The Heart Flashcards
The heart, greater blood vessels, trachea & esophagus is situated in the chest in a cavity called _____
The heart itself is in a cavity slightly to the left side in a subdivision of the _______ and is known as the ________ cavity
Mediastinum x2
Pericardial cavity
The membranous structure that surrounds the heart is known as the ______
That structure is composed of two layers, the ______ ____ , a tough outer layer that attaches heart to surrounding structures & the ____ _____, a thing inner serous membrane that prouduces serous fluid
Pericaridum
Fibrous pericaridum
Serous pericaridum
Explain the 3 spots of heart
Apex
Base
Diaphragmatic surface
Apex, base,
Whats the difference between the pulmonary circuit and the systemic circuit
Pulmonary= heart-> lungs -> blood
Systemic= heart -> body-> heart
Under higher pressure then pulmonary circulation
The pericardium is the outmost layer of the heart what are the other two layers?
- pericardium -> fibrous pericardium+ serous pericardium (also has two layers -> visceral or parietal serous pericardium
- Myocardium
- Endocardium
What is pericarditis?
Inflammation of the pericardium causing serevre substernal pain, effusion
Your asked to check if a patient has cardiac tamponande by checking becks triad, whats becks triad?
Low bp
Muffeled heart sounds
Distented neckveins/ juglar pressure
Muscular ridges found in the heart are what?
Pectinate muscle
There is pectinate in the atrium and resembles muscular ridges, a similar muscle is found but differently named in the right ventricle, what is it called?
The papillary muscle
______ _____ attach directly to the papillary muscle and work together to open and close the tricuspid and bicuspid valves
Chordae tendinae
What vein returns oxygenated blood to the heart?
Pulmomary vein (comes from lung to heart)
What are the two cells found in cardiac muscle tissue?
Pacemaker cells
Contractile cells
What are the 3 types of pacemaker cells?
Sinoatrial node (SA Node)
Atrioventricular node (AV Node)
Purkinje fibre system (AV bundle, R & L bundle branches & terminal branches)
___ node is the normal pacemaker of the entire heart; electrical rhythums created by this node are known as sinus rhythums.
SA Node
If SA node ceases to funtion the AV node can successfully pace the heart
What are the implications of the plateu phase after a contractile cell preforms an action potential
The plateau phase lengthens cardiac action potential to about 200 to 300 ms call,
This slows heart rate and provides time required for heart to fill with blood
and also increases the strength of hearts contraction (startlings law of the heart)
Cardiac valves are one way doors used to direct blood flow,
both AV valves are forced _____ by blood _______
Both Semilunar valves are forced ______ by ______ blood
Forced Shut by blood pushing agiasnt them
Forced open by outgoing blood
What are the two main heart sounds?
Lub-> s1-> when AV valves close-> when ventricles contract-> louder at apex
Dub-> s2-> when semilunar vavlues close-> when ventricles relax
Define these:
- Heart rate
- stroke volume.
- cadiac output
- Heart rate
- beats per minute (cardiac cycles per min)
2.stroke volume.
-amount of blood pumped in one heart beat-> calculated as
EDV-ESV= SV
- cadiac output
- amount of blood pumped in one minute (SV x HR = CO)
What 3 factors influence stroke volume?
- Preload-> the length or degree of stretch in ventricular cells before they contract -> frank-stirling law-> explains relationship —>increased stretch = increased strength of contraction
- Contractility-> hearts intrinsic pumping ability or abilty to generate tension-> Inotropic agents (medications) can affect contractility
- Afterload-> refers to force that ventricles must overcome in order to eject blood into their respective arteries (resistance)
- > largerly determined by BP in arteries of both pulmonary and systemic circuits
