Heart structure and circulatory systems Flashcards
(37 cards)
Two types of circulatory systems?
Open and closed
Explain circulation of blood in open circulatory system 3
Heart pumps blood into spaces collectively called haemocoel, within the body cavity
Tissues bathe in the blood directly and material exchange takes place
Blood flows slowly back to the heart
What aids blood in flowing back to the head region in creatures with open circulatory systems
Movement of muscles and valves called peristalsis
Example of creatures with an open circulatory system
Insects
What characterises a closed circulatory system 4
Blood is transported in blood vessels
Blood is pumped by a muscular heart at high pressure
Tissues are not in direct contact with the blood
Blood contains the pigment haemoglobin
What is the result of blood being pumped at high pressure in closed systems
Rapid blood flow
What ARE tissues in direct contact with in closed systems
They bathe in tissue fluid
Advantages of closed systems
Blood flow is more rapid
Can be directed to where it is needed
More efficient delivery of O2 and glucose/ removal of waste, CO2
Example of creatures with closed circulatory system
Earthworm, humans
Two types of closed systems
Single and double
Single circulatory system (fish)?
Blood stays in vessels on a single pathway around the body.
Blood passes through the heart once before returning to the gills
Why does blood in a single, closed system only make one pass of the heart before again reaching the same point?
Gas exchange capillaries and those of other body systems are in the same circulation
Double closed circulatory system?
Blood must pass through the heart at least twice before returning to the same point in the body
Why does blood make 2 passes of the heart in a double closed system?
The pulmonary and systematic circulations are separate
Example of organism with double closed circulatory system
Mamals
Characteristics of heart of single closed system
2 chambers
One atrium
One ventricle
Overall single circulation
Characteristics of heart with double closed system (mammalian heart)
4 Chambered for both pulmonary and systemic circulatory systems
Double pump working synchronously, keeping O2 and de-O2 seperate
Made of cardiac muscle which is myogenic
Sequence of blood flow in single circulatory system
Heart
Gills
Body
Heart
Sequence of blood flow in pulmonary circulatory system
Heart
Lungs
Heart
Sequence of blood flow in systemic circulatory system
Heart
Body
Heart
Two systems in double circulatory system?
Systemic (body)
Pulmonary (lungs)
What does mammals being endothermic mean?
Produce their own body heat
Why do mammals req a double circulatory system
They are endothermic, so have high metabolic rate and energy req
So cells need alot of O2 and glucose/ efficient removal of waste
Is blood pressure increased or decreased after passing throught the lungs
Increased for more efficient delivery of resources to the body tissues
