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1
AP 2 LECTURE NOTES

• CARDIOVASCULAR SYSTEM

2
HEART

• Location
• Mediastinum
• Apex on left above diaphragm
• place stethoscope
• between the 5th and sixth ribs on line midpoint
  of clavicle
• upper border of heart base near 2nd rib

3
Size and Shape of Heart

• adult male about 310 g
• adult female about 225g
• approximate dimension 12 cm x 9 cm x 6 cm

4
Coverings of the heart

• serous pericardium
• fibrous pericardium - outside of pericardium sac
• parietal pericardium layer- inside the fibrous
  pericardium
• visceral pericardium layer- layer on the heart

5
Coverings of the heart, cont.

• epicardium same as visceral pericardium
• pericardial space ( cavity)
• pericardial fluid ( serous) 10-15 ml

6
STRUCTURE OF THE WALL OF THE HEART

• epicardium ( outer layer)
• myocardium ( middle layer)
• cardiac muscle tissue
• endocardium
• endothelium ( simple squamous)
• trabeculae ( beam like projections)

7
CHAMBERS OF THE HEART (4)

• atriums ( right and left)
• upper chambers of the heart
• note term auricles only refers to 'flaps'
• note interatrial septum divides right and left
  atrium

8
CHAMBERS OF THE HEART,cont.

• ventricles ( right and left)
• two lower chambers of the heart
• Note interventricular septum
• divides right and left ventricles

9
VALVES OF THE HEART (4)

• A-V valves ( atrioventricular valves)
• tricuspid valve
• RIGHT A-V valve
• between the right atrium and right ventricle
• bicuspid valve ( mitral valve)
• LEFT A-V valve
• between the left atrium and left ventricle

10
SEMILUNAR valves

• pulmonary semilunar valve
• between the right ventricle and pulmonary trunk
• aorta semilunar valve
• between the left ventricle and the aorta arch

11
OTHER STRUCTURES FOUND IN THE HEART

• chordae tendineae
• papillary muscles
• 'skeleton' of the heart

12
MAJOR BLOOD VESSELS

• bring blood to the heart (4)
• Superior and inferior vena cava
• bring blood to the right atrium
• Pulmonary trunk
• pulmonary trunk leads out of the right ventricle
• splits into right and left pulmonary arteries
• which go to the lungs

13
MAJOR BLOOD VESSELS, cont

• Pulmonary veins
• come from the lungs
• go to the left atrium
• aorta
• blood comes from the left ventricle
• goes to the aorta arch
• blood leaving the arch goes to systemic
  circulation

14
BLOOD SUPPLY OF HEART TISSUE

• coronary arteries
• nourish myocardium cells
• right coronary artery comes off of the aorta
  (high in oxygen)
• left coronary artery
• anterior interventricular artery
• circumflex artery

15
Blood suppy to cardiac muscles

• anastomosis- one or more branches from the
  proximal part of an artery to a more distal part
  of itself
• provides collateral circulation
• anastomosis in coronary blood vessels are
  infrequent

16
BLOOD SUPPLY OF HEART TISSUE

• coronary veins
• great cardiac vein
• coronary sinus

17
CONDUCTION SYSTEM OF THE HEART (4)

• Sinoatrial node
• S-A node pacemaker of the heart
• located in the upper part of the right atrium
• Atrioventricular node
• A-V node
• found in the lower part of the right atrium

18
Conduction- heart

• Atrioventricular bundle
• bundle of His found in septum
• Purkinje fibers
• outside wall of ventricle and end in papillary
  muscles

19
NERVE SUPPLY OF THE HEART

• sympathetic fibers
• superior, middle and inferior cardiac nerves
• increase heart rate
• parasympathetic fibers
• from Vagus Nerve (X)
• slows heart rate

20
Nerve supply to heart

• cardiac plexuses are formed from sympathetic and
  parasympathetic fibers
• near aorta arch
• most fibers go to S-A node
• some fibers go to A-V node

21
Fetal circulation

• umbilical cord
• 2 arteries and 1 umbilical vein
• note umbilical vein in HIGH in oxygen so is
  indicated in red
• ductus venosus
• connection to fetal vena cava

22
Fetal circulation

• foramen ovale
• hole in the interatrial septum
• blood in the fetal heart goes from right atrium
  to left atrium
• ductus arteriosus
• shunt which allows blood in the fetal heart to
  go from pulmonary trunk to aorta arch
• these special features disappear at birth