BIO topic one-lifestyle health & risk

What type of muscle is the heart made from

Cardiac muscle

State the pathway of blood starting at the vena cava

Vena cava (superior/inferior), right atrium, right atriventricular valve, right ventricle, right semilunar valve, pulmonary artery, lungs pulmonary vein left atrium left av valve, left ventricle, left semilunar, aorta, body

What type of blood does the left and right side of heart pump

Right deoxygenated

Left oxygenated

Why do animals need a heart

It’s a internal transport system that generates enough pressure to pump blood around the body and overcome the limits of diffusion to ensure quick delivery of oxygen

Function and location of coronary artery

Surface of heart to supply heart cells with oxygen

name of heart muscles contracting and relaxing

Systole and diastole

What is the cardiac cycle

Complete cycle of heart relaxing to fill with blood and contracting to pump it. Including atrial systole ( atria contract open av valves force blood into ventricles) ventricular systole ( ventricles contract opening semilunar valves forcing blood to arteries) and cardiac diastole ( chambers of heart are relaxed semilunar valves closed and av open to slowly allow blood through atria to ventricles)

Name the 3 blood vessels and the structures within them and their function

Artery outer coat with collagen fibres and connective tissue for strength to withstand high blood pressure, smooth muscle cause vasoconstriction to maintain high blood pressure and elastic fibres to stretch and recoil to maintain high blood pressure. Endothelium to reduce resistance to blood flow. Narrower lumen for higher blood pressure

Vein same outer coat for strength, less smooth muscle as skeletal muscle aid movement of blood, less elastic fibres, same endothelium, large lumen for lower blood pressure to protect thinner walls from damage.

Capillary only has endothelium with small pores to allow diffusion and aid tissue fluid formation, narrow lumen allows slow blood flow to allow for all o2 to diffuse

Why do some organisms not need a circulatory system?

Unicellular organisms don’t need one as they have large surface area to volume ratio so short diffusion pathway, sufficient oxygen demand to meet low metabolic and oxygen demand.

Describe an open circulatory system

No blood vessels, blood held within body cavity, organs bathed in blood, diffusion between blood and organs, blood never low pressure (insects)

What is a closed circulatory system

What are the two types of closed circulatory systems

Blood in vessels transported at high pressure

Single- flows once through heart, low pressure (fish)

Double- twice through heart, high pressure at body, lower at lungs where diffusion happens

Advantages of double closed circlatory system

Oxy and deoxy don’t mix, tissues receive maximum oxygenated blood

Different pressure to prevent damage

Blood gets extra boost for higher pressure to reach body cells

What are the properties of water and explain them

Water is a polar molecule this means there are unevenly distrubuted electrical charge, slightly positive hydrogen slightly negative oxygen.

Good solvent due to this hydrogen bonds can form between ions cause other polar molecules to dissolve.

High specific heat capacity hydrogen bonds take lots of energy to break, maintain internal temp and environment temp.

Surface tension, form hydrogen bonds pulled equally in top layer pulled down. Net inward force .

What does hydrophobic and hydrophilic mean

Water repelling, not soluble in water

Water attracting, soluble.