Bio topic D4

Muscle

Indepedent from nervous system => move on itself

Connected intercalted disks

They are branched

Have more mitochondria => more ATP => more activity

Heart conduction

Systole

Diastole

Atrial contraction

Ventricular contraction

Rest

  1. SA node (controls heartbeat) sends signal for contraction
  1. Sends signal to atrial myocardium
  1. Atria contracts, blood is pushed into ventricles
  1. SA node sends signal AV node
  1. Sends signal to bundle of hiss
  1. Bundle of hiss sends signal to pump blood from ventricles
  1. Blood from ventricles is pushed to arteries

Heart sound

Lubb: sound of AV valves close/open

Dubb: sounds of semilunar valves close/open

Electrocardiograph (ECG)

P wave: signal atria contraction

QRS complex: blood is pushed from atria to ventricle

T wave: ventricle pushes blood arteries

Irregular waves

frillbilation:everything irregular

Tahycardia: beat too slow

Bradycardia: beat too fast

Arrythmias: normal beating, inconsistent rhythm

Cardiac Output

Heart rate x Stroke volume

Heart rate: how fast or slow the hearts beat (bpm)

Stroke volume: how much blood is pumped (mL)

Heart disorders

Thrombosis: blood clotting cause heart attack or stroke

Cardiac (or Coronary) Heart Disease: arteries are blocked by plaque

Hypertension: blood pressure too high

Treatments

Defrillbilator

Artificial Pacemaker

replace SA node to sends signal

Synchronize contraction => normalize signals