chap 9- transport in animals Flashcards
What is the circulatory system?
System of blood vessels with pump and valves causing one way movement of blood
Describe circulation in a fish
- Single circulation, blood flows through heart once per circuit
- Blood pressure lower than mammals - too low for kidney function
What are the advantages of double circulation?
- Blood passes through heart twice per circuit
- Increased blood pressure through lungs
- Increased pressure to tissues
Explain the thickness of the heart walls
- Left ventricle thicker - must push blood round whole body
- Right wall thinner as only pushes blood to lungs
- Atria walls thinner than ventricles, only push to ventricles
What is the function of the septum?
Separates oxygenated and deoxygenated blood in the heart
Describe the movement of the blood around the body starting at the right atrium
- Deoxygenated blood enters the right atrium via the vena cava
- Right atrium contracts forcing blood through tricuspid valve into right ventricle
- Blood enters the right ventricle and leaves via the pulmonary artery
- Blood flows to the lungs
- Blood become oxygenated
- Blood returns to the heart and enters the left atrium via the pulmonary vein
- Left atrium contracts forcing blood through bicuspid valve into the left ventricle
- Left ventricles contracts forcing blood into the aorta
- Oxygenated flows around the body and is used in respiration
How can heart activity be monitored?
- By an ECG, pulse rate and listening to valves with stethoscope
What does physical activity do to pulse rate?
- Increases it
How would you investigate effect of exercise on pulse rate?
- Take pulse at rest, perform exercise, take pulse rate again
What is coronary heart disease?
- Blockage of coronary arteries
- Part of the heart muscle stops contracting, causing a heart attack
- Vital tissues don’t get oxygen
What are the risk factors?
- Diet
- Stress
- Smoking
- Genetic predisposition
- Age
- Gender
Explain the effect of exercise on pulse rate
- Muscles burn more oxygen in respiration
- Muscle creates waste products
- Increased oxygen demand and waste products needs increased circulation
- Pulse rate increases to keep up with demand
How can diet and exercise prevent coronary heart disease?
- Poor diet and lifestyle are risk factors
- Low levels of cholesterol and low saturated fatty acids in diet
- Exercise strengthens heart muscle and reduces stress
How can heart disease be treated
- Drug treatment with e.g. aspirin
- Surgery e.g. Bypass operation or angioplasty (stent)
blood vessels
1) artery
2) vein
3) cappilary
Artery
Thick wall, muscular, carries
blood away from heart
How is artery adapted to
function?
Elastic walls expand and
relax, hick walls withstand
high pressure
Vein
Thin walled, wide lumen,
takes blood back to heart
How is vein adapted to
function
Valves prevent back flow, low
pressure, large diameter
creates low resistance
Capillary
One cell thick, branched
structure, extends through all
tissues
How is capillary adapted to
function
Short diffusion distance, large
surface area maximises
exchange of substances
Name the main blood vessels going to and from the heart
- Vena cava
- Aorta
- Pulmonary vein
Name the main blood vessels going to and from the lungs
- Pulmonary artery
- Pulmonary vein
Name the main blood vessels going to and from the kidney
- Renal artery
- Renal vein
