Animal Transport Flashcards
Name essentials features of a transport system
Blood or fluid to carry dissolved substances and cells
System of blood vessels distributing blood around the body
A pump to circulate the blood in the vessels
Valves to prevent back-flow
Name advantages and disadvantages of an open circulatory system and give an example of where it occurs
Advantage: No blood pigment required
Disadvantage: Low pressure, blood moves slowly
Found in insects
Name advantages and disadvantages of a closed circulatory system and give an example of where it occurs
Advantage: More efficient, high pressure
Disadvantage: Blood vessels and pigment required
Found in Earthworms
Name advantages and disadvantages of a single circulatory system and give an example of where it occurs
Advantage: Blood passes through heart once
Disadvantage: Very low pressure, blood returns to heart slowly
Found in fish
Name advantages and disadvantages of a double circulatory system and give an example of where it occurs
Advantages: High pressure, more efficient, blood pressure maintained
Disadvantages: Heart requires four chambers
Found in mammals
Features of venules
Larger lumens than arterioles and thinner walls
Features of arterioles
Thinner than arteries, muscular walls with the ability to vasoconstrict and vasodilate
Features of arteries
Thick muscular walls Oxygenated blood except in pulmonary vein Away from the heart High blood pressure Branch into arterioles
Features of veins
Thinner, less muscular walls Large lumen, irregularly shaped Deoxygenated blood except in the pulmonary vein Form from venules Contain valves Low blood pressure
Features of capillaries
Thin walls; one cell thick
Pores in walls make them permeable
Small diameter, slow blood down
Allows for diffusion between blood and tissue fluid
Describe the intrinsic contraction of heart muscle
Myogenic
What valve is between the left atrium and ventricle
Bicuspid valve
What valve is between the right atrium and ventricle
Tricuspid valve
Describe the pressure in the heart when the semi-lunar valves are open
Blood enters aorta, aorta pressure high
Describe the pressure in the heart when the atrioventricular valves are open
Atrial systole, pressure high in atria
Describe the pressure in the heart when the atrioventricular valves are closed
Ventricular systole, pressure high in ventricles
What does the P wave on an ECG show
Depolarisation through the atria during atrial systole
What does the QRS wave on an ECG show
Depolarisation through ventricles just before ventricular systole
What does the PR segment show on an ECG
Delay at the AV node
How would you identify atrial fibrillation on an ECG
The tracing shows tiny, irregular fibrillations between heartbeats. The rhythm is irregular and erratic, and there may be no P wave
How would you identify a myocardial infarction (heart attack) on an ECG
The QRS complex appears wider, and the ST complex may also appear elevated
How would you identify an enlarged left ventricle on an ECG
The QRS complex has a greater amplitude and voltage
What is a granulocyte
Phagocytic white blood cells
What is an agranulocyte
Lymphocytic white blood cells
What is a thrombocyte
A platelet
What is an erythrocyte
A red blood cell
How is oxygen transported with haemoglobin
It associates with haemoglobin in the alveoli and dissociates as the tissues requires oxygen
Describe the path of the electrical impulse in the heart
Begins at the SA node before depolarising to both atria causing them to contract. The impulse is halted at the AV node to prevent the ventricles from contracting to soon, before the impulse travels down the Bundle of His to the Purkinje fibres, causing the ventricles to contract from the bottom upwards
Describe the Bohr effect
The presence of carbon dioxide in the blood causes the formation of carbonic acid which causes the haemoglobin to reduce its affinity for oxygen and release it into the tissues
What is myoglobin
Found in skeletal muscle and has a very high affinity for oxygen, allowing it to store oxygen until the muscle is short of it, eg, in sustained exercise.
Describe the structure of myoglobin
Has a tertiary structure with only one haem
Describe the haemoglobin affinity curve for organisms living in hypoxic conditions
The curve is shifted to the left
What are the three ways carbon dioxide is carried in the blood
Dissolved in blood plasma
Carbamino-haemoglobin
Hydrogen carbonate ions
Describe how carbon dioxide becomes hydrogen carbonate ions and the chloride shift.
Carbonic anhydrase catalyses the reaction between CO2 and water to form carbonic acid. A hydrogen dissociates, lowering the pH, and forcing the hydrogen carbonate ions out of the cell. This lets chloride ions in to balance the pH.
What is the role of haemoglobin during the transport of CO2
A pH buffer by combining with hydrogen ions to form haemoglobinic acid
Describe the formation of tissue fluid
When the hydrostatic pressure as the blood enters the capillary is greater than the osmotic pressure in the tissues, blood plasma is forced out of the pores in the capillaries and into the tissue
Describe the reabsorption of tissue fluid
At the venous end of the capillary bed, the hydrostatic pressure is less than the osmotic pressure, forcing the tissue fluid back into the blood stream
What are lymphatic vessels for
Draining away excess tissue fluid
What is retention of tissue fluid called
Oedema
What remains in the capillaries when the fluid is forced out
Red blood cells and plasma proteins
