Module 5

• Blood - Fluid that transports oxygen and nutrients to the cells and carries away carbon dioxide and other waste products.
• Open Circulatory System – Process involving the pumping of blood into a hemocoel with the blood diffusing back to the circulatory system between cells.
• Closed Circulatory System - In this type of system, blood is pumped by a heart through vessels, and does not normally fill body cavities.
• Arteries - Carry oxygenated blood and nourishment from the heart to the tissues of the body.
• Veins - Carry oxygen-depleted blood to the right upper chamber atrium) of the heart.
• Capillaries - Any of the minute blood vessels that form networks throughout the bodily tissues; it is through the capillaries that oxygen, nutrients, and wastes are exchanged between the blood and the tissues.
• Rhesus Factor (Rh) - An antigen occurring on the red blood cells of many humans (around 85 percent) and some other primates.
• Cardiac Cycle - One complete sequence of pumping and filling with blood.
• Bronchiole - The site where oxygen is exchanged for carbon dioxide

  during the process of respiration.
• Alveoli - Any of the small air spaces in the lungs where carbon dioxide leaves the blood and oxygen enters it.
• Basic Components of Circulatory System:

  • Heart (muscular pump)
  • Blood (circulatory fluid)
  • Blood Vessels known as

  1. Arteries
  2. Veins
  3. Capillaries
• Functions of the Circulatory System

  • connects the aqueous environment of the body cells to the organs that exchange gases
  • absorb nutrients
  • dispose of wastes
  • CO2 from respiration (breathing)
  • Chemical byproducts from other organs
  • Waste from things you eat and

  drink
• OPEN CIRCULATORY SYSTEM - Circulatory fluid (hemolymph) bathes organs DIRECTLY.
• Hemolymph is also the interstitial fluid that bathes body cells in Open Circulatory System.
• Open circulatory system is common in invertebrates. (ARTHROPODS, MOLLUSCS, LOBSTERS, CRABS)
• CONTRACTION - pumps the hemolymph through the circulatory

  vessels into interconnected sinuses, spaces

  surrounding the organs.
• RELAXATION - draws hemolymph back in through pores, which are

  equipped with valves that close when the heart

  contracts
• CLOSED CIRCULATORY SYSTEM

  • Circulatory fluid (blood) is contained in blood vessels
  • Distinct from the interstitial fluid
  • Common in vertebrates: ANNELIDS (including earthworms), CEPHALOPODS (including squids and octopuses)
  • More effective at transporting fluid.
  • Meet high metabolic demands.
• The closed circulatory system pump blood into large vessels that branch into smaller ones that infiltrate the organs.
• Closed circulatory system - Chemical exchange:

  blood and the interstitial fluid

  the interstitial fluid and body cells
• Plasma - The liquid component of the blood in which the following blood cells are suspended:
• Red blood cells (erythrocytes) - Carry oxygen from the lungs to the rest of the body
• White blood cells (leukocytes) - Help fight infections and aid in the immune process.
• Platelets (thrombocytes). These help in blood clotting.
• Rhesus / Rh factor – Protein found on the surface of the red blood cells.
• ARTERIES - transports blood away from the heart, muscular
• CAPILLARIES - exchange of substances, has very thin walls
• VEINS - transports blood back to the heart, has valves and thinner in structure
• The aorta is the bodyʼs largest artery. It starts at the heart and

  travels up the chest (ascending aorta) and then down into the stomach (descending aorta).
• The coronary arteries branch off the aorta, which then branch into

  smaller arteries (arterioles) as they get farther from your heart.
• Capillaries - These blood vessels connect very small arteries (arterioles) and veins (venules).
• Capillaries - Have thin walls that allow oxygen, carbon dioxide, nutrients and waste products to pass into and out of cells.
• Veins - These blood vessels return oxygen-depleted blood to the heart.

  Veins start small (venules) and get larger as they approach your heart.
• SUPERIOR VENA CAVA carries blood from the upper body (head and

  arms) to the heart.
• INFERIOR VENA CAVA brings blood up from the lower body (stomach,

  pelvis and legs) to the heart. Veins in the legs have valves to keep blood from flowing backward.
• Atrium - receives blood
• Ventricle - pumps blood
• Artery - transports blood away from the heart, muscular
• Vein - transports blood back to the heart, has valves and thinner in structure
• Capillary - exchange of substances, has very thin walls