Unit 9 Flashcards
Saclike body found in…
Jellyfish and flatworms
No circulatory system
Saclike body in which cells exchange materials
Fluid in coelom transports material
Fluid in coelom
Round worms and starfish
Open circulatory system
Heart pumps hemolymph via vessels into tissue spaces
Open circulatory system found in…
Molluses and Arthropods
Closed Circulatory system
Blood pumped by the heart into a system of blood vessels
Closed circulatory system found in…
Segmented worms, some molluses, chordates, and all vertebrates
Closed circulatory system aka
Cardiovascular system
Parts of the heart
Atria and ventricles
Atria
Receives blood
Ventricles
Pumps blood from heart to vessels
Vessels
Arteries
Capillaries
Veins
Arteries
Carry blood away from heart and muscles
Arterioles
Smaller artery that can constrict or dilate to regulate temperature
Capillaries
Very thin to allow for exchange of materials with tissues
Venules
Small capillaries that can constrict or dilate to regulate temperature
Veins
Carry blood to the heart, less muscle so when empty will collapse
What is larger to minimize resistance veins or arteries?
Veins
Why do veins have one way valves?
To prevent back flow
Capillary exchange
Oxygen and nutrients exit a capillary near the arterial end and carbon dioxide and waste molecules enter a capillary near the venous end
Fish circulatory pathways
Single loop circulations from heart to gills to the body with a single atrium and single ventricle
Systemic circuit
Heart to body and then back to the heart
Pulmonary circuit
Heart to lungs and back to the heart forever
Amphibians circulatory pathways
Two atria with a single ventricle and mixing of oxygenated and deoxygenated blood results
Reptiles, mammals, birds circulatory pathways
Heart divided by septum into separate sides for more efficiency
Blood composition
Plasma
Red blood cells
White blood cells
Platelets
Plasma
Liquid portion of the blood, water with dissolved molecules, such as nutrients, wastes, salts, and proteins
Red blood cells
Predominant cell type in the blood, has hemoglobin to carry oxygen, manufactured in bone marrow (erythrocytes)
White blood cells
(Leukocytes) larger and less numerous than red blood cells (1:1000 ratio) used immensely
Platelets
(Thrombocytes) cell fragments that help form blood clots