The document provides a comprehensive overview of cardiovascular anatomy, detailing the structure and function of the heart along with its chambers, conducting system, blood supply, and fetal circulation. Key objectives include understanding the heart's anatomy, the flow of blood, and the relationship of the heart to thoracic structures. It emphasizes the importance of this knowledge in the context of anesthesia care and the implications of cardiac conditions in geriatric patients.

1. CARDIOVASCULAR
ANATOMY
KCHS/KRNA M 2016 CLASS
Hosea C.

2. OBJECTIVES
 AT THE END OF THE LESSON THE
LEARNER SHOULD BE ABLE TO:
 Describe the structure and function of the heart
 Definition of cardiac circle
 Describe the conducting system of the heart
 Describe the blood flow through the heart
 Describe the blood supply to the heart
 Appreciate the location of the major great
vessels.
 Developmental anatomy of the heart (fetal
circulation)

3. DESCRIPTION
 The heart is a four-chambered, conical, muscular
pump in the middle mediastinum. It is
suspended by the great vessels.

4. HEART
 The heart is the muscular pump responsible for
blood circulation
 It is an organ of four chambers- the right and the
left atria and the right and the left ventricles
 The two atria receive venous blood.
 The right ventricles propels blood to the lungs
and the left ventricle propels blood around the
systemic circulation.
 Depending on the body’s changing needs, the
heart can vary its output from 5 to 35 liters of
blood per minute.

5. ANTERIOR SURFACE OF THE HEART

6. HEART IN ANTERIOR VIEW

7. POSTERIOR VIEW OF THE HEART

8. HEART IN POSTERIOR VIEW

9. CHAMBERS OF THE HEART

10. SURFACE MARKINGS
 The surface markings follow a quadrilateral
shape (distances from midline): third right costal
cartilage (2 cm), second left costal cartilage (3
cm), fifth left intercostal space (7 cm) and sixth
right costal cartilage (2 cm).

11. SURFACE MARKINGS

12. RELATIONSHIP OF THE HEART TO
THE THORAX

13. STRUCTURE
 The heart consists of four chambers:
 1. Right atrium – receives deoxygenated blood from the
body via the venae cavae (inferior and superior). The
outflow of blood occurs through the tricuspid valve into the
right ventricle. The sino-atrial node is situated in the
upper part of the right atrium, and the atrioventricular
node lies near the base of the tricuspid valve.
 2.Right ventricle – receives blood from the right atrium
and expels it through the pulmonary valve and trunk.
 Some of the rough internal wall muscle fibres (trabeculae)
specialize into papillary muscles, which attach to the
tricuspid valve cusps (in a similar fashion to the mitral
valve on the left side of the heart). The pulmonary valve is
tricuspid and leads into the pulmonary trunk

14. STRUCTURE
 3. Left atrium – receives oxygenated blood from
the lungs via the four pulmonary veins, which
open superoposteriorly. The blood then passes
through the mitral (bicuspid) valve into the left
ventricle
 4. Left ventricle – thickest-walled chamber that
distributes blood to the body via the aorta. The
aortic valve is tricuspid – with right, left and
posterior cusps. Small sinuses lie above the cusps
that give rise to the two coronary arteries – right
and left respectively

15. FLOW OF BLOOD THROUGH THE
HEART

16. INTERNAL CHAMBERS OF THE
HEART

17.  As shown in the diagram, the right atrium
receives venous blood from the inferior vena cava
and superior vena cava. A small amount of
cardiac venous blood enters the right atrium by
means of the thebesian veins. This blood is low in
oxygen and high in carbon dioxide.
 A one-way valve, the tricuspid valve, lies
between the right atrium and the right ventricle.
The tricuspid valve gets its name from its three
valve leaflets, or cusps. The tricuspid leaflets are
held in place by tendinous cords called chordae
tendinae ,which are secured to the ventricular
wall by the papillary muscles.

18.  When the ventricles contract, the tricuspid valve closes
and blood leaves the right ventricle through the pulmonary
trunk and enters the lungs by way of the right and left
pulmonary arteries. The pulmonary semilunar valve
separates the right ventricle from the pulmonary trunk.
 After blood passes through the lungs, it returns to the left
atrium by way of the pulmonary veins. These vessels are
best seen in a posterior view of the heart.
 The returning blood is high in oxygen and low in carbon
dioxide. The bicuspid valve (also called the mitral
valve) lies between the left atrium and the left ventricle.
This valve, which consists of two cusps, prevents blood
from returning to the left atrium during ventricular
contraction.

19.  Similar to the tricuspid valve, the bicuspid valve
is also held in position by chordae tendinae and
papillary muscles. The left ventricle pumps blood
through the ascending aorta .
 The aortic valve, which lies at the base of the
ascending aorta, has semilunar cusps (valves)
that close when the ventricles relax. The closure
of the semilunar valves prevent the backflow of
blood into the left ventricle.

20. PULMONARY AND SYSTEMIC
CIRCULATION

22. CONDUCTING SYSTEM OF THE
HEART
 Sino-atrial node – in the superior right atrial
wall (near the superior vena caval opening) and
initiates conduction impulse. The node is in direct
contact with the atrial cells and causes a wave of
depolarisation, resulting in contraction of both
atria.
 Atrioventricular node – at the base of the right
atrial septal wall (near the tricuspid valve) and
receives impulses from the atrial depolarization.
There is no direct neural route between the two
nodes, which allows for a slight delay and
prevents simultaneous atrial and ventricular
contraction

23. CONDUCTING SYSTEM OF THE
HEART
 Bundle of His – nerve fibre bundle (AV bundle)
that receives the electrical impulse from the AV
node and continues within the interventricular
septum. At the base it divides into two terminal
bundle branches (right and left). These continue
in the walls of their respective ventricles,
terminating in Purkinje fibres, which penetrate
the muscular walls and initiate ventricular
contraction.

24. CONDUCTING SYSTEM OF THE
HEART

25.  The afferent fibers from the aortic arch baroreceptors
travel with the vagus nerve (tenth cranial).
 The baroreceptors regulate the arterial blood pressure by
initiating reflex adjustments to changes in blood
pressure. For example, when the arterial pressure
decreases, the neural impulses transmitted from the
baroreceptors to the vasomotor and cardiac centers in
the medulla also decrease. This causes the medulla to
increase its sympathetic activity, which in turn causes
an increase in the following:
• Heart rate
• Myocardial force of contraction
• Arterial constriction
• Venous constriction.

26. PERICARDIUM
 Heart is enclosed within a conical fibroserous sac
– the pericardium.
 The outer layer is attached to the following
structures:
- Adventitia of the great vessels
-Sternopericardial ligament – to the
posterior sternum
-Central tendon of diaphragm –
where it is fused inferiorly

27. PERICARDIUM
 Outer fibrous layer is a tough fibrous structure
with openings to allow the aorta, pulmonary
trunk and superior vena cava to pass through
 Serous pericardium has two
 components:
-Outer parietal pericardium – lines the inner
surface of the fibrous sac and becomes continuous
with the visceral layer around the great vessels
 -Inner visceral pericardium – in direct
contact with the heart and forms a potential
space between the pericardial layers.

28. LAYERS OF PERICARDIUM

29. BLOOD SUPPLY TO THE HEART
 The blood supply of the heart originates directly from the
aorta by means of two arteries: the left coronary artery
and the right coronary artery.
 The right coronary artery arises from the anterior aortic
sinus and passes forwards between the pulmonary trunk
and the right atrium to descend in the right part of the
atrioventricular groove.
 At the inferior border of the heart it continues along the
atrioventricular groove to anastomose with the left
coronary at the inferior interventricular groove. It gives off
a marginal branch along the lower border of the heart and
an interventricular branch that runs forwards in the
inferior interventricular groove to anastomose near the
apex of the heart with the corresponding branch of the left
coronary artery.

30. BLOOD SUPPLY TO THE HEART
 The left coronary artery, which is larger than the
right, arises from the left posterior aortic sinus.
Passing first behind and then to the left of the
pulmonary trunk.
 The left coronary artery divides into the
circumflex branch and the anterior
interventricular branch. The circumflex branch
runs posteriorly and supplies the left atrium and
the posterior wall of the left ventricle. The
anterior interventricular branch travels toward
the apex of the heart and supplies the anterior
walls of both ventricles and the interventricular
septum.

31. BLOOD SUPPLY TO THE HEART
 The right coronary artery supplies the right atrium and
then divides into the marginal branch and the posterior
inter ventricular branch .
 The marginal branch supplies the lateral walls of the right
atrium and right ventricle.
 The posterior interventricular branch supplies the
posterior wall of both ventricles

32. VENOUS DRAINAGE
 The venous system of the heart parallels the coronary
arteries.
 Venous blood from the anterior side of the heart empties
into the great cardiac veins; venous blood from the
posterior portion of the heart is collected by the middle
cardiac vein
 The great and middle cardiac veins merge and empty into a
large venous cavity within the posterior wall of the right
atrium called the coronary sinus. A small amount of
venous blood is collected by the thebesian veins, which
empties directly into both the right and left atrium.
 The venous drainage that flows into the left atrium
contributes to the normal anatomic shunt, the phenomenon
whereby oxygenated blood mixes with deoxygenated blood.

33. ARTERIAL SUPPLY AND VENOUS
DRAINAGE

34. NERVE SUPPLY
 Autonomic supply:
● Parasympathetic – from the vagus nerve
(cardio-inhibitory)
● Sympathetic – cervical (C1–4, C5 and C6, C7–
T1) and upper thoracic (T2–5) ganglia (cardio-
accelerator) via the superficial and deep cardiac
plexuses
● Phrenic nerve (C3–5) supplies the pericardium

35. THE GREAT VESSELS
 AORTA
 Commences at the aortic valve and terminates at its
bifurcation into the common iliac arteries (L4 level). There
are four parts:
 1. Ascending – 5 cm long, posterior to sternum. It gives off:
● Right coronary artery
● Left coronary artery
o 2.Arch – runs upwards, backwards and to the left. It gives
off:
● Brachiocephalic, which divides into:
o ● Right common carotid
o ● Right subclavian
o ● Left common carotid
o ● Left subclavian

36. THE GREAT VESSELS
 3. Descending thoracic aorta – starts at level T4
and runs down to the aortic opening in the
diaphragm (T12). It gives off:
● Visceral branches – pericardial, bronchial,
esophageal, mediastinal and phrenic
 ● Somatic branches – posterior intercostals,
dorsal, muscular, lateral cutaneous and
mammary

37. THE GREAT VESSELS
 4. Abdominal aorta – starts at the aortic opening in the
diaphragm and ends at the common iliac bifurcation. It gives
off:
● Lumbar arteries (paired)
● Visceral arteries (paired) – inferior phrenic,
suprarenal, renal and gonadal
● Midline (unpaired) arteries:
● Celiac trunk – supplies the foregut (via left gastric,
common hepatic and splenic)
● Superior mesenteric – supplies the midgut (via inferior
pancreaticoduodenal, jejunal ileal, ileocolic, right and middle
colic)
● Inferior mesenteric – supplies the hindgut (via left
colic,sigmoid and superior rectal)

38. THE GREAT VESSELS

39. SCHEMATIC DIAGRAM OF THE
INFERIOR VENA CAVA AND ITS
BRANCHES

40. PRINCIPAL RELATIONS OF THE
ARCH OF THE AORTA

41. MAJOR ARTERIES OF THE HEAD
AND NECK

42. ARTERIES OF UPPER LIMB

43. ARTERIES OF THE LOWER LIMB

44. MAJOR ARTERIES

45. MAJOR VEINS OF HEAD AND NECK

46. SUPERFICIAL VEINS OF THE RIGHT
UPPER LIMB

47. DORSAL METACARPAL VEINS OF
THE RIGHT HAND

48. VEINS OF THE LEG

49. FETAL CIRCULATION

50. FETAL CIRCULATION
 Umbilical vein – oxygenated blood enters the
body via the umbilical vein. After mixing with
deoxygenated blood in the ductus venosus, it
reaches the right atrium (via inferior vena cava
that receives blood from trunk and limbs)
 Right atrium – anatomical relationship of the
venae cavae ensures that most of the blood in the
right atrium (from the inferior vena cava)
bypasses the right ventricle and goes directly to
the left atrium via the patent foramen ovale.

51. FETAL CIRCULATION
 Left atrium – blood from the left atrium mixes
with (deoxygenated) blood from the lungs and is
expelled via the left ventricle into the aorta, and
ultimately around the body.
 Mixing – some blood does not flow directly from
the right into the left atrium, but instead it is
directed to the right ventricle (mainly blood from
the superior vena cava). This deoxygenated blood
flows through the lungs and pulmonary trunk,
and then via the ductus arteriosus into the aorta

52. FETAL CIRCULATION

53. FETAL CIRCULATION
 Transitional circulation – following the clamping
of the umbilical cord at birth, and with the large
decrease in pulmonary vessel pressure with
inspiration, significant pressure and flow
changes occur. The fall in right atrial pressure
and increase in left atrial pressure causes the
foramen ovale to close, as the septum secundum
and septum primum oppose.

54. FETAL CIRCULATION
 This is an immediate functional closure only. As
a result, all blood from the right atrium is now
forced into the right ventricle. The ductus
arteriosus also constricts due to the high partial
pressure of oxygen (functionally complete by 12
hours). The change to adult circulation is
complete by 3 months, by which time the
foramen ovale is anatomically fused (fossa ovalis)
and the ductus arteriosus is obliterated.

55. SUMMARY
 Cardiovascular anatomy is vital aspect in
anesthesia care.
 Understanding the normal cardiac anatomy is
important so as to guide in understanding the
abnormal
 Conduction defects and coronary heart disease
have an impact in geriatric anesthesia
 Fetal circulation is important in understanding
abnormal defects
 Supply and demand in cardiovascular system
must be understood as it relates to all aspects of
anesthesia care