Topic 1 - Lifestyle and Risk Flashcards
(106 cards)
What do animals require to survive?
Essential substances like oxygen and carbon dioxide
What method do small organisms use to transport substances?
Diffusion
What happens to the surface area to volume ratio as the size of the organism increases?
It decreases
What increases as the size of the organism grows?
Diffusion distance and metabolic rate
What becomes insufficient for larger organisms, necessitating a different transport system?
Diffusion
What is a mass transport system in larger organisms composed of?
Heart and circulation
What are the four features of a mass transport system?
- A network to move through (e.g., vessels)
- A medium for movement (e.g., blood)
- Controlled direction
- Maintenance of speed
What is the role of valves in a mass transport system?
To control the direction of flow
What is the significance of hydrogen bonding in water?
Creates cohesion and adhesion for effective transport
What type of molecule is water, and why?
Polar molecule due to uneven distribution of charge
What is the result of water’s high heat specific capacity?
Minimizes temperature fluctuations in living organisms
Fill in the blank: Water is a _______ solvent.
polar
True or False: The contraction of the heart helps maintain the speed of blood flow.
True
What is the effect of hydrogen bonding on water’s temperature stability/specific heat capacity?
Requires a lot of energy to change temperature
What do arteries carry to the body tissues?
Oxygenated blood
Other than the pulmonary artery
What is the lumen size of arteries and why is it significant?
Small lumen
Maintains high blood pressure
What type of lining do arteries have and why?
Smooth inner endothelial lining
Reduces resistance to blood flow
What components allow arteries to control their diameter?
Thick layer of smooth muscle and elastic fibres
Contract and relax to dilate and constrict blood vessels
What provides strength and support to arteries?
Collagen fibres
Lots of collagen fibres are present
What do veins carry to the lungs?
Deoxygenated blood
Except the pulmonary vein
What is the lumen size of veins and its significance?
Large lumen
Minimises resistance to flow
What features characterize the structure of veins?
Thinner layer of muscle, reduced elastic fibres, and valves
Valves prevent backflow
What are capillaries and their key characteristics?
Very small blood vessels
Fit between cells with a narrow lumen and thin endothelium
What is the structure of the heart?
Four chambers
Right and left atria, right and left ventricles