Chapter 8 - Transport In Animals Flashcards
(248 cards)
1
Q
Substances are said to not have entered or left an organism until…
A
it crosses the cell surface membrane
2
Q
Is diffusion good enough for large organisms
A
No
3
Q
Why isn’t diffusion good enough for large organisms
A
wouldn’t be fast enough to meet the metabolic requirements of cells
4
Q
Why wouldn’t diffusion be fast enough to meet the metabolic requirements of cells in large cells
A
• Increasing transport distances
• Surface area: volume ratio
• Increasing levels of activity
5
Q
What is mass flow
A
• bulk movement of materials
6
Q
Is there diffusion in mass flow systems
A
Yes = only at specific exchange sites at the start and end of the route travelled by the substances
7
Q
Advantages of mass transport systems
A
• Bring substances quickly from one exchange site to another
• Maintain the diffusion gradients at exchange sites and between cells and their fluid surroundings
• Ensure effective cell activity by keeping the immediate fluid environment of cells within a suitable metabolic range
8
Q
Examples of mass flow systems
A
circulatory system
or xylem + phloem
9
Q
Draw a human circulatory system
A
10
Q
What are circulatory systems
A
• systems that transport fluids containing oxygen, nutrients and waste
11
Q
Define single system
A
blood passes through the heart once during one complete circuit of the body
12
Q
Define double system
A
blood passes through the heart twice during one complete circuit of the body
13
Q
Example of organism with single circulatory system
A
Fish
14
Q
Example of organism with double circulatory system
A
Mammals
15
Q
Draw a fish circulatory system
A
16
Q
What are gills the site of
A
oxygen and carbon dioxide are exchanged with the atmosphere and the blood
17
Q
Describe the fish circulatory system
A
• Deoxygenated blood is pumped to the gills from the heart
• oxygenated blood flows from the gills to the rest of the body
o It travels through the capillaries in organs, delivering oxygen and nutrients
• The blood returns to the heart
18
Q
What’s different about a fish’s heart
A
only has one atrium and one ventricle
19
Q
Draw a humans circulatory system
A
20
Q
Describe the circulatory system in humans
A
- deoxygenated blood pumped via pulmonary artery to lungs
- oxygenated blood returns to heart via pulmonary vein
- oxygenated blood = left atrium = left ventricle = pumped to rest of body via aorta
- deoxygenated blood returns via vena cava
- deoxygenated blood = right atrium = right ventricle = pumped to lungs
21
Q
What separates both sides of the heart
A
Septum
22
Q
What is the general rule about blood that has passed through an organ
A
any blood that has just passed through an organ goes straight back to the heart, not to another organ
23
Q
What is the exception to this rule - any blood that has just passed through an organ goes straight back to the heart, not to another organ
A
hepatic portal vein
- allows blood from the gut to flow to the liver
24
Q
Where is the heart located
A
In the chest cavity
25
Function of arteries
carry blood away from the heart.
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Function of arterioles
Connect arteries to capillaries
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Size of an artery
0.4 - 2.5 cm diameter
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Size of arterioles
30 micrometers = diameter
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Size of capillaries
5-10 micrometers = diameter
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Size of venules
7 micrometers - 1 mm = diameter
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Advantages of double circulation
maintains higher blood pressure and average speed of flow
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How does double circulation ensure higher blood pressure and average speed of flow than single
• When blood enters a capillary network = pressure and speed drops significantly
• In a single circulatory system, the blood has to pass through two capillary networks before returning to heart
• In a double circulatory system, the blood only passes through one capillary network before returning to the heart.
= maintains higher BP + SoF
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What is significant about higher blood pressure and average speed of flow
helps maintain steeper concentration gradient = efficient gas exchange
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What is a closed circulatory system
blood is pumped around the body and is always contained within a network of blood vessels
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What is an open circulatory system
blood is not contained within blood vessels but is pumped directly into body cavities
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Organisms with closed system
o All vertebrates and many invertebrates
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Organisms with open system
arthropods and molluscs
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Type of circulatory system = human
• closed double circulatory system
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What is the pulmonary system in humans
right side of the heart pumps deoxygenated blood to the lungs for gas exchange
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What is systemic circulatory system
oxygenated blood can be pumped efficiently (at high pressure) around the body
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How many main blood vessels to insects have
1
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What is the main blood vessel in insects called
Dorsal vein
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What is insect blood called (it’s not really blood)
haemolymph
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Describe the circulatory system in insects
tubular heart in the abdomen pumps haemolymph into the dorsal vessel
• The dorsal vessel delivers the haemolymph into the haemocoel - BODY CAVITY
• Haemolymph surrounds the organs and eventually re-enters the heart via one-way valves called OSTIA
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What is the haemocoel
Body cavity in insects
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What is different about the way blood is transported in humans and insects
Unlike the blood in a mammals circulatory system =
haemolymph is not specifically directed towards any organs in an insect
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Why can insects survive with this less efficient circulatory system
because oxygen is delivered directly to their tissues via tracheae that connect directly to the outside
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Three layers of artery’s
tunica adventitia/externa, tunica media and tunica intima
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Structure of tunica intima = arteries
made up of an endothelial layer
a layer of connective tissue
+ layer of elastic fibres
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How thick is the endothelium layer in arteries
One cell thick
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Advantages of endothelium layer
very smooth and reduces friction for free blood flow
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Structure of tunica media = arteries
made up of smooth muscle cells and a thick layer of elastic tissue
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Is the tunica media thick or thin in arteries
Thick
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Function of later of muscle in tunica media = arteries
strengthen the arteries so they can withstand high pressure.
o enables them to contract and narrow the lumen for reduced blood flow
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Function of elastic tissue = tunica media = arteries
maintain blood pressure in the arteries = stretches and recoils to even out any fluctuations in pressure
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Structure of tunica externa
= made up of collagen
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Function of collagen = tunica externa = artery
strong protein protects blood vessels from damage by over-stretching
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Do arteries have wide or narrow lumen
Narrow
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Function of narrow lumen = arteries
maintain a high blood pressure
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Is there a pulse in arteries
Yes
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Structure of arterioles
- muscular layer
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Function of muscular later in arterioles
maintain a high blood pressure
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When would having arteries that maintain a high blood pressure ever be a good thing
During exercise blood flow to the stomach and intestine is reduced which allows for more blood to reach the muscles
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Difference between arteries and arterioles = structure
arterioles have a lower proportion of elastic fibres and a large number of muscle cells
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Structure of veins
- tunica intima
- tunica media
- tunica externa
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Structure of tunica media = veins
- thinner than arteries
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Why is there no need for a thick muscular tunica media
veins don't have to withstand high pressure
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Do veins have wide or narrow lumens
Wide
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Advantages of veins having wide lumens - 3
larger lumen helps to ensure that blood returns to the heart at an adequate speed
reduces friction between the blood and the endothelial layer of the vein
rate of blood flow is slower in veins but a larger lumen means the volume of blood delivered per unit of time is equal
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Do veins have valves
Yes
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Function of valves in veins
To prevent back flow
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Is there a pulse in veins
No
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Structure of venues
o have few or no elastic fibres + large lumen
- very thin muscular layer
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Why is there no need for thick muscular layer in venules
o blood is at low pressure after passing through the capillaries
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Which one of these is an artery + which one is a vein
Artery then vein
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What do capillaries form
Networks / capillary beds
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Purpose of capillary beds
important exchange surfaces within the circulatory system
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Structure of capillaries
- small diameter = lumen
- wall of the capillary is made solely from a single layer of endothelial cells
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The wall of the capillary also lines what
the lumen in arteries and veins
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Function of small diameter lumen in capillaries
o forces the blood to travel slowly = provides opportunity for diffusion to occur
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Function of thin capillary walls = single layer
reduces the diffusion distance for oxygen and carbon dioxide between the blood and the tissues of the body
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What’s special about the capillary walls
have gaps = pores
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Function of pores in capillaries l
allow blood plasma to leak out and form tissue fluid
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Three types of muscle
smooth / skeletal / cardiac
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What’s special about cardiac muscle
Myogenic
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What does myogenic mean
contracts without nervous impulse from the brain
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Average mass of human heart
Around 300g
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What is the heart protected by in the chest cavity
the pericardium, a tough and fibrous sac
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Describe the structure of the heart
• left and right sides of heart separated by a wall of muscular tissue = septum.
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Why is the septum important
ensuring blood doesn’t mix between the left and right sides of the heart
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Two names of the septum = portions
interatrial septum + interventricular septum
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What is the interatrial septum
• portion of the septum which separates the left and right atria
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What is the interventricular septum
• portion of the septum which separates the left and right ventricles
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What is the pericardium
a thin, outermost lining that protects and surrounds your heart = not acc part of heart
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Function of the pericardium
• As heart beats = expands to fill with blood + constricts to expel blood out
• Because changes size = cause friction with other organ systems + tissue within the chest cavity
• Excess friction = wear down tissue + decrease health/efficacy of exposed tissue
• THEREFORE…heart contained within sac = pericardium
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What is contained within the pericardium
lubricating fluids- serous fluid
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Function of serous fluid
reduces friction within pericardial sac + protects from pathogen
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What produces these lubricating fluids / serous fluids
controlled by epicardium
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When do valves open
when the pressure of blood behind them is greater than the pressure in front of them
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When do the valves close
o Close when the pressure of blood in front of them is greater than the pressure behind them
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Label this = 14 labels
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Valve between right atrium + right ventricle
atrioventricular = tricuspid valve
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Valve between right ventricle + pulmonary artery
pulmonary valve= semi lunar
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Valve between left atrium + left ventricle
mitral valve = bicuspid valve = atrioventricular
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Valve between left ventricle + aorta
aortic valve = semi lunar valves
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Blood vessels bringing blood to the heart
vena cava and pulmonary vein
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blood vessels taking blood away from the heart
pulmonary artery and aorta
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What is the heart again
A muscle
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How does the heart ( the muscle) receive blood itself
through arteries on its surface = coronary arteries
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Dangers of coronary arteries
important that these arteries remain clear of plaques, as this could lead to angina or a heart attack (myocardial infarction)
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Function of coronary arteries
- bring oxygen for respiration of heart
- supply nutrients + remove waste products
112
What to remember in the heart topic
REMEMBER FLIPPED = LEFT SIDE OF HEART ON RIGHT SIDE OF PAGE
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Define systole
period of contraction
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Define diastole
period of relaxation
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Which ones longer - systole or diastole
Diastole
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Characteristics of plasma
straw-coloured liquid = around 55% of blood
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3 types of fluid in body
blood / tissue fluid / lymph
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What is plasma mostly comprised of
WTAER
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Advantage of water being mainly plasma
water is a good solvent = many substances can dissolve in it = transported around the body
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How is tissue fluid formed
• As blood passes through capillaries, some plasma leaks out through gaps in the walls of the capillary to surround the cells of the body
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Difference between plasma + tissue fluid
similar = tissue fluid contains far fewer proteins
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Why does tissue fluid contain less proteins
too large to fit through gaps in the capillary walls
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Function of tissue fluor.
• Exchange of substances between cells and the blood
E.g = carbon dioxide produced in aerobic respiration will leave a cell, dissolve into the tissue fluid surrounding it, and then diffuse into the capillary
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How much liquid leaves the plasma to form tissue fluid depends on…
Hydrostatic + oncotic pressure
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What is Hydrostatic pressure
pressure exerted by a fluid e.g. blood
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What is oncotic pressure
type of osmotic pressure exerted by proteins in the blood plasma
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Explain how hydrostatic + oncotic pressure interact to form tissue fluid
• When blood is at the arterial end of a capillary = hydrostatic pressure is great enough to force fluid out of the capillary
• increased protein content in blood creates a water potential gradient (osmotic pressure) between the capillary and the tissue fluid
• At the venous end of the capillary, the hydrostatic pressure within the capillary is reduced
• water potential gradient between the capillary and the tissue fluid remains the same as at the arterial end, so water begins to flow back into the capillary from the tissue fluid
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How much fluid goes back to blood + how much becomes tissue fluid
90% of the fluid = reabsorbed at the venous end
o 10% remains as tissue fluid = collected by lymph vessels and returned to the circulatory system
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Effect of high blood pressure on formation of tissue fluid
the pressure at the arterial end is even greater
o pushes more fluid out of the capillary and fluid begins to accumulate around the tissues.
o called oedema
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How is lymph formed
• Some tissue fluid re-enters the capillaries = some enters the lymph capillaries
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Why can there be larger molecules in the lymph
• Larger molecules that are not able to pass through the capillary wall enter the lymphatic system as lymph
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Entry points to lymphatic system
o Small valves in the vessel walls
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How does the lymph move along the lymphatic system
by compression caused by body movement.
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What prevents back flow in lymphatic system
Valves
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Why do lazy people get swollen limbs
No body movement = lymph builds up = swelling
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Where does the lymph go
eventually reenters the bloodstream through veins located close to the heart
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Where does the lymph enter the circulatory system
The thoracic duct ( near vena cava)
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What would happen if plasma proteins that were able to escape, were not moved from the tissue fluid into the lymphatic system
lower the water potential (of the tissue fluid) and prevent the reabsorption of water into the blood in the capillaries
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Features of the lymphatic system
- lymphatic capillaries
- lymph nodes
- lymphatic tissue
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What are lymph nodes
sacs = trap pathogens + contain a lot of white blood cells
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What + where + function of lymphatic tissue
in spleen / thymus / tonsils = large amount of white blood cells + involved in their developmen
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Why would we die if we had no lymphatic system
- rate of water loss too large
• Lead to build up of tissue fluid
• Important role in secondary line of defence
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Describe of atrial systole
• Heart is full of blood + ventricles are relaxed
• Both the atria contract + blood passes to the ventricles
• The atrio-ventricular valves open due to blood pressure
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Is atrial systole - passive or active
Mostly passive = • 70% blood = flows passively = atria do not have to contract a lot
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Describe ventricular systole
• Atria relax
• Ventricle walls contract = forcing blood out
• Pressure of the blood forces the atrioventricular valves to shut
• Pressure = opens semi-lunar valve
• Blood passes into aorta + pulmonary arteries
• Blood from vena cava + pulmonary veins enter arteries
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What makes up one heartbeat
• One systole and diastole
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In diastole, are the atrioventricular valves open or closed
Open
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In diastole are the semi lunar valves open or closed
Closed
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In systole are the atrioventricular valves open or closed
Closed
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In systole are the semilunar valves open or closed
Open
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How do pressure changes force valves open
• The contraction of the muscles in the wall of the heart reduces the volume of the heart chambers and increases the pressure of the blood within that chamber
• When the pressure within a chamber/vessel exceeds that in the next chamber/vessel the valves are forced open and the blood moves through
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Label this - 7
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What is happening at point A + between point A and B
At A
both left atrium and left ventricle are relaxed
• Pressure sits at roughly 0 kPa
Between a A + B
Left atria contracts and empties blood into the left ventricle
- atrial systole
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What’s happening at point B
- beginning of the ventricular systole
• Left ventricular pressure increases
• AV valve shuts
• Pressure in the left atria drops as the left atrium expands
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What is happening at point C
pressure in the left ventricle exceeds that in the aorta
• Aortic valve opens
• Blood enters the aorta
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Wha is happening at point D
diastole
• Left ventricle has been emptied of blood
• Muscles in the walls of the left ventricle relax and pressure falls below that in aorta
• Aortic valve closes
• AV valve opens
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What is happening at point E
expansion of the left ventricle
• There is a short period of time during which the left ventricle expands
• This increases the internal volume of the left ventricle which decreases the pressure
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Why is the maximum pressure in the ventricles substantially higher than in the atria
because there is much more muscle in the thick walls of the ventricles which can exert more force when they contract.
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What does cardiac output mean
the volume of blood that is pumped by the heart (the left and right ventricle) per unit of time
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Cardiac output of an average adult
roughly 4.7 litres of blood per minute when at rest
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How would being fitter effect cardiac output
have higher cardiac out puts due to having thicker and stronger ventricular muscle s in their hearts
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When does cardiac output increase
When you are exercising
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Why does cardiac output increase when you are exercising
so that the blood supply can match the increased metabolic demands of the cells
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Formula for cardiac output
Cardiac output = heart rate x stroke volume
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What is heart rate
number of times a heart beats per minute
OR
number of cardiac cycles per minute
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What is stroke volume
volume of blood pumped out of the left ventricle during one cardiac cycle
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Stroke volume on a graph
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Describe the rhythm of heart
intrinsic rhythm
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What is SAN
sinoatrial node
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What is the sinoatrial node
a group of cells in the wall of the right atrium.
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What is another term for the SAN
Pacemaker
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Function of the SAN
• Sets rate of contraction for heart
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How does the SAN set the rate of contraction for heart
• Spontaneously contracts + generates nerve impulse causing both atria to contract
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What is the Annulus fibrosus
a region of non-conducting tissue
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Function of Annulus fibrosus
prevents the depolarisation spreading straight to the ventricles
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What is the AVN
atrioventricular node
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What is the atrioventricular node
region of conducting tissue between atria and ventricles
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What is the bundle of His
collection of conducting tissue in the septum of the heart
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Describe how the beating of the heart is controlled
• SAN initiates a wave of depolarisation that causes the atria to contract
depolarisation is carried to the atrioventricular node (AVN)
• After a slight delay, the AVN is stimulated and passes the stimulation along the bundle of His
• The bundle of His divides into two conducting fibres, called Purkyne tissue, and carries the wave of excitation along them
• The Purkyne fibres spread around the ventricles and initiate the depolarization of the ventricles from the apex (bottom) of the heart
• This makes the ventricles contract and blood is forced out of the pulmonary artery and aorta
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Why is it important that there is a slight delay
means that the ventricles contract after the atria = delay allows the atria to contract = fully emptying blood
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Explain the roles of the sinoatrial node, the atrioventricular node and the Purkyne fibres in a heartbeat.
• The Sinoatrial node sends out a wave of excitation and this spreads across both atria, causing atrial systole.
• Non-conducting tissue called the Annulus fibrosus prevents the excitation from spreading to the ventricles and so this ensures that atria and ventricles don’t contract at the same time.
• The Atrioventricular node then sends the wave of excitation to the ventricles after a short delay of around 0.1 - 0.2 seconds, ensuring that the atria have time to empty their blood into the ventricles.
• The Purkyne fibres conduct the excitation down the septum of the heart and to the apex, before the excitation is carried upwards in the walls of the ventricles.
• This means that during ventricular systole, the blood contracts from its base and blood is pushed upwards and outwards.
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What are electrocardiograms used for
• used to monitor and investigate the electrical activity of the heart using electrodes
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What is the P wave
o Caused by the depolarisation of the atria, which results in atrial contraction (systole)
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What is the QRS complex
o Caused by the depolarisation of the ventricles, which results in ventricular contraction (systole)
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Why is the QRS complex so large
largest wave because the ventricles have the largest muscle mass
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What is the T wave
o Caused by the repolarisation of the ventricles, which results in ventricular relaxation (diastole)
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What is the U wave
still uncertain of the cause of the U wave
some think it is caused by the repolarisation of the Purkyne fibres
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Define tachycardia
o When the heart beats too fast
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Rate = tachycardia
o over 100 bpm
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Who is normally bradycardic
o A lot of fit individuals or athletes
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Rate = bradycardic
o resting heart rate below 60 bpm
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What is an ectopic heartbeat
condition is caused by an early heartbeat followed by a pause
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What is fibrillation
irregular heartbeat will disrupt the rhythm of the heart
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What is heart block
o Separation of the P wave and QRS complex
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What is hypertrophy
Enlargement of something
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How can you tell one side of the heart is hypertrophic
o QRS complex = distorted
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What type of disease is hole in heart
Congenital
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How does hole in the heart work + how does it cause anaemia
between atria or ventricles = allows mixing of oxygenated and deoxygenated blood – blood passes from RA to LA = some blood does not enter ventricles + pulmonary artery = reduces systolic pressure = dangerous = some blood bypasses lungs = less 02 loaded = less respiration = anaemia
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What is wrong
Tachycardia = peaks too close together
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What is wrong
Bradycardic = peaks too far apart
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What is wrong
Small and unclear P wave indicates atrial fibrillation
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What is wrong
Elevation of the ST section indicates heart attack
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What is wrong
Deep S wave = ventricular hypertrophy = increase in muscle thickness
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What forms when oxygen binds to haemoglobin
oxyhaemoglobin
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Is the reaction between Oxygen + Haemoglobin reversible
YES
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What is cooperative binding = in terms of oxygen and haemoglobin
binding of the first oxygen molecule results in a conformational change in the structure of the haemoglobin molecule, making it easier for each successive oxygen molecule to bind
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Why is haemoglobin never really 100% saturated
• Fourth molecule = very hard to bind on = due to all these changes
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We don’t say concentration of a gas what do we say
Partial pressure
209
Draw the structure of haemoglobin
210
What are the three main ways carbon dioxide is transported from cells
- dissolves directly in the blood plasma and is transported in solution
o Carbon dioxide can bind to haemoglobin, forming carbaminohaemoglobin
o A much larger percentage of carbon dioxide is transported in the form of hydrogen carbonate ions (HCO3-)
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How are hydrogen carbonate ions formed = describe
• Carbon dioxide diffuses from the plasma into red blood cells = partial pressure
• Inside red blood cells carbon dioxide combines with water to form H2CO3
CO2 + H2O ⇌ H2CO3
o enzyme carbonic anhydrase which catalyses the reaction between carbon dioxide and water
• Carbonic acid dissociates readily into H+ and HCO3- ions
H2CO3 ⇌ HCO3– + H+
• Hydrogen ions can combine with haemoglobin, forming haemoglobinic acid and preventing the H+ ions from lowering the pH of the red blood cell
o Haemoglobin is said to act as a buffer in this situation
• The hydrogen carbonate ions diffuse out of the red blood cell into the blood plasma where they are transported in
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Why does H2CO3 form more slowly in plasma than in the cytoplasm of red blood cells
o plasma contains very little carbonic anhydrase
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What is the chloride shift
movement of chloride ions into red blood cells that occurs when hydrogen carbonate ions are formed
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Why does the chloride shift occur
• Negatively charged hydrogencarbonate are transported out of red blood cells via a transport protein in the membrane
• To prevent an electrical imbalance, negatively charged chloride ions are transported into the red blood cells via the same transport protein
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What would happen if there was no chloride shift
red blood cells would become positively charged as a result of a build up of hydrogen ions formed from the dissociation of carbonic acid
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What is the Bohr shift
occurs when a high partial pressure of carbon dioxide causes haemoglobin to release oxygen into respiring tissues
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How are hydrogen carbonate ions formed = diagram
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What does the Oxygen Dissociation curve show
• shows the rate at which oxygen associates, and also dissociates, with haemoglobin at different partial pressures of oxygen (pO2)
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What does saturated haemoglobin mean
all of its oxygen binding sites are taken up with oxygen = four oxygen molecules
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What does affinity for oxygen mean
ease with which haemoglobin binds and dissociates with oxygen
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When haemoglobin has a high affinity…
binds easily + dissociates slowly
222
o When haemoglobin has a low affinity for oxygen….
slowly + dissociates easily
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Describe + explain the shape of the curve
• shape of the haemoglobin molecule = difficult for the first oxygen molecule to bind to haemoglobin = binding of the first oxygen occurs slowly = shallow curve at the bottom left corner of the graph
• After the first oxygen = haemoglobin protein changes shape = easier for the next haemoglobin molecules to bind = this speeds up binding = steeper part of the curve in the middle of the graph
• The shape change of haemoglobin leading to easier oxygen binding = cooperative binding
• As the haemoglobin molecule approaches saturation = longer for the fourth oxygen molecule to bind due to the shortage of remaining binding sites = levelling off of the curve in the top right corner of the graph
224
If you read this left to right, what does it show
rate at which haemoglobin binds to oxygen at different partial pressures of oxygen
225
Read the curve from left to right
o At low pO2 = oxygen binds slowly to haemoglobin = cannot pick up oxygen and become saturated as blood passes through the body's oxygen-depleted tissues
Haemoglobin has a low affinity for oxygen at low pO2, so saturation percentage is low
o At medium pO2 = oxygen binds more easily to haemoglobin and saturation increases quickly = small increase in pO2 causes a large increase in haemoglobin saturation
o At high pO2 = oxygen binds easily to haemoglobin = haemoglobin can pick up oxygen and become saturated as blood passes through the lungs
Haemoglobin has a high affinity for oxygen at high pO2, so saturation percentage is high
increasing the pO2 by a large amount only has a small effect on the percentage saturation of haemoglobin = oxygen binding sites on haemoglobin are already occupied
226
If you read this from right to left what does it show
rate at which haemoglobin dissociates with oxygen at different partial pressures of oxygen
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Read this from right to left
o In the lungs, where pO2 is high, there is very little dissociation of oxygen from haemoglobin
o At medium pO2 = oxygen dissociates readily from haemoglobin = corresponds with the partial pressures of oxygen present in the respiring tissues of the body
a small decrease in pO2 causes a large decrease in percentage saturation of haemoglobin = easy release of plenty of oxygen to the cells
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Do fetal haemoglobin have a higher or lower affinity for oxygen
Higher
229
Draw a graph with adult and foetal haemoglobin
230
Why does foetal blood have a higher affinity for oxygen
Getting oxygen from maternal blood
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What makes some haemoglobin have a higher or lower affinity for oxygen
Structure
232
What is myoglobin
Darn red pigment found in muscle cells = NOT BLOOD = has no role in oxygen transport
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What is myoglobin used for
Oxygen transport
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Does myoglobin have a higher or lower affinity for oxygen compared to adult
Higher
235
Draw a graph with foetal + myoglobin + adult haemoglobin
236
Myoglobin has a high affinity for oxygen, what does that mean
Picks up oxygen readily, but will only give up oxygen at very low oxygen concentration levels = providing a reserve supply
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How does carbon dioxide effect the oxygen dissociation curve
- as pCO2 levels increase = rate at which oxygen is unloaded is increases
238
Draw an oxygen dissociation curve with ranges of carbon dioxide
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How are organisms adapted to diff levels of oxygen
Organisms = live in an environment with low concentrations of oxygen = have haemoglobin with high affinity for oxygen
240
If you have higher affinity,
Curve shifted to left
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Draw a graph with foetal + adult + llama haemoglobin
Lama = lives in high altitudes
242
Summarise the Bohr effect into a flow chart
243
Structure of tunica intima artery
- endothelium
- squamous epithelial cells
- elastic tissue
244
Function of endothelium in tunica intima artery
Helps flow
245
Function of squamous epithelial cells in tunica intima artery
Narrow lumen maintains pressure
246
Structure of tunica media artery
Muscle
Elastic issue
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Function of muscle in tunica media artery
Stops rupture
248
Function of elastic tissue in tunica media artery
role of elastic recoil in moving blood + smooths out pulsatile flow
