Term
Where is the heart located? |
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Definition
Mediastinum (Middle Thorax)
Rests on the Diaphragm |
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Term
Where is the Apex and Base of the heart? |
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Definition
- Apex: Bottom point of heart
Points to left hip.
- Base: Top of heart
Points to right shoulder.
[image]
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Term
What is the sac that encloses the heart? |
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Definition
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Term
What are the layers of the Pericardium? |
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Definition
[image]
Parietal Pericardium continues on to cover the heart itself and is then called the Visceral Pericardium. |
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Term
What are the layers of the heart wall? |
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Definition
- Epicardium Aka Visceral pericardium (Inner layer of pericardium): Outer heart wall
- Myocardium: heart muscle
- Endocardium: Innermost layer
- Simple squamous epithelium called endothelium which is continuous with blood vessel endothelium.
- Creates a seamless path for blood
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Term
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Definition
Atria: Receiving chambers
Ventricles: Discharging chambers
[image] |
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Term
Seperation of the Heart Chambers |
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Definition
- Interatrial septum
- Interventricular septum
- Externally you can see the anterior and posterior Interventricular sulci
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Term
What are major landmarks that both Atria share |
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Definition
- Internally they have pectinate muscles
- Externally they have Auricles
- In the Interatrial septum they have the fossa ovalis
- Atrial walls are relatively thin because they don't have to pump blood far and blood is assisted by gravity.
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Term
What is the Fossa Ovalis of the Atria? |
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Definition
The Fossa Ovalis is a depression which is a remnant of the foramen ovale.
The foramen ovale is present in the fetal heart. It directs the blood from going into the non-functional fetal lungs.
Immediately at birth the foramen ovale closes leaving a small depression in the interatrial septum called the Fossa Ovalis. |
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Term
What are the blood vessels of the Right Atria? |
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Definition
- Superior Vena Cava: Blood returning to heart from above the Diaphragm
- Inferior Vena Cava: Blood returning to heart from below the Diaphragm
- Coronary Sinus: Blood returning to heart from the heart wall
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Term
What are the blood vessels of the Left Atria? |
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Definition
- 4 Pulmonary veins: 2R & 2L
- Blood high in O2 because it's coming directly from the lungs.
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Term
What are the Ventricles and their characteristics? |
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Definition
- Discharge chambers
- Thicker walls- especially the left ventricle which send blood through the body.
- Trabeculae carnae: Muscle bundles
- Papillary Muscles: Anchor the heart valves by collagen strings.
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Term
Vessels associated with the Right Ventricle |
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Definition
Pulmonary trunk: Branches off to the R & L pulmonary arteries, to the lungs. |
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Term
Vessels associated with the Left Ventricle |
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Definition
Aorta: artery that sends blood to the rest of the body. |
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Term
What is the pathway of blood through the heart?
Pulmonary Circuit & Systemic Circuit |
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Definition
Pulmonary Circuit:
R atrium-->R ventricle-->pulmonary trunk-->
R & L pulmonary arteries-->lungs for oxygenation-->
Systemic Circuit:
L atrium-->L ventricle-->Aorta-->Body tissues
-->Veins-->Superior & Inferior Vena Cava
-->back to R atrium
[image] |
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Term
Circulation of the coronary arteries:
-R & L Coronary arteries are the first 2 branches off the aorta.
-L coronary splits off into the Anterior ventricular artery and the circumflex artery
-R coronary artery continues over to the posterior side and becomes the posterior interventricular sulcus. posterior branch of the coronary is called the marginal artery
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Definition
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Term
What is anastomosis and how does it relate to coronary circulation? |
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Definition
Anastomosis: Joining of blood vessels
Anterior interventricular artery joins the posterior interventricular artery at the heart apex. |
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Term
The anterior interventricular artery travels in what sulcus? |
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Definition
Interventricular sulcus
[image] |
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Term
The circumflex artery and the coronary artery travel in what sulcus? |
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Definition
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Term
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Definition
Pain in the heart due to insuufficient blood supply |
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Term
What is Myocardial Infarction? (MI) |
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Definition
Heart Attack:
Due to lack of blood causing cell death |
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Term
Where do Cardiac veins return blood to? |
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Definition
The Coronary Sinus in the Right Atrium. (Posteriorly)
[image] |
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Term
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Definition
Atrioventricular Valves- passage way from atria to ventricles |
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Term
What type of valve is the Right AV valve? |
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Definition
Right AV Valve:
Tricuspid valve- has 3 cusps
** Remember: tri rhymes with right |
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Term
What type of valve is the Left AV Valve? |
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Definition
left AV Valve:
bicuspid valve: has 2 cusps
usually called mitral valve
** 2 cusps look like bishops hat: miter |
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Term
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Definition
Pressure differences cause the valves to open and close with the flow of blood.
Chordae tendinae, which are attached to the papillary muscles, keep valves from opening the wrong way under pressure. |
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Term
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Definition
SL valves: Semilunar valves
Guard the exit of each ventricle |
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Term
What is the right ventricle semilunar valve? |
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Definition
Pulmonary semilunar valve- goes to the lungs |
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Term
What is the left ventricle semilunar valve? |
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Definition
Aortic Semilunar Valve- goes to the body |
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Term
What are incompetent valves? |
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Definition
Valves that do not close all the way.
[image] |
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Term
What are stenotic valves? |
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Definition
Valves that do not open all the way due to calcification.
[image] |
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Term
How can a strep throat lead to valve disorders? |
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Definition
If strep throat goes untreated, the body will produce antibodies that develop stenotic valves. |
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Term
What are the characteristics of Cardiac Muscle tissue? |
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Definition
- Striations
- One nucleus
- Intercalated discs
- the fibers branch
- Gap junctions
- Desmosomes
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Term
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Definition
- Located in Intercalated discs
- Have opening in the middle to allow ions to pass freely
- Allows depolarization to spread rapidly throughout the heart so the heart contracts as one unit
[image]
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Term
What does Functional Syncytium mean? |
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Definition
"one giant cell"
Means that the heart behaves as a single coordinated unit. |
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Term
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Definition
Protein patches that anchor 2 cells together to prevent pulling apart during contraction
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Term
What is unique about heart muscle contraction compared to skeletal muscle contraction? |
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Definition
- AP comes from the heart itself, not a neuron.
- called Automaticity or Autorythmicity
- Plateau phase of the AP- extends the period of depolarization so that the heart can contract long enough to eject all the blood from the ventricles
- The heart is a Functional Syncytium and all cells contract together as a whole unit.
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Term
What are the Three phases of heart cell contraction? |
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Definition
- Depolarization: Na+ enters cell
- Plateau Phase: Ca2+ enters through slow Ca2+ gates.
- This phase extends the period of depolarization
- Ca2+ that entered the cell causes the SR to release more Ca2+
- Repolarization: Ca2+ channels close and K+ channels to gates to open. K+ exits the cell and the cell repolarizes
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Term
What is the pacemaker potential?
[image] |
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Definition
- the slow, positive increase in voltage across the cell's membrane that occurs between the end of one action potential and the beginning of the next action potential
- Takes place in the autorythmic cells to initiate contraction:
- Opening of Na+ channels by previous APs hyperpolarization
- Membrance potential never has a flat line.
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Term
What is the Intrinsic Conduction System of the Heart?
(5 parts) |
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Definition
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Term
What is the Sinoatrial Node? (SA node) |
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Definition
- Pacemaker of the heart
- Located in Right atrium near the entrance of the superior vena cava
- Depolarizes at 75 bpm- faster than other components of intrinsic conduction system, therefore it causes them to depolarize at its rate
- Produces sinus rythm--Normal rythm
- Depolarization spreads rapidly through the atria and causes atrial contraction
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Term
What is the Atrioventricular Node? (AV node) |
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Definition
- Located in lower interatrial septum of right atrium.
- Produces AV delay (.01 sec) to allow the atria to contract before the ventricles
- AV delay is produced by narrowing of cells in AV node and fewer gap junctions
- Depolarizes at 50 bpm therefore, if SA node is not functioning as pacemaker, the AV node sets the pace of the heart at 50 bpm.
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Term
What is the AV Bundle?
(Bundle of His) |
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Definition
- In upper interventricular septum
- Is the only electrical pathway into the ventricles
- Shortly divides into R & L Bundle branches that travel in the interventricular septum
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Term
What are the Purkinje Fibers? |
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Definition
- Start at the apex (from the AV bundle branches) and go up the walls and spread throughout the myocardium.
- If SA node and AV node fail as pacemakers then the Purkinje fibers set pace of heart at 30 bpm
- At this rate life is not sustainable and person will need to have artificial pacemaker put in.
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Term
What is Electrocardiography? (ECG) |
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Definition
Measuring the electrical changes in the heart |
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Term
What do the waves of an ECG mean? |
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Definition
[image]
**Atrial repolarization is hidden in QRS complex |
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Term
What are the heart sounds and their meanings?
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Definition
heart sound: LUB DUP
First sound (LUB): caused by the closing of the AV valves
Second sound (DUP): caused by the closing of the SL valves
** Sound is produced by the vibration of the heart wall when the valves close.** |
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Term
What does the heart murmur of an Incompetent valve sound like? |
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Definition
Incompetent valves produce a "whish" sound when the ventricle contracts and the blood regurgitates back the wrong way |
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Term
What does the murmur of a stenotic valve sound like? |
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Definition
Stenotic valves don't open well and therefore produce a high pitched whistling sound as the blood is forced through a narrow opening. |
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Term
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Definition
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Term
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Definition
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Term
What is Cardiac Output? (CO) |
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Definition
Cardiac Output (CO): the amount of blood pumped by a ventricle in one minute
CO is determined by heart rate and stroke volume
HRxSV=CO
HR=beats per minute
SV=amount of blood in one beat |
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Term
What is the typical resting CO? |
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Definition
resting HR(heart rate): 75 bpm
SV(stroke volume): 70mL
75bpm x 70mL=5250mL/min
every minute the heart pump ~5L of blood: the entire blood volume. |
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Term
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Definition
The amount the heart is able to perform beyond that which is required under ordinary circumstances of daily life |
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Term
What is Athlete's Bradycardia? |
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Definition
Slow heart rate due to strengthening the heart and increasing SV |
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Term
What is the bpm of bradycardia and of tachycardia? |
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Definition
bradycardia: <60 bpm
tachycardia: >100 bpm |
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Term
How is SV calculated?
(stroke volume) |
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Definition
Calculated as the difference between what the ventricle has before contraction and what is left after contraction.
SV= EDV-ESV
EDV:End diastolic volume- the amount of blood at end of diastole(relaxation)
ESV:End systolic volume- the amount of blood at end of systole (contraction) |
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Term
What is the Frank Starling law? |
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Definition
Frank Starling Law: The more blood to stretch a ventricle, the stronger a contraction is produced. |
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Term
What are the factors that influence SV? |
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Definition
Preload: The amount of stretch of a ventricle by blood.
**Frank Starling Law
Afterload: The pressure of arterial blood
High blood pressure will make it harder to pump blood into the arteries and will decrease stroke volume
Working against pressure can damage the heart. |
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Term
How does the Autonomic Nervous System influence the heart? |
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Definition
Sympathetic System: Increase heart rate by Norepinephrine and Epinephrine(adrenal medulla)
Parasympathetic System: Decrease heart rate by ACh |
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