Exam (elaborations)
Nursing 210 - EXAM 1 2024/2025
- Course
- Institution
Nursing 210 - EXAM 1 2024/2025 Nursing 210 - EXAM 1 2024/2025 Nursing 210 - EXAM 1 2024/2025
[Show more]
Content preview
Nursing 210 - EXAM 1basic cardiac review: - ANS --> the heart is a muscular organ located behind the sternum, between the
2nd & 6th rib.
- major function is to circulate blood.
- the bottom tip point of the heart is called the apex.
- right side of heart pumps blood to the pulmonary circulation.
- the left side of the heart pumps blood to the body.
- the heart contracts & relaxes in an organized rhythm by mechanical & electrical factors.
- the mechanical power comes from all of the muscular contractions between the atria & the ventricles:
diastole & systole.
- diastole occurs when the ventricles receive blood from the atria.
- systole is the contraction of the ventricles to send blood to the pulmonary artery & to the aorta.
- systole & diastole occur simultaneously between the right & left sides of the heart.
- automaticity is the ability of cardiac cells & muscle to generate its own electrical activity.
,- cardiac conduction system transmits electrical impulses to cause the heart to contract.
- electrical cells possess the properties of automaticity, excitability, conductivity, & refractoriness.
- excitability is the ability of the cell to respond by depolarizing in response to an electrical impulse.
- contractility refers to the ability of the cell to shorten when depolarized by an electrical impulse.
- electrical activity is divided into 2 phases: depolarization & repolarization.
- depolarization is a stimulated state (contraction); the active electrical phase associated with systole.
- repolarization is a recovery state; a resting state of the muscle when the ventricles fill, known as
"diastole".
- depolarization & repolarization occur because of a cellular shift of - & + charged ions in and around
myocardial cells.
- at rest, K+ is in greater amounts intracellularly; Ca+ & Na+ are in greater amounts extracellularly.
- when the cell
The cardiac cycle - ECG - ANS - electrical activity can be graphed & measured on paper.
- changes in the waves & measured segments indicate alteration in the normal electrical conduction
system.
,P Waves: - ANS - P Waves occur when the SA node fires an impulse to depolarize the atria.
- P Waves indicate atrial depolarization.
- a P Wave is rounded in shape & is usually upright.
- a P Wave is usually no more than 0.3 mV high.
- changes can mean the impulse came from somewhere other than the SA node.
- absence of a P Wave can mean SA node failure.
PR Interval: - ANS - PR interval = total time of atrial depolarization (from beginning of atrial
depolarization to the beginning of ventricular depolarization).
- from the SA node to the AV node, the impulse is delayed before reaching the Bundle of His.
- it is a pause after the P Wave, tracing returns to the isoelectric line.
- a normal PR interval is 0.12 - 0.20 seconds.
- the PR interval is measured from the beginning of the P wave to the start of the QRS complex.
QRS Complex: - ANS - QRS complex is caused by ventricular depolarization.
- Q is the first negative deflection (if present).
, - R is the first upward stroke (usually tall).
- S is the negative stroke after the R.
- we measure the length from the beginning of the Q to the end of the S.
- the normal length of QRS is 0.04 - 0.12 seconds.
- a wide (abnormal) QRS indicates conduction problems in the ventricles.
- a normal width of a QRS complex should be less than 0.12 seconds.
QT Interval: - ANS - the QT interval measures the total amount of time that is takes for the ventricles to
both depolarize & repolarize all together.
- the QT interval is from the beginning of the QRS complex to the end of the T Wave.
- the slower the heart rate, the longer the QT.
- the QT time is usually 0.32 - 0.44 seconds.
- the QT time is not used in rhythm determination.
ST segment: - ANS - the ST segment connects the QRS complex with the T wave.
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller lectjoseph. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $15.49. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
75632 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now