Transport In Animals - Module 3 Flashcards
List the 3 reasons why animals needs transport systems
- We are large organisms - diffusion will not provide what we need
- Small surface area to volume ratio, inner cells wont be provided with what they need
- We have a high metabolic rate, we require lots of energy for respiration
What is a single circulatory system?
Blood only passes through the heart once per cycle
What type of circulatory system do fish have? And why?
Single closed system - this is because their energy levels are lower and a temperature doesn’t need to be maintained
What is a double circulatory system?
When the blood passes through the heart twice per circuit
What are the two circuits in a double circulatory system?
- Pulmonary system - carries deoxygenated blood to lungs to pick up oxygen
- Cardiac cycle - takes oxygenated blood to tissues
What is an open circulatory system?
Where blood is not always contained in vessels but rather circulates through the body cavity
What is a closed circulatory system?
Blood remains in vessels
What kind of circulatory system to insects have?
Open circulatory system
What are the advantages of a double circulatory system?
- Quick blood flow dies to pressure form heart
- Blood pressure to tissues can be increased without increasing pressure through delicate lungs
Describe the function and structure of the arteries
Arteries Carry oxygenated blood away from the heart to tissues
- high blood pressure
- thick muscular walls
- small lumen
The walls of the artery contain collagen, elastin and smooth muscle
What is different about the pulmonary artery?
The pulmonary artery carries deoxygenated blood from the heart to the lungs
Describe the structure and function of the veins
Veins carry deoxygenated blood from tissues back to the heart
- low blood pressure
- thin walls
- large lumen
- valves to prevent back flow of blood
What is different about the pulmonary vein?
The pulmonary vein carried oxygenated blood from the lungs to the heart
Describe the structure and function of the capillaries
The capillaries allow exchange between blood and tissue as well as linking veins to arteries
- thin walls
- walls are made of flattened endothelium
- lumen Is narrow, 1 erythrocyte wide allowing time for diffusion by slowing blood flow down
What are 2 adaptations of the capillaries?
- Large surface area for diffusion
- Short diffusion distance
Why is it useful that capillaries are only 1 erythrocyte wide?
It slows blood flow down meaning more time for gaseous exchange
What is the calculation for cardiac output?
Cardiac output = heart rate x stroke volume
What 3 ways is carbon dioxide transported in the blood?
- Dissolved in blood
- Combined with haemoglobin as carbominohaemoglobin
- As hydrogen carbonate ions
How does carbon dioxide for hydrogen carbonate ions to travel in the blood?
- Carbon dioxide will react with water to form carbonic acid
CO2 + H2O = H2CO3 - The carbonic acid will release H+ protons forming HCO3- ions as it dissociates
It binds with haemoglobin forming haemoglobinic acid - The HCO3- ions move out of the erythrocyte by diffusion so Cl- diffuse into the erythrocyte to balance the charge, known as chloride shift
What is chloride shift?
When chloride ions move into erythrocyte to balance the charge of the cell as HCO3- ions move out of the cell
What is the role of the coronary arteries and where are they located?
The coronary arteries is to provide oxygen to the heart tissues for respiration and they are located on the exterior surface of the heart
What enzyme catalyses the reaction between carbon dioxide and water in the blood?
Carbonic anhydrase
What do arterioles do?
Carry blood from artery into capillary
Why are the collagen and elastic layers of the arterioles thinner than those in the artery?
Because the blood pressure is lower so the arterioles doesn’t have to withstand as much pressure
Why is the muscle layer of an arterioles thicker than that in the artery?
Because it controls the blood flow through the capillaries
What happens when the smooth muscle layer of the arterioles contracts?
Vasoconstriction occurs and blood flow to capillaries is reduced
What happens when the smooth muscle layer of the arterioles dilates?
Vasodilation occurs and blood flow to capillaries is increased
When does vasodilation occur?
When the body’s oxygen requirements increase
What is tissue fluid?
The fluid that passes out of the blood in the capillaries and baths tissue cells
What are the components of blood?
CELLS
- rbc
- wbc
- platelets
PLASMA
- glucose
- oxygen
- ions
- plasma proteins
Where does tissue fluid move out of the capillary?
The arterial end
Why is tissue fluid forced out of capillary at the arterial end of the capillary?
Because the hydrstatic pressure is higher can the oncotic pressure so the tissues fluid is forced out
Which end of the capillary does tissue fluid move into the capillary?
The venous end
Why does tissue fluid move back into the capillary at the venous end?
Because the hydrostatic pressure is now lower than the oncotic pressure allowing it to move back in my osmosis
What happens to tissue fluid that doesn’t get reabsorbed by the blood?
It moves into lymph nodes
(Google this topic)
Why is the heart myogenic?
It initiates its own heart beat
What does carbon dioxide do the oxygen disassociation curve?
Carbon dioxide shifts the oxygen dissociation curve to the right - this is known as the Bohr effect
What does carbon dioxide do to haemoglobin affinity for oxygen?
Decreases haemoglobin affinity for oxygen to decrease
What is different about fetal haemoglobin?
It has a higher affinity for oxygen
Why can’t fetal haemoglobin have a really increased affinity for oxygen?
Because if oxygen affinity was too increased it would stop haemoglobin from depositing oxygen to the tissues
What happens to oxygen affinity as partial pressure of oxygen increases?
Oxygen affinity increases as the structure of haemoglobin changes to make it easier
Why is it difficult for the 4th oxygen to bind to haemoglobin?
It is difficult as there is only 1 binding site left meaning there is less chance of a successful collision
