Anatomy II: Cardiovascular Physiology Flashcards
Explain the circuits of blood flow for the Pulmonary Circuit.
- Deoxygenated blood is pumped to the lungs by the right side of the heart.
- Gas exchange occurs between air in the alveoli and blood in the pulmonary capillaries.
- The oxygenated blood is returned to the left side of the heart.
Explain the circuit of blood flow for the Systemic Circuit.
- Oxygenated blood is pumped to the body by the left side of the heart.
- Gas exchange occurs between tissues and blood in the systemic capillaries.
- Deoxygenated blood is returned to the right side of the heart.
The heart helps maintain ______ of pressure that blood exerts on blood vessels (blood pressure).
HOMEOSTASIS
______ and _______ of heart ’s contraction are major factors that influence blood pressure and blood flow to organs
RATE; FORCE
What type of organ is the heart (atria) and what does it produce?
Endocrine Organ
Produces atrial natriuretic peptide (ANP)
What does Atrial Natriuretic Peptide (ANP) do?
Lowers BP by decreasing sodium ion retention in the kidneys., and reduces osmotic water reabsorption and volume and pressure of blood in the blood vessels.
What is the most dangerous consequence/effect of Coronary Artery Disease?
Myocardial Infarction (MI) - Plaque in coronary arteries ruptures, and blood clots form which obstructs blood flow to the myocardium.
List Some Symptoms of Myocardial Infarction (MI).
- Sweating
- Anxiety
- Shortness of Breath
- Nausea
- Vomiting
WOMEN MAY SUFFER WITH BACK, JAW, OR ARM PAIN INSTEAD OF CHEST PAIN USUALLY*
How is CAD DEFINITIVELY Diagnosed?
An Angiogram or Angiography
Define: Coronary Angioplasty
Commonly performed invasive procedure to open blocked or narrowed heart arteries.
A small balloon is inflated inside the artery to clear the blockage, often with a stent placed to keep the artery open.
This helps improve blood flow to the heart.
Does the heart act voluntarily or involuntarily?
INVOLUNTARILY
Define: Coronary Artery Bypass Grafting
More invasive than Angioplasty; It involves taking a healthy blood vessel from another part of the body and using it to create a bypass around blocked or narrowed heart arteries.
This helps restore proper blood flow and reduces the risk of heart problems.
Define: Voltage
Difference in electrical potential between two points
Define: Membrane Potential
Voltage difference that exists across membranes of all cells.
Define: Resting Membrane Potential
Membrane potential of excitable cell when it is not being stimulated.
AVERAGES AROUND -60 TO -90 mV.
Define: Current
Flow of ions or electrons with chemical or electrical gradient.
Depolarization vs Repolarization
Depolarization is when the heart muscle “fires” to contract, and Repolarization is when the muscle “resets” and relaxes.
Depolarization : Happens when sodium (Na+) ions rush into the cell, making the inside of the cell more positive.
Repolarization: Potassium (K+) ions move out of the cell, restoring the negative charge inside the cell.
Describe the steps of an action potential in a contractile cell. (4 Steps)
- Slow Initial Depolarization Phase: Membrane slowly depolarizes to threshold because more cations leak in than leak out in the HCH channels in the plasma membrane.
- Full Depolarization Phase: At THRESHOLD, Voltage-gated Ca2+ channels OPEN, and Ca2+ ENTERS the cell, allowing it to DEPOLARIZE.
- Repolarization Phase: Ca2+ Channels CLOSE, and Voltage-gated K+ channels OPEN, allowing for K+ OUTFLOW and membrane repolarization.
- Minimum Potential Phase: K+ Channels REMAIN open, and membrane HYPERPOLARIZES. This opens the HCH channels and repeats the cycle.
The concentration of sodium and calcium ions in extracellular fluid (ECF) is ______ than in cytosol;
the concentration of potassium ions in ECF is ______ than in cytosol.
HIGHER; LOWER
Describe the steps of a Long Refractory Period in Cardiac Muscles. (4 Steps)
- Rapid Initial Depolarization Phase: Voltage-gated Na+ Channels activate, and Na+ ions enter, rapidly depolarizing the membrane.
- Initial Repolarization Phase: Na+ channels are inactivates and some K+ channels Open. K+ ions leak out causing a small initial repolarization.
- Plateau Phase: Ca2+ channels open and Ca2+ enter as K+ exits, prolonging the depolarization.
- Repolarization Phase: Na+ and Ca2+ channels close, while K+ continues to exit, causing repolarization.
Disturbances in Heart Rate: Bradycardia
Heart rate under 60 beats per minute.
Disturbances in Heart Rate: Tachycardia
Heart rate over 100 beats per minute. (Sinustachycardia is regular, fast rhythm)
What’s the disturbance in conduction pathways called?
AV Node Blockage
What is ventricle-fibrillation?
Immediately life-threatening and manifests on ECG with Chaotic activity.
TREATED WITH ELECTRICAL SHOCK TO THE HEART (DEFIBRILLATION).
Describe the cardiac conduction system and its role in contraction (3 steps)
- SA node generates action potential, which spreads to AV node and atrial cells.
- Action potential is conducted to AV bundle and then to right and left bundle branches.
- Action potential spreads from bundle branches to the contractile cells of the ventricle.
How do pressure changes lead to valve movement and blood flow in the contracted left ventricle?
- High pressure in ventricle causes aortic valve to OPEN due to blood flow.
- High pressure in ventricle causes mitral valve to CLOSE due to upward-rushing blood flow
How do pressure changes lead to valve movement and blood flow in the relaxed left ventricle?
- Blood flows backward in the aorta, closing it.
- Pressure from blood in the left atrium pushes mitral valve open, allowing blood in the left atrium to drain into the RELAXED ventricle.
When does “Heart Murmur” occur and what causes them?
When the heart is turbulent, and are CAUSED by defective valves.
Heart undergoes average of _______ cardiac cycles (beats) per minute. This is known as _______.
60-80; HEART RATE
Define: Cardiac Output
Amount of blood pumped into pulmonary and systemic circuits in 1 minute (amt. of blood pumped out in 1 min.)
Heart rate is one determinant of ______ ________.
CARDIAC OUTPUT
What is another determinant of Cardiac Output?
Stroke Volume - Amount of blood pumped in one heartbeat.
What are the 3 factors that determine Stroke Volume?
- Preload
- Contractility
- Afterload
Explain the 3 factors that determine Stroke Volume.
- Preload - Determined by volume of blood coming from polmonary circuit.
- Contractility - Determined by hearts intrinsic pumping ability (heart’s contraction force)
- Afterload - Determined by pressure in systemic circuit (BP in Aorta or Pulmonary Trunk)
What is the equation for Cardiac Output?
Beats/min x # ml/beat = # ml/min
Multiple Heart rate by Stroke volume
# beats /min ( HR) × # ml /beat (SV) = # ml /min
SO, for average person
72 beats/min (HR) x 70 ml/beat (SV) = 5040 ml/min
Low preload leads to ____ EDV. (what does this mean?)
LOW
This means cardiac muscle cells are much less stretched and thus, contracts weakly.
What is the term used to describe any disease regarding the heart?
Cardiomyopathy
How does heart failure affect stroke volume?
It DECREASES stroke volume, which in turn REDUCES cardiac output.
What is the resting stroke volume for the avg heart? (and equation)
70 ml
120 ml (EDV) - 50 ml (ESV) = 70 ml (SV)
Repolarization vs Depolarization (in Cardiovascular context)
Depolarization: Electrical activation where Na⁺ enters cells, making them more positive → triggers contraction; Action potential enters in for Cardiac Muscle cells. (P wave = atria, QRS complex = ventricles).
Repolarization: K⁺ exits cells, restoring negative charge → allows relaxation (T wave = ventricles).
In ventricular failure, what is it called when blood backs up within the pulmonary circuit?
Pulmonary Congestion
Backup of blood flow ________ pressure in these vessels, driving fluid out of pulmonary capillaries and into the lungs; this is called ________ ______.
INCREASES; PULMONARY EDEMA
STUDY THE GRAPHS (4 PHASES) CARDIAC CYCLE
WILL BE ON SHORT ANSWER.
