Blood vessels

Lecture 16

What three layers compose blood vessels?

1. Tunica (“Coat”) Intima

2. Tunica Media

3. Tunica Adventitia (Tunica Externa)

What are the two layers of the TUNICA

INTIMA?

Endothelium

Subendothelium

Which layer of blood vessels contains

smooth muscle tissue?

TUNICA MEDIA

Which layer of blood vessels has elastic

fibers?

TUNICA MEDIA

What are the functions of smooth muscle

and elastic fibers?

SMOOTH MUSCLE Allows blood to be directed to

parts of body by vasoconstriction

ELASTIC FIBERS. Allows blood vessels to stretch

during systole and return to normal size.

What are the three functions of the

TUNICA ADVENTITIA (TUNICA

EXTERNA)

TUNICA ADVENTITIA (TUNICA EXTERNA):

a. Protects the blood vessel (strong)

b. Gives vessel strength for shape

c. Anchors vessel to surrounding

tissue; loosens with age.

What is a blood vessel that supplies a blood

vessel called?

VASO VASORUM

8. Which vessels carry blood away from the

heart, arteries or veins?

9.Which vessels have a smaller lumen, veins or

arteries?

10. Which have thicker walls?

11. Which have more elastin?

12. Which vessels are more round?

13. Which have valves?

 Arteries

 Arteries

 Arteries

 Arteries

 Arteries are more round, veins are more oval

 Veins have valves, arteries do not. Lymph

vessels also have valves

Do arteries always contain oxygenated

blood?

No; the pulmonary and umbilical arteries have

deoxygenated (blue) blood.

What are the 2 large TYPES OF

ARTERIES?

16. What is the largest type of blood vessel?

17. What do they contain a lot of?

18. What type of artery is distal to elastic

arteries, and consists of most of the

19. named arteries?

20. What layer in these arteries is thick?

ELASTIC ARTERIES

 There of lots of elastic fibers in the tunica media

 Muscular Arteries

 Tunica media is thick

21. What type of blood vessel can close the

lumen completely when it contracts?

What is a sac-like outpouching of an artery

called?

Aneurysm

What are three causes of an aneurysm?

– Defect in part of the artery wall

– High blood pressure

– Congenital (present at birth)

How to Recognize a Stroke (“STROKE”)

S * Ask the individual to SMILE.

T * Ask the person to TALK and SPEAK A

SIMPLE SENTENCE (Coherently; i.e. It is

sunny out today)

R * Ask him or her to RAISE BOTH ARMS.

O * Open the mouth and stick out the tongue

K * Keep them comfortable and still

E * Get EMERGENCY help (911)

If one side of the body responds differently

than the other side, or if they have trouble

with the task, call 911.

Which artery in the thigh is a good place to

take a pulse?

Femoral artery: good place to take a pulse since it is

superficial, but that also makes it susceptible to injury.

The circle of Willis forms a loop around which

structures?

Circle of Willis forms a loop around the pituitary gland

and the optic chiasma

27. Which are the smallest blood vessels, and are

found everywhere?

28. Which layer do they have?

CAPILLARIES

They only have an endothelium

Where is the only site of nutrient, gas exchange, and waste exchange in the cardiovascular system?

capillaries

The diameter of a typical capillary is similar to

that of what?

Capillary diameter is similar to an erythrocyte

31. What are the three types of capillaries?

32. Which are the most common?

33. Which have pores?

34. Which have very large gaps?

Continuous – most common

Fenestrated (“window”) – have pores

Discontinuous (Sinusoids) – have very large gaps

Which capillaries are found where lots of

fluids need to be moved back and forth, such

as in the small intestine?

What type of capillaries are found in the red

marrow because their gaps are so large, a

RBC can fit through?

What type of capillaries are found in the red

marrow because their gaps are so large, a

RBC can fit through?

37. What is found at the start of each capillary?

38. What is the function of this structure?

PRE-CAPILLARY SPHINCTER controls the flow of

blood to individual capillaries. It directs the blood flow

to specific cells.

If one cell is starving, the capillary next to it will open.

The sphincter opens and closes depending on the needs

of individual cells.

Blood always flows to those cells and tissues that

need it. There is not enough blood to go around.

Name the 2 varieties of VEINS

VENULE: This is the smallest. It takes blood from the capillary to the vein.

VEIN: takes blood towards the heart.

How is blood able to get uphill and return to

the heart without backing up?

Skeletal muscle pushes on the vein to move the blood uphill, and the valves keep it from falling backwards and backing up.

What are the only BLOOD vessels that have

valves

Veins are the only BLOOD vessels that have valves (although LYMPH vessels also have valves).

Name 3 BLOOD PUMPS

1. the heart

2. elastic arteries

3. muscles constricting the veins

What vessel is often used to bypass a

damaged coronary artery in coronary bypass

surgery, and is the most likely vein to

become varicose?

Greater Saphenous vein

What vessel drains from the danger triangle

into the dural sinuses of the brain?

facial vein

What vessel is oxygen poor, but contains the lowest concentration of nitrogen waste?

renal vein

Name 3 Veins that are rich in oxygen and

nutrients:

1. umbilical vein

2. hepatic portal vein

3. pulmonary vein

47. What is the term for a vein that has

incompetent valves?

48. What is the name of the condition when a

person has inflamed veins?

49. What are three treatments for this

condition?

VARICOSE VEINS

PHLEBITIS

LASER, SCLEROSING, SURGERY

What is edema?

the accumulation of excess tissue fluid in loose

connective tissue

51. What are the two types of EDEMA?

52. Which is more severe?

1. pitting: worse in the evening

2. non-pitting: This is more severe because it does not go away easily. Just as swollen in the morning as in the evening.

53. What causes VENOUS STASIS ULCERS?

54. Who gets them most often?

55. What are three issues that must be treated

when one gets a venous stasis ulcer?

 Varicose veins with excess acid products from

the blood plasma (sugar, carbon dioxide, etc),

which eventually erode all the way to the skin.

 Common in diabetics.

 Treatment must address sugar levels, vein

problem, and the open wound.

Why is PHLEBITIS dangerous?

Phlebitis can be associated with the

formation of blood clots (thrombosis),

usually in the deep veins of the legs, the

condition is called Deep Vein

Thrombophlebitis (DVT).

What are the signs and Symptoms of DVT?

• Redness (erythema) and warmth with a

temperature elevation of a degree or more above

the baseline

• Pain or burning along the length of the vein

• Swelling (edema)

• Vein being hard, and cordlike

• Need to go to the emergency room if all

symptoms are present

58. What are SPIDER VEINS?

59. Are they dangerous?

60. What are two treatments?

61. What vessel in the fetus connects the

pulmonary trunk to the aortic arch so that

most of the blood bypasses the immature

lungs?

Small superficial veins become varicose and do

not function properly.

Unsightly appearance but are not dangerous.

Injections of alcohol or saline into the vein will

sclerose them (scar them shut), or laser

Ductus arteriorsis

What structure in the fetus connects the

right atrium to the left atrium?

Foramen ovale

what does the foramen ovale become shortly after birth?

Fossa Ovalis