chapter 9 Flashcards
Describe the circulatory system
A system of blood vessels with a pump and valves to ensure one way flow of blood
Describe the single circulation of fish
2 chambers
single circulation
blood goes through heart only once
Inefficient because blood pressure is lost through capillaries in gills
Describe double circulation of mammals includ the circulation names
4 chambers
double circulation
Pulmonary circulation:
heart to lungs
low pressure
right side
deoxy blood
Systemic circulation :
heart to rest of body
high pressure
left side
oxygenated blood
Describe double circulation
The blood passes the heart twice during one complete circulation
State the importance and advantages of double circulation
To separate the oxygenated and deoxygenated blood .
to maintain high blood pressure at systemic circulation > to supply cells with more oxygen and glucose for respiration to make more energy, faster and more frequently
State the structures of the heart
Vena Cava ( inferior / superior ) - entering heart [ deoxygenated blood ]
right atrium
tricuspid valve
right ventricle
semilunar valve
Pulmonary artery - away from heart to lungs
Pulmonary veins ( entering heart from lungs )[ oxygenated blood ]
left atrium
bicuspid valve
left atrium
semilunar valve
Aorta ( away from heart )
Septum ( seperates 2 sides of heart )
coronary artery ( inside muscle tissues , supplying oxygen and nutrients to heart )
Which sides recieve oxygenated blood and deoxgenated blood
oxygenated : left side
deoxygenated : right side
explain the relative thickness of the muscle walls
- ventricles have thicker muscle walls than atrium >? > ventricles pump blood out of heart so need higher pressure
- Left ventricle has thicker wall than right ventricle > need higher pressure as its pumping for longer distance
What is the function of the septum
to separate the oxygenated and deoxygenated blood and prevent them from mixing
Describe the function of the valves
basic function:
prevent blood flowing backwards to ensure blood flow in 1 direction
AV valves:
tricuspid : seperate right atrium and right ventricle
Bicuspid : seperate left atrium and left ventricle
semilunar valves: only artery with valves
Describe the movement of the valves and the contractions of the heart
AV valves open when atrium contract, close when ventricles contract
Semilunar : open when ventricle contracts
Describe the pathway of blood through the heart
Deoxygenated blood from body tissues flow into right atrium via vena cava
Once the right atrium has filled with blood , the atrium contracts, tricuspid valve opens.
blood is pushed through the tricuspid valve into the right ventricle . The walls of the right ventricle contract, semilunar valve opens.
Blood is pushed into the pulmonary artery to the lungs
The blood travels to the lung and moves through the capillary at the alveoli where gas exchange occurs.
Oxygenated blood returns to the left atrium via the pulmonary vein . Left atrium contracts and bicuspid valve opens
Blood then enters the left ventricle , which contracts and semilunar valve opens.
Blood is pumped through the aorta, to rest of the body tissues
State how the activity of the heart is monitered
- Electrocardiogram
- Measuring pulse rate
- listening to the sounds of valves closing using a stethoscope
how is heart rate and pulse rate measured?
bpm : beats per minute
Why does heart rate increase during exercise?
So that sufficient blood is supplied to working muscles , to provide them with enough OXYGEN and GLUCOSE for increased RESPIRATION
increase in heart rate allows carbon dioxide to be removed at a faster rate
also likely that muscle cells have been respiring anaerobically during exercise so have a built up of LACTIC ACID
heart continues to beat fast after exercise to ensure enough oxygen is still being delivered to muscle cells ( to repay oxygen debt )
extra oxygen used to break down lactic acid that has been built up