Transport systems in animals

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Transport systems in animals
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Well be discussing

• Functions of a transport/circulatory system
• Invertebrate circulation
• Diffusion
• Aided by gastrovascular cavity
• Water vascular system
• Open circulatory system
• Closed circulatory system
• Vertebrate circulation
• Fishes
• Amphibians

• Reptiles
• Birds
• Mammals
• Pathway of blood
• Cardiac cycle
• Maintenance of heartbeat
• Principles governing blood circulation
• Lymphatic system
• Blood composition and function
• Cardiovascular disease

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Functions of the circulatory system

• Transports materials
• Nutrients from digested food
• Respiratory gases CO2 and O2
• Waste materials toxins and nitrogenous wastes
• Antibodies
• Hormones
• Enzymes
• Immune functions
• Maintains homeostasis
• Blood pH
• Heat transport

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How are materials transported in multicellular
organisms?Phylum Porifera
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How are materials transported in multicellular
organisms?

• Gastrovascular cavity in simple invertebrates
• Cnidarians (e.g. Hydra) and flatworms (e.g.
  planarians)
• No system required
• Single opening exchange of materials with the
  environment
• Central cavity for digestion and distribution of
  substances throughout the body
• Body walls two cell layers thick ? materials
  undergo diffusion

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How are materials transported in multicellular
organisms?

• Water vascular system in echinoderms
• multi-purpose locomotion, food and waste
  transport, respiration
• movement of muscles pump water into canals
• closed system of canals connecting tube feet
• madreporite ? ring canal ? radial and lateral
  canal ? tube feet ? ampullae

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How are materials transported in multicellular
organisms?

• Open circulatory system
• Phylum Arthropoda, Phylum Mollusca (with one
  exception)
• hemolymph
• heart(s) ? sinuses ? ostia ? heart(s)
• diffusion from sinuses to organs
• often serve a support purpose
• disadvantage loss of pressure in sinuses
• insects well-developed respiratory systems, O2
  not transported through the blood

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How are materials transported in multicellular
organisms?

• Closed circulatory system or cardiovascular
  system
• cephalopods, annelids, vertebrates
• presence of blood vessels
• advantages
• rapid flow
• may direct blood to specific tissues
• blood cells and large molecules remain within
  vessels
• can support higher levels of metabolic activity

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General plan of the cardiovascular system

• Heart
• Atrium
• Ventricle
• Blood vessels
• Arteries
• Arterioles
• Capillaries and capillary beds
• Venules
• Veins
• Blood

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Vertebrate adaptations of the cardiovascular
system

• FISHES
• Single-circulation
• Fish heart
• 2-chambered
• atrium and ventricle
• African lungfish heart
• 3-chambered
• 2 atria
• LA O2-rich blood
• RA O2-poor blood
• spiral fold
• partially divided ventricle

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Vertebrate adaptations of the cardiovascular
system

• Amphibians
• Pulmocutaneous and systemic circulation are
  partly separated
• Amphibian heart
• 1 ventricle
• 2 atria
• LA O2-rich blood
• RA O2-poor blood
• advantage oxygen-rich blood reaches the bodys
  organs faster
• disadvantage some mixing of O2-rich and poor
  blood occurs

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Vertebrate adaptations of the cardiovascular
system

• Reptiles
• Reptilian heart
• 3-chambers (crocodilians have 4)
• 2 atria
• 1 ventricle (2 in crocodiles and alligators)
• partially divided, decreases mixing

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Vertebrate adaptations of the cardiovascular
system

• Birds and Mammals
• 4 chambered heart
• 2 atria
• 2 ventricles
• full separation of pulmonary and systemic
  circuits
• Advantages
• no mixing of oxygenated and deoxygenated blood
• gas exchange is maximized
• pulmonary and systemic circuits operate at
  different pressures
• Importance
• Endothermic ? high nutrient and O2 demands in
  tissues
• Numerous vessels ? great deal of resistance, so
  requires high pressure

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Blood flow in mammals

• R side of heart
• pulmonary circuit
• L side of heart
• systemic circuit
• one way valves
• atrioventricular valves
• semilunar valves

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Blood flow in mammals

1. right atrium receives O2-poor blood from superior
   and inferior venae cavae
2. from right atrium into the right ventricle
   through the tricuspid valve
3. pumped into the pulmonary artery through the
   pulmonary semilunar valve to lungs
4. O2-rich blood from lungs is returned to the left
   atrium via the pulmonary veins
5. enters the left ventricle via the mitral or
   bicuspid valve
6. exits the left ventricle into the aorta via the
   aortic semilunar valve
7. circulated to body tissues