Circulation and Blood Nelson p

Practice Sets  Importance of a Circulatory System Read p Read p Questions p243 #1-4 Questions p243 #1-4  Blood Vessels Read p Questions p.253 #1-4 Questions p.253 #1-4  Mammalian Heart Read p Questions 1-4 Questions 1-4

Differentiate between OPEN and CLOSED circulatory systems  Closed System – the blood is always contained in either the heart or blood vessels. It never leaves them. Example worms, humans, octopus  Open System – The blood is contained in a heart(s) and blood vessels but at some point is pumped into the body cavity and bathes the cells. This is when the oxygen/nutrients leave the blood and the wastes/carbon dioxide enter the blood.  Example: snails, lobsters, crabs

3. One advantage and one disadvantage of an open system  Advantage – does not require a lot of energy to build and repair blood vessels, create pressure  Disadvantage – blood cannot be directed to specific areas - Limits the size that the organism can grow to

4. similaritiesdifferences Sponge All require the delivery of nutrients and removal of waste All cells bathed with fluid from environment No heart Snail Open system Heart present Earthworm Closed system Heart present

5.  MCO’s need a circulatory system to ensure that nutrients are brought to and wastes are removed from every cell in the organism including the cells deep within the organisms body.

Blood Vessels How do arteries differ from veins? Arteries Arteries  Carry blood away from the heart  Thick walls made of muscle and connective tissue  Able to stretch Veins Veins  Carries blood towards heart  Walls made of smooth muscle  Blood pressure is very low(15-20mmHg)  Valves prevent blood from flowing backwards

 Veins (con’t)  Muscular contractions assist forward movement of blood  Reservoir for blood (50% of volume)

What causes a pulse?  A pulse occurs when the diameter of the artery changes as the heart contracts and relaxes

Define vasodilation and vasoconstriction.  Vasoconstriction occurs when a nerve impluse causes muscle in the arterioles to contract and this reduces the diameter of the blood vessel and decreases the flow of blood to tissues  (become pale)  Vasodilation occurs when the muscle in the arterioles relaxes and the diameter of the blood vessel increases and the flow of blood to the tissue increases  (blushes, release heat)

What are the functions of capillaries? The functions of the capillaries are The functions of the capillaries are  site of gas exchange between blood and cells

Practice Set (cont’d)  Mammalian Heart Read p Questions p.258 # 1-4 Questions p.258 # 1-4  Components of Blood Read p Practice p. 246 #1-8 Practice p. 246 #1-8

The Mammalian Heart What is the function of the AV valves and the semilunar valves?  Ensure the one-way flow of blood throughout the circulatory system

What is angina and what causes it?  Coronary circulation includes the blood vessels which supply the heart muscles with oxygen and nutrients.  Angina occurs when a coronary artery is blocked and not enough oxygen can get to the heart. It caused chest pains and may blocked and not enough oxygen can get to the heart. It caused chest pains and may lead to heart attack lead to heart attack

What are coronary bypass operations and why are they performed?  A coronary bypass operation involves replacing a coronary artery blocked by fat and plaque deposits with a vein removed from another part of the patient’s body

Differentiate between the systemic circulatory system and the pulmonary circulatory system.

Components of Blood Why is blood considered to be a tissue Blood is considered to be a tissue because it is made of several types of cells which work together for a common purpose

2.Name the two major components of blood. 1. plasma – 2. blood cells -

List three plasma proteins and indicate the function of each. Plasma Proteins 1. Albumins – maintain osmotic pressure (water balance) 2. globulins – help protect against invading microbes 3. fibrinogens – role in clotting of blood

4. What is haemoglobin? Haemoglobin is a molecule containing an iron pigment molecule in a protein molecule. It’s function is to increase the ability of blood to carry oxygen (X70)

What is anemia? Anemia is an illnes caused by a lack of red blood cells. It’s symptom is extreme fatigue (tiredness) and is sometimes caused by too little iron in the diet.

What causes the production of pus? Pus is produced from the fragments of used white blood cells

What is the role of platelets? The role of platelets is to initiate (start) the blood-clotting reponse to and injury.