Lecture 02: Introduction to blood vessels

Question 1

What is the innermost layer of the blood vessels?

-What are it’s 3 sub components, describe them.

Answer 1

Tunica Intima

1) Inner lining of simple squamous epithelial cells- attached to a basement membrane
2) Middle layer- of fine connective tissue made up of collogen
3) Internal elastic lamina- outer elastic layer

Question 2

What is the middle layer of the blood vessels?

-What is it made up of?

Answer 2

tunica media

- SMOOTH MUSCLE, elastic fibers, connective tissue components

Question 3

What is the outermost layer of the blood vessels?

-what is it made up of?

Answer 3

Tunica Externa
-mostly elastic and COLLAGENOUS fibers. (in large vessels this layer has dedicated nerves, tiny blood vessels and lymphatics)

Question 4

Why do arteries have a thicker wall?

-What component makes the arterial wall thicker?

Answer 4

because they are transporting blood to all parts of the body (unlike veins–> to the lungs)
- arteries have a thicker tunica media (smooth muscle)

Question 5

the _____ ______ is relatively much thinner in veins.

• Veins usually have little or no _____ _____, except in the largest of veins.
• Veins have periodic ______ to prevent backflow

Answer 5

the ___tunica__ ___media___ is relatively much thinner in veins.

• Veins usually have little or no __smooth___ __muscle___, except in the largest of veins.
• Veins have periodic ___valves___ to prevent backflow

Question 6

What are the smallest definable arteries?

Answer 6

arterioles

Question 7

What are the components of arterioles?

- thus, they are more easily regulated by what?

Answer 7

they have relatively more smooth muscular tissue and less elastic tissue
- the autonomic nervous system (smooth muscle–> involuntary)

Question 8

What are the smallest arterioles called?

• what do they lack as compared to regular arterioles?
• Their tunica media is densely supplied with what type of nervous tissue fibers?

Answer 8

They are called terminal arterioles

• they lack an internal elastic layer
• Tunica media densely supplied with sympathetic (fight of flight) nerve fibers

Question 9

What are the smallest definable veins?

Answer 9

venules

Question 10

which veins have smooth muscle in them?

Answer 10

the very largest veins (Ex. superior and inferior vena cava)

Question 11

veins and venules operate at ___ pressure

Answer 11

low

Question 12

what structure in the veins prevent back flow of blood?

Answer 12

veins have bicuspid valves to prevent back flow

Question 13

venules receive what type of blood?

Answer 13

capillary blood

Question 14

what do venules lack?

Answer 14

they have no tunica media

Question 15

what do venules lack?

Answer 15

they have no tunica media (smooth muscle)

Question 16

What are the smallest and thinnest of vessels?

- what are they made up of?

Answer 16

capillaries

-they are usually constructed of only a single layer of tunica intima (endothelium)

Question 17

What are the smallest and thinnest of vessels?

- what are they made up of?

Answer 17

capillaries

-they are usually constructed of only a single layer of tunica intima (endothelium)

Question 18

in which structure does the greatest loss of blood pressure take place?
-__ _____ and ___ ____also takes place across the wall

Answer 18

capillaries

-gas transfer and nutrient transfer