The document discusses the anatomy and physiology of the cardiovascular system. It covers topics such as heart anatomy, heart valves and circulation, cardiac muscle tissue, the cardiac conduction system, the cardiac cycle, cardiac output, regulation of stroke volume, exercise and the heart, and blood supply to the myocardium. The key points are:
1. The heart is located in the mediastinum and has four chambers - two upper atria and two lower ventricles.
2. Blood flows through the heart in two circuits - systemic circulation through the left side of the heart and pulmonary circulation through the right side.
3. Cardiac output is calculated as stroke volume multiplied by heart rate and is regulated by factors like pre
3. 1. The heart is located in the mediastinum;
about two-thirds of its mass is to the left of
the midline.
2. The heart is shaped like a cone lying on
its side; its apex is the pointed, inferior
part, whereas its base is the broad,
superior part.
3. The pericardium is the membrane that
surrounds and protects the heart; it
consists of an outer fibrous layer and an
inner serous pericardium, which is
composed of a parietal and a visceral
layer.
4.
5.
6.
7.
8.
9. 4. Between the parietal and visceral layers of the
serous pericardium is the pericardial cavity, a
potential space filled with a few milliliters of
pericardial fluid that reduces friction between the
two membranes.
5. Three layers make up the wall of the heart:
epicardium (visceral layer of the serous
pericardium), myocardium, and endocardium.
6. The epicardium consists of mesothelium and
connective tissue, the myocardium is composed
of cardiac muscle tissue, and the endocardium
consists of endothelium and connective tissue.
10.
11. 7. The heart chambers include two superior
chambers, the right and left atria, and two
inferior chambers, the right and left ventricles.
8. External features of the heart include the
auricles (flaps on each atrium that slightly
increase their volume), the coronary sulcus
between the atria and ventricles, and posterior
surfaces of the heart, respectively.
9. The right atrium receives blood from the
superior vena cava, inferior vena cava, and
coronary sinus. It is separated from the left
atrium by the interatrial septum, which contains
the fossa ovalis. Blood exits the right atrium
through the tricuspid valve.
12.
13.
14. 10. The right ventricle receives blood from
the right atrium. It is separated from the
left ventricle by the interventricular septum
and pumps blood through the pulmonary
valve into the pulmonary trunk.
11. Oxygenated blood enters the left
atrium from the pulmonary veins and exits
through the bicuspid (mitral) valve.
15. 12. The left ventricle pumps oxygenated
blood through the aortic valve into the
aorta.
13. The thickness of the myocardium of
the four chambers varies according to the
chamber’s function. The left ventricle, with
the highest workload, has the thickest
wall.
14. The fibrous skeleton of the heart is
dense connective tissue that surrounds
and supports the valves of the heart.
21. 1. Heart valves prevent backflow of blood within
the heart. The atrioventricular (AV) valves, which
lie between atria and ventricles, are the tricuspid
valve on the right side of the heart and the
bicuspid (mitral) valve on the left. The semilunar
(SL) valves are the aortic valve, at the entrance
to the aorta, and the pulmonary valve, at the
entrance to the pulmonary trunk.
2. The left side of the heart is the pump for the
systemic circulation, the circulation of blood
throughout the body except for the air sacs of
the lungs. The left ventricle ejects blood into the
aorta, and blood then flows into systemic
arteries, arterioles, capillaries, venules, and
veins, which carry it back to the right atrium.
26. 3. The right side of the heart is the pump
for pulmonary circulation, the circulation of
blood through the lungs. The right
ventricle ejects blood into the pulmonary
trunk, and blood then flows into pulmonary
arteries, pulmonary capillaries, and
pulmonary veins, which carry it back to the
left atrium.
4. The coronary circulation provides blood
flow to the myocardium. The main arteries
of the coronary circulation are left and
right coronary arteries; the main veins are
29. 1. Cardiac muscle fibers usually contain a
single centrally located nucleus.
Compared to skeletal muscle fibers,
cardiac muscle fibers have more and
larger mitochondria, slightly smaller
sarcoplasmic reticulum, and wider
transverse tubules, which are located at Z
discs.
2. Cardiac muscle fibers are connected via
end-to-end intercalated discs.
Desmosomes in the discs provide strength
and gap junctions allow muscle action
potentials to conduct from one muscle
fibers to its neighbors.
30.
31. 3. Autorhytmic fibers form the conduction
system, cardiac muscle fibers that
spontaneously depolarize and generate action
potentials.
4. Components of the conduction system are the
sinoatrial (SA) node (pacemaker),
atrioventricular (AV) node, atrioventricular (AV)
bundle (bundle of His), bundle branches, and
Purkinje fibers.
5. Phases of an action potential in a ventricular
contractile fiber include rapid depolarization, a
long plateau, and repolarization.
6. Cardiac muscle tissue has a long refractory
period, which prevents tetanus.
32.
33. The SA node, AV node, bundle of
His and branch bundles
34. 7. The record of electrical changes during
each cardiac cycle is called an
electrocardiogram (ECG). A normal ECG
consists of a P wave (atrial
depolarization), a ORS complex (onset of
ventricular depolarization), and a T wave
(ventricular repolarization).
8. The P-Q interval represents the
conduction time from the beginning of
atrial excitation to the beginning of
ventricular excitation. The S-T segment
represents the time when ventricular
contractile fibers are fully depolarized.
38. 1. A cardiac cycle consists of the systole
(contraction) and diastole (relaxation) of both
atria, plus the systole and diastole of both
ventricles. With an average heartbeat of 75
beats/min, a complete cardiac cycle requires 0.8
seconds.
2. The phases of the cardiac cycle are (a) atrial
systole, (b) ventricular systole, and (c) relaxation
period.
3. S1, the first heart sound (lubb), is caused by
blood turbulence associated with the closing of
the atrioventricular valves. S2, the second sound
(dupp), is caused by blood turbulence
associated with the closing of semilunar valves.
39.
40. CARDIAC CYCLE
SYSTOLE is the phase of contraction and
DIASTOLE is the period of heart
relaxation.
41. PHASES
1. Relaxation - the heart muscle
repolarizes.
Isovolumetric Relaxation - As the heart
relaxes, it expands. The volumes of the
ventricles increase until ventricular
pressure is lower than atrial pressure, the
AV valves open and ventricular filling (by
trickling) begins.
The diastole lasts 0.4 seconds at rest.
42. 2. Completion of Ventricular filling.
The atria send the final 25% of blood by
contracting.
Then 130 ml of blood (END
VENTRICULAR DIASTOLIC VOLUME) is
present in each ventricle at rest.
43. 3. Isovolumetric contraction - the
ventricles begin to contract and the
semilunar valves have not opened.
4. Ventricular ejection - 70 ml of the 130
E.D.V. is ejected, 70 ml is the stroke
volume.
The end systolic volume is 60 ml.
44. The red line is the EKG. The blue line is aortic
pressure. The green line shows heart sounds.
45. Blood Pressure and Sounds
The systolic pressure is the pressure read
at the first sound heard in a stethoscope
when the blood pressure cuff, which has
closed off flow of the brachial artery, is
released and the first spurt of blood comes
through the artery below the cuff.
The diastolic pressure is read when the
last sound is heard.
46.
47. Blood Pressure and Sounds
The numbers, e.g., 120 systolic/80 diastolic, are
normal for an adult.
During ventricular contraction, the atrio-
ventricular valves make turbulence which makes
the 'lubb' sound;
Semilunar valves snap shut and produce
turbulence which makes a 'dupp' sound.
Elevation of B.P. above 140 systolic indicates
arteriosclerosis or other problems which cause
increased blood volume or heart rate.
48. The red line is the EKG. The blue line is aortic
pressure. The green line shows heart sounds.
50. 1. Cardiac output (CO) is the amount of blood
ejected per minute by the left ventricle into the
aorta (or by the right ventricle into the pulmonary
trunk). It is calculated as follows: CO (mL/min) =
stroke volume (SV) in mL/beat x heart rate (HR)
in beats per minute.
2. Stroke volume (SV) is the amount of blood
ejected by a ventricle during each systole.
3. Cardiac reserve is the difference between a
person’s maximum cardiac output and his or her
cardiac output at rest.
51. CARDIAC OUTPUT
At rest
CO = stroke volume (70ml) X = heart rate (75/min) =
5250 ml/min
STRESS (EXERCISE)
CO = 140ml/beat (x) 150 beats/min = 21,000 ml/min
The four fold rise in cardiac output is due to an increased
rate of ventricle filling and increased contractile force due
to additional stretching of muscle fibers.
Cardiac reserve is that extra (above resting) capacity of
cardiac output. The cardiac reserve of athletes may be
seven or eight times the resting output.
52. 4. Stroke volume is related to preload
(stretch on the heart before it contracts),
contractility (forcefulness of contraction),
and afterload (pressure that must be
exceeded before ventricular ejection can
begin).
5. According to the Frank-Starling law of
the heart, a greater preload (end-diastolic
volume) stretching cardiac muscle fibers
just before they contract increases their
force of contraction until the stretching
becomes excessive.
53. REGULATION OF STROKE
VOLUME
1. Preload factors increase stretch and
contractility. Rapid filling and the stretching
of the cardiac muscle of the ventricles during
diastole by larger volumes of blood increases
the force of the contracting muscle fibers. This is
called the
FRANK- STARLING LAW OF THE HEART.
When heart rate exceeds 160/min. heart
efficiency declines. Why?
Remember the outputs of the right and left
ventricles are the same normally.
54.
55. REGULATION OF STROKE
VOLUME
2. Contractility
The sympathetic accelerator neurotransmitters,
NE from the sympathetic cardiac accelerator
nerves, and NE and EP from the adrenal
medulla increase the rate of Ca++ movement
through the slow Ca++ channels of the
Pacemaker cells.
The parasympathetic Vagus nerve secretions of
Ach have the opposite effect. Ep and NE bind to
beta receptors to increase heart rate.
56.
57. REGULATION OF STROKE
VOLUME
3. Afterload factors - the pressures of
blood in the pulmonary trunk and the
aorta must be exceeded before blood can
move out of the heart.
Arteriosclerosis increases afterload
pressures.
58.
59. 6. Nervous control of the cardiovascular
system originates in the cardiovascular
center in the medulla oblongata.
7. Sympathetic impulses increase heart
rate and force of contraction;
parasympathetic impulses decrease heart
rate.
8. Heart rate is affected by hormones
(epinephrine, norepinephrine, thyroid
hormones), ions (Na+, K+, Ca2+), age,
gender, physical fitness, and body
temperature.
70. Blood Supply to the Myocardium
The heart muscle requires a rich oxygen
supply to meet its own metabolic needs.
The coronary arteries (R & L) branch of
the aorta just above the aortic valve,
encircle the heart, and penetrate the
myocardium. They supply the capillaries of
the myocardium with blood.
71.
72.
73. Blood Supply to the Myocardium
(cont.)
The Right coronary artery (RCA) and its
branches perfuse
the right atrium,
right ventricle,
inferior portion of the left ventricle, and
posterior septal wall,
the sinoatrial (SA) node, and
the atrioventricular (AV) node.
74.
75. Blood Supply to the Myocardium
The left coronary artery (LCA) has two
major branches, the left anterior
descending (LAD) and the circumflex
arteries.
76. Blood Supply to the Myocardium
(cont.)
The LAD supplies blood to
the anterior wall of the left ventricle,
the anterior ventricular septum, and
the apex of the left ventricle.
77.
78. Blood Supply to the Myocardium
(cont.)
The circumflex artery provide blood to
the left atrium,
the lateral and posterior surfaces of the
left ventricle, and
occasionally the posterior interventricular
septum.
In some clients, the circumflex artery, the
circumflex artery supplies the SA and AV
nodes.
79.
80. Blood Supply to the Myocardium
Unlike other arteries, 75% of the coronary artery
blood flow occurs during diastole, when the
heart is relaxed. For adequate blood flow
through the coronary arteries, the diastolic blood
flow increases with increased activity and
increased stimulation of the sympathetic
nervous system.
The coronary veins return blood from the
myocardium to the right atrium. These veins
usually run parallel to the arteries.
81. Heart Rate
Normal 60-100X/mnt.
Dipengaruhi oleh exercise, ukuran tubuh, usia,
sex, hormone, temperature, bekanan darah,
kecemasan dan stress, dan sakit.
Olah raga dapat meningkatkan HR. Seorang
athlete memiliki HR yang lebih rendah, seorang
yang lebih besar juga memiliki HR yang lebih
rendah.
Bayi memiliki HR yang lebih cepat (120-160)
Wanita memiliki HR lebih cepat dari laki-laki.
82. Cardiac Pressure
Tekanan ini dapat diambil dengan
menggunakan sebuah kateter pulmonary
artery pressure (Swan-Ganz).
Tekanan di dalam jantung dapat diukur
dan ukuran ini untuk menentukan seperti
preload, afterload, volume filling
pressure, dan resistance.
83. Cardiac Pressure
Nilai Normal
Pulmonary Artery: Systole (15-30mmHg);
Diastole (3-12mmHg)
Aorta: Systole (96-140mmHg); Diastole (60-
90mmHg)
Left Atrium: 4-12mmHg
Right Atrium: -1 – 8mmHg
Left Ventricle: Systole (15-28mmHg); Diastole
(4-12mmHg)
Right Ventricle: Systole (100-140mmHg);
Diastole (0-8mmHg)
84. Arterial Pressure
Arterial pressure adalah: Tekanan darah
yang melawan dinding arteri.
Tipe dari arterial pressure adalah:
Systolic pressure
Diastolic pressure
Pulse pressure
Mean arterial pressure
85. Systolic & Diastolic Pressure
SP adalah tekanan maximum darah yang
melalui pembuluh darah pada saat
jantung kontraksi. Normal 100-140mmHg.
DP adalah tekanan darah melalui
pembuluh darah pada saat jantung
relaksasi. Normal 60-90mmHg.
BP sering mengekspresikan tekanan
systolic/diastolic.
86. Pulse pressure
Pulse pressure adalah perbedaan tekanan
antara sistolik dan diastolik 40-60mmHg,
hal ini merefleksikan stroke volume dan
elastisitas arteri.
87. Mean Arterial Presssure (MAP)
MAP adalah sama dengan 1/3 dari pulse
pressure (PP) + diastolic blood pressure
(DBP)
MAP 1/3 PP + DBP
MAP digunakan untuk Hemodynamic
monitoring.
Dua hal penentu dari BP adalah CO dan
peripheral vascular resistance (PVR)
dengan vormula: BP = CO X PVR
88. Sirkulasi Darah sangat bergantung pada:
CO
PVR
Elastisitas arteri
Volume darah
Blood viscosity (kekentalan darah)
89. Venous Pressure
VP adalah tekanan darah di dalam vena. Di
dalam vena yang kecil tidak terdapat tekanan.
Tekanan vena antara 12-15 mmHg.
In large veins leading to the heart (e.g., jugular
vains), pulsations reflect back from right arterial
contractions. Blood flows back to the heart via
the venous system with assistance from:
vessel wall tone,
The pumping action of skeletal muscles
The negative thoracic pressure during
inspiration.