Chapter 8 Transport in Animals Flashcards
1
Q
What is the need for specialised transport systems in animals?
A
- metabolic demands are HIGH
- SA:V ratio is LOW
- molecules (like hormones) need transporting from where they are produced to where they are needed
- food, digested - needs transporting to cells (cells metabolism)
- waste products of metabolism - removed from cells - transported to excretory organs
2
Q
Types of circulatory systems (2)?
A
OPEN and CLOSED
3
Q
3 KEY features of a MASS TRANSPORT SYSTEM?
A
(1) liquid transport medium (circulates around systems)
(2) vessels (carrying transport medium)
(3) pumping mechanism - to move the transport medium
4
Q
OPEN circulatory systems??
A
- transport medium pumped straight from the heart to body cavity (HAEMOCOEL)
- transport medium is under LOW pressure
- comes into direct contact with tissues and cells
(exchange takes place here) - returns to the heart through an open-ended vessel
5
Q
OPEN circulatory systems in invertebrates??
A
- gas exchange through the tracheal system
- transport medium - haemolymph
(only carries food and nitrogenous waste) - body cavity is split by a membrane
- the heart extends along the length of the thorax and abdomen
- haemolymph circulates but a steep diffusion gradient CANNOT be maintained for efficient diffusion
6
Q
A