things to know bios class 1

8/8/2019 things to know bios class 1

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Things to Know:- Pericardium (functions, layers: fibrous, serous, parietal, visceral(epicardium), pericardial cavity/fluid)- Myocardium- Endocardium- Vessels (superior and inferior venae cavae, right and left pulmonary veins(from the lungs/poorly oxegenated)) towards the heart- Vessels (pulmonary trunk/ R+L arteries, ascending aorta) away from the heart- Vessels that supply/drain the heart (arteries-right & left coronary, veins)

-Atria: three recieving chambers of the heart-Ventricles: discharging chambers of the heart-Heart valves: ensure unidirectional blood flow throughout heart-Atrioventricular valves prevent backflow into the atria when ventricles contract-Semilunar valves prevent backflow of blood into the ventricles-Cardiac muscle (striated, short, fat, branced, and interconnected)-Connective tissue: endomysium-Intercalated discs anchor cardiac cells together and allow ion passage

***Know blood flow in & out (what it passes through)right side: Blood enters the heart through two large veins, the inferior and superior vena cava, emptying oxygen-poor blood from the body into the right atrium. Blood flows from your right atrium into your right ventricle through the open tricuspid valve. When the ventricles are full, the tricuspid valve shuts.This prevents blood from flowing backward into the atria while the ventricles contract (squeeze).Blood leaves the heart through the pulmonic valve, into the pulmonary artery and

to the lungs.

Entering heart: Venae Cavae---Right Atrium---Tricuspid valve---RIght Ventricle---Pulmonary Semilunar Valve---Pulmonary Artery---Lungs

left side: The pulmonary vein empties oxygen-rich blood, from the lungs into theleft atrium.

Blood flows from your left atrium into your left ventricle through the open mitral valve. When the ventricles are full, the mitral valve shuts.This prevents blood from flowing backward into the atria while the ventricles contract (squeeze).Blood leaves the heart through the aortic valve, into the aorta and to the body.

Leaving heart: Lungs---Pulmonary Vein---Left Atrium---Biscupid Valve---Left Ventricle---Aortic Semilunar Valve---Aorta---Body (systemic circulation)

This pattern is repeated, causing blood to flow continuously to the heart, lungsand body.

Pulmonary circuit: low pressure system (lungs & heart)Systemic circuit: high pressure system (heart & body)

which veins/arteries etc. have high Oxygen or CO2

-Heart muscle is stimulated by nerves and is self-excitable, contracts as a unitConduction System-Autorhythmic cells: initiate action potentials, have unstable resting potentials (pacemaker potentials), use calcium influx instead of sodium-Sequence of Excitation

Extrinsic Innervation


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-Heart is stimulated by the sympathetic cardioacceleratory center-Heart is inhibited by the parasympathetic cardioinhibitory center

Electrocardiography

Cardiac CycleSystole: contraction of heart muscle-atria relax, AV close, SL open, ventricular ejection phase, blood is sent to bodyDiastole: relaxation of heart muscle-early diastole: ventricles relax, SL close-late diastole: blood pressure is low, blood enters atria and ventricles, AV valves are open

Heart Sounds-first sound (lub) occurs as AV (atrioventricular) valve closes and signified beginning of systole-second sound (dub) occurs when SL(semilunar) valve closes at the beginning of ventricular diastole

Cardiac Output- the amount of blood pumped by each ventricle in one minute (theproduct of heart rate and stroke volume)Heart Rate- # of heart beats per minute (60-70 beats per minute) beats/minStroke Volume- amount of blood pumped out by a ventricle with each beat mL/beatCardiac Reserve- difference between resting and maximal CO

CO=HRxSV cardiac output=heart rate x stroke volumeCO ml/min

ischemia- lack of blood flow

factors affecting stroke volume:*preload- venous return, amount ventricles are stretched by contained blood*contractility- cardiac cell contractile force*afterload- back pressure exerted by blood in large arteries leaving the heart

frank-starling law of the heart=the greater the volume of blood entering the heart during diastole (end-diastolic volume),the greater the volume of blood ejected during systolic contraction (stroke volume) and vice-versa.

*know phases of the cardiac cycle, what is happening during each phase on an ecg

most important intrinsic factor: preload, or degree of stretch of cardiac muscles before contraction is critical factor controlling stroke volumeslow heartbeat and exercise increase venous return to the heart, increasing SVmost important extrinsic factor: contractility, because the increase comes from:increased sympathetic stimuli (epinephrine, norepinephrine) certain hormones (glucagon, thyroid hormones, thyroxine), Ca2+ and some drugs(+inotropes) (-inotropes inhibit contractility)factors that decrease contractility- acidosis(lowers Ph-normal is 7.4), increased K+, calcium channel blockers

inotrope- increase or decrease contractility

chronotrope- increase or decrease heart rate

know where oxegenated vs. deoxegenated blood flows


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tricuspid valve: between right atrium and ventriclepulmonary valve: right ventricle and pulmonary arterymitral valve: left atrium and left ventricleaortic valve: left ventricle and aorta

"Your heart uses its four valves to ensure your blood flows only in one direction. Healthy valves open and close in coordination with the pumping action of your

heart's atria and ventricles.

Each valve has a set of flaps called leaflets or cusps. These seal or open the valves. This allows pumped blood to pass through the chambers and into your blood

vessels without backing up or flowing backward.

Oxygen-poor blood from the vena cavae fills your heart's right atrium. The atrium contracts (atrial systole). The tricuspid valve located between the right atrium and ventricle opens for a short time and then shuts. This allows blood to enter into the right ventricle without flowing back into the right atrium.

When your heart's right ventricle fills with blood, it contracts (ventricular systole). The pulmonary valve located between your right ventricle and pulmonary artery opens and closes quickly.

This allows blood to enter into your pulmonary arteries without flowing back into the right ventricle. This is important because the right ventricle begins to refill with more blood through the tricuspid valve. Blood travels through the pulmonary arteries to your lungs to pick up oxygen.

Oxygen-rich blood returns from the lungs to your heart's left atrium through thepulmonary veins. As your heart's left atrium fills with blood, it contracts. Th

is event also is called atrial systole.

The mitral valve located between the left atrium and left ventricle opens and closes quickly. This allows blood to pass from the left atrium into the left ventricle without flowing backward.

As the left ventricle fills with blood, it contracts. This event also is calledventricular systole. The aortic valve located between the left ventricle and aorta opens and closes quickly. This allows blood to flow into the aorta. The aorta

is the main artery that carries blood from your heart to the rest of your body.

The aortic valve closes quickly to prevent blood from flowing back into the leftventricle, which is already filling up with new blood."

Causes of congestive heart failure:coronary atherosclerosispersistent high blood pressuremultiple myocardial infarctsdilated cardiomyopathy (DCM)

lumen- an opening

Three major types of blood vessels: arteries, which carry blood away from the heartcapillaries, which enable the exchange of water and chemicals between the bloodand tissuesveins, which carry blood from the capillaries back to the heart.

arteries and veins have same internal structure: 3 tunic layers


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tunica intima, tunica media (largest), and tunica adventitiacapillaries are just a later of endothelium.

arterial vs. venous blood vessels (arterial- away, venous- towards)lungs oxegenate the blood.

Blood pressure (BP) is the pressure exerted by circulating blood upon the wallsof blood vessels.

factors that influence BP:-heart rate (rate of pumping) higher rate, higher pressure-blood volume (amount of blood present in the body)-resistance in blood vessels (higher resistance, higher pressure) size of arteries (vasoconstrictors vs. vasodilators)-viscosity (thickness of fluid)

capillaries: smaller the ions, quicker the diffusion, higher the pressure gradient, faster diffusion.capillary hydrostatic pressure:

net filtration pressure:osmotic pressure: force sucking fluid in (high concentration of solutes: hyperosmolar, less water, more concentrated, want to suck in water)

hypercapnea: high CO2 in blood, pH is going to be high

pre-capillary sphincters

how BP is regulated by the body:Brain- produces neurotransmitters, like catecholamines, to increase HR and increase contraction of blood vesselsKidneys: produce renin when BP is low, angiotensin, causing vessels to tighten.

kidneys can also absorb salt or sodium from your urine, increasing amount of fluid in body & BP.if too much fluid, kidneys will flush water and sodium out through urine to lower fluid in body, lower BP.

low pH: acidotic

know pulmonary system vs. systemic system. which has lower pressure? where do they lead? oxegenated blood?

know main arteries and veins of the bodyarteries: away from the heart, almost always oxegenated blood (xcept pulmonary)veins: towards the heart, de-oxegenated (xcept pulmonary)

KNOW:ascending aorta (aortic arch)right common carotid arterybrachiocephalic arteryright subclavian arteryvertebral arteryaxillary arterybrachial arteryradial & ulnar arteries

KNOW:


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things to know bios class 1