3.3 Organisms exchange substances with their environment - Mass Transport in Animals Flashcards
What are haemoglobins?
A group of proteins found in different organisms
What is the structure of haemoglobin?
Quaternary structure
What do haemoglobin and red blood cells transport?
Oxygen
What does the oxyhaemoglobin dissociation curve represent?
Variations in loading, transport, and unloading of oxygen
What is the affinity of haemoglobin for oxygen?
The ability of haemoglobin to attract or bind to oxygen
Define saturation of haemoglobin with oxygen
When haemoglobin is holding the maximum amount of oxygen it can bind
What is loading/association of haemoglobin?
The binding of oxygen to haemoglobin
What is unloading/dissociation of haemoglobin?
When oxygen detaches or unbinds from haemoglobin
Fill in the blank: The binding of oxygen to haemoglobin is known as _______.
Loading/association
Fill in the blank: When oxygen is released from haemoglobin, this process is called _______.
Unloading/dissociation
What is the oxyhaemoglobin dissociation curve?
It shows how oxygen is loaded in regions with a high partial pressure of oxygen and unloaded in regions of low partial pressure of oxygen.
In which regions is oxygen loaded and unloaded?
- Loaded in alveoli (high partial pressure of oxygen)
- Unloaded in respiring tissues (low partial pressure of oxygen)
What does ‘partial pressure’ refer to in the context of oxygen transport?
The pressure exerted by oxygen in a mixture of gases.
Define cooperative binding in relation to haemoglobin.
The affinity of haemoglobin for oxygen changes depending on how many oxygen molecules are already associated with it.
How many oxygen molecules can haemoglobin associate with?
Four oxygen molecules.
What happens to the shape of haemoglobin as oxygen molecules bind?
The shape changes, making the binding of further oxygen molecules easier.
Where does haemoglobin readily load with oxygen in humans?
In the alveoli, where there is a high partial pressure of oxygen.
What is the Bohr effect?
A phenomenon where a high concentration of carbon dioxide causes the oxyhaemoglobin curve to shift to the right.
What causes the affinity for oxygen to decrease in the Bohr effect?
The acidic nature of the carbon dioxide changes the shape of haemoglobin slightly.
True or False: The affinity of haemoglobin for oxygen is higher in areas with low partial pressure of oxygen.
False.
Fill in the blank: The oxyhaemoglobin dissociation curve illustrates the relationship between _______ and the loading/unloading of oxygen.
partial pressure of oxygen.
What is the Bohr effect?
The phenomenon where the affinity of hemoglobin for oxygen decreases in respiring tissues due to a decrease in pH from carbon dioxide forming carbonic acid
What happens when carbon dioxide dissolves in liquid?
Carbonic acid forms, leading to a decrease in pH and a change in the shape of hemoglobin
How does the Bohr effect benefit respiring tissues?
It allows hemoglobin to deliver oxygen effectively to respiring cells for aerobic respiration
What is the relationship between partial pressure of carbon dioxide and hemoglobin’s affinity for oxygen?
High partial pressure of carbon dioxide at respiring tissues decreases affinity (curve shifts right); low partial pressure in alveoli increases affinity (curve shifts left)
What does a leftward shift of the oxygen-hemoglobin dissociation curve indicate?
Increased affinity for oxygen and therefore more oxygen loading
What does a rightward shift of the oxygen-hemoglobin dissociation curve indicate?
Decreased affinity for oxygen and therefore more oxygen unloading
Name an animal that possesses myoglobin.
Lugworms, whales, or human fetuses
What is the primary function of myoglobin?
To act as an oxygen store with a very high affinity for oxygen, even at low partial pressures
Fill in the blank: Myoglobin has a very high affinity for oxygen, even at very low _______.
partial pressures
True or False: Myoglobin dissociates from oxygen readily.
False
What type of haemoglobin do llamas have?
A type with a higher affinity for oxygen
Why do llamas have a higher affinity for oxygen?
To load oxygen onto haemoglobin despite low partial pressure
What is the effect of high altitude on atmospheric pressure?
There is a lower partial pressure of oxygen
Which animals require more oxygen for respiration due to their fast metabolism?
Fast-moving rodents or birds
Fill in the blank: Animals with ______ metabolism need more oxygen for respiration.
fast
What is necessary for contracting muscles during respiration?
More oxygen
What are the key terms related to mass transport in animals?
- High altitude
- Fast metabolism
- Higher affinity
- Lower affinity
- Respiration
True or False: Llamas can effectively load oxygen onto their haemoglobin at high altitudes.
True
What does the saturation of haemoglobin indicate?
The amount of oxygen bound to haemoglobin
What type of circulatory system do mammals have?
A closed, double circulatory system
This system ensures efficient blood flow and gas exchange.
What does ‘closed’ mean in the context of the circulatory system?
The blood remains within the blood vessels
This prevents blood from leaking into surrounding tissues.
What is the purpose of the double circulatory system in mammals?
It allows blood to pass through the heart twice in each circuit
This includes one circuit for the lungs and another for the rest of the body.
Why does blood flow through the lungs at a lower pressure?
To prevent damage to the capillaries in the alveoli and reduce speed for gas exchange
Lower pressure allows for effective oxygen and carbon dioxide exchange.
What happens to oxygenated blood after it leaves the lungs?
It goes back through the heart to be pumped out at a higher pressure to the rest of the body
This ensures oxygen reaches all respiring cells.
Fill in the blank: The circulatory system in mammals is a _______ circulatory system.
double
This system is essential for efficient transport of oxygen and nutrients.
True or False: The circulatory system in mammals is open.
False
Mammals have a closed circulatory system.
List the two circuits in the mammalian circulatory system.
- Blood to the lungs
- Blood to the rest of the body
These circuits facilitate gas exchange and nutrient delivery.
What is the significance of high pressure in the systemic circuit?
It ensures that blood reaches all the respiring cells in the body
High pressure is necessary for effective circulation throughout the body.
What are the major blood vessels in the circulatory system that need to be named?
Coronary arteries, vena cava, aorta, pulmonary artery, pulmonary vein, renal artery, renal vein
These vessels are associated with the heart, lungs, and kidneys.
What does the term ‘pulmonary’ refer to?
Lungs
The term is used to describe blood vessels related to the lungs.
What does the term ‘renal’ refer to?
Kidneys
The term is used to describe blood vessels related to the kidneys.
What is the function of arteries in the circulatory system?
Carry blood Away from the heart
‘A’ for Away helps remember this function.
What is the function of veins in the circulatory system?
Carry blood back into the heart
‘V’ for Veins and ‘IN’ helps remember this function.
What connects arterioles to capillaries?
Arterioles
Arterioles are smaller than arteries and connect to the capillaries.
What connects capillaries to venules?
Capillaries
Capillaries are the smallest blood vessels that connect arterioles to venules.
Fill in the blank: The _______ are smaller than arteries and connect to the capillaries.
Arterioles
List the components of the circulatory system mentioned.
- Arteries
- Arterioles
- Capillaries
- Venules
- Veins
These components work together to transport blood throughout the body.
True or False: The pulmonary vein carries blood away from the lungs.
False
The pulmonary vein carries oxygenated blood back to the heart from the lungs.
What is the function of the thicker muscular layer in arteries?
To control the volume of blood through constriction and dilation
Arteries need to manage blood flow due to higher pressure compared to veins.
Why do veins have a relatively thin muscular layer?
They cannot control the flow of blood
Veins operate under lower pressure, which allows for a thinner wall structure.
What is the purpose of the thicker elastic layer in arteries?
To help maintain blood pressure
The elastic layer allows arteries to stretch and recoil with the heartbeat.
How does the elastic layer in veins compare to that in arteries?
Veins have a relatively thin elastic layer
This is due to the lower blood pressure in veins.
What structural feature helps prevent arteries from bursting?
Thicker walls
The thicker walls of arteries withstand high pressure within the vessels.
What structural advantage do veins have due to their thin walls?
They can be easily flattened, aiding blood flow to the heart
This feature assists in the return of blood up against gravity.
What is the role of valves in veins?
To prevent the backflow of blood
Valves ensure blood only flows down pressure gradients, assisting in its return to the heart.
What are capillary beds, and why are they significant?
They are many-branched capillaries at exchange surfaces that slow blood flow
Slowing blood flow maximizes diffusion efficiency.
What is the diameter of capillaries, and why is it important?
Narrow diameter
This allows red blood cells to fit through and maximizes diffusion by shortening the pathway.
Fill in the blank: Arteries have a thicker _______ than veins to manage blood pressure.
elastic layer
The thicker elastic layer is crucial for maintaining arterial pressure.
True or False: The walls of veins are thicker than those of arteries.
False
Arteries have thicker walls to withstand higher pressure than veins.
What is the structure and function of blood vessels summarized in?
A table
The table includes details about muscular layer, elastic layer, valves, pressure, and their roles in blood transport.
What is thicker in arteries compared to veins to allow constriction and dilation?
Muscular layer
This thickness helps control the volume of blood in arteries.
What layer in arteries helps maintain blood pressure?
Elastic layer
The elastic layer allows walls to stretch and recoil in response to the heartbeat.
What is the primary function of valves in veins?
Restrict blood flow into the capillaries
Valves prevent backflow of blood in veins.
What is the characteristic of capillaries regarding muscle and elastic layers?
No muscle layer and no elastic layer
This allows for easy diffusion and exchange of materials.
What is the composition of tissue fluid?
Water, glucose, amino acids, fatty acids, ions, and oxygen
Tissue fluid surrounds cells and facilitates the exchange of substances.
What is the purpose of tissue fluid?
To enable the delivery of useful molecules to cells and to move waste into the bloodstream
This process helps in the removal of waste from the body.
True or False: The wall of arteries is thicker than veins.
True
The thicker walls in arteries are necessary to withstand higher pressures.
Fill in the blank: Tissue fluid is the liquid which surrounds _______.
cells
This fluid is essential for nutrient delivery and waste removal.
What characteristic of capillaries aids in material exchange?
One cell thick
This thinness minimizes the diffusion distance for exchanging materials.
What happens to the pressure in veins compared to arteries?
It is lower
This lower pressure is why veins have thinner walls.
What is the term for the pressure that drives fluid out of capillaries?
Hydrostatic pressure
Hydrostatic pressure is the force exerted by the fluid within the capillary walls.
What process describes the movement of water and small molecules out of capillaries?
Ultrafiltration
Ultrafiltration occurs due to high hydrostatic pressure in the capillaries.
What is the term for the potential energy of water in a system?
Water potential
Water potential is influenced by solute concentration and pressure.
What is the process by which water moves across a semipermeable membrane?
Osmosis
Osmosis is the movement of water from an area of lower solute concentration to an area of higher solute concentration.
What is the role of capillaries in the circulatory system?
Exchange of substances
Capillaries allow for the exchange of water, nutrients, and waste between blood and tissues.
What happens to red blood cells and large proteins in the capillaries?
They remain within the capillaries
Red blood cells and large proteins cannot pass through the small gaps in the capillary walls.
What causes the high hydrostatic pressure in capillaries?
Narrow diameter of arterioles
The smaller diameter of arterioles increases the pressure as blood enters the capillaries.
Fill in the blank: Water is reabsorbed back into the capillaries at the venule end by _______.
osmosis
What happens to hydrostatic pressure as blood moves from arterioles to venules?
It decreases
Hydrostatic pressure decreases due to the loss of liquid as blood moves through the capillaries.
What effect do large molecules in capillaries have on water potential?
They lower water potential
The presence of proteins in the capillaries creates a lower water potential, encouraging water reabsorption.
What is formed from the fluid that exits capillaries?
Tissue fluid
Tissue fluid surrounds cells and provides them with nutrients and oxygen.
True or False: All components of blood can pass through capillary walls.
False
Only liquid and small molecules can pass through; larger components like red blood cells are too big.
What is the function of lymphatic vessels in relation to tissue fluid?
Transport lymph
Lymphatic vessels collect excess tissue fluid and return it to the circulatory system.
What is the liquid transferred to the lymphatic system called?
Lymph
Lymph eventually drains back into the bloodstream near the heart.
What is the primary function of coronary arteries?
Supply the cardiac muscle with oxygenated blood
Coronary arteries branch off from the aorta.
What unique property does cardiac muscle have?
Myogenic
Cardiac muscle can contract and relax without nervous or hormonal stimulation.
True or False: Cardiac muscle can fatigue.
False
Cardiac muscle never fatigues as long as it has an adequate supply of oxygen.
What happens if coronary arteries become blocked?
Myocardial infarction (heart attack)
Blockage prevents oxygen supply to cardiac muscle, leading to cell death.
Fill in the blank: The walls of the heart have a thick ______ layer.
Muscular
This muscular layer is essential for the heart’s function.
What is the significance of mitochondria in cardiac muscle?
Provides energy for contraction
Mitochondria are crucial for aerobic respiration in cardiac cells.
What is equilibrium in the context of tissue fluid absorption?
Reached when not all liquid is reabsorbed by osmosis
Some tissue fluid is absorbed into the lymphatic system.
What is the function of the left ventricle?
Pumps blood to the rest of the body at a higher pressure
This ensures blood reaches all cells in the body.
Why does the left ventricle have a thicker muscular wall compared to the right ventricle?
To enable larger contractions of the muscle to create a higher pressure
What are the four major blood vessels connected to the heart?
- Aorta
- Pulmonary artery
- Vena cava
- Pulmonary vein
What is the function of the vena cava?
Carries deoxygenated blood from the body into the right atrium
What does the pulmonary vein carry?
Oxygenated blood from the lungs to the left atrium
What is the function of the pulmonary artery?
Carries deoxygenated blood from the right ventricle to the lungs
What does the aorta do?
Carries oxygenated blood from the left ventricle to the rest of the body
Fill in the blank: The _____ carries deoxygenated blood from the body into the right atrium.
vena cava
Fill in the blank: The _____ carries oxygenated blood from the lungs to the left atrium.
pulmonary vein
True or False: The left ventricle pumps blood at a lower pressure than the right ventricle.
False
What type of blood does the pulmonary artery carry?
Deoxygenated blood
What type of blood does the aorta carry?
Oxygenated blood
What are the four valves found inside the heart?
- Semilunar valves
- Atrioventricular (AV) valves
- Bicuspid valve
- Tricuspid valve
The semilunar valves are located in the aorta and pulmonary artery, while the AV valves are located between the atria and ventricles.
What is the function of the semilunar valves?
Prevent backflow of blood from the arteries into the ventricles
The semilunar valves open when the pressure is higher in the ventricle compared to the arteries.
What is the role of the atrioventricular (AV) valves?
Prevent backflow of blood from the ventricles into the atria
The AV valves open when the pressure is higher in the atria compared to the ventricles.
What is the bicuspid valve also known as?
Left atrioventricular valve
It is located between the left atrium and left ventricle.
What is the tricuspid valve also known as?
Right atrioventricular valve
It is located between the right atrium and right ventricle.
How do valves open and close?
Valves open if pressure is higher behind them and close if pressure is higher in front
This mechanism ensures proper blood flow direction.
What is the function of the septum in the heart?
Separates the right and left sides of the heart
This separation maintains a high concentration of oxygen in the oxygenated blood.
What is cardiac output?
Volume of blood leaving one ventricle in one minute
It is calculated using the formula: Cardiac output = heart rate X stroke volume.
What is the formula for calculating cardiac output?
Cardiac output = heart rate X stroke volume
Where heart rate is beats per minute and stroke volume is the volume of blood per beat.
What is the heart rate?
Beats of the heart per minute
It is a measure of how often the heart beats.
What does stroke volume refer to?
Volume of blood that leaves the heart each beat (dm3)
It is a key component in determining cardiac output.
What are the three stages of the cardiac cycle?
Diastole, Atrial systole, Ventricular systole
The cardiac cycle describes the sequence of events in the heart during one complete heartbeat.
What occurs during diastole?
The atria and ventricular muscles are relaxed, allowing blood to enter the atria via the vena cava and pulmonary vein.
This stage increases pressure within the atria as blood flows in.
What happens during atrial systole?
The atrial muscular walls contract, increasing pressure and causing atrioventricular valves to open, allowing blood to flow into the ventricles.
The ventricular muscular walls are relaxed during this phase.
What is the main event during ventricular systole?
The ventricle muscular walls contract, increasing pressure beyond that of the atria, causing atrioventricular valves to close and semilunar valves to open.
Blood is then pushed out of the ventricles into the arteries.
During which phase do the atrioventricular valves open?
Atrial systole
This occurs as the atria contract and push blood into the ventricles.
True or False: Blood is pushed out of the ventricles during diastole.
False
Blood is pushed out during ventricular systole.
Fill in the blank: The pressure in the ventricles increases during _______.
Ventricular systole
This increase in pressure is what causes the semilunar valves to open.
What happens to the semilunar valves during ventricular systole?
They open
This allows blood to be ejected into the pulmonary artery and aorta.
What is the relationship between atrial pressure and ventricular pressure during contraction?
Ventricular pressure exceeds atrial pressure during ventricular systole.
This pressure difference is crucial for proper blood flow.
What is the significance of the atrioventricular valves closing?
Prevents backflow of blood into the atria during ventricular contraction.
This ensures that blood flows in the correct direction.
What is the primary function of blood vessels linked to the heart?
Transport oxygenated and deoxygenated blood
Includes the aorta, pulmonary arteries, pulmonary vein, and coronary arteries.
How many chambers does the heart have?
Four chambers: right atrium, right ventricle, left atrium, left ventricle
Each chamber plays a distinct role in the circulation of blood.
What phenomenon describes the cooperative nature of oxygen binding to hemoglobin?
The oxygen-hemoglobin dissociation curve
This curve illustrates how hemoglobin’s affinity for oxygen changes with varying levels of oxygen concentration.
What effect does carbon dioxide have on hemoglobin’s affinity for oxygen?
Decreases affinity due to shape change
The increase in carbon dioxide concentration alters hemoglobin’s structure, reducing its ability to bind oxygen.
What are the three key stages of the cardiac cycle?
Atrial systole, ventricular systole, and diastole
These stages involve changes in pressure and volume within the heart chambers.
Fill in the blank: The coronary arteries supply the _______ with oxygenated blood.
heart muscle
Essential for maintaining the heart’s energy needs for contraction and relaxation.
True or False: The structure and function of capillaries are linked to gas exchange in the alveoli.
True
Capillaries facilitate the exchange of gases between blood and alveolar air.
What happens in regions with low partial pressure of oxygen?
Oxygen is released from hemoglobin
This occurs in respiring tissues where oxygen demand is high.
What is the significance of the Bohr effect?
Shifts the oxygen-hemoglobin dissociation curve to the right
This indicates decreased affinity for oxygen in response to increased carbon dioxide levels.
What is ultrafiltration in the nephron of the kidney linked to?
The structure and function of capillaries
Capillaries play a crucial role in filtering blood to form urine.
What is the role of energy in cardiac muscle function?
Required for continuous contraction and relaxation
Energy is necessary for the heart to maintain its rhythmic activity.
