Blood Vessel

Question 0

Functions of Tunica Intima

Answer 0

• provide smooth surface for blood to pass

* in capillaries(smallest of BV) would function in diffusion/transport

Question 1

Tunica intima

Answer 1

• most internal layer
  1) simple squamous w/basement membrane=endothelium

*Also layer of areolar CT that binds endothelium to the next layer—tunica media

Question 2

Tunica Media

Answer 2

• middle layer/muscle layer

* main tissue—>smooth muscle

Question 3

Function of Tunica Media

Answer 3

• smooth muscle helps w/ vasoconstriction/dilation, helps control BP, temperature regulation, perfusion
• also has areolar Ct

Question 4

Perfusion

Answer 4

How much blood gets to certain area of body

Question 5

Tunica Externa

Answer 5

• external layer
• sometimes there but not always
• made of areolar CT; important in connecting BV to other structures

Question 6

Functions of Tunica Externa

Answer 6

*place for BV to perfuse tunica media (middle layer)

Question 7

Arteries

Answer 7

Carry blood away from the heart

Question 8

Elastic Arteries

Answer 8

• largest
• lots of elastic fibers in 3 layers; to allow stretching of BV to accommodate large bursts of blood coming out of ventriclesEx) 2.5 cm (inch in diameter) to 1 cm = elastic

Question 9

Muscular Arteries

Answer 9

• 2nd largest
• 1 cm to 3 mm in diameter
• have very thick tunica media; important in controlling perfusion

Question 10

Arterioles

Answer 10

• last artery (small)
• 3 mm-10 mm in diameter
• May not have tunica Externa
• extremely important in regulating BP

*BP ⬆️ (relax tunica media)
BP ⬇️ (arteries contract, raising BP)

Question 11

Capillaries function:

Answer 11

Transport of nutrients/waste into/out of he blood stream

Question 12

Anatomy of capillaries:

Answer 12

• only have tunica intima

* endothelium & basement membrane

Question 13

Normal capillaries (continuous)

Answer 13

• most in body
• have complete layer of endothelium joined by tight junctions & complete layer of basement membrane
• have intracellular clefts:tiny holes between endothelial cells
• travel must occur thru endothelial cells or clefts (in/out of bloodstream)

  - two things travel
      1) leukocytes travel b/w cleft
      2) plasma (not plasma proteins)

Question 14

1st specialized capillary–>Fenestrated capillaries:

Answer 14

• extremely thin layer
• more numerous intracellular cleft
• complete basement membrane

Question 15

Function of Fenestrated capillaries:

Answer 15

*allow movement of large volume if water/fluid

     Ex) small intestine, choroid plexus, some             
           endocrine glands, kidneys

Question 16

Last—>sinusoid capillaries:

Answer 16

*very incomplete endothelium, basement membrane

Question 17

Sinusoid capillaries function:

Answer 17

*allow movement of formed elements rapidly

   Ex) bone marrow, spleen, liver

Question 18

At origin of every capillary is:

Answer 18

*a sphincter;smooth muscle

Question 19

When arterioles contract:

Answer 19

Prevents blood from going in capillaries

Question 20

When arterioles relaxed:

Answer 20

They open, allowing blood to come in

Question 21

Arterial anastomoses

Answer 21

*many arteries leading to 1 capillary bed

Question 22

Venous anastomoses

Answer 22

Many veins receive blood from bed

Question 23

Arteriovenous anastomoses

Answer 23

A shunt to bypass capillary bed all together

Question 24

Portal system

Answer 24

Blood flows thru 2 capillary beds, with 2 capillary beds separated by portal vein

Question 25

Simple pathway

Answer 25

1 artery, 1 capillary bed, 1 vein

Question 26

Venules

Answer 26

• very small in diameter (8-100 mm)

* merge to form larger & larger venules until merged to form vein

Question 27

Difference in veins/venules

Answer 27

Veins > 100 mm

Question 28

Veins

Answer 28

• very thin tunica media
• > 100 mm
• very low BP

Question 29

blood moves thru veins because of

Answer 29

skeletal muscle contractions

Ex) bedridden person

Question 30

Series of valves (vein)

Answer 30

*oppose gravity; prevent blood from falling to your toes

   (Skeletal muscle can bring blood back to 
      heart)

Question 31

Where’s my blood?

Answer 31

18% lungs

12% heart

70% systematic circulation (rest of body)

Question 32

Systematic circulation

Answer 32

70 %

• 15% in arteries, capillary beds
• 55% in veins

–body has strict control of the 15% to get oxygen in/out of blood

Question 33

Blood pressure

Answer 33

• force of moving blood(due to heart contraction) on the internal wall of BV
• strongest at heart; decreases farther away from it

Question 34

Blood pressure gradient

Answer 34

Difference in blood pressure 1 end of BV to the other

Question 35

Systolic BP

Answer 35

Top of BP during ventricular contraction

Normal = 120 mm Hg

Question 36

Diastolic BP

Answer 36

Bottom of BP during ventricular relaxation

Normal = 80 mm Hg

Question 37

Blood pressure cuff

Answer 37

Sphygmomanometer

• increase pressure of cuff until prevent blood flow thru brachial artery
• slowly reduce pressure =
  1) listen to 1st sounds (systolic) –strong enough to overcome pressure of cuff
  2) listen to last sound (diastolic) –pressure of cuff in longer prevents blood flow at all

Question 38

Pulse pressure

Answer 38

“Felt” when taking HR

*difference in blood pressure when heart is contracting vs. relaxing

Systolic-diastolic (120-80=40 mm Hg)

Question 39

Mean arterial pressure

Answer 39

Avg pressure in arteries

Pressure mostly at diastolic

Question 40

MAP

Answer 40

Diastolic pressure + 1/3 pulse pressure)

Normal = 80 + 1/3(40) is 93 mm Hg

Avg entire minute

Allows doctor for measurement of perfusion

Need at least 60 mm Hg if lower there is not enough blood getting to vital organs

Above 110 can be high due to athletics. If to high pressure can damage important organs such as kidneys and edema (swelling)