transport in animals Flashcards
give 3 reasons why specialised transport systems are needed
metabollic demands are high
surface area to volume ratio is smaller
size of organism
what is an open circulatory system
no blood vessels and is in an open cavity
what is the blood in insects called
heamolymph
what is a closed circulatory system
blood vessels and does not come into direct contact with cells
what is a single closed circulatory system
only around the body once
what is a double closed circulatory system
travels twice around the body
why are elastic fibres useful in blood vessels
they can stretch and recoil providing felxibility
why is smooth muscle useful in blood vessels
contracts and relaxes to change the size of the lumen
why is collagen useful in blood vessels
provides structural shape
name the structures in arteries (3 features)
endothelium
elastic layer
smooth muscle layer
what are aterioles roles
feed blood into capillaries
what are capillaries role
metabollic exchange
what is tissue fluid
contains dissolved oxygen and nutrients which supplies tissues with essential solutes
what is hydrostatic pressure
the pressure that forces blood out of capillaries allowing substances within tissue fluid to be exchanged
what is osmotic pressure
the pushes fluid into the capillaries
where does excess tissue fluid that isn’t transported back into the capillaries go
lymphatic system with lymphnodes and lymphocytes
how does the water from tissue fluid move to the blood again (3 marks)
tissue fluid has a positive water potential
blood has a negative water potential
water moves down a water potential gradient via osmosis
how many polypeptide chains does haemoglobin have
4
2 alpha and 2 beta
what is the haem group of haemoglobin
iron
how many oxygen molecules can haemoglobin carry
4
what is partial pressure of oxygen a measure of
oxygen concentration
what does SAN act as
pacemaker
how is the electrical impulse passed from the atria to the ventricle
SAN sends electrical excitation
atria contracts
electrical excitation is detected by the AVN
AVN sends electrical excitation down Purkyne fibres, down apex
ventricles contract
where is the SAN located
right atrium
what is the His a collection of
conducting tissue
what do ECG’s measure
hearts electrical activity
what are the 3 traces in an ECG
P wave
QRS wave
T wave
what does the P wave indicate in an ECG
atrial systole
what does the QRS wave indicate in an ECG
ventricle systole
what does the T wave indicate in an ECG
ventricle diastole
what is an ectopic heartbeat
an added heart beat
what is atrial fibrillation
the heart cannot pump heart properly
how to treat atrial fibrillation
surgery or treatment
what is the bohr shift
dissociation curve shift to the right
how does a pump in the heart give an efficient transport system
creates hydrostatic pressure
how is blood being a fluid make it an efficient transport system
transport medium
how do blood vessels give it an efficient transport system
maintains high pressure
describe the flow of blood starting from the vena cava
vena cava
right atrium
right ventricle
pulmonary artery
lungs
pulmonary vein
left atrium
right atrium
aorta
describe the cardiac cycle
blood flows into the atria via the veins passively
AV valves are open
artria muscles contract
atrial pressure increases
blood pushed into the ventricles
ventricle muscles contract
pressure increases in ventricles
AV close
SL valves open
blood pumped into aorta
ventricular volume decreases
pressure in arteries increases
forces the SL valves to shut
atrial and ventricle muscles relax
what is the equation for cardiac output
cardiac output= stroke volume x heart rate
what is ultrafiltration in the formation of lymph
when plasma is forced out of the capillaries through the capillary walls into the tissues
what filters lymph
lymphnodes
why does the artery wall have a thick layer of collagen
stop them from bursting or collapsing
why do arteries have a layer of smooth muscle
control how large the lumen is to maintain pressure
why do arteries have folded epithelium
allows lumen to expand under pressure
how is carbon dioxide removed 85% of the time
CO2 diffuses into erythrocyte
broke down by carbonicohydrase
forms carbonic acid
dissociates with haemoglobin
HCO3 leaves
chloride diffused in to balance charge (chloride shift)
chlorine acts as a buffer and binds to haemoglobin
haemoglobin acid
why is the formation if carbaminohaemoglobin potentially dangerous for the body if CO2 is not excreted
haemoglobin needs to carry oxygen not CO2, less oxygen to respiring tissues
why is the formation of hydrogen potentially dangerous for the body
it makes it too acidic which could denature proteins
what is the role of smooth muscle tissue
maintains blood pressure as it regulates the size of the lumen
what is the role of leucocytes
to fight pathogens
what is the process if plasma seperation under pressure known as
ultrafiltration
are leucocytes found in blood or tissue fluid
both
suggest one way in which lymph is different from tissue fluid
lymph has toxic waste materials
suggest three safety measures you should take to reduce the risk from pathogens
sharp instruments
sterilise the tables after dissection
wear gloves
why is each AV valve attached to the ventricle wall by tendons
prevents backflow by stopping the AV valves from operating when in systole
why is the heart myogenic
the contraction is controlled by the SAN valve
what prevents the SAN from causing immediate contraction of the ventricles
conducting tissue
why is it important that the electrical wave from the SAN takes time to reach the ventricles
enough time for blood to rush until the ventricles from the atrium
