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