Sensory Cues for Fat and their Role in Fat Intake Invited Guest Speaker: Dr. Tim Gilbertson Nov. 11 Thursday 11 AM Olin Theater Dr. Gilbertson is Professor & Associate Department Head of Biology and serves as the Associate Director of the Center for Advanced Nutrition at Utah State University. Dr. Gilbertson's research is focused on the investigation of the mechanisms the body uses to recognize nutrients & how this process is regulated by nutritional need. His lab studies the way nutrients including fats, carbohydrates and minerals are detected by chemosensory cells in the oral cavity and in several nutrient-sensitive, post-ingestive organs. The research spans from genes through behavior with expertise in molecular biology, proteomics, electrophysiology, imaging, biochemistry and analysis of behavior.

8 November 2010 Cardiovascular Physiology Poiseulle’s Equation The Heart The Cardiac Cycle Lab this week: Frog Heart Physiology Arrive early if you want to pith.

1QQ # 25 for 8:30 am Which are formed elements? a) leukocytes b) erythrocytes c) platelets d) serum e) plasma Which are part of the microcirculation? Arteries b) arterioles c) capillaries d) venules e) veins

1QQ # 25 for 9:30 am Which provide for fine motor control of the face and extremeties a) corticospinal tract b) corticubulbar tract c) reticulospinal tract d) vestibulospinal tract e) pyramidal tracts Spindle afferents have synapses monosynaptically on motoneurons of synergistic muscles on interneurons that inhibit motoneurons of antagonistic muscles on second order neurons in the dorsal column nuclei.

What’s missing? Microcirculation Exchange Vessels S 1 Pulmonary circuit CO = 5 liters/min Pressure gradients makes fluids move. Moving fluids flow, but flow is limited by resistance. Resistance creates pressure. CO = 5 liters/min Systemic Circuit Resistance Vessels Microcirculation Exchange Vessels Capacitance vessels

Q= ΔP πr4 8Lη Poiseulle’s equation F=Q=ΔP/R Flow = Pressure gradient/Resistance from Ohm’s Law (V=IR) Radius of arterioles regulates Q to organs Double radius … 16x flow Half radius….1/16th flow R = 8Lη/πr4 Q= ΔP πr4 8Lη Poiseulle’s equation Smooth muscles determine radius

Cardiac Output = Heart Rate X Stroke Volume CO = HR x SV 5L/min = 72 beat/min x 70 ml/beat The Cardiac Cycle animation

Figure 12.07 Tricuspid Bicuspid =Mitral Problems with valves: ….Stenosis (narrowing) →Heart Murmurs (turbulent flow past a constriction) note: origin of neonatal heat murmurs (foramen ovale) ….Prolapse (eversion) allows backflow (also generates murmurs) Heart murmurs ≠ heart sounds Figure 12.07 S 4 Bicuspid =Mitral Tricuspid Heart sounds and valve closings Semilunar Valves Animation

Figure 12.11 S 5 SA node cells do not have stable resting membrane potential, spontaneously produce AP, are Pacemaker cells

S 6 Intercalated Discs: mechanical attachments of cardiac myofibers to each other, with gap junctions (electrical synapses) to conduct AP Analogy: Falling dominoes

Figure 12.13 Cardiac Myofiber S 7 Plateau phase Cardiac Myofiber action potential Long refractory period prevents summation in cardiac myofibers Cardiac Myofiber

Figure 12.17 S 8 Excitation-Contraction Coupling Calcium-induced calcium release What ends the twitch? Ca++ channels blockers: How and where do they work? When are they used?

What prevents the AP from being conducted from ventricles back to atria? Fibrous connective tissue between atria and ventricles prevents the conduction of action potential. Only route is via AV node, bundle of His, bundle branches, Purkinje fibers, and to ventriclular myofibers.

Figure 12.14 Pacemaker Cells in Conducting System: Ectopic Pacemaker Locations other than SA Node Pacemaker Cells in Conducting System: SA Node and Bundle of His

S 11 Figure 12.22 Intrinsic Rate = 100 beat/min

Effect of “Beta blockers” Figure 12.23 NE EPI ACh mAChR Beta-adrenergic receptors Effect of “Beta blockers” Effect of atropine

S 13 Figure 12.18 1st Heart Sound = Closure of Atrioventricular (AV) valves at beginning of Ventricular Systole 2nd Heart Sound = Closure of Semilunar valves at beginning of Ventricular Diastole