animal transport Flashcards
(39 cards)
what are the features of a respiratory system
suitable medium to carry materials
pump e.g heart to move blood
valves to maintain flow in one direction
in some animals
respiratory pigment to increase oxygen transportation
branching network so things can be transported around the whole body
what is an open circulatory system
blood does not move around the body in vessels bathes tissues in cavity called haemocoel
what is a closed circulatory system
blood moves in vessels
What type of organism has an open circulatory system
insects
Have a long dorsal shaped heart that runs the entire length of the body and pumps blood at low pressure into the haemocoel
Oxygen diffuses directly from the tracheoles into the tissues so is not carried in blood
What is a single circulatory system
blood only passes around the body once
What is a double circulatory system example
mammals
What is an example of a single circulatory system
fish
Ventricle pumps deoxygenated blood to the capillary network reduces its pressure
Oxygenated blood is carried to tissues and then deoxygenated blood returns to the atrium
Which organisms contain respiratory pigment
earth works and mammals
what are the features of arteries
elastic tissue
not permeable
smaller lumen
oxygenated blood flows at high pressure and speed away from the heart
what are the features of veins
thin muscular wall
small amount of elastic tissue
not permeable
transports deoxygenated blood to the heart at low pressure and speed
semi lunar valves to stop backflow
what are the features of capillaries
no muscle or elastic tissue
large lumen
permeable
no valves
links arteries to veins so blood changes from oxygenated to deoxygenated
what is the tunica intima
single layer of endothelium which reduces friction
what is the tunica externa
a layer of collagen fibres which prevent overstretching
what is the tunica media
elastic fibres and smooth muscle
thicker in arteries than veins
elastic fibres stretch to accomodate changes in blood flow and recoil to push blood along arteries which is felt as the pulse
smooth muscles contracts to regulate blood flow and maintain blood pressure
what are the functions of arteries
carry blood away from heart
thick muscular walls withstand the high pressure and they branch into arterioles
what is the function of capillaries
form a network that penetrates all tissues and organs blood collects into venules which take blood into veins to return it to heart
what is the function of veins
larger diameter and thinners walls than than arteries and lower blood pressure
carry deoxygenated blood back to heart
what can happen if veins dont work correctly
varicose veins or heart failure
what happens in the atrial systole
the atrium walls contract and the blood pressure in the atria increases , this pushes the blood through the tricuspid and bicuspid valves down into the ventricles , which are relaxed.
what happens in the ventricular systole
The ventricular walls contract and increase the blood pressure in the ventricles. this forces blood up through the semi - lunar valves ,out of the heart , into the pulmonary artery and the aorta . This blood cannot flow back from the ventricles into the atria because the tricuspid and bicuspid valves are closed by the rise in ventricular pressure . The pulmonary artery carries deoxygenated blood to the lungs and the aorta carries oxygenated blood to the rest of the body .
what happens in diastole
The ventricle relax . The volume of the ventricles increases and so pressure in the ventricles falls. This risks the blood in the pulmonary artery and aorta flowing backwards into the ventricles . That tendency to flow backwards causes the semi - lunar valves at their bases to shut , preventing blood to the rest of the body . The atria also relax during diastole , so blood from the vena cavae and pulmonary veins enters the atria and the cycle starts again.
what is the sinoatrial node (san)
sinoatrial node is in the the walls of the right atrium . it generates electrical impulses which spread to left and right atria so they contract together .
what is the purkinje fibres
excitation is transmitted to purkinje fibres in ventricle walls which carry it up through muscles in the walls . impulses cause cardiac muscle in each ventricle to contract which pushes blood up to the aorta and pulmonary artery and empties ventricles.
what is the atrioventricular node ( AVN )
introduces a delay in the transmission of electrical impulse . relays electrical impulses to the left and right ventricles.
