The Circulatory system is one of the important organ systems in The human body consists of Heart and great vessels that circulate blood and
transport nutrients, oxygen/carbon dioxide and hormones to various cells in the
body.
Consists of,
Heart
Blood vessels (Arteries, Veins,
Capillaries)
Blood consists of plasma, RBC, WBC, and
platelets.
HEART: A muscular organ located in the chest at mediastinum between the lungs
behind the sternum and above the diaphragm muscle. It pumps oxygenated blood to the
various parts of the body and deoxygenated blood to the lungs.
The heart wall has three layers (Outer epicardium,
Middle myocardium, & Inner endocardium) Heart is enclosed by a sac called
pericardium with pericardial fluid.
In the human heart, there are four chambers,
1. Right and
Left atrium
2. Right and
Left ventricle.
There are four valves present in the human heart,
1. Aortic valve - Between left ventricle and
Aorta.
2. Pulmonary valve - Between the right ventricle and
pulmonary artery.
3. Bicuspid valve / mitral valve - Between left
atrium and left ventricle.
4. Tricuspid valve - Between right atrium and
right ventricle.
The heart valves are attached to the ventricular walls
via the chordae tendineae
they are attached to the papillary muscles so that
the cusps are held in position.
The pericardium is double-walled sac covering the heart
and greater vessels. Contain pericardial fluid.
Pulmonary circulation and Systemic circulation
The
pulmonary circulation is the circulation of the blood between
heart and lungs for purification of blood. The oxygen-less blood from the
Superior and Inferior vena cava enters into the right atrium of the heart and
flows through the tricuspid valve into the right ventricle; from their blood is
pumped to the lungs through the pulmonary artery.
Gas exchange happens in the lungs at alveoli. The
carbon dioxide is moved from blood capillaries to the lungs and oxygen is moved
from lungs to blood capillaries.
Four pulmonary vein returns the oxygen-rich
blood to the left atrium of the heart.
The
systemic circulation is the circulation of the blood to all
parts of the body from the heart. Systemic circulation is the portion of the cardiovascular system which transports oxygenated blood away from the heart
through the aorta from the left ventricle.
Coronary
Circulation: Supplying blood to heart muscles by Right
and Left Coronary arteries. The vessels
that remove the deoxygenated blood from the heart muscle are known as cardiac
veins.
Branches of the coronary circulation,
From Aorta
1. Right coronary artery (RCA)
AV node artery
Right marginal artery
Posterior descending artery
Posterio-lateral artery
2.
Left coronary artery / Left main coronary artery (LMCA)
Left circumflex artery (LCX)
Obtuse marginal artery
Left anterior descending artery
(LAD)
Diagonal artery
The Aorta is the largest artery in the human body
arises from the left ventricle of the heart. The aorta distributes oxygenated
blood to all parts of the body through the systemic circulation.
The venae cava are large veins that return deoxygenated
blood from the body into the heart. The superior vena cava and the inferior
vena cava, both empty into the right atrium.
Arteries: Carry
oxygen-rich blood away from the heart. Arteries branch into small passages
called arterioles and then into the capillaries
Capillaries:
Are
the smallest and thinnest of the blood vessels in the body. Capillaries carry blood very close to the
cells of the tissues of the body in order to exchange gases, nutrients, and
waste products
Veins: Carry
oxygen-poor blood back to the heart. Capillaries merge into Venules – Veins -
Vena cava.
The arteries possess stronger and thicker walls than
the veins, three layers are,
1. Tunica intima
2.
Tunica media
3. Tunica externa
Electrical conduction system of the heart
The heart has the ability to create its own electrical
impulses for continues involuntary functioning.
Impulses travel in the following order,
1.
The sino-atrial (SA) node
2.
The atrioventricular (AV) node
3.
The bundle of His
4.
The LT & RT bundle branches
5.
The Purkinje fibres
Blood: The human body contains
about 4 to 5 litres of blood. Blood is made up of RBC, WBC, platelets and
plasma.
A. RBC
(RED BLOOD CELLS) / ERYTHROCYTES
— Erythrocytes transport oxygen in the blood
through the red pigment hemoglobin
B. WBC
(WHITE BLOOD CELLS) / LEUKOCYTES
— Important functions in the body’s immune
system.
— Neutrophils, eosinophils, basophils,
lymphocytes and monocytes
C. PLATELETS
/ Thrombocytes
— Responsible for the clotting of blood.
— Platelets normally remain inactive in the
blood until they reach damaged tissue or leak out of the blood vessels through
a wound.
D. PLASMA
— The liquid portion of the blood that makes up
about 55% of the blood’s volume.
— Around 90% of plasma is made of water.
BLOOD
PRESSURE: Refers to the pressure in large arteries of the
systemic circulation,
— SYSTOLIC
- Ventricles contracts
— DIASTOLIC -
Ventricles relax
Normal Values:
Normal BP: 120 / 80 mmHg
Pulse rate - 72 beat per min
RBC – 4 to 6 million cells per microliter of blood
WBC – 4000 to 11000 per microliter of blood
Platelet – 150,000 to 450,000 cells per microliter of
blood
Common Disease of Circulatory System:
1. Aortic aneurysm - is a bulge in a section of the
aorta.
2. Coronary artery disease (CAD) – is a disease in
which a waxy substance called plaque builds up inside the coronary
arteries.
3. Deep vein thrombosis - A blood clot in a deep vein,
usually in the legs.
4. Rheumatic Heart disease – Permanent damage to heart
valves is caused by rheumatic fever.
5. Atherosclerosis – Is a disease of the arterial
vessels, in which the walls of the blood vessels became thickened and hardened
by plaques.
6. Hypertension – Is a condition in which the arteries
have persistently elevated blood pressure.
7. Hypercholesterolemia – Is the presence of high
levels of cholesterol in the blood.
8. Myocardial Infarction - is the irreversible death
(necrosis) of heart muscle secondary to prolonged lack of blood (oxygen)
supply.
MEDICAL TERMS:
1. Heart - Cardio
2. Vessels - Angio / Vasculo / Vaso
3. Artery - Arterio
4. Veins - Phlebo
5. Blood - Hemato
6. RBC - Erythrocytes
7. WBC - Leukocytes
8. Platelet - Thrombocytes
MEDICAL ABBREVIATIONS:
1. ABI - Ankle-brachial index
2. ABG - Arterial blood gas
3. ASHD - Arteriosclerotic heart disease
4. BP - Blood pressure
5. CABG - Coronary artery bypass graft
6. CAD - Coronary artery disease
7. CHF - Congestive heart failure
8. CPR - Cardiopulmonary resuscitation
9. CVP - Central venous pressure
10. DVT - Deep vein thrombosis
11. ECG – Electrocardiogram
12. ESR - Erythrocyte sedimentation rate
13. FHT - Fetal heart tones
14. HB – Hemoglobin
15. HDL - High-density lipoprotein
16. HTN – Hypertension
17. ICA - Internal carotid artery
18. LAD - left anterior descending
19. LCA - Left coronary artery
20. LDL - Low-density lipoprotein
21. LVH - Left ventricular hypertrophy
22. MI - Mitral insufficiency; myocardial infarction
23. PICC - Peripherally inserted central catheter
24. PTCA - Percutaneous transluminal coronary angioplasty
25. RVH - Right ventricular hypertrophy
26. SVT - Supraventricular tachycardia
27. WBC - White blood cell
____________________________________________________