Heart: Structure, Blood & Vital Signs

Heart: Structure, Blood & Vital Signs

Understanding the cardiovascular system Year 8 Science Australian Curriculum

What do you already know about your heart?

Think about what you feel when you exercise Where can you feel your pulse? What do you think blood contains?

The Heart: Your Body's Engine

Muscular organ about the size of your fist Beats approximately 100,000 times per day Pumps about 7,500 litres of blood daily Located slightly left of centre in your chest

Heart Structure Diagram

Four Chambers of the Heart

{"left":"Right Atrium: Receives deoxygenated blood from body\nRight Ventricle: Pumps blood to lungs for oxygen","right":"Left Atrium: Receives oxygenated blood from lungs\nLeft Ventricle: Pumps oxygenated blood to body"}

Heart Valves: One-Way Doors

Prevent blood from flowing backwards Four main valves in the heart Open and close with each heartbeat Create the 'lub-dub' sound we hear

Virtual Heart Dissection

Imagine we're dissecting a heart What would we see first? How thick are the chamber walls? Can you identify the major blood vessels?

Finding Your Pulse

Pulse = heartbeat felt in arteries Common locations: wrist, neck, temple Each pulse is one heartbeat Normal resting rate: 60-100 beats per minute

Measure Your Heart Rate

Find your pulse at your wrist Count beats for 15 seconds Multiply by 4 for beats per minute Record your resting heart rate

What affects your heart rate?

Think about when your heart beats faster What about when it beats slower? Age, fitness, emotions, temperature?

What is Blood Made Of?

55% plasma (liquid portion) 45% blood cells and platelets Red blood cells carry oxygen White blood cells fight infection Platelets help blood clot

Blood Separation by Centrifuge