Chapter 18 Heart
What is the Apex of the heart?
Lower left "pointed" section of heart
Heart is surrounded & protected by____?
Pericardium: Double walled sac that protects / cushions the heart from hitting rib cage.
Pericardium has two layers, they are_____ & _____
1. Visceral Layer or Epicardium: Visceral because it is adjacent to the actual organ.
2. Parietal Layer: Parietal because it is adjacent to the actual cavity.
The Pericardial cavity is fluid filled for what reason?
To cushion the organ & to prevent friction from its constant pumping action.
Name the three layers of the heart wall.
Epicardium: Visceral layer of the serous pericardium
Myocardium: Cardiac Muscle
EndoCardium: Continuous w/lining of the blood vessels as in bv lined with simple squamous cells.
Heart is divided into 4 sections
Upper: Right and Left Atrium (plural=Atria)
Lower: Left and Right Ventricles
What is the difference between a vein & an artery?
Arteries go away from the heart
Veins go towards
Why are some blood vessels blue and some red?
Some of them are oxygenated. The Red ones are highly oxygenated.
Blood Flow through the heart:
1) Blood flows into Inferior & Superior Vena Cava 2) Into the right atrium 3) to the right ventricle 4)Then up & out pulmonary arteries 5)To the pulmonary capillaries in the lungs (picks up oxygen & gets rid of Carbon Dioxide) 6) Back to the heart through pulmonary veins 7)Enters the left atrium 8) Down to left ventricle 9) Then out Aorta to rest of the body 10) Circulates again blood from lower part of body enters in inferior vena cava & upper part enters superior vena cava
Define Cardiac Output
The amount of blood pumped out by each ventricle in one minute.
Define Heart Rate
Heart Rate is the number of times the heart beats on one minute (75 beats per minute bpm is average)
Define Stroke Volume
Stroke Volume (SV) is the amount of blood pumped by each ventricle with each heartbeat. Avg is 70 ml per beat in an adult at rest.
An anastomoses is a "junction" between blood vessels & blood vessels are connected. Their purpose is to provide a "detour" for blood, if there is a blockage in a vessel this is an alternative route so blood flow can still reach the area.
What connects an artery to a vein?
Define Functional Syncytium
The hearts blood flow and electrical conduction working together as one unit (in sync)
What does a gap junction do?
Allow ions to pass; electrically coupled adjacent cells
Desmosomes prevents what?
Prevents cells from separating during contraction
Define Cardiac Output or CO
CO is the amount of blood that is pumped out of the heart within one minute
What is the formula for cardiac output or CO?
CO = HR X SV = L/MIN
CO(ml/min)= HR (75B/PM)X SV (70ML/Beat)= 5.25L/M
What is the formula for Stroke Volume or SV?
SV = EDV - ESV
EDV= end diastolic volume
ESV= end systolic volume
Define EDV or end diastolic volume
After the SA node sends signal, the atria contracts, after atria contracts the ventricles are "filled". The amount of blood in the ventricles is the "End Diastolic Volume"
Define ESV or End Systolic Volume
At the end of contraction when "most" blood has been pushed out of the ventricles there is a small amount left in the bottom of the ventricles. This amount is the end systolic volume because it happens at the end of systole / contraction.
Afterload is the pressure that must be overcome for the ventricles to eject blood