U2 Circulatory Systems Flashcards
What happens when an organism’s metabolic rate increases to meet an increasing demand for energy?
Its rate of aerobic respiration and oxygen intake increase
This means that an organism with high metabolic rates need efficient transport systems to deliver large supplies of oxygen to respiring cells
Single circulatory system
composed of one atrium and one ventricle
Blood passed through a two-chambered heart once for each complete circuit of the body.
e.g.fish
DIAGRAM
To the gills
⬆️
Ventricle
Atrium
⬆️
From the body
Incomplete double circulatory system
Heart consists of one ventricle and two atria.
Therefore, some oxygenated blood (from the lungs) is mixed with deoxygenated blood (from the body)
e.g.amphibians and reptiles
DIAGRAM
To the lungs⬅️➡️To the body
From the body➡️Right atrium / Left atrium⬅️from the lungs
Ventricle
Ventricle:
-deoxygenated and oxygenated blood mix
-partially oxygenated blood delivered to tissues
Complete double circulatory system
Heart consists of two atria and two ventricles which are separated
No mixing of oxygenated and deoxygenated blood
The oxygenated blood can be pumped out at a higher pressure
e.g. birds and mammals
DIAGRAM
Pulmonary artery Aorta (to body)
Vena cava. Pulmonary vein
Right atrium. Left atrium
Right ventricle. Left ventricle
3 external abiotic factors that can affect organisms
temperature
ph
salinity
What are conformers?
Their internal environment is dependent upon the external environment.
For example a conformed temperature will also decrease
Advantages and disadvantages of conformers
+ They do not require energy to keep their inner state relatively stable (low metabolic costs)
- They may have a narrower range of ecological niches unless they can tolerate (adapt) or resist variation in their external environments
Why do most conformers have behavioural responses?
To allow them to control their internal environment even slightly
r.g. lizards bask in the sun to raise their body temperature
What are regulators?
They use metabolism to maintain a steady internal environment despite changes in the external environment
Advantage and disadvantage of regulators
+ requires high energy expenditure to maintain homeostatus
- offers a wider range of ecological niches
Homeostasis
Our internal environment must be maintained for us to survive
This is possible due to negative feedback control
state of steady internal environment being maintained
What is negative feedback control?
The process by which a change in factor (eg body temp) triggers a mechanism which results in that factor returning to its normal level (norm or set point)
receptor detects change in factor and sends electrical impulses/messages to the effector which uses a corrective mechanism to return the factor back to the norm
What can thermoregulators do?
maintain their body temperature
What is essential for thermoregulators?
ENERGY for heat is ESSENTIAL for them so they have a HIGHER METABOLIC RAGE
Why is it important for endotherms to regulate their body temperature to around 35-40 degrees?
this is the optimum temperature for most enzymes (which control most reactions in the cells)
Regulating temp also ensures HIGH DIFFUSION RATES to meet the metabolic needs of tissues (If they can’t then metabolic pathways will not function at their best)
(endotherm=an animal that is dependent on or capable of the internal generation of heat)
