heart structure and_function

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Heart Structure

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Blood travels through the heart twice before returning to the body

The double circulatory system


•Why do we say that humans have a ‘double circulation’?• Amphibians and fish have a

‘single’ circulation system. What do you think this means?


• The cardiac muscle cells are said to be ‘MYOGENIC’ i.e. they does not need electrical impulses from a nerve to make them contract. If the cardiac muscle is supplied with oxygen and nutrients (a task carried out by the coronary arteries which you can see running over the surface of the heart) it will continue to contract at a steady pace.


External view of the heart

pulmonary artery

pulmonary vein

coronaryartery

left ventricle

right ventricle

inferior vena cava

right atrium

pulmonary vein

aorta

superiorvena cava


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)


The right atrium collects deoxygenated blood and pumps it to the right ventricle

right atrium


The right ventricle pumps deoxygenated blood to the lungs

right ventricle


The pulmonary artery carries deoxygenated blood from the right ventricle to the lungs

aorta


The septum separates the left and right sides of the heart

septum


The pulmonary veins carry oxygenated blood from the lungs to the left atrium

Pulmonary veins


The left atrium collects the oxygenated blood and pumps it to the left ventricle

Left atrium


The left ventricle pumps oxygenated blood to the body via the aorta

Left ventricle


The aorta carries the oxygenated from the left ventricle to the rest of the body

Aorta

Aortic arch


Atrio-ventricular valves prevent backflow of blood into the atria when ventricles contract

Bicuspid valve(mitral valve)

Tricuspid valves

Tendon


The semi-lunar valves prevent backflow of blood from the arteries into the ventricles

Aortic semi-lunar valve

Pulmonarysemi-lunar valve


Summary Quiz

Identify the part of the heart indicated by an arrow .There are 10 questions in total.


Question 1


Question 2


Question 3


Question 4


Question 5


Question 6


Question 7


Question 8


Question 9


Question 10


Answers1 left ventricle2 vena cava3 right atrium4 pulmonary artery5 aorta6 pulmonary vein7 left atrium8 atrio-ventricular (tricuspid) valve9 semi-lunar (aortic) valve10 right ventricle

An ECG – or electrocardiogram - is a simple and useful test which records the rhythm and electrical activity of your heart.

Click up hereThis will only work if you are watching this as a slide show

QRS = Ventricular systole

P = Atrial systole

T= Ventricular diasole

The ECG can:

• Assess your heart rhythm• Diagnose poor blood flow to the heart muscle

(ischemia)• Diagnose a heart attack• Evaluate certain abnormalities of your heart,

such as an enlarged heart

• Trace the flow of blood through the heart, identifying the major blood vessels, chambers and heart valves

• Describe and explain the normal ECG cycle. Explain the events of the cardiac cycle and say how these relate to the heart sound


Finish

heart structure and_function

Education

right ventricle right

heart valves

lungs right ventricle

backflow of blood

heart rhythm

heart septum

blood travels

heart attack