3.2 - adaptations for transport Flashcards
describe the vascular system of insects
- open circulatory system
- dorsal-tube shaped heart
- respiratory gases not carried in blood
what’s an open circulatory system
- transport medium pumped by heart not contained in vessels, but moves freely
- transport fluid comes into direct contact w/ cells
describe the vascular system of earthworms
- vascularisation
- closed circulatory system
- respiratory gases carried in blood
what’s a closed circulatory system
- blood pumped by heart contained in blood vessels
- blood doesn’t come into direct contact w/ cells
advantages of a closed circulatory system
- blood pressure can be maintained
- blood supply to different organs can vary
- lower volumes of transport fluid required
what type of circulatory system do fish have
single circulatory system
what’s a single circulatory system
- blood travels one circuit
- blood flows through heart + pumped around body before retuning to heart
what type of circulatory system do mammals have
double circulatory system
what’s a double circulatory system
- blood flows through heart twice in 2 circuits
- blood pumped from heart to lungs before returning to heart, then pumped around body, after which returning to heart again
what are the benefits of a double circulatory system
- maintains blood pressure around whole body
- uptake of O2 more efficient
- delivery of O2 + nutrients more efficient
- blood pressure can differ in pulmonary + systemic circuits
describe the double circulatory system in humans
blood flows through heart twice in 2 circuits:
- pulmonary circuit
- systemic circuit
name the 4 chambers of the mammalian heart
- left atrium
- right atrium
- left ventricle
- right ventricle
describe the pathway of blood around the body, naming the structures of the heart
pulmonary vein → left atrium → left ventricle → aorta → body → vena cava → right atrium →. right ventricle → pulmonary artery → lungs
where are the atrioventricular valves found + what’s their function
- found between atria + ventricles
- prevents backflow of blood from ventricles into atria
what are the 2 types of atrioventricular valves
- bicuspid (left side)
- tricuspid (right side)
where are the semilunar valves found + what’s their function
- found between ventricles + arteries
- prevents backflow of blood from arteries into ventricles
name the 5 types of blood vessel
- arteries
- arterioles
- capillaries
- venules
- veins
describe the pathway of blood through the blood vessels
heart → arteries → arterioles → capillaries → venules → veins → heart
what’s the function of arteries
carries blood away from heart to tissues, under high pressure
relate the structure of arteries to their function
- thick muscular walls to handle high pressure w/out tearing
- elastic tissue allows recoil to prevent pressure surges
- narrow lumen to maintain pressre
what’s the function of veins
carry blood towards heart under low pressure
relate the structure of veins to their function
- thin walls due to lower pressure
- valves to ensure blood doesn’t flow backwards
- less muscular + elastic tissue as they dont have to control blood flow
what’s the function of capillaries
form large network through tissue of body + connect arterioles to venules
relate the structure of capillaries to their function
- walls only one cell thick, short diffusion pathway
- v narrow, can permeate tissues + red blood cells can lie flat against wall, reducing diffusion distance
- numerous + highly branched, providing large SA