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1.12. Heart Structure
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Heart is a hollow organ. Situated slightly towards left side in the middle of the thoracic cavity. It is made up of CARDIC MUSCLE.
It is conical shape with apex facing downwards and broad base directed upwards.
It is the size of the fist of the person.
It protected on all sides by rib case and by vertebral Coolum on the back side.
External features
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Pericardium
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Pericardium Heart is enclosed in a double layered, Transparent, Thin sac called “ PERICARDIUM”
The Space between the inner and outer layers is called “PERICARDIAL SPACE”
Pericardial space filled with a fluid called “PERICARDIAL FLUID”
Pericardium and Pericardial fluid protects the heart from physical shocks or blows.
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Pericardium Heart is enclosed in a double layered, Transparent, Thin sac called “ PERICARDIUM”
The Space between the inner and outer layers is called “PERICARDIAL SPACE”
Pericardial space filled with a fluid called “PERICARDIAL FLUID”
Pericardium and Pericardial fluid protects the heart from physical shocks or blows.
Fluid.
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Heart is internally divided in to Four chambers.
Two upper chambers called “AURICLES”
Two lower chambers called “VENTRICLES”
The verticle groove indicates the presence of right and left chambers.
Left Ventricle
Right Auricle.
Left Auricle.
Right Ventricle
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Very large vein that brings the blood to heart from all parts of the body are called “ Vena Cavae” or Caval Veins.
Very large Arteries that brings the blood away from heart to all parts of the body are called “ AORTAE” (Aorta = singular)
Left Ventricle
Right Auricle.
Left Auricle.
Right Ventricle
Vena Cavae
Aorta
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Blood Vessels that bring Blood to heart
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3 large veins that bring blood to all parts of the body.
SUPERIOR VENA CAVA INFERIOR VENA CAVA PULMONARY VEINS
SUPERIOR VENA CAVA; Collects deoxygenated blood from upper parts of the body ( Head and Neck)
INFERIOR VENA CAVA; Collects deoxygenated blood from lower parts of the body ( Abdomen, Hands and Legs)
PULMONARY VEIN; Brings oxygenated blood from lungs and opens in to the left Auricle.
Blood Vessels that bring Blood to heart
In addition to this CORONARY VEINS bring deoxygenated blood from the walls of the heart. These also opens into right auricle
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Blood Vessels that carry Blood away from heart
systemic
Or Pulmonary Aorta
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Heart receive oxygenated blood and supply to all parts of the body
2 large aortae that send blood to all parts of the body.
SYSTEMIC AORTA or SYSTEMIC TRUNK PULMONARY AORTA
SYSTEMIC AORTA or SYSTEMIC TRUNK Arises from left ventricle and carries blood to all parts of the body except lungs.
PULMONARY AORTA; Originates in the right ventricle.Out side the heart it divides in to 2 branches – RIGHT & LEFT PULMONARY ARTERIES. Which carry blood to left and right Lungs.
A pair of CORONARY ARTERIES carry oxygenated blood to the heart muscle.
In some people coronary arteries get blocked, when this happen muscle cells do not receive oxygenated blood and stop working. This is called Heart Attack.Patient may die due to failure of heart muscle.
Blood Vessels that carry Blood away from heart
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Heart has 4 chambers . 2 upper – Auricles. 2 lower - ventricles
These 4 chambers are separated by WALLS or SEPTAE ( Septum = Singular).
Rt and Lt Auricles – Vertical Inter Auricular Septum.
This wall prevents the mixing of deoxygenated and oxygenated blood (rt auricle , Lt auricle)
Rt and Lt Ventricles – Vertical Inter Ventricular Septum
This wall prevents the mixing of deoxygenated and oxygenated blood (rt ventricle , Lt ventricle)
1.12.2. INTERNAL STRUCTURE OF HEART
Inter Auricular Septum.
Inter Ventricular Septum.
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Walls of ventricles thicker and muscular because it pumps blood to various parts of the body.
Wall of Lt ventricle is thicker then rt ventricle. (Pumps more distence i;e fingers
Auricles and Ventricles separated from each other by transverse ( Horizontal) Septum – AURICULO - VENTRICULAR SEPTUM.
There are 2 openings in this septum called Auriculo ventricular Apertures
Rt auricle opens in to Rt ventricle through – Rt Auriculo ventricular AperturesLt auricle opens in to Lt ventricle through – Lt Auriculo ventricular Apertures
1.12.2. INTERNAL STRUCTURE OF HEART
Rt Auriculo ventricular Apertures.
Lt Auriculo ventricular Apertures
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Heart has valves which allow the blood flow in one direction And prevents its flowing back.
The valves held in position by tough connective Tissue strands.
These strands are called “CHORDAETENDINAE”
VALVES IN THE HEART
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VALVES IN THE HEARTSno Name of the Valve Location Allows blood to flow
from
1 Tricuspid Valve(3 flaps or Cups )
Right Auriculo Ventricular Aperture
Right Auricle to Right Ventricle
2 Bicuspid (Mitral ) Valve(2 flaps or Cups)
Left Auriculo Ventricular Aperture
Left Auricle to Left Ventricle
3 Pulmunary Valve(3 half moon shape or semilunar valves)
At the origin of pulmonary aorta in the right ventricle.
Allows blood to flow right ventricle in to pulmonary aorta
4 Aortic Valve( 3 semilunar valves)
At the origin of aorta in the left ventricle
Allows blood to flow from left ventricle in to the aorta.
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Diff between Right and Left AuriclesSno Right Auricle Left Auricle
1 Larger in size Smaller in size
2 Receives blood through superior and inferior vena cave
Receives blood through pulmonary vein
3 Receives deoxygenated blood from all parts of the body except lungs.
Receives oxygenated blood from lungs
4 Pumps blood in to right ventricle Pumps blood in to left ventricle
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Sno Right Ventricle Left Ventricle
1 Smaller in Size Larger in size
2 Pulmonary aorta takes its origin Systemic aorta takes its origin
3 Receives deoxygenated blood from right auricle
Receives oxygenated blood from left auricle
4 Pumps deoxygenated blood to lungs Pumps oxygenated blood to all parts of the body except lungs
5 Tricuspid valve guards the right auriculo ventricular aperture
Bicuspid (Mitral) Value guards the left ariculo-ventricular aperture.
Diff between Right and Left Ventricles
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1.12.3. Heart – Mechanism of functioning Cardiac muscle responsible for Contraction and relaxation of Heart.
Heart contract and relaxes 70 – 80 times/ minute
HEART BEAT: Heart beat represent 1 contraction and 1 relaxation of the heart. Contraction phase called SYSTOLE. Relaxation phase called DIASTOLE
One Heart beat has 3 stages.1. Auricular Systole : Both auricles contract at the same time and
pump blood in to ventricles 2. Ventricular Systole: Both ventricles contract at the same time and pump blood in to vessels. (Auricles begin to relax during this stage)
3. Ventricular diastole : Both auricles and ventricles relax
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Blood flow circuits There are two circuits for the flow of blood
PULMONARY CIRCUTE: Blood flow from Heart and Lungs.
SYSTEMIC CIRCUTE: Blood flow from Heart and Organs of the body.
Heart pumps blood in to two circuits called DOUBLE CIRCUTE HEART
P VP A
AORTAVena cava
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Pulmonary Circuit Deoxygenated blood from organs is collected in to Rt auricle and then sent in to Rt Ventricle. From rt ventricle to lungs.
In the lungs blood is oxygenated and returned to the left Auricle by pulmonary veins.
P VP A
AORTAVena cava
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Systemic Circuit Oxygenated blood from left Auricle is pumped in to left ventricle
From left ventricle blood is pumped into systemic aorta.
This aorta supplied blood to various parts of the body.
The deoxygenated blood from various parts of the body collected in to superior , inferior venacava and finally in to rt auricle.
P VP A
AORTAVena cava
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Blood Pressure The blood with which blood flows in the blood vessel is called BLOOD PRESSURE.
ARTERIES – Receive blood so High BP in arteries.
The BP gradually decreases when blood flows in to capillaries.
When this blood is collected in veins BP greatly reduced.
BP high in Arteries. Less in Veins
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Blood PressureBLOOD PRESSURE measured by doctors by a instrument called “SPHYGMOMANOMETER” and is written as 120 / 80 (systolic/diastolic)
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Hypertension or High Blood PressureIn some people BLOOD PRESSURE will be very high more then the usual 120 / 80 such a condition is called High Blood Pressure.
Reason for high bp : Blocking of arteries by cholesterol.
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Coronary Angioplasty
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Thank you
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External view of the heart
pulmonary artery
pulmonary vein
coronaryartery
left ventricle
right ventricle
inferior vena cava
right atrium
pulmonary vein
aorta
superiorvena cava
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The vena cava carries deoxygenated blood from the body to the right atrium
superior vena cava(transports blood from the head)
inferior vena cava(transports blood from rest of body)
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The right atrium collects deoxygenated blood and pumps it to the right ventricle
right atrium
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The right ventricle pumps deoxygenated blood to the lungs
right ventricle
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The pulmonary artery carries deoxygenated blood from the right ventricle to the lungs
aorta
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The septum separates the left and right sides of the heart
septum
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The pulmonary veins carry oxygenated blood from the lungs to the left atrium
Pulmonary veins
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The left atrium collects the oxygenated blood and pumps it to the left ventricle
Left atrium
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The left ventricle pumps oxygenated blood to the body via the aorta
Left ventricle
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The aorta carries the oxygenated from the left ventricle to the rest of the body
Aorta
Aortic arch
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Atrio-ventricular valves prevent backflow of blood into the atria when ventricles contract
Bicuspid valve(mitral valve)
Tricuspid valves
Tendon
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The semi-lunar valves prevent backflow of blood from the arteries into the ventricles
Aortic semi-lunar valve
Pulmonarysemi-lunar valve
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Summary Quiz
Identify the part of the heart indicated by an arrow .There are 10 questions in total.
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Question 1
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Question 2
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Question 3
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Question 4
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Question 5
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Question 6
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Question 7
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Question 8
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Question 9
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Question 10
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Answers1 left ventricle2 vena cava3 right atrium4 pulmonary artery5 aorta6 pulmonary vein7 left atrium8 atrio-ventricular (tricuspid) valve9 semi-lunar (aortic) valve10 right ventricle
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Finish