1. Biology 212 Anatomy & Physiology I
Blood Vessels

3. Pulmonary Circuit

4. Systemic Circuit

5. Arteries:
Always carry blood from heart toward capillaries
Have higher blood pressure within them
Have thicker walls relative to size of lumen
Never have valves
Veins:
Always carry blood from capillaries toward heart
Have lower blood pressure within them
Have thinner walls relative to size of lumen
May have valves

6. Elastic (Large) Arteries: Aorta, pulmonary trunk, & their close branches
Large Veins:
Return blood to heart
Muscular (Medium) Arteries: Distribute blood to head, limbs, & organs
Medium Veins:
Gather blood from head, limbs, & organs
Distributing (Small) Arteries: Distribute blood within organs and tissues
Small Veins:
Gather blood from tissues
Arterioles:
Distribute blood within organs & tissues
Venules:
Gather blood from capillaries. Also some exchange of same materials as capillaries
Capillaries:
Primary site for exchange of gases, nurients, ions, wastes, hormones, cells, etc.

7. Pathway Variations:

9. Entire circulatory system (heart, all vessels) lined by simple squamous epithelium called endothelium
Capillaries consist only of epithelium and very thin layer of areolar connective tissue.
Larger vessels, either veinous or arterial, also have layers of connective tissue and/or smooth muscle surrounding this endothelium.

11. Contraction of right ventricle provides force to drive blood through pulmonary circuit & contraction of left ventricle provides force to drive blood though systemic circuit,
But: not entire story:
During systole, large mass of blood pushed out of ventricle under pressure, into elastic artery. Elastic walls of artery expand to absorb this pressure & volume.
During diastole (aortic and pulmonary valves closed), stretched walls of these arteries squeeze back against blood, forcing it to flow into more distal arteries.
Arterioles restrict blood flow, so blood in arteries remains under pressure. This pressure = major force pushing blood through arterioles into capillaries.

20. Deep Veins

21. Superficial Veins

24. Deep Veins

25. Superficial Veins

26. You should be able to identify the following arteries, know from where each artery receives blood, and know to where each artery delivers blood.
Aorta Pulmonary trunk
Brachiocephalic artery Pulmonary arteries
Subclavian arteries Common carotid arteries
Axillary arteries Internal carotid arteries
Brachial arteries External carotid arteries
Radial arteries Vertebral arteries
Ulnar arteries Basilar artery
Common iliac arteries Renal arteries
Internal iliac arteries Celiac trunk
External iliac arteries Hepatic artery
Femoral arteries Splenic artery
Popliteal arteries Left gastric artery
Anterior tibial arteries Superior mesenteric arteries
Posterior tibial arteries Inferior mesenteric arteries
Gonadal arteries Coronary arteries
Example: Each external iliac artery receives blood from the common iliac artery on that side and delivers blood to the femoral artery on that side

27. You should be able to identify the following veins, know from where each vein receives blood, and know to where each vein delivers blood.
Superior vena cava Hepatic portal vein
Inferior vena cava Splenic vein
Brachiocephalic veins Inferior mesenteric vein
Subclavian veins Superior mesenteric vein
Axillary veins Common iliac veins
Brachial veins Internal iliac veins
Radial veins External iliac veins
Ulnar veins Femoral veins
Cephalic veins Popliteal veins
Basilic veins Anterior tibial veins
Median cubital veins Posterior tibial veins
Vertebral veins Greater saphenous veins
Internal jugular veins Lesser saphenous veins
External jugular veins Gonadal veins
Example: Each external iliac vein receives blood from the femoral vein on that side and delivers blood to the common vein on that side