CIRCULATION OF MAMMALS Flashcards
(32 cards)
Why do large and multicellular animals need a circulatory system?
To transport substances around the body
How is the blood pumped around the body?
Round a closed circuit made up the heart and the blood vessels
What does the blood do?Most simply
It travels around the body and collects material fro some places and unloads them in others
What is 1 thing the blood transports?
O2 from the lungs to the cells of the body for respiration
What is 2nd thing the blood transports?
CO2 from the cells of the body to the lungs
What is 3rd thing the blood transports?
Nutrients from the gut to all of the the cells of the body
What is 4th thing the blood transports?
Urea from the LIVER–) TO THE KIDNEYS
What are a few other things the blood transports
Hormones,antibodies and distributing heat round the body
Do single celled organisms have a circulatory system?
No, they do not need one
Why don’t single celled organisms not have a circulatory system?
One celled organisms get O2 through the surface membranes of their cells, the rest of the cell then uses the 02
What is supply rate?
The AREA of the cells SURFACE determines how much 02 the organism CAN GET
What is demand rate?
The VOLUME of the cell determines how much O2 the organism uses
How to you express the ratio of supply to demand?
SA/V
Which organism has a bigger SA;V ratio an amoeba or a human baby?WHY?
An amoeba, the smaller the organism the bigger the SA;V
Why do single celled organism have such a large SA;V?is it helpful?
Their cell surface membrane has a LARGE ENOUGH AREA to supply all the 02 their volume demands
What is the gas exchange organ in a fish?
the gills
Why can’t large animals rely on diffusion TO GET ALL THE OXYGEN THEY NEED?
Not enough surface to supply all the volume
What are the 2 types of circulation in animals?
Single and double circulatory system
What is a single circulatory system?
The blood is pumped from the heart—–) gas exchange organ ——)directly to the rest of the body
What is a double circulatory system?
The blood is pumped from the heart–)lungs —) back into the heart —) then to the rest of the body
What is different from a single to a double circulatory system?
Blood passes through the heart once
= in a COMPLETE CIRCUIT of the body
What is different from a double to a single circulatory system?
The heart passes through the heart TWICE
= in one complete circuit of the body
What are the two parts of the double circulatory system?
Pulmonary and systemic circulation
What is pulmonary circulation?
When blood is pumped through to the lungs where its oxygenated
