Topic 1 - Lifestyle, Health & Risk Flashcards
What is the Heart and Circulations Job in the Body?
To transport substances around the body
How are Substances Transported Through the Body in Small Organisms?
Diffusion
How are Substances Transported Through the Body in Larger Organisms?
Mass transport system
What is an Open Circulatory System?
- Blood circulates in open spaces
- Heart pumps blood into cavities surrounding organs
- When the heart relaxes blood is drawn back to heart through valves
What is a Closed Circulatory System?
- Blood is enclosed in blood vessels
- Blood travels faster and at high pressure
- Blood flows through arterioles to capillaries
- Blood returns to heart via the veins
What Animals Have a Single or Double Circulatory System?
Those with a closed circulatory system
How are Substances Transported in a Single Circulatory System?
- Deoxygenated blood pumped to gills
- Gaseous exchange happens in gills (CO2 in Blood diffuses to water and oxygen from water diffuses into gills)
- Blood flows round whole body before retiring to the heart
Give an Example of an Organism with a Single Circulatory System?
Fish
How are Substances Transported Through a Double Circulatory System?
- Right ventricle pumps deoxygenated blood to lungs
- Oxygenated blood returns to heart by left ventricle and is pumped round the body
- The blood is given a boost to flow quickly
- High metabolic rate as Substances delivered quicker
Give an Example of an Organism with a Double Circulatory System?
Birds or mammals
Why is it Called a Double Circulatory System?
Because blood flows through the body twice for every complete circuit
Give Examples of Water Properties.
- Polar molecule
- Hydrogen end=positive
- Oxygen end=negative
- Dipole molecule
What is a Polar Molecule?
A molecule with an unevenly distributed charge (also known as a dipole molecule)
Why Do Chemicals Disolve Easily in Water?
- Because it’s dipole nature allows reactions to occur in cells
- Ionic compounds mean that positive part is attracted to negative end of water etc.
How Are Hydrophobic Substances Transported?
They bind with proteins (e.g lipids bind with proteins to become lipoproteins)
What are the Thermal Properties of Water?
- Requires large amount of energy to raise temperature by a small amount
- Large amount of energy needed to break hydrogen bonds
- Warms/cools slowly
- Useful for organisms as it is easier to maintain body temperature
Describe the Structure of an Artery.
- Narrow lumen
- Thick layer of muscle/elastic tissue
- More collagen
- No valves
Describe the Structure of a Vein.
- Wide lumen
- Less muscle/elastic tissue
- Less collagen
- Valves ensure blood flows one way
Describe the Structure of a Capillary?
- One cell thick
- Thin walls for quick diffusion
What are Coronary Arteries?
Arteries that supply blood to the heart
What Does the Right Atrium Do?
Draws in deoxygenated blood from vena cava and into the lungs
What Does The Left Atrium Do?
Draws in oxygenated blood from pulmonary veins and pumps around the body
Why Are The Walls of the Left Atrium More Muscular Than The Right Atrium?
Because it needs to pump blood around the whole body
What Do Ventricles Do?
Push blood out of the heart
Why Are Ventricle Walls More Muscular Than The Atria?
Because they need to pump blood out of the heart
What Are Atrioventricular Valves?
Valves in between the atria and ventricles to stop blood flowing back into the atria when the heart contracts
What Are Semi-Lunar Valves?
Valves in between the ventricles and the pulmonary arteries/aorta to stop blood flowing back when the heart contracts
What Is Diastole?
- Relaxation of the heart
- Low blood pressure
- Blood at higher pressures is drawn back to ventricles
- This closes the SL valve
What is Atriole Systole?
- Atria contract
- Blood flows in from the vena cava and pulmonary veins
- Increased pressure forces open atrioventricular valves
- Blood enters ventricles