C-2

Question 1

What are the blood vessels in the vascular system? and what order do the go in?

Answer 1

• Arteries
• Arterioles
• Capillaries
• Venules
• Veins

Question 2

Arteries:
What are they made of?
What is there purpose?
Subdivision of arteries-

Answer 2

• Strong elastic vessels
• Adapted to: carry blood away from the heart under HIGH PRESSURE- which is created by the VENTRICLES
• subdivided into smaller, thinner arteries
• keep dividing util diameter of artery reaches a certain size-> smallest arteries subdivided into ARTERIOLES

Question 3

The wall structure of ALL Arteries and the LARGEST Arterioles are composed of:

A layer in the artery is referred to as a:

Answer 3

1. Tunica Interna
2. Tunica Media
3. Tunica Externa

Layer= Tunica

Question 4

Tunica Interna

Composed of:

Answer 4

• Single Layer of simple squamous
• Creates a smooth surface for streamline blood flow.
  - termed Laminar Flow
• Easily damaged

Question 5

Tunica Media

Composed of:

Answer 5

-Majority of walls structure contains
A. Smooth muscle fibers that can narrow the diameter - termed vasoconstriction
- (turn down signal-vasodilation)
-(turn up signal- vasoconstriction)
B. Elastic CT stretches for increases in blood volume- withstands BLOOD PRESSURE

Question 6

Tunica Externa

Composed of:

Answer 6

• Thin CONNECTIVE TISSUE and/or LOOSE CT (areolar or reticular)
• attaches vessels to surrounding tissues

Question 7

Arteries & Large Arterioles
Innervated by:
Connected to:
When stimulated:
When inhibited:

Answer 7

• innervated by the AUTONOMIC NERVOUS SYSTEM- mainly SYMPATHETIC division
• connected to the SMOOTH MUSCLE CELLS of the TUNICA MEDIA
• When STIMULATED- contraction causes decreases in the vessels diameter (vasoconstriction)
• when INHIBITED- vessels diameter increases termed (vasodilation).

There is always some autonomic activity going on all the time- the amount determines a vessels diameter

Question 8

Number of arteries vs. large arterioles

Answer 8

• The number of Arterioles is far greater then the number of Arteries
• Because of this-the AUTONOMIC NERVOUS SYSTEM controls BLOOD PRESSURE and BLOOD FLOW mainly at the level of the ARTERIOLES i.e. amount of vasoconstriction or vasodilation

Question 9

The pressure of blood flow through the vessels:

Why Blood flow is controlled at a certain point:

Answer 9

ANS controls BLOOD PRESSURE and BLOOD FLOW mainly at the level of the ARTERIOLES.
-as arteries divide, blood volume and pressure it creates is divided.
RESULT: volume & BP decrease with each division.
@ capillaries BP has decreased
@ start of VENOUS SYSTEM very little blood pressure

Control must occur at ARTERIOLES before the decreases in volume & BP of the venous system

Question 10

Role of other blood vessels vs. capillaries

Answer 10

all other blood vessels strictly for transport. At the capillaries is where the DIFFUSION occurs

Question 11

Capillaries
Composed of:
Purpose of:

Answer 11

-smallest diameter vessels
-connect small ARTERIOLES to the VENOUS system.
composed of: SINGLE LAYER of SIMPLE SQUAMOUS
- allows diffusion from: from the blood to the tissues
- from the tissues into the blood

“BUSINESS END OF the CV system.”