Lecture 11 - Study of the heart PDF

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Study of the heart...

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HR x SV = CO Heart rate x Stroke Volume = Cardiac Output (6L/min) (6.000 mL/min) Couch potato has higher heart rate Athlete has higher stroke volume Related to the strength of the heart (contractility) how forcefully the heart can contract Fear can increase stroke volume/heart rate Goal is to get as much oxygen to tissue when you exercise Heart rate goes up when we exercise Blood dopingA way to give you an unfair advantage by giving your more oxygen faster, by getting more blood to your tissues RED BLOOD CELLS (RBC)= Erytrocytes Etrytro- red Cytes- cells Leukocytes- white blood cells Red blood cells contain TONS of hemoglobin (blood protein) Protein that carries oxygen and CO2 (mutually exclusive, can only carry one at a time) Classic blood doping- take out pint of self blood, then put blood back in Athletes “donate” a pint of blood Blood is spun down in a centrifuge Red blood cells are forced to the bottom of the centrifuge and stored in cold temperatures Red blood cells are re-injected back into the body after the blood cells have rejuvenated Deema? Retention of fluid leaking out of capillaries Can drown you in your own fluid Can cause high blood pressure Will make blood more sluggish/thick Does not go through your circulatory system as good Can cause strokes Hormones are usually proteins/lipids- natural chemicals that are sent directly into your bloodstream Erythropoietin (EPO)- naturally produced hormone made by our kidneys Goes into the blood stream (target: red bone marrow) tells bone marrow to make more blood

cells Synthetic EPO was originally for anemic people, or people with drug killing rapidly dividing bone marrow cells (cancer patients) Lance Armstrong was caught with EPO What initiates contraction of the heart? A group of the cells in the heart itself (pacemaker cells)- myogenic SA node cells “Sinoatrial” Located in the upper right side of the right atrium When they contract, they send action potential, heart cell is connected by gap junctions, and electrical signal spreads like a wave, and you have SA node and AV node

Pacemaker has its own rate Rate of SA Node at rest is about 100 beats per minute Our pacemaker is regulated by nerves and hormones Normally a nerve slows down the pacemaker VAGUS NERVE- inhibits contraction of pacemaker cells (cardiac cells) Releases neurotransmitter to do that Acetylcholine- slows down the heart Epinephrine/Adrenaline- Hormone that increases the heart rate Epinephrine (a hormone) INcreases Heart Rate and INcreases Stroke volume (cardiac contractility)

Baroreceptors- receptors that are found stickin into certain blood vessels that monitor the pre ssure of the blood while it goes by baroreceptors- located in the aorta and carotid arteries measure blood pressure and help regulate heart rate Heart attack- blockage in coronary arteries that supply blood with oxygen Heart cells do not replenish themselves Structure and function of blood vessels Capillaries are one cell layer thick Things can diffuse easily in and out Arterioles lead directly to capillary beds Mostly at basal resting base Vasodilation- get blood vessels to open up and more blood can come through Vasoconstriction- get blood vessels to close up and less blood can come through Smooth muscle lining arterioles can constrict or relax Epinephrine play a big role in blood vessel diameter Fight or flight hormone Vasoconstrictor for arterioles leading to the gut Vasodilator for arterioles leading to skeletal muscles It depends on the receptor Sphincter- smooth muscle At the ends of the arterioles, at the beginnings of the artery beds Regulate actual blood flow to Arteriole will got to many capillary beds Blood pressure- resistance of blood against the walls, against the resistance of the blood pressure cuff Highest pressure is in the aorta Lowest pressure is vena cava Measures highest/lowest pressure of the blood in major artery Highest- contracting Relaxing- pressure is lowered Systolic pressure- highest pressure- ventricular contraction Diastolic- lowest pressure- ventricular relaxation Law of Continuity

Related to speed of the blood going through the circulatory system A certain volume of liquid will travel through the smaller diameter vessel/pipe faster than a larger diameter vessel End of chapter 5: energy and enzymes Muscles nerves Cardiovascular systems 2 labs Alleles- versions of a gene...