circulatory system

Circulatory System (text page 478)

 

  1. What are the functions of a circulatory system?

 Transports gases, nutrients and waste; regulates temperature and transports chemicals; protects against blood loss and disease-causing microbes.

 

  1. What are the components of the human circulatory system?  Heart, blood vessels, blood


  1. Fill in the table to compare arteries and veins.

 

Arteries

Veins

Name of smaller version

arterioles

venules

Elasticity

yes

no

What moves blood

Forced from heart

Contraction of surrounding muscles

Thickness of walls

thicker

thinner

Inner diameter size

Smaller 

larger 

Direction of blood

Away from heart

Towards heart 

Valves?

no

yes 

Type of blood it carries

Usually oxygenated

Usually deoxygenated

 

  1. What are the smallest blood vessels called?  Describe their structure.

 Capillaries are spread out in a fine network.  The walls of the capillaries are only 1 cell thick for gas exchange.  The inner diameter is just large enough for blood cells to pass through.

 

 

 

  1. On the diagram below fill in the following structures:  large arteries, small arteries, arterioles, capillaries, large veins, small veins and venules.




 

 

  1. Show on the diagram below,

a. where the arterioles, venules and capillaries are located.

b. the pulmonary circuit and the systemic circuit.


























 

  1. What are the components of blood?

Plasma, white blood cells and platelets and red blood cells

 

  1. How do erythrocytes carry oxygen?

 RBCs contain hemoglobin.  Hemoglobin contains iron.  Hemoglobin binds oxygen to carry it around the body.

 

 

  1. What is the function of white blood cells?

 They are a part of the body’s immune system.

 

  1. What is the function of platelets?

 Platelets play a key role in blood clotting when blood vessels are broken.

 

  

  1. How do your blood vessels help to warm you up?

 Vasoconstriction constricts the blood vessels near the surface of the skin to keep the blood warmer throughout the body’s core. 

 

 

  1. How do your blood vessels help to cool you down?

 Vasodilation dilates the blood vessels near the surface of the skin to allow blood to cool and then the cooled blood returns to the core of the body to cool it down.