Block 3 Objectives Flashcards
Know the relative volume of plasma
55%
Know what is contained in the blood plasma
Plasma proteins, water, gases, and nutrients
Know the key blood proteins
Albumin is the main one, with globulin and fibrinogen
Know the relative volume (%) of red blood cells
45%
Know the key role of red blood cells
Oxygen transport via hemoglobin
Know the 4 chambers of the heart and the order of blood flow through the heart
Right and left atria, right and left ventricles
Right atrium –> Tricuspid valve –> Right ventricle –> Pulmonary valve –> Pulmonary arteries –>Lungs –> Pulmonary veins –> Left atrium –> Bicuspid valve –> Left ventricle –> Aortic valve –> Aorta –> Aortic arteries –> Body tissues –> Venae cavae
Compare and contrast the pulmonary and systemic circulation
Pulmonary Source: Right ventricle
Pulmonary Arteries: Pulmonary arteries, low O2
Pulmonary Veins: Pulmonary veins, high O2
Pulmonary Termination: Left atrium
Systemic Source: Left ventricle
Systemic Arteries: Aorta, high O2
Systemic Veins: Venae cavae, low O2
Systemic Termination: Right atrium
Know the four main valves of the heart, their location, and understand when/why they open and close
Tricuspid: Right side between atria and ventricle
Mitral: Left side between atria and ventricle
Pulmonary: Right side between ventricle and pulmonary artery
Aortic: Left side between ventricle and aorta
AV Valves: Open when atrium pressure is higher/diastole, close when ventricle pressure is higher/systole
Semilunar Valves: Open when ventricle pressure is higher/systole, close when atrium pressure is higher/diastole
Know the cardiac cycle (Phases)
Ventricular filling, isovolumetric contraction, ventricular ejection, and isovolumetric relaxation
Know the relative pressures and volumes at each phase
Ventricular Filling: Very low pressure, low volume and increasing
Isovolumetric Contraction: Developing pressure, volume increasing
Ventricular Ejection: High pressure, high volume and decreasing
Isovolumetric Relaxation: Falling pressure, volume decreasing
Know the cell type and their locations that initiates the action potential in the heart
Pacemaker Cells: Initiate its own action potential
Cardiac Muscle Cells/Myocytes: Sinoatrial (SA) Node
Understand how the action potential travels from one cell to the next
Gap junctions and syncytium
Understand what is meant by a functional unit (Syncytium)
It is when the cells that are connected contract together from one stimulation event
Know the electrical conduction pathway in the heart
SA node, atrial myocytes, AV node, Bundle of His, Purkinje fibers, and ventricular myocytes at apex and then top.
Know the difference in action potentials between the pacemaker cells and cardiac muscle cells
Pacemaker cells can be modulated, with no resting membrane potential and reaches the threshold for AP on its own.
Cardiac muscle cells have a negative resting membrane potential, reach threshold by depolarization due to APs from the SA node, and has Ca2+ which makes plateaus. Rapid depolarization
Understand how the autonomic nervous system modules heart rate
The sympathetic nervous system increases heart rate via release of epinephrine/norepinephrine and binding Beta1 receptors to open more funny Na+ channels.
The parasympathetic nervous system secretes ACh, which binds muscarinic AchR that opens K+ channels to leave the cells
Know the three ECG waveforms and what they represent in terms of regional excitation
P Wave: Shows atrial depolarization
QRS Complex: Shows ventricular depolarization
T Wave: Ventricular depolarization
Know the order of the vasculature and the key defining role of each part of the vasculature
Arteries: Pressure reservoir which has elastic walls to maintain pressure and flow of blood when the ventricle is not ejecting
Arterioles: Regulate blood flow/pressure with smooth muscle contraction
Capillaries: Perfuse cells via a single layer leaky wall
Veins: Volume reservoir due to one-way valves, smooth muscle contraction, and increases venous return
Understand how changes in each part of the vasculature can affect cardiac function
Contraction of smooth muscle increases venous return while relaxation decreases it
Vasodilation decreases blood pressure in arteries but increases blood flow while vasoconstriction increases blood pressure and decreases blood flow
This affects capillaries as well, with vasodilation giving more blood and vasoconstriction giving less
Understand the starling forces and why plasma fluid is filtered at the start of the capillary bed (to the ISF) and then reabsorbed at the end of the capillary bed (from the ISF back into capillaries)
Plasma fluid is filtered at the start due to hydrostatic pressure being higher than oncotic pressure. After hydrostatic pressure drops below oncotic pressure at the end, it is reabsorbed due to the gradient
Understand the role of the lymphatics in preventing edema
The lymphatics filter blood back to the vena cava at the right atrium to prevent edema. It takes proteins and such from tissues and returns them to the bloodstream
Know the equation for CO and why it is important
CO = SV x HR
Important as tissues care about cardiac output as it gives oxygen and nutrients to the body’s tissues
Understand that CO is the same from right and left ventricles
As the pulmonary and systemic circulations are in a closed loop, they must have the same amount of blood ejected
Know how heart rate is modulated and the effects of CO
Heart rate is modulated via the autonomic nervous system. Sympathetic would increase heart rate via epinephrine and norepinephrine while parasympathetic would decrease it via acetylcholine
