cardiac-anatomy

My heart skip skips a beat

HEARTBEATS!!

The pause is to allow the atria to fully empty into the ventricle.

Heartbeat on an ECG trace

P Interval (Ventricular Diastole)

  • Atria and ventricles are relaxed
  • blood is flowing into the atria from the veins. 
  • Atrial pressure increases above that of the ventricle, AV valves open allowing blood to flow into the ventricle

P Wave (Atrial Systole) P-Q

Signal transduction from SA to AV nodes. 

  • SA node fires 
  • Atria contract causing atrial systole 
  • which forces all blood into the ventricles
  • emptying the atria.

Q Interval (End of Ventricular Diastole)

Depolarisation of interventricular (IV) septum 

  • AV valves remain open - all remaining blood squeezed into the ventricles. 
  • impulse from the SA node reaches the AV node 
  • which spreads the signal throughout the walls of the ventricles via bundles of His and Purkinje fibres
  • R peak is the end of ventricular diastole and the start of systole.

R Interval (Ventricular Systole)

Ventricular contraction

  • All blood is now within the ventricles
  • so pressure is higher than in the atria - AV valves close
  • ventricles start to contract although pressure is not yet high enough to open the SL (semilunar) valves

ST Segment (Ventricular Systole)

Ventricular contraction

  • Pressure increases until it equals Aortic pressure,
  • SL valves open
  • blood is ejected into the Aorta (and pulmonary artery) as ventricles contract
  • At this time the atria are in diastole and filling with blood returning from the veins.
  • plateau in ventricular arterial pressure

T Wave (Ventricular Diastole)

T= moment of Ventricular repolarisation immediately before ventricular relaxation

  • Ventricles relax
  • ventricular pressure is once again less than the aortic pressure 
  • so SL valves close
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Home is where the heart is…

…and when you apply this stunning anatomy themed wallpaper to your study/living room/love nest then the age old adage could not be more appropriate.

Aorta have this in the office but in the meantime, while I save up some pennies, bring your own walls to life by visiting the designer and retailer of these unique works of heart at the anatomyboutique

i-heart-histo

Source: www.anatomyboutique.com

Heart Inside Pericardial Sac

There are two layers to the pericardium: the outer fibrous pericardium, which is the tough tissue that protects the heart and anchors it in place, and the inner serous pericardium, which further cushions the heart against trauma and lubricates the area between the muscle and tough fibrous pericardium, so that no friction is formed while the heart pumps blood.

Atlas and Text-Book of Topographic and Applied Anatomy. Oskar Schultz and George D. Stewart, 1905.

The Signs as Cardiac Rhythms
  • Aries: Normal Sinus Rhythm
  • Taurus: Ventricular fibrillation
  • Gemini: Ventricular tachycardia
  • Cancer: Atrial flutter
  • Leo: Torsades des Pointes
  • Virgo: Asystole
  • Libra: Junctional tachycardia
  • Scorpio: Wandering Atrial Pacemaker
  • Sagittarius: Sinus arrest
  • Capricorn: Bradycardia
  • Aquarius: 3rd degree AV block
  • Pisces: Atrial fibrillation