Summary
Summary human anatomy & physiology -heart
- Course
- Institution
I passed this course with the help of this summary with an 8.5! It contains all lecture material including all slides.
[Show more]
Seller
Follow
lvd26
Reviews received
Content preview
Summary Human anatomy & physiologyLecture 1: Introduction to the heart
From a cardiomyocyte to a heart beat
A tale of two circulations
Pulmonary circulation > low pressure system
Systemic circulation> high pressure
➢ Thickness of the wall
,Function of the heart
• Pumping deoxygenated blood to the lungs
• Pumping oxygenated blood to all the organs in the body
• Together with blood vessels: providing adequate perfusion of all organs & tissues of the
body
• Contraction and relaxation determine cardiac output (and the amount of blood)
• How can they be sustained →
– Coordination of contraction and relaxation of 2-3 billion CMs
Excitation-contraction coupling (=action potential at the cellular level)
Contraction of the heart following electrical stimulation of cardiomyocytes
Automation of the heart
• The heart can beat independent of hormonal or neuronal input (but there can be input)
AUTOMATION
• Spontaneous active
• Pacemaker cells (SA node> heart rhythm)
Conduction through the heart
You don’t want your
atria and ventricles
to contract
simultaneously, thus
slow conduction AV
node.
So, first atria
contracts, and then
after being filled with
blood, the ventricles
,Nerve cells in the heart give fast signals to the ventricles
Conduction between cardiomyocytes (electric coupled, slow conduction)
, Action potentials in cardiomyocytes
Can you deduce why automation of heart beat occurs from SA node cells?
• Unstable resting potential • Stable resting potential: -85 mV
• Slow depolarisation prepotential • Quick depolarisation
(pacemaker potential) • Plateau
• Quick repolarisation
Basis for the resting membrane potential
Membrane potential
determined by:
- concentrations differences of ions
AND permeability to ions
-Largely determined by K+ gradient
(see Nernst equation)> high inside,
low outside
Cell in rest is permeable to K+
Cell is slightly negatively charged
Ion channels open and close & action potential of ventricular cell
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 lvd26. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $9.76. 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