2. Circulation I Flashcards
(23 cards)
What is the primary function of circulation systems?
To carry O2 from the respiratory system to the body and CO2 to the respiratory system to be expelled.
What are the main components of circulation systems?
- Fluid: blood
- Pump: heart
- Conduits: arteries and veins
What type of circulation do mammals have?
Closed circulation
In many invertebrates, how is blood circulated?
Blood bathes tissues directly, open circulation.
What is blood?
A fluid that can absorb oxygen.
What is the role of oxygen-binding pigments in blood?
They can increase oxygen-carrying capacity.
What molecule gives red blood its color?
Haemoglobin
What molecule is associated with green blood?
Chlorocruorin
What molecule is associated with blue blood?
Hemocyanin
What molecule is associated with violet blood?
Hemerythrin
What are the characteristics of closed circulatory systems?
- High pressure
- High oxygen delivery
- Can regulate flow
- Metabolically expensive
- Creates vulnerabilities if an important artery is punctured
What are the characteristics of open circulatory systems?
- Low pressure
- Low oxygen delivery
- Cannot regulate flow
- Metabolically cheaper
- Less liability when injured
How does diffusion occur in insect circulation?
Diffusion happens in sinuses, not capillaries.
What type of heart do insects have?
Dorsal, tubular heart with multiple ostia.
What system do insects use to deliver O2 to tissues?
Tracheal system
What is the structure of arteries?
Three layers: * Connective tissue (elastic) * Smooth muscle fibers * Endothelium
What do veins do?
Carry blood from capillaries to the heart.
What prevents backflow in veins?
Valves
What are capillaries?
Thin walled blood vessels concentrated into capillary beds.
What occurs at capillaries?
Exchange of gas, nutrients, waste, and hormones across thin walls.
What is the heart?
Muscular structure that contracts in a rhythmic pattern.
What types of hearts exist in mollusks and vertebrates?
Chambered hearts
What is a peristaltic pump?
A rhythmic contraction of blood vessels pushing fluid along the system.
