General Circulatory System Structures

Question 1

What is blood used for

Answer 1

medium to transport substances between body tissues

Question 2

What percent of blood consist of cells and what percent consist of plasma

Answer 2

40% cells 60% plasma

Question 3

Define hematocrit

Answer 3

it is the fraction of blood volume occupied by cells

Question 4

What are the 3 types solid elements of blood

Answer 4

-RBC’s= most abundant -WBC’s -Platelets

Question 5

What are the components of plasma

Answer 5

-Electrolytes -Proteins -

Question 6

What are the most common electrolytes in plasma

Answer 6

Na, K, Cl, BiCarb

Question 7

What are the 3 classifications of proteins in plasma

Answer 7

Albumins, Globulins, Fibrinogens -these do NOT readily cross capillary

Question 8

What are the 3 layers of arteries and veins

Answer 8

-tunica externa (adventitia) -tunica media -tunica interna (intima) modifications of these account for the different types of vessels

Question 9

What are the characteristics of the tunica externa (adventitia)

Answer 9

-primarily composed of collagen, small amount of elastic -anchors vessels to surrounding tissue -contains nerves and vessels that supply the vessel walls

Question 10

Nervi vasorum

Answer 10

small nerves within the tunica externa (adventitia) that control contraction and dilation of smooth muscle

Question 11

Vasa vasorum

Answer 11

small vessels that transport O2 and nutrients to cells of blood vessel walls

Question 12

Compare and contrast tunica externa (adventitia) of the arteries and veins

Question 13

What are the characteristics of the tunica media

Answer 13

Consist of 2 layers external elastic lamina layer and smooth muscle layer

Question 14

What are the characteristics of the external elastic lamina layer of the tunica media

Answer 14

only found in arteries, has variable number of window like openings to facilate diffusion between layers of the vessel

Question 15

What are the characteristics of the smooth muscle layer of the tunica media

Answer 15

regulates the diameter of the vessel lumen

has some elastic fibers associated w/ it

Question 16

True or false vessels are only innervated by sympathetic nerve fibers only

Answer 16

True

Question 17

Compare and contrast tunica media of arteries and veins

Answer 17

Artries=Normally thickest layer, Smooth muscle cells and elastic fibers predominate, contains external elastic lamina (membrane)

Veins=Normally thinner than tunica externa, Smooth muscle cells and collagenous fibers predominate

Question 18

What are the characteristics of the tunica interna (intima)

Answer 18

It is in direct contact with blood and consist of 3 layers

• internal elastic lamina
• basement membrane
• endothelial layer

Question 19

What are the characteristics of the internal elastic lamina layer of the tunica interna (intima)

Answer 19

• Only in arteries
• has variable number of window like openings that facilitate diffusion across layers

Question 20

What are the characteristics of the basement membrane layer of the tunica interna (intima)

Answer 20

Consist of collagen fibers that provides support to the endothelial layer

-permeable

Question 21

What are the characteristics of the endothelial layer of the tunica interna (intima)

Answer 21

• Most internal layer of the vesel
• Produces a variety of products
• Angiogenesis= repair of blood vessels or production of new blood vessels
• Actively participates in inflammatory response

Question 22

What products does the endothelium of the blood vesel produce

Answer 22

1. Vasodilators
   
   • Nitric oxide
   • Prostacyclin (type of prostaglandin)
2. Vasoconstrictors
   
   • Endothelin
   • Thromboxane (type of prostaglandin)
3. Platelet factors
   
   • Van Willebrand factor (needed for platelett adhesion)
   • Tissue plasminogen (promotes fibrolysis)

Question 23

Compare and contrast tunica intima of arteries and veins