Lecture 9: Intro to Cardiovascular Physiology Flashcards

1
Q

functions of the cardiovascular system?

A
  • GAS TRANSPORT (delivers oxygen to tissues and returns CO2 to lungs)
  • regulates body temp
  • transports hormones to site of action
  • transports waste
  • transports nutrients
  • stabilize pH
  • transport cells that fight infection
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2
Q

what is carbonic anhydrase and why is it so important

A

an enzyme that facilitates the reaction of CO2+H20 <–> HCO3- + H+

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3
Q

CO2 in the blood generates ____?

A

H+

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4
Q

why does the body have to constantly transport gases

A

b/c ATP is not stored, it must be continuously produced in cells by the oxidation of metabolic fuels (Krebs cycle + Oxidative phosphorylation)

Glucose (or fatty acids) + O2 –> CO2+H20+ATP

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5
Q

What issues arise in the absence of carbonic anhydrase

A

inability to aerobically metabolize glucose and an accumulation of H+ ions

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6
Q

why does an overabundance of positive charges caused by H+ ions interfere with RBCs

A

too much H+ damages RBCs by binding to hemoglobin and other proteins

protein function is compromised as H+ ions bind to the carboxyl group of the amino acids that make up the proteins, changing their conformation and therefore function

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7
Q

pH of arterial blood

A

7.45
cannot survive if arterial blood is <6.8 or >8.0

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8
Q

affects of acidosis

A

denaturation of metabolic enzymes and ion channels

decreased CNS function can lead to coma, death

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9
Q

affects of Alkalosis

A

neurons become hyper-excitable

tingling, fasciculation, paralysis of respiratory muscles

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10
Q

What are the components of the true circulatory system

A

muscular pump (heart)
fluid (blood)
conduits (blood vessels)

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11
Q

what animals lack a true circulatory system and why

A

sponges, jellyfish and flatworms

they do have a contractile pumping device

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12
Q

what are platelets formed from

A

megakaryocytes

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13
Q

the liquid portion of blood is made of _____?

A

plasma (92% of plasma is water)

plasma contains proteins, electrolytes, gases in solution and nutrients

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14
Q

intracellular vs extracellular fluid

A

intracellular - fluid contained w/in all body cells

extracellular - blood plasma & interstitial fluid bathes and surrounds cells)

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15
Q

why is blood kept separate from interstitial fluid

A

bc it has specific transport functions and transport components that aren’t found in the interstitial fluid

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16
Q

drains capillary beds and forms veins which deliver blood back to the heart (bulk flow)

A

VENULES

17
Q

carry blood away from the heart and branch into arterioles that feed capillary beds (bulk flow)

A

arteries

18
Q

mechanism by which dissolved substances move across the wall of blood vessels

A

diffusion

19
Q

what is bulk flow

A

blood flowing through the heart and blood vessels is via bulk flow

20
Q

What variables does bulk flow depend on

A

pressure, volume, diameter

21
Q

what is blood pressure (P) and what factors determine it

A

force of blood exerted against walls of vessels

determined by rate & pressure

22
Q

what is blood flow (F)

A

volume of blood flowing through a structure per unit time (ml/min)

23
Q

Blood flow rate is proportional to what

A

resistance

24
Q

what is resistance (R) and what factors determine it

A

opposition to blood flow through a vessel

determined by diameter and viscosity of the fluid

25
Q

what is cardiac output (CO)?

A

the volume of blood pumped each minute by one ventricle

26
Q

blood always flows from a region of higher pressure to a region of lower pressure by _____

A

bulk flow

27
Q

what causes blood flow to increase

A
  • as pressure difference between 2 points increases
  • as resistance to flow decreases
28
Q

how does heartworm (dirofilaria immitis) cause primary cardiovascular dysfunction

A

heart worms lodge themselves in the Right Ventricle and Pulmonary Artery

  • this blocks flow to the pulmonary circuit and cardiac output
  • resulting in: shortness of breath and exercise intolerance due to the dramatic change in pressure differential
29
Q

How do blood worms (Strongylus vulgaris) affect cardiovascular function

A

bloodworms lodge themselves in mesenteric arteries

  • causes decreased blood flow to the intestines, causing ISCHEMIA –> decreased motility, secretion and absorption in the GI tract
30
Q

what type of circulatory system do fish have

A

single circuit: heart –> gills –> body –> heart

31
Q

How are fish able to have a low pressure system

A

b/c they have a lower metabolic rate and therefore their set point for body temp is much lower

low pressure = low blood flow rate = less supply of gases and nutrients

32
Q

what are the advantages of a 4-chambered heart

A
  • oxygenated blood is completely separate from deoxygenated blood
  • high pressure systemic circuit + low pressure pulmonary circuit
  • high pressure systemic circuit supports high metabolism

-low pressure pulmonary circuit protects fragile lung tissue

33
Q

what is Patent ductus arteriosus (PDA

A

normally within a few minutes to days after birth, the ductus arteriosus closes

in PDA, it remains open, resulting in abnormal blood flow b/w the pulmonary artery and aorta

34
Q

what would happen in the pulmonary and systemic circuits were not seperated

A
  • volume overload of left heart
  • left ventricular and arterial dilation
  • left sided congestive heart failure
35
Q

what makes it possible for there to be limited mixing of deoxygenated/oxygenated blood in 3-chambered hearts like in frogs/reptiles

A

spiral valve in conus arteriosus

36
Q

in a 3 chambered heart, there is high blood pressure/flow to what system

A

systemic capillaries