8/13/2019 General anatomy, End Arteries

1/28

General AnatomyDr. Gamal Taha, Lecturer of Anatomy

End

Arteries

8/13/2019 General anatomy, End Arteries

2/28

Circulatory System An efficient mode of transport for oxygen, nutrients,

and waste productsto and from body tissues.

Heartis the mechanical pump that propels the bloodthrough the vessels.

Heart and blood vessels form a closed-loop system.

Blood vessels can pulsateand change shapeinaccordance with the bodys needs.

8/13/2019 General anatomy, End Arteries

3/28

Blood Vessels

Systemic circulation

Consists of the blood vessels thatextend to and from the body tissues.

Pulmonary circulation Consists of the vessels that take the

blood to the lungs for gas exchange.

8/13/2019 General anatomy, End Arteries

4/28

Three Main Classes of Blood

Vessels Arteriesconvey blood awayfrom the

heart to the body tissues, get smaller as

they go away from the heart.

Veinscarries blood to the heart andbecome progressivelylargeras they

merge and get closer it.

And, Capillaries, that are connecting both

of them.

8/13/2019 General anatomy, End Arteries

5/28

8/13/2019 General anatomy, End Arteries

6/28

8/13/2019 General anatomy, End Arteries

7/28

Three Main Classes of Blood

Vessels Anastomosis: Site where two or more

vessels merge to supply the same bodyregion.In other words, connectionbetween different arteries to maintain thearterial supply if the main artery isoccluded.

Arterial anastomoses: alternate route

Veins tend to form many more anastomosesthan do arteries.

8/13/2019 General anatomy, End Arteries

8/28

Three Main Classes of Blood

Vessels End Arteries

Arteries that do not form anastomoses

Only one route, if an end artery isoccluded the tissues supplied by it wouldsuffer infarction

E.g.: Renal artery, Splenic artery

8/13/2019 General anatomy, End Arteries

9/28

Types of End ArteriesAnatomical End Arteries

The arteries have no anastomosis at all

with neighboring arteries e.g. CentralRetinal Artery

Functional End Arteries

Have small anastomoses, but it is notsufficient to compensate for occlusionof the main artery

E.g.: Coronary Arteries

8/13/2019 General anatomy, End Arteries

10/28

8/13/2019 General anatomy, End Arteries

11/28

8/13/2019 General anatomy, End Arteries

12/28

8/13/2019 General anatomy, End Arteries

13/28

Arteries

In the systemic circulation,carry oxygenated

blood to the body tissues.

Pulmonary arteries carry deoxygenatedbloodto the lungs.

8/13/2019 General anatomy, End Arteries

14/28

8/13/2019 General anatomy, End Arteries

15/28

8/13/2019 General anatomy, End Arteries

16/28

Capillaries

Allow gas and nutrient exchangebetween

the blood and the body tissues to occurrapidly.

Smallestblood vessels, connect arteriolesto venules.

8/13/2019 General anatomy, End Arteries

17/28

Capillaries

An adult human has been estimated to

have some60,000 miles (96,560 km) ofcapillaries with a total surface area of

some 800-1000 square meters, an area

greater than three tennis courts.

8/13/2019 General anatomy, End Arteries

18/28

8/13/2019 General anatomy, End Arteries

19/28

The Three Basic Kinds of

Capillaries Continuous

capillaries

They are continuousin the sense that

the endothelial cells

provide anuninterrupted lining

8/13/2019 General anatomy, End Arteries

20/28

The Three Basic Kinds of

Capillaries Fenestrated

capillaries

Have pores in theendothelial cellsand allow small

molecules andlimited amounts ofprotein to diffuse

8/13/2019 General anatomy, End Arteries

21/28

The Three Basic Kinds of

Capillaries Sinusoids, or

discontinuous

capillariesspecial type of

fenestrated capillariesthat have larger

openings allow red andwhite blood cells

various serumproteinsto pass

http://en.wikipedia.org/wiki/Blood_plasmahttp://en.wikipedia.org/wiki/Blood_plasma

8/13/2019 General anatomy, End Arteries

22/28

8/13/2019 General anatomy, End Arteries

23/28

Veins Drain capillariesand return the blood to the heart.

Walls are relatively thinand the vein lumen is larger.

Systemic veinscarry deoxygenated bloodto the rightatrium of the heart, while pulmonary veinscarry

oxygenated bloodto the left atrium of the heart.

Hold about 60% of the bodys blood at rest.

Veins function as blood reservoirs.

8/13/2019 General anatomy, End Arteries

24/28

8/13/2019 General anatomy, End Arteries

25/28

Portal circulation

Portal venous systemoccurs when

a Capillary Bed pools into another capillarybed through veins,without first going

through the heart.

8/13/2019 General anatomy, End Arteries

26/28

Hepatic Portal System A venous network that drains the GI tract and

shunts the blood to the liverfor processing andabsorption of transported materials.

Blood exits the liver through hepatic veinsthatmerge with the inferior vena cava.

Is needed because the GI tract absorbs digestednutrients, and these nutrients must be processedand/or stored in the liver.

8/13/2019 General anatomy, End Arteries

27/28

8/13/2019 General anatomy, End Arteries

28/28