Bioengineering 6000- Systems Physiology Frog LabSlide 1 Leftovers Bioengineering/Physiology 6000.
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Transcript of Bioengineering 6000- Systems Physiology Frog LabSlide 1 Leftovers Bioengineering/Physiology 6000.
Frog Lab Slide 2 Bioengineering 6000- Systems Physiology
Altitude and Pulmonary Edema
• At sea level, reduced oxygen concentration comes from restricted air flow and capillaries constrict to increase flow in unrestricted airways
• At altitude, reduced oxygen concentration is widespread but the resulting capillary constriction is uneven
• Result is increase pressure in some alveolae and edema
• Edema is patchy but still very dangerous
Frog Lab Slide 3 Bioengineering 6000- Systems Physiology
Comments on Anatomy Lab
Bioengineering/Physiology 6000
Frog Lab Slide 4 Bioengineering 6000- Systems Physiology
Comments• Structure;
– Intro/overview– Methods– Results and observations– Discussion
• Writing– Clear, concise, factual– Careful wording for accuracy– Facts over opinion
• Preparation– Figures and captions– Incorporate figures and tables in the text– All measurements in SI system
Frog Lab Slide 5 Bioengineering 6000- Systems Physiology
Frog Lab: Control of the Heart
Bioengineering/Physiology 6000
Frog Lab Slide 6 Bioengineering 6000- Systems Physiology
Regulation of Heart Rate
SA Node
ACh
ACh: • increases pK
• reduces If
(muscarinic receptor)
Epi,NE
Epi/NE; • increases If
(1-adrenergic receptor)
Frog Lab Slide 7 Bioengineering 6000- Systems Physiology
Regulation of Cardiac Contractility• Increase in amplitude or rate of
rise of isometric tension at fixed length,
• Free [Ca+2]i is key component• Positive inotropic agents:
– epinephrine: stimulate receptors and increase Ca+2 influx and uptake (load SR)
– Caffeine: increases sensitivity of myofilaments and causes release of SR Ca+2
• Negative inotropic agents:– ACh: acts mostly on atria to
shorten AP and reduce [Ca+2]i – Cadmium: resembles Ca+2
enough to block channel
Mus
cle
tens
ion
Passive (rest) tension
Total tension
Twitch tension
Muscle length
Effect of NE/E
Frog Lab Slide 8 Bioengineering 6000- Systems Physiology
Effect of E/NE on Contraction
• constant pretension• reduced shortening
(limited by max tension curve)
• reduced stroke volume
1
2
3
4
tens
ion
[g]
muscle length
maximum isotonic tension
Pre
ssur
e
Volume
Left Ventricle
strokevolume
Frog Lab Slide 9 Bioengineering 6000- Systems Physiology
Amphibians (e.g., Frog)
• Shared ventricle but blood separated
– Spiral fold
– Initial flow through pulmonary because of reduced pressure
– Resistance to flow varies with breathing (inhale reduces resistance)
Frog Lab Slide 10 Bioengineering 6000- Systems Physiology
Lab Interventions
• Cold Ringer’s solution• ACh• Epinephrine• Isoproterenol • Ca2+-free solution• Caffeine• Cadmium chloride• Potassium chloride