Studied by 19 people
Right side recieves
Deoxygenated blood
Left side recieves
Oxygenated blood
Right side pumps to
Lungs
Left side pumps to
Body
Coronary artery function
Supply the cardiac muscles with nutrients for respiration
Coronary vein function
Return deoxygenated blood back to heart muscle
Walls of heart made of
Cardiac muscle
Cardiac cycle
Sequence of events from one heartbeat to the next heartbeat with three phases
Three stages of cardiac cycle
Diastole
Atrial systole
Ventricular systole
What part of heart involved in diastole? Contract or relaxes?
Atria and ventricles relax
Which valves are open and closed in diastole
Semifinal closed, atrioventricular sometimes open
Where is movement of blood in diastole
Blood enters atria which passively goes into the ventricles. Coronary arteries fill during diastole top
Part of heart involved in atrial systole? Contract or relax?
Atria walls contract
Valves open and closed in atrial systole
Atrioventricular open, semilunar closed
Movement of blood in atrial systole
Atria to ventricles
Part of heart involved in ventricular systole? Contract or relax?
Ventricles contract
Valves open and closed in ventricular systole
Atrioventricular close and semilunad open
Movement of blood in ventricular systole
Ventricles to pulmonary artery and aorta
Why do we need a heart
To generate pressure and pump blood around the body
to overcome limitations of diffusion to ensure fast delivery of oxygen to body cells
Why is left side of heart thicker
Contains more muscle to generate higher blood pressure to pump blood further distance
What is in the centre of the heart to stop the sides mixing
Septum
What are the 3 blood vessels
Vein, artery and capillaries
Mass transport system
Substances transported in the flow of a fluid with a mechanism for moving the fluid around the heart
Good transport system needs
Fluid to carry nutrients and oxygen
Pump to push fluid around body
Exchange surfaces
Factors that effect need for transport systems
Size (SA:V ratio)
Metabolic rate and activity level
How animals keep warm
3 types of circulatory system and examples
Open -insects
Closed, single - fish
Closed, double- mammals
Stage 1 and 2 of diastole
Atria and ventricles relax
Blood flows into the atria from veins. Elastic recoil of atrial walla generates low pressure in atria helping to draw blood into heart
Stage 3,4 and 5 of diastole
Under influence of gravity, blood in arteries flows down towards ventricles closing the semilunar valves
Atria fill with blood
Pressure in atria increases pushing open atrioventricular valves
Stage 6 and 7 in atrial systole
Blood flows into relaxing ventricles
Both atria contract
Stage 8 and 9 in ventricular systole
Remaining blood is forced through atrioventricular valves into the ventricles
Ventricles contract after slight delay
Stage 10 and 11 in ventricular systole
Pressure in ventricles increases and blood us forced upwards, closing the atrioventricular valves
Blood is forced into the aorta and pulmonary artery, opening the semilunar valves
Why are sides of heart seperate
Steep concentration gradient fir faster diffusion
Maximum oxygen carried by mass flow
Maintains pressures for more efficient delivery of oxygen and lower in lungs to not damage it
Parts of artery
Outer collagen coat
Thick muscular wall
Thick smooth muscle
Thick elastic fibre
Smooth endothelial
Narrow lumen
No valves
Parts of vein
Outer collagen coat
Smooth endothelium
Wide lumen
Thin smooth muscle
Thin elastic fibre
Valves
Parts of vein
Outer collagen coat
Smooth endothelium
Wide lumen
Valves
Thin smooth muscle
Thin elastic fibre
Valves
Why does artery have thick muscular wall
To withstand highblood pressure
Why does artery have collagen coat
Strength to prevent artery bursting and to withstand high blood pressure
Why does artery have thick smooth muscle
It contracts to constrict artery to maintain blood pressure
Why does artery have thick elastic fibre
Allow artery to stretch and recoil to squeeze blood forward and maintain blood pressure
Why does artery have smooth endothelium
Reduces friction
Why does artery have narrow lumen
Maintain high blood pressure
Why does artery not have valves
Blood is always forced forward by heart contraction and elastic recoil
Why does vein have collagen
Strength
Why does vein have smooth endothelium
Reduces resistance to blood flow
Why does vein have wide lumen
Make vessel easier to squeeze between skeletal muscles
Why do veins have valves
Prevent backflow
Why do veins have thin smooth muscle
Less ability fo4 comtraction to constrict blood vessel
Why does vein have thin elastic fibre
Less elastic recoil
Why capillary wall only 1 cell thick
Help exchange of dissolved substances between blood and cells by reducing diffusion distance
Why does capillary have very narrow lumen
Slows flow of blood to allow time for exchange more efficiently
Walls of blood cell in contact with wall to reduce diffusion distance
Why do capillaries have tiny holes in their walls
Allow passage of materials through wall into tissue fluid
What is an open circulatory system
Blood held in organ cavity and organs are bathed in blood
Pressure in open circulatory system
Low
What is closed circulatory system
Blood held in blood vessels
Pressure in closed circulatory system
High
Blood pressure when reaching body capillaries in single circulatory system,
Low pressure
Blood pressure when reaching body cappilaries in double circulatory system
High pressure
Where is blood pumped in single circulatory system
To gills then around rest of body then back to heart
Where is blood pumped in double circulatory system
Lungs then back to heart which pumps oxygenated blood through aorta to rest of body then returned to heart by vena cava
Repressurisation
Blood gets an extra boost when returns from lungs to heart to allow heart to pump oxygenated blood at higher pressure to body
Why do animals need circulatory system
Low sa:v ratio
Diffusion isn’t efficient
Circulatory system carries oxygen and nutrients around body
Why do organisms need mass transport system
To move molecules quickly between gas exchange surfaces and cells in organisms that have smaller sa:v ratio where diffusion is inadequate
What is water made of
1 oxygen and 2 hydrogen
Charge on water molecule
Hydrogen slightly positively charged
Oxygen slightly negatively charged
How do water molecules join
The slightly positive charged is attracted to the slightly negative ends of surrounding water molecules
Why can molecules dissolve in water
Dipole nature of water
Hydrophobic
Water loving (polar) substances that dissolve
Hydrophobic
Water hating (non polar) substances that don’t dissolve
Specific heat capacity
Amount of energy required to raise temp of 1cm³ of water by 1°c
Why is specific heat capacity so high
Large amount of energy required to break hydrogen bonds
Another name for blood clot
Thrombus
Why do blood clots form
Minimise blood loss
Prevent pathogens entering
How do blood clots form
Platelets stick to damaged blood vessel. Thromboplastin produced by platelets and damaged tissue
Thromboplastin in presence of calcium ions and vitamin k converts prothrombin to thrombin
Thrombin converts fibrinogen to fibrin which causes mesh of insoluble fibre
Mesh traps platelets and red blood cells forming blood clot
What does thromboplastin with calcium ions and vitamin k do
Convert prothrombin to thrombin
What does thrombin do
Convert fibrinogen into fibrin
What does fibrin do
Forms mesh of insoluble fibres which traps platelets and red blood cells causing blood clot
What us atherosclerosis
Hardening of arteries
Main risk factors if atherosclerosis
Coronary heart disease and stroke
How is atherosclerosis formed
Damage to endothelium triggers inflammatory response where white blood cells accumulate and cholesterol enters blood vessel
Causes fatty buildup called atheroma
Calcium salts and fibrous tissue build up resulting in plaque
Cause artery to lose elasticity and harden
Lumen narrows which increase blood pressure
Atherosclerosis positive or negative feedback
Positive feedback because increases blood pressure which causes more damage to endothelium
What causes damage to endothelium
High blood pressure
Toxins from cigarette smoke
Infections such as chlamydia
What is blood pressure a measure of
The hydrostatic force of the blood against the walls of a blood vessel
elevated blood pressure known as
Hypertension
Systolic pressure
Maximum blood pressure when heart contracts in ventricular systole
Diastolic pressure
Lowest blood pressure when heart relaxes in diastole
Peripheral resistance
Contact between blood and walls of blood vessel causes friction which slows blood flow
Where is peripheral resistance strongest
Vein
Where is peripheral resistance lowest
Artieries
Healthy systolic blood pressure
100-140mmHg
Healthy diastolic blood pressure
60-90mmHg
Oedema
Fluid build up in tissues and causing swelling
Oedema forms
Tissue fluid forms when plasma is forced put of capillaries, carrying with it nutrients and oxygen
Cells absorb nutrients and oxygen from tissue fluid and give out waste
Tissue fluid moves back into capillaries by osmosis
20% of tissue fluid drains into blind ended lymph capillaries. It flows through lymph vessels and returns thr lymph fluid to the blood via the thoriac duct in the neck
How is tissue fluid formed
When plasma is forced out of the capillaries, carrying with it nutrients and oxygen
What happens to tissue fluid that isnt reabsorbed
It drains into blind ended lumph capillaries. It flows through the lymph vessels and return thr lymph fluid to thrblood via the thoracic duct in thr neck
How much tissue fluid isn’t reabsorbed
20%
3 monosaccharides
Glucose, galactose, fructose
3 disaccharides
Maltose, sucrose, lactose
Bond which joins monosaccharides
Glycosidic bond
General formula for monosaccharides
(CH20)n
Which two polysaccharides make starch
Amylose and amylopectin
Note 
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