circulation 8

Question 1

closed circulatory system

Answer 1

capillary connections, blood does not directly connect cells, higher bp=strong heart and higher cost
-small diameter caps create vascular resistance

Question 2

open circulatory

Answer 2

sinuses between cells, no endothelial lining

• hemolymph directly contacts cells
• low resistance to flow in large dinuses, so lower opreating cost, but also slower circulation time due to less local control of flow

Question 3

red pink and blue resp pigments that bind O2 in invertebrates

Answer 3

red: rbc hemoglobins in mollucs and annelids, or extra cell hemoglobins and chlorocruorin in bivalve molluscs and arthropods
pink blood cell hemerythrins (amino acids) seen in marine worms
blue hemocyanin, extracellular in arthropods and molluscs

Question 4

ostial hearts in invertebrates

Answer 4

-single cardiac chamber
-pericardial sinus surrounding outisde heart is filled with hemolymph
-CNS stimulates heartbeat, therefore its neurogenic
-

Question 5

ostial heart cycle

Answer 5

systole: cardiac muscle contract in unison, jejecting hemolymph into arteries and stretching suspensory ligaments
diastole: cardiac muscles relax, recoil of suspensory ligaments expands the heart chamber, drawing hemolymph from sinus via ostia into the heart
NOTE: some energy of contaction is stored in elactic suspensory ligaments to enable blood to be sucked into heart during relaxing

Question 6

segmental arrangement

Answer 6

common for open circulatory systems, have multiple neurogenic hearts in large dorsal distribution vessels

Question 7

insects

Answer 7

terrestrial insects have very high metabolic rate

• tracheal resp system moves O2 directly to tissues, while open circ moves nutrients, wastes, white cells and hormones
• multiple segmented hearts, NO RESP pigments
• sluggish flow rates and hydraulic function
• accessory pumps can pressurize wing and limb vessels; so body movements assist hemolymph flow

Question 8

crustaceans

Answer 8

• aquatic+terrestrial, some capable of high metabolic rates
• open circ moves GASES (insects dont), nutrients, wastes, wbc, hormones
• most crustaceans are small, hav segmental ostial hearts, large sinus volumes, and resp pigments
• DECAPODS are larger, active, and have GILLS
• SINGLE ostial heart, arterial outflow sphincters for regional control
• hemocyanin, and smaller tissue sinuses

Question 9

bivalve molluscs

Answer 9

sedentary filter feeders, low metabolic rates, some even live in hypoxic environ
-open cic, single ostial heart, some vessels

Question 10

cephalopod molluscs

Answer 10

• have TRUE CAPILLARIES AND CLOSED CIRC
• CHAMBERED, MYOGENIC HEARTS
• paired branchial heart pumps deoxy blood to gills, systemic herat pumps oxygenated blood
• hemocyanin(blue) dissolved in blood

Question 11

annelids

Answer 11

tubeworms, earthworms, and leeches have low metablolic rates, but can live in hypoxic environ
-tubeworms have open circ, chambered heart, vessels, hemolymph flow in sinuses, body wall movements via cilia
but earthworms have closed circ, five segmental contractile tubes, vessels, and connecting vessels

Question 12

what animals have no circulatory system

Answer 12

sponges: due to using convection for digestion powerered by flagella, cell contractions, or cilia