Circulatory 1 Objectives + more Flashcards
List the 3 components of the circulatory system, and cite its primary functions.
- Heart – serves as a pump to propel blood through vessels
- Blood vessels – carries blood to tissues
- Blood - to fill your blood vessels
**primary fxn: TRANSPORT
: Transport to cells to help produce energy. - Delivers to tissues the oxygen & nutrients needed for metabolic processes
- Carries waste products of cellular metabolism to excretory organs (Kidneys) for elimination
- Circulates electrolytes & hormones needed to regulate body function
- Transports core heat to periphery where it can be dissipated in the external environment (aids temperature regulation)
- Transports immune substances (Antibodies) that contribute to body’s defense mechanisms
Describe the functions of each of the following parts of the heart and the potential nursing problems that might result if the function is altered/impaired: atria, ventricles, heart valves, pericardium, myocardium, and endocardium.
Atria fxn: (1) two upper chambers that collect the blood as it returns from the heart to the rest of the body. (2) serve as pumps to fill the ventricles.
If fxn of atria is impaired: (1) Not much blood will go out with each beat so CO will DROP. (2) If blood doesn’t get pumped from atria to ventricles, then blood will start to pool/stagnate which =CLOTS. Clots could drain into ventricles and get pumped out to other parts of body & occlude arteries.
Ventricle fxn: (1) two lower chambers (MAIN PUMPING CHAMBERS)
If fxn of ventricles is impaired: CO will DROP as well.
Heart valve fxn: to keep blood going in the right direction through the heart (to make sure its not going backwards)
Pericardium: sac around the heart the helps heart maintain position inside the chest & provides protection.
Myocardium: THICK Mid LAYER muscle layer of heart wall/actually performs to work of the heart
ENdocardium: INner later that provides lining of heart.
The “work” of the heart is?
contract, relax, and pump blood through blood vessels.
where does the right ventricle pump blood to?
if right ventricle fails?
to the lungs to get oxygenated
=pulmonary circulation
fails? =poor oxygenation
where does the left ventricle pump blood to?
if left ventricle fails?
to rest of body.
=systemic circulation
oxygenated blood doesn’t get to tissues=failure of major organs since its not getting oxygenated blood
Define cardiac output, and explain how it is affected by each of the following: heart rate, stroke volume, preload, afterload, and cardiac contractility.
CO: the amount of blood that gets pumped out of the heart per min.
Heart Rate (HR): An increase in heart rate leads to an increase in cardiac output. This is because more heartbeats per minute result in more blood being pumped out of the heart over the same period.
Define cardiac output, and explain how it is affected by each of the following: heart rate, stroke volume, preload, afterload, and cardiac contractility.
Stroke Volume (SV): Stroke volume is the amount of blood pumped by the heart with each beat. An increase in stroke volume leads to an increase in cardiac output, as more blood is ejected with each heartbeat. Factors affecting stroke volume include preload, afterload, and cardiac contractility.
Define cardiac output, and explain how it is affected by each of the following: heart rate, stroke volume, preload, afterload, and cardiac contractility.
Preload: Preload refers to the degree of stretch of the cardiac muscle fibers at the end of diastole, just before contraction begins. An increase in preload generally increases stroke volume and, subsequently, cardiac output. This is because increased preload stretches the cardiac muscle fibers, leading to a more forceful contraction during systole.
Define cardiac output, and explain how it is affected by each of the following: heart rate, stroke volume, preload, afterload, and cardiac contractility.
Afterload: Afterload is the resistance the heart must overcome to eject blood during systole. Increased afterload tends to decrease stroke volume and, consequently, cardiac output. This is because higher afterload makes it more difficult for the heart to pump blood out into circulation.
Define cardiac output, and explain how it is affected by each of the following: heart rate, stroke volume, preload, afterload, and cardiac contractility.
Cardiac Contractility: Cardiac contractility refers to the strength of the heart’s contractions. An increase in contractility leads to an increase in stroke volume and, subsequently, cardiac output. This is because stronger contractions result in more blood being ejected with each heartbeat.
what is Starling’s Law of the heart?
The greater the stretch of the myocardial fibers, the stronger the force of the contraction.
what are the factors that affect contactility?
Factors that affect contractility are called inotropic influences.
what are the 3 types of blood vessels?
arteries: take blood from your heart to the rest of body
capillaries: transfer of gases and nutrients from blood to cell
veins: carry blood back to the heart
Discuss the structure and function of the different types of blood vessels, and describe the nursing problems that might result if their function is impaired.
three main types of blood vessels: arteries, veins, and capillaries
Arteries fxn: carry blood to tissues (tissue
perfusion)
nursing prob: Atherosclerosis & Arteriosclerosis
Veins fxn: Veins transport blood at a lower pressure compared to arteries. They rely on skeletal muscle contractions and the presence of valves to help propel blood back to the heart. Veins also act as reservoirs, storing excess blood volume.
nursing probs: Venous insufficiency & DVT
Capillaries fxn: Capillaries facilitate the exchange of substances between the blood and surrounding tissues, including oxygen, carbon dioxide, nutrients, and waste products. Their thin walls and large surface area enable efficient diffusion of molecules.
Nursing probs: impaired wound healing & capillary leak syndrome.
Identify the determinants of blood pressure (5)
Cardiac output, Peripheral vascular resistance, ANS, kidneys, and ADH.
1.CO and the factors that affect those determinants
Cardiac output – amount of blood heart
pumps per minute. Affected by:
o heart rate
o myocardial contractility
o venous return
o blood volume
- Peripheral vascular resistance and the factors that affect those determinants
- Peripheral vascular resistance –
resistance blood encounters as it is
pumped through vessel. Affected by:
o arterial constriction & elasticity
- ANS and the factors that affect those determinants
- Autonomic nervous system
o sympathetic activity increase HR,
contractility, & vessel
constriction
o parasympathetic activity decrease HR
- Kidneys and the factors that affect those determinants
*Kidneys
o adjust sodium & water excretion to
keep BP WNL
o activates RAAS as needed
(affects blood volume & vessel
constriction)
ADH and the factors that affect those determinants
- Antidiuretic hormone (ADH) –
affects blood volume & vessel
constriction
Identify the mechanisms through which the body controls/regulates cardiac function and blood flow.
-ANS: Balances sympathetic & parasympathetic activity. Affects HR diameter of vessels but not blood volume.
1. Functions through medullary control centers (In medulla)
2. Receives input from other areas of the nervous system (ex: hypothalamus), & from arterial baroreceptors & chemoreceptors
-KIDNEYS: Involved in blood volume regulation & diameter of vessels but not HR.
-ADH/VASOPRESSIN: hormone from posterior pituitary released in response to decreased blood volume/ decreased BP>vasoconstriction, & decreased excretion of water = increased BP
Identify the predisposing factors of the following disorders, and explain the rationale underlying their nursing problems, assessment findings, and basic interventions: a) primary hypertension; b) atherosclerosis; c) coronary heart disease/coronary artery disease (differentiate between chronic ischemic heart disease and acute coronary syndrome); and d) heart failure (differentiate between right and left heart failure).
Primary hypertension: BP is higher than
120/80, but no identifiable disease that is
the causing factor.
PF:
* family history
* older age
* race (African American)
* lifestyle factors
o high Na intake
o obesity
o physical inactivity
o high alcohol consumption
o low K intake
Identify the predisposing factors of the following disorders, and explain the rationale underlying their nursing problems, assessment findings, and basic interventions: a) primary hypertension; b) atherosclerosis; c) coronary heart disease/coronary artery disease (differentiate between chronic ischemic heart disease and acute coronary syndrome); and d) heart failure (differentiate between right and left heart failure).
Specific kind of arteriosclerosis due to fibro-fatty lesions in
the wall of the artery that forms raised, thickened areas
(also called plaques).
PF:* older age
* family history (of premature CHD)
men before 45 & women before 55
* male gender
* smoking
* Hypertension
* Diabetes mellitus: high glucose
blood content becomes arterial wall
irritant; & blood sugar is high
because glucose can’t go into cells
so they break down fat & we see
high blood lipid levels.
* increased/high total cholesterol levels >200 mg/dL; low/ decreased HDL < 40mg/dL (the highest contributor)
Also possibly:
* obesity
* physical inactivity
* stress)
coronary heart disease/coronary artery disease (differentiate between chronic ischemic heart disease and acute coronary syndrome);
Coronary Heart Disease (CHD)/Coronary Artery Disease (CAD)/Atherosclerotic heart disease (ASHD):
Chronic Ischemic Heart Disease. Caused by impaired blood flow in the artery.
-Usually caused by Atherosclerosis in the coronary artery
-The heart gets blood through the blood from the coronary arteries, so if the arteries are clogged, the heart muscle cells won’t get enough oxygen & will become ischemic or infarcted.
-Depending on which coronary artery is occluded, that will determine which areas of the heart will be damaged in a heart attack.
-Not as severe as acute
-Comes on more gradually
Acute Coronary Syndrome (ACS) -Comes on more quickly & is more severe.
-You don’t live with it forever, you either get rid of it, or you die.
d) heart failure (differentiate between right and left heart failure).
Heart failure is a condition where the heart is unable to pump blood efficiently to meet the body’s needs.
In LHF, the left ventricle of the heart is unable to adequately pump blood to the body’s systemic circulation.
Symptoms:
Dyspnea (shortness of breath), especially during exertion or when lying flat (orthopnea).
Paroxysmal nocturnal dyspnea (sudden awakening from sleep due to shortness of breath).
Fatigue and weakness.
Fluid retention leads to pulmonary congestion and peripheral edema (swelling of the legs and ankles).
In RHF, the right ventricle of the heart is unable to effectively pump blood to the lungs for oxygenation, leading to congestion in the systemic venous circulation.
Symptoms:
Peripheral edema, particularly in the legs and ankles.
Ascites (fluid accumulation in the abdominal cavity).
Hepatomegaly (enlargement of the liver).
Jugular venous distention (JVD), visible as engorged neck veins.
Weight gain due to fluid retention.
what happens if the atria arent filling the ventricles?
CO drops *1st prob that occurs if atria are not doing their job
2nd problem that can occur if atria arent doing their job?
blood starts pooling in the atria, which leads to clotting, & that clot is then pumped into the ventricles, then into arteries–> ischemia & tissue damage.
if venticles arent doing their job, what happens to CO?
Also drops
where does right ventricle pump blood to?
what is this circulation called?
to the lungs to get oxygenated
pulmonary circulation
if right ventricle fails, what potential problem will you have?
if RV is not pumping blood to lungs, blood won’t get oxygenated=poor oxygenation
where does left ventricle pump blood to?
what is this circulation called?
pumps out to rest of the body
systemic circulation
if LV fails, what happens?
oxygenated blood doesn’t get to tissues= failure to major organs bc not getting oxygenated blood.
job of heart valves:
keep blood going in right direction thru heart. Prevents blood from going
backwards.
Pericardium:
A sac that surrounds the heart
& helps it maintain its position & provides
protection
Myocardium:
Thick, muscle layer that
performs the work of the heart.
Endocardium:
Inner layer that provides
lining of the heart.
contract/relax is referred to as:
cardiac cycle
systole: heart conracts
diastole: heart relaxes/fills (d as in relax when you die)
the faster the HR, the faster the CO, UNTIL…
HR is so fast that the ventricles wont have time to fill in between each beat
HR is mostly determined by your
Autonomic Nervous System (ANS):
sympathetic & parasympathetic
** if you have a change in any of these activities, that’ll change your HR and eventually change your C.O.
3 Things that determine how big SV is?
Preload: volume entering ventricles/ready to get pumped out
Contractility: the force of contraction that’s not dependent on pre/afterload
Afterload: resistance left ventricle must be overcome to circulate blood.
if elastic gets too stretched out, it doesn’t snap back anymore =
LESS SV & LESS CO
The more blood in the ventricle, the more the heart muscle fibers are stretched, the more they’re stretched, the greater the force of contraction… THIS IS CALLED
STARLING’S LAW OF THE HEART
(greater the stretch (elasticity) of the myocardial fibers, the stronger the force of contraction
the higher the afterload, the lower the
SV & CO is going to be
The higher the pressure in your arteries, the higher your BP gets, the harder the heart will have to work to pump blood & the LESS
that the blood is going out w each beat
decreased contractility ex(s)
Hypoxia (not enough O2 to tissues)
Heart Attack (heart muscle cells don’t get enough O2 = cell death) Part of heart wall dies
Hypercapnia: increased CO2 in bloodstream
Myocardial Ischemia: blood flow to heart is reduced=heart muscle doesn’t receive enough O2
metabolic acidosis:too much acid in body = kidney disease
to have blood flow you must have:
patent blood vessels (unclogged)
a force (provided by arterial bp) to move blood thru system
equation that affects BLOOD PRESSURE
BP= CO x PVR
CO= amt of blood pumped out of heart per min. *the more CO you have, the higher the BP.
PVR = resistance blood encounters as it tries to move through blood vessels
increased bp = what actions?
give them a diuretic or drug to slow heart rate
Vasodilator (dilates vessels, decreases peripheral vascular resistance)
decreased bp = what actions?
change BV, IV fluids, drug that causes vasoconstriction
Cholesterol guidelines
Total: < 200 mg/dl
HDL: > 40 mg/dl good cholesterol
LDL: < 100mg/dl bad cholesterol
Triglycerides: < 200 mg/dl
