase rate of discharge (heart rate increaes).

371

What is afterload?

The tensile load the heart or a muscle must exert itself.

372

Will blood pressure affect cardiac output?

not normally only when aterial pressure becomes so high that it is too dificult to pump against.

373

How is reflex (extrinsic) control of cardiac output done? How much can it increase the cardiac output?

Mostly by nerves of the autonomic nervous system. Can increae up to 30 L/Min.

374

What part of the heart will sympathetic and the parasympathetic innervations mainly go to?

Sympathetic- The Ventricles. Parasympathetic- The Nodal tissues.

375

what nerve supplies parasympathetic innervation for the heart?

Vagus or X cranial nerve.

376

What will the sympathetic nervous system activate the body to do?

Cope with stress or situations of heightened response.

377

What will the parasympathetic nervous system do for the body?

attends to digestive, elimination and glandular functions.

378

What will sympathetic and parasympathetic neurons secrete?

Sympathetic- norepinephrine parasympathetic- acetylcholine.

379

What will the autonomic nervous system mostly do to the cardiovascular system?

Readiness regulator. Or sympathetic

380

In what 3 ways will nerves effect cardiac muscle?

1. Dromotropic effect- conduction speed 2. Chronotropic effect- rate of contraction 3. Inotropic effect- strength of contraction

381

What receptors will work with norepinephrine and where are they found at?

Beta 1 adrenergic receptors and they are found on cardiac myocytes.

382

What happens to cardiac muscle cells when their beta1 adrenergic receptors bind with norepinephrine?

This will increase dromotropism, chronotropism, and inotropism This increases the heart rate to about 200 beats/min. And this increases stroke volume to 100%

383

What else will norepinephrine do to cardiac muscle cells?

Renders them receptive to circulating epinephrine that comes from adrenal glands.

384

When we exercise how will sypmathetic nervs effect stroke volume and heart rate?

They both increase, but stroke volume is increased early and heart rate steadily increases with work.

385

What is the maximum efficiency of the heart?

140-160 beats per minute.

386

What is tachycardia?

a heart rate greater than or equal to 100 beats/min.

387

Is Tachycardia normal?

If not at rest then it can be, but at rest this would be a problem.

388

If sympathetic nervous system stops what effect will this have on the heart? Will this ever happen if so when?

It can reduce the cardiac output by 25%. It should never happen because there is a background level of sympathetic activity from the brain.

389

What will Beta2 receptors found on cardiac vasculature do when sympathetically stimulated?

cause vasodilation.

390

What is beta blockade?

Drugs called beta blockers limit the cardiac output like a governor on a car by blocking the beta 1 adrenergic recpetors from receiving their signals from the sympathetics.

391

When cardiac muscles have the acetylcholine receptors they will respond to what?

Acetylcholine from the parasympathetic system.

392

Where will most acetylcholine receptors be found at?

On the SA and AV nodal cells.

393

What will happen to the cardiac cells stimulated by acetylcholine through acetylcholine receptors?

A negative dromotropism, chronotropism, and inotropism Leading to a decreased heart rate at about 30-40 beats/min. And a decreaed stroke volume of 25%.

394

What happens to the parasympathetics of the heart when the heart receives sympathetic innervation?

It is attenuated, and vice versa.

395

What is bradycardia?

a heart rate at or below 60 beats per minute.

396

Is bradycardia normal?

In healthy people it can be and abnormal in other conditions.

397

Reflex control of the heart generally enhances what?

Natural performance.

398

What type of control is rapid and even anticipatory?

Reflex control.

399

What happens when preload of the heart becomes too great?

The heart enters a state of decompensation and decreased ejection and increases venous return. This leads to congestive heart failure.

400

What is congestive heart failure?

An inability of the heart to produce an adequate cardiac output.

401

Congestive heart failur is also considered to be a form of what?

A decompenstaed heart.

402

What type of condition is congestive heart failure?

chronic condition.

403

What are the physciological findings of congestive heart failure?

Failure of the law of the heart. More blood in does not give us more blood out anymore.

404

Where will blood backup into with congestive heart failure?

commonly in lungs and periphery like the ankels, and feet.

405

People with congenstive heart failure get fatigued due to what?

decreased cardioac output.

406

what is CAD?

Coronary artery disease.

407

What is CAD a major source for?

Congestive heart failure.

408

What is A-V heart block due to?

An arrhythmia due to a blockage in the electrical conduction system.

409

What are the subtypes of A-V heart block?

1st degree- mild interruptions, second degree- moderate interruption, third degree- severe interruption/disruption.

410

How common are the different types of A-V heart block, and what symptoms will they have?

First degree is common and symptom free. Second degree is less common and causes irregular heart beats, thrid degree is a complete disruption and results in cardiac output problems.

411

What are the laboratory findings for A-V heart block?

Abnormal ECG.

412

How will all heart cell contractions originate?

With a myocyte action potential.

413

Since each cardiac cell has its own unique action potential that allows them to spontaneously depolarize and impulse and then propagate this to the neighboring cells how will the heart not get out of control?

It has a wiring system called the conduction system.

414

What makes cardiac conduction system cells different from cardiac muscle cells?

They lost ability to contract a lot, but can conduct depolarization impulses rapidly.

415

What region of cardiac muscle cells is fastest to recycle (have a short refractory period)?

SA node.

416

Because the SA node is fastest at recycling what will it be able to do?

It usually leads the pack and is known as the pacemaker because it produces a sinus rhythm.

417

What else besides the SA node can become the pacemaker of the heart?

Any patch of cardiac tissue that fires faster than the SA node.

418

Why will cardiac muscle cells usually not mis-fire (impulsing before the SA node)?

They have a longer refractory period.

419

What happens when the SA node is stretched?

It tends to fire faster and increase the heart rate.

420

Will contraction impulses spread faster across the atria or ventricles?

Faster across the atria.

421

What will the fibrous skeleton do with the electrical impulses?

It will prevent it from leaking into ventricles except at the AV node.

422

What will the AV node do to the impulse propagation?

It holds it up for 1/10th of a second.

423

Why is the impulse delayed at the av nodes?

it allows the atria to have enough time to physically contract before ventricles contract allows them to be topped off.

424

Besides creating a pause in the impulse propagation what will the AV node do to the electrical impulse?

It wont allow it to go backwards a one way street.

425

What will the parasympathetic and sympathetic stimulation do to the SA and AV nodes?

Paraympathetic- hyperpolarizes the SA and AV nodes, Sympathetic- hypo-polarizes the nodes.

426

What is the electrocardiogram?

a display from a supersensitive voltmeter called and electrocadiograph.

427

What will an electrocardiogram represent?

a collective voltage of thousands of cells.

428

What will the ECG's P wave correspond to?

atrial depolarization.

429

What will the ECG's QRS complex correspond to?

Ventricular depolarization.

430

What will the ECG's T wave correspond to?

Ventricular repolarization.

431

What will the Q wave from the QRS complex correspond to?

Depolarization of the emerging bundle of AV nodes.

432

What will ther R wave from the QRS complex correspond to?

Rapid depolarizatoin of the ventricles.

433

What will the S wave from the QRS complex correspond to?

rapid reversal of the impulse directoin at apex and now towards the base.

434

The QRS complex happens real fast and what will it mean if it is not smooth or slow?

indication of a serious problem in the ventricles.

435

What is the flat line on the ECG called?

A segment.

436

What is a combination of waves or wave segment on an ECG?

Interval.

437

What is the PR segment of an ECG due to?

AV nodal slowdown.

438

What is the ST segment of an ECG due to?

IT is during the absoluted refractory period.

439

Why would the ST segment be examined?

To see if there is serious problems in the muscle cells of the ventricles.

440

How did the pr segment get its name?

Beacuse this happens when the Q wave is absent.

441

What is the PR segment showing?

A long delay in the AV node that indicate some sort of electrical system blockage between atria and ventricals.

442

What is an interesting use of an ECG?

To calculate the direction of specific voltage directions.

443

What is it called when we plot the direction of electrical current flows in the heart?

Vectorcardiography.

444

How can one synthesize a mean QRS vector? This is AKA?

By summating the QRS voltage. AKA electrical axis of the ventricles.

445

What is the average location of the electrical impulse?

60 degrees going from the subjects left arm.

446

What will changes in the vector of the electrial axis of the ventricles show?

Changes/ damage to the ventricles.

447

What is the normal range of the QRS vector? What will a shift out of this range be termed?

-10 degrees to 100 degrees. known as axis deviation

448

What is an ECG Lead?

The specific location of the volt-meter electrodes on the subject not the electrodes themselves.

449

Why are there so many different ECG leads?

So we can get different views of the heart.

450

What is the key purpose of the conduction system?

TO create a synchrony.

451

What is asnchronous contractions called?

Arrhythmia.

452

What are 4 different ways in which an arrhythmia can occur?

1. Abnormal rhythmicity of the pacemaker itself. 2. Blocks in the conducting system. 3. Abnormal impulse pathways. 4. Spontaneous generation of spurious impulses in the heart.

453

What 2 things can cause tachycardia?

1. Increased body temperature. 2. Sympathetic stimulaton of the heart.

454

How many beats per minute will the heart increase with a body temperature increase of 1 degree F? And what is the limit on this?

10 BPM increase per 1 degree F and this only goes up to 105 Degrees F.

455

What 3 things will make the sympathetic system increase the Heart beat?

1. Exercise. 2. Reflex acton due to decreased Cardiac output. 3. Thoughts= anxiety, excitement.

456

Bradycardia is usually due to what?

Athletic conditioning.

457

When will bradycardia be abnormal?

When we have a decreased resting heart rate due to parasympathetic stimulation that is a result of pressure sensors in the neck that have become compressed.

458

What is sinus arrhythmia due to? What will it cause?

Ventilation when we inhale it increases the heart rate and when we exhale it decreases heart rate. It causes chages in sympathetic and parasympathetic signals.

459

What is a atrioventricular block?

a disturbance in the conduction impulses from the atria to the Ventricles.

460

An atrioventricular block is often due to what?

Ishemia of the AV node.

461

Name 3 subtypes of atrioventricular block and what they are like?

1st degree- minor lengthening of the PR interval. 2nd degree- a serious lengthening of the PR interval, and occasionaly missing a beat in the ventricles. 3rd degree- Ventricular escape

462

What is an intraventricular block?

The same as an artrioventricular block, but in the purkinje system which gives an abnormal QRS interval.

463

What is ectopic mean?

Out of place.

464

What is ectopic foci?

An electrical event out of proper location.

465

What are 2 types of ectopic foci?

1. Premature contraction. 2. Fibrillation

466

A premature contraction is often termed as what?

An extrasystole or premature beat or ectopic beat.

467

What are 2 types of premature contractions and how serious are they?

1. Atria- harmless. 2. Ventricle- can be deadly.

468

What causes a premature contracion?

hyper-excitablity of myocardial tissue and it will depolarize at the wrong time.

469

What are 2 ways myocardial tissues can depolarize at the wrong time?

1. Over-use of stimulants and lack of sleep. 2. Local ischemia.

470

How will local ischemia cause premature contractions?

It will not have the oxygen to make the atp that is needed to run pumps and maintain the membrane potential.

471

What can premature contractions lead to?

an abnormal impulse pathway like a electrical chaos.

472

What is Fibrillation?

When electrical chaos will have impulses spread and split and re-enter areas.

473

What will atria and ventricular fibrillation lead to?

Atria- tolerable, but not good for the atria. Ventricles- Deadly within 2-3 minutes.

474

Why will ventricular fibrillation be deadly within 2-3 minutes?

It will give no true contraction so no ejection of blood.

475

Name 2 ways fibrillation starts?

1. Electrical shock. 2. Myocardial ischemia (most common cause).

476

What is Impulse re-entery mechanism?

impulse goes around and the cells are past the refractory period when the impulse gets back and so they impulse again and this can get out of control.

477

What will cause impulse re-entery?

slow impulse conduction, or long impulse paths.

478

What is defibrillation?

A technique to interrupt ventricular fibrillation by applying a large electrical shock, and after the full depolarization the hope is that the SA node will impulse first and bring the heart out of fibrillation.

479

When is fibrillation done intentionaly?

During surgeries to keep the heart still.

480

How long after ventricular fibrilation will defibrillation need to occur to stop fibrillation?

1 minute or heart is too weak unless cpr has been done to help minimize damage to the heart prior to defibrillation.

481

What is A-V heart block?

an arrhytmia due to a blockage in the electrical system of the heart.

482

What are 2 causes of A-V heart block?

1. Coronary artery disease. 2. Inflammation of nodal tissue.

483

What are the treatments for A-V heart block?

mediaction for mild cases and a pacemaker for severe cases.

484

Renal artery stenosis is a disorder of what?

Vascular occlusion in the kidneys.

485

What are 2 clinicl features of renal artery stenosis?

1. Hypertension. 2. Abdominal bruit (a noise).

486

What type of people are associated with renal artery stenosis?

Obesity, tobacco, retinopathy (disease of the retina)

487

People with renal artery stenosis when scaned show what?

A narrowing of the renal artery that decreases flow into kidneys by 70 % or higher.

488

What happens to a kidney that has a decreased blood flow from renal artery stenosis?

It shrinks

489

What is one of the most important negative feedback loops in the entire body?

The control of blood pressure.

490

What is it called when we compress a fluid in a finite container?

Fluid pressure.

491

Blood pressure is high in the left ventricle and in the aorta and the large vessels and the pressure does what?

it pulsates

492

What happens to blood pressure as it gets into the arterioles?

It starts to dampen out so it wont pulsate as much.

493

What is pulse pressure?

Take systolic blood pressure and subtract the diastolic blood pressure from it. This is usually 40 mm hg

494

when will pulsatile pressure be gone normaly?

In the capillaries.

495

What helps arteries dampen the pulsatile pressure?

The elastin in the large vessels.

496

When we measure blood pressure in clinics what type of blood pressure are we measuring?

Systemic arterial blood pressure.

497

What is the average blood pressure in the larger arteries?

100 mm Hg

498

What is augmentation?

it is due to pulse reflection in the arterial tree causing a summation of pulse waves.

499

What may augmentation correlate to?

An aneurysm in large arteries

500

Is resistance in large or small arteries high or low?

Large arteries it is low. Small arteries it is high.