Metabolic Rate 2.3 Flashcards
What is Metabolic Rate?
The quantity of energy used by the body over a given time. It is measure in kilojoules or kilocalories.
What can metabolic rate be measured as?
Oxygen consumption per unit time
Carbon Dioxide produced per unit time
Energy (heat) production per unit time
Ways to measure metabolic rate (equiptment)
Respirometers, oxygen probes, carbon dioxide probes and calorimeters.
What do Respirometers do?
Measure the oxygen uptake by an organism
What do Calorimeters do?
Measure the heat generated by an organism over a period of time
What is the Basal Metabolic Rate? BMR
At rest (periods of inactivity) the metabolic rate is known as the BMR. At rest it is low. During rest the body only uses energy to keep vital organs functioning properly.
What is the general rule of metabolic rate?
The greater the mass of an organism, the higher the organism’s metabolic rate.
Why is BMR higher per unit of body mass?
The higher metabolic rate of small animals need a greater delivery of oxygen to tissues around the body
What do high metabolic rates require?
Efficient delivery of oxygen to cells since aerobic respiration must be high to supply sufficient ATP for the cellular processes.
What do Arteries do?
Carry blood Away from the heART (under high pressure)
What are capillaries and what do they do?
They are the smallest blood vessels which exchange nutrients, gases and waste products between the blood and body tissue
What do veins do?
Carry blood into the heart (under low pressure)
The heart and its chambers?
The heart has two types of chambers atria (singular atrium) and ventricles.
What are Atria
A heart chamber where blood enters.
What are ventricles?
Heart chamber where blood leaves the heart
What has a closed circulatory system and what is it?
All vertebrates have closed circulatory systems where the blood is contained in a continuous circuit of blood vessels and is kept moving by a muscular pump (the heart)
What have single circulatory systems and what is it?
Fish. A heart with two chambers - an atrium and a ventricle. The blood passes through the heart only once.
In fish the blood flows to the gills at ____ pressure
High
In fish the blood is delivered to the capillaries at ____ pressure
Low
Is the blood flow in fish efficient?
No it is primitive and ineffecient
What is a double circulatory system?
Blood passes through the heart twice. Blood is pumped to both the lungs and the body both at high pressure.
Is double more efficient than single?
yes
What has an incomplete double circulatory system and what is it?
Reptiles and Amphibians
There is only one ventricle and some mixing of oxygenated blood from the lungs and deoxygenated blood from the body.
Why is mixing not a major problem in Amphibians?
The blood returning from the body has been partially oxygenated through it’s skin.
What has a complete double circulatory system and what is this?
Birds and mammals.
4 chambers - 2 Atria and 2 Ventricles
Blood passes through the heart twice during each complete circuit of the body.
What does the double circulatory systems in birds and mammals enable?
Higher metabolic rates to be maintained.
Is there mixing in birds and mammals blood?
No
Why are complete double circulatory systems more efficient
The oxygenated blood can be pumped out at a higher pressure.
