1. THE HEART <3

4. BLOOD AND THE HEART FUN FACTS
♦ An average adult human contains
about 5 liters (5.3qt) of blood.
♦ The blood makes up about onethirteenth
of the body’s weight.
♦ The adult heart weighs about 280 grams (10 oz.)
♦ At rest, the heart pumps out about 80 millimeters
(2.6 oz) of blood with each beat.
♦ The heart beats, on average, 70 times each
minute at rest.
♦ This means all the blood is circulated (goes
round the body once) in about one minute.
♦ During strenuous exercise the heart can pump
six to eight times the amount of blood that it
pumps at rest.

5. Superior vena cava and
inferior vena cava – bring
deoxygenated blood to
right atrium
Pulmonary artery – takes
blood away from right
ventricle to the lungs for O2
Pulmonary veins – bring oxygenated blood
from lungs to left atrium
Aorta – takes blood away from left ventricle to
rest of the body

6. Chambers and Valves
• SEPTUM divides into R and L halves
• Upper chambers – RIGHT ATRIUM and LEFT ATRIUM
• Lower chambers – RIGHT VENTRICLE and LEFT VENTRICLE
• Four heart valves permit flow of blood in one direction

7. -TRICUSPID VALVE – between right atrium and
right ventricle
-BICUSPID (MITRAL) VALVE – between left atrium
and left ventricle
-Semilunar valves are located where blood leaves
the heart - PULMONARY SEMILUNAR VALVE
and AORTIC SEMILUNAR VALVE

8. The heart=a muscular double pump with 2 functions
The right side receives oxygen-poor blood from the body and tissues and then pumps it to the lungs to pick up oxygen and dispel carbon dioxide
Its left side receives oxygenated blood returning from the lungs and pumps this blood throughout the body to supply oxygen and nutrients to the body tissues

9. Two circulations
Systemic circuit: blood vessels that transport blood to and from all the body tissues
Pulmonary circuit: blood vessels that carry blood to and from the lungs

10. Chambers of the heart sides are labeled in reference to the patient facing you
Two atria
Right atrium
Left atrium
Two ventricles
Right ventricle
Left ventricle

11. Valves three: tricuspid one: bicuspid
(cusp means flap)
“Tricuspid” valve
RA to RV
Pulmonary valve
RV to pulmonary trunk (branches R and L)
Bicuspid valve (the bicuspid one)
LA to LV
Aortic valve
LV to aorta

12. Function of AV valves

13. Function of semilunar valves
(Aortic and pulmonic valves)

14. Meet the Heart

15. Pattern of flow (simple to more detailed)
Body RA RV
Lungs LA LV
Boby
Body to right heart to lungs to
left heart to body
Body, then via vena cavas and coronary sinus to RA, to RV, then to lungs via pulmonary arteries, then to LA via pulmonary veins, to LV, then to body via aorta
From body via SVC, IVC & coronary sinus to RA; then to RV through tricuspid valve; to lungs through pulmonic valve and via pulmonary arteries; to LA via pulmonary veins; to LV through mitral valve; to body via aortic valve then aorta
LEARN THIS

16. PHYSIOLOGY OF THE HEART
The heart is a double pump. When the heart
beats…
Right Heart
Deoxygenated blood flows into heart from vena
Cava ---right atrium ---tricuspid valve--- right
ventricle --pulmonary semilunar valve---
pulmonary artery ---lungs (for oxygen)
Left Heart
Oxygenated blood flows from lungs via pulmonary
Veins--- left atrium--- mitral valve--- left ventricle---
aortic semilunar valve--- aorta --- general
circulation (to deliver oxygen)

17. Control of Heart Contractions
SA (sinoatrial) NODE = PACEMAKER
• Located in right atrium
• SA node sends out electrical impulse
• Impulse spreads over atria, making them
contract
• Travels to AV Node
AV (atrioventricular) NODE
• Conducting cell group between atria and
ventricle
• Carries impulse to bundle of His
BUNDLE OF HIS
• Conducting fibers in septum
• Divides into R and L branches to network of
branches in ventricles (Purkinje fibers)
PURKINJE FIBERS
• Impulse shoots along Purkinje fibers causing
ventricles to contract

18. Flow Through the Heart

19. Heart Contraction SA Node Sinalarterial node “Pacemaker” AV Node
Atrioventricular node
Allows impulse to cross
into ventricles
Purkinje Fibers
Bundle of His
Bundle Branches

20. Heart Contraction Flow Chart
SA Node fires ↓ Impulse spreads across atria Atria depolarizes Atria contract (lub) Blood is pumped to the ventricles AV Node receives impulse from SA Node Impulse passes through bundle of His Impulse passes through Purkinje fibers Ventricles depolarize and contract (dub) Blood is pumped into the lungs and out to the body

21. Electrical conduction system:
specialized cardiac muscle cells that carry impulses throughout the heart musculature, signaling the chambers to contract in the proper sequence
(Explanation in next slides)

22. Conduction system SA node (sinoatrial) In wall of RA
Sets basic rate:
Is the normal pacemaker
Impulse from SA to atria
Impulse also to AV node via internodal pathway
AV node
In interatrial septum

23. Conduction continued SA node through AV bundle (bundle of His)
Into interventricular septum
Divides
R and L bundle branches
become subendocardial
branches (“Purkinje
fibers”)
Contraction begins
at apex

25. EKG→ measures heart electricity
P Wave→ Atria contract & Depolarize
PQ Interval→ Impulse is passing through the bundle of His to the Purkinje fibers
QRS Wave→ Ventricles depolarize and contract
T Wave→ Ventricles repolarize

26. Cardiac Cycle
Blood enters the atria through the vena cava (R) and the Pulmonary vein (L) ↓
Atria will contract
Blood is pushed through the AV valves into the ventricles
Ventricles contract and AV valves close
Blood is pushed though the pulmonary and aortic semilunar valves into the pulmonary trunk and the aorta
Ventricles relax and valves close

27. Cardiac Cycle Tutorial
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