Transport in Animals Flashcards
what substances are transported in animals?
blood, oxygen, R/WBC, glucose, CO2, hormones, vitamins and amino acids
what do transport systems consist of?
blood, heart, blood vessels
why do some animals not need a transport system?
diffusion- large surface area to volume ratio
what are the reasons for a transport system?
- need a supply of oxygen and glucose
- removes waste product
- diffusion is not fast enough for multicellular organisms
what are the three key factors for a transport system?
- size
- level of activity
- surface area to volume ratio
why is size relevant in relation to a transport system?
- several layers of cells prevent fast diffusion
- diffusion is not sufficient for needs - increased distance
- hormones/ enzymes made in one place, needed in another
- oxygen taken in one place and needed everywhere
- waste from cells to excretory organs
why is level of activity relevant in relation to a transport system?
- active animals require more oxygen for respiration
- must be delivered quickly if the organism is metabolically active
why is surface area to volume ratio relevant in relation to transport system?
- large multicellular organisms have a smaller surface area to volume ratio so surface area is not enough to absorb/ remove substances
- diffusion distance to inner cells has also increased as volume of an organism is larger
what are the components of a circulatory system?
- pump to move fluid
- circulatory fluid/ transport medium
- interconnecting vessels
what is a closed circulatory system?
- blood confined in blood vessels
- heart pumps blood under pressure into vessels which branches off and infiltrate organs before returning to the heart
what is an open circulatory system?
when there are very few vessels to contain the transport medium and is pumped straight from the heart into the body cavity of the animal
what is a double circulatory system?
- blood flows through the heart twice on one circuit of the body (vertebrates, echinoderms and squid)
- 2 circuits
- pulmonary circuit- carries deoxygenated blood to lungs to
collect oxygen and excrete CO2
- systematic circuit- carries oxygenated blood to cells
what are some examples of processes that supply things to single organism cells?
- diffusion
- osmosis
- active transport
- endocytosis
- exocytosis
why cant diffusion transport the substances into and out of the inner core of the body in bigger organisms?
the distances between the cells and the outside of the body gets greater as the organism increases in size so diffusion would be too slow and the organism would not survive
what features in common do most circulatory systems have?
- a liquid transport medium that circulates around the system (blood)
- vessels that carry the transport medium
- a pumping mechanism to move the fluid around the system
what is a mass transport system?
when substances are transported in a mass of fluid with a mechanism for moving the fluid around the body
what is a haemocoel?
the open body cavity that the transport medium is pumped into from the heart
what type of pressure is the transport medium under in the haemocoel?
low pressure
how does the transport medium return to the heart in an open circulatory system?
through an open ended vessel
where are open-ended circulatory systems usually found?
in invertebrate animals
what is insects blood called?
haemolymph
what does haemolymph not carry?
oxygen and carbon dioxide
what does haemolymph transport?
food, nitrogenous waste product and the cells involved in defence against disease
what is a closed circulatory system?
when the blood is enclosed in blood vessels and does not come into contact with the cells of the body
how do substances enter and leave the blood in a closed circulatory system?
by diffusion through the walls of the blood vessels
how can blood that is flowing to a particular tissue be adjusted?
by the widening or narrowing of blood vessels
what does blood pigment carry?
respiratory gases
what are the types of closed circulatory systems?
single and double closed circulatory system
where are single closed circulatory systems found?
a number of groups including fish and annelid worms
what is the path blood takes in a single closed circulatory system?
the blood flows through the heart and is pumped out to travel all round the body before returning to the heart
how many capillaries does blood pass through in a single closed circulatory system?
two sets
what occurs in the first set of capillaries in a single closed circulatory system?
it exchanges oxygen and carbon dioxide
what occurs in the second set of capillaries in a single closed circulatory system?
substances are exchanged between the blood and the cells
what happens as a result of blood passing through the two sets of capillaries in a single closed circulatory system?
the blood pressure in the system drops considerably so the blood returns to the heart quite slowly
what is the most important system in transporting substances around the body?
the double closed circulatory system
what are the two circulations the blood goes through in a double closed circulatory system?
- blood is pumped from the heart to the lungs to pick up oxygen and unload CO2, and then returns to the heart
- blood flows through the heart and is pumped out to travel all around the body before returning to the heart again
how many capillary networks does the blood pass through in each circuit in the double closed circulatory system?
one capillary network
what happens because of the blood only passing through one capillary network in the double closed circulatory system?
means a relatively high blood pressure and fast flow can be maintained
what are some examples of different components utilised in some blood vessels?
- elastin fibres
- smooth muscle
- collagen
how are elastin fibres utilised in blood vessels?
composed of elastin and can stretch and recoil, providing vessel walls with flexibility
how is smoot muscle utilised in blood vessels?
contracts and relaxes which changes the size of the lumens
how is collagen utilised in blood vessels?
provides structural support to maintain shape and volume of the vessel
which way do arteries carry bood?
away from the heart to the tissues of the body
what type of blood do arteries carry?
oxygenated blood, except in the pulmonary artery which carries deoxygenated blood from the heart to the lungs
do the arteries have high or low pressure
high
what do artery walls contain?
elastin fibres, smooth muscle and collagen
what do arterioles do?
link the arteries and capillaries
what happens when the smooth muscle in the arteriole contracts and what is the proper name for it ?
it constricts the vessel ad prevents blood flowing into a capillary bed which is called vasoconstriction