1. Cardiovascular System
Part II

2. Blood Vessels Vascular system:
A closed transport system where blood circulates through the blood vessels
Arteries:
Blood enters from the heart into the circulatory system from these and moves into the …
Arterioles:
Smaller branches off the arteries which feed into the..
Capillaries:
Contained within the tissues and branch out becoming smaller and smaller. The only connection between arteries and veins. Serves the needs of the body’s cells by exchanging blood between tissue cells and blood.
Venules:
Smaller branches off the veins. Drain from the capillaries and enter into the …
Veins:
Empty blood from the circulatory system back into the heart.

3. Blood Vessels Blood Vessel Walls:
Contain three layers/walls called “Tunics”
Tunica Intima:
Lines the interior of the vessels and is a thin layer of endothelial tissue on top of a thin layer of loose connective tissue. It has a slick surface to decrease friction as blood flows through it.
Tunica Media:
Bulky middle “coat” made of smooth muscle and elastic tissue. The smooth muscle is controlled by the Sympathetic NS and is active in changing the diameter of the vessels and in bringing BP up or down
Tunica Externa:
Outermost layer made up of fibrous connective tissue. It functions to support and protect the vessels.

4. Artery Walls and Functions
Much thicker than veins
Must be able to expand as the blood is forced into them and then recoil as the blood moves out.
Walls must be strong and stretchy in order to accomplish these goals

5. Vein Walls and Function
Thinner walls located further from the heart
Pressure in veins is continually low
They contain valves which prevent backflow
Veins are modified to make sure the blood returning to the heart is the same amount as blood being pumped out of the heart.

6. Skeletal Muscle Activity and Venous Return
The action of muscle movement enhances venous return by contracting and relaxing causing the blood in the veins to move towards the heart.

7. Respiratory Pump
When we inhale pressure in the thorax decreases causing the veins near the heart to expand and fill with blood.

8. Major Arteries and Systemic Circulation
Aorta:
Largest artery of the body.
Parts of the aorta are named for their location and/or shape
Ascending Aorta: curves upward from the left ventricle and when it arches to the left it becomes the aortic arch.
Right and Left Coronary Arteries:
Only branches of the ascending aorta and serve the heart.

9. Major Arteries and Systemic Circulation
Aortic Arch:
Brachiocephalic Artery: first branch of the aortic arch which splits into…
Right common carotid artery: serves the brain, skin and muscles of the neck
Right Subclavian Artery: serves part of the brain and right arm
Left Common carotid Artery: second branch off the aortic arch which splits into …
Left internal carotid: serves the brain
Left External carotid: serves the skin and muscles of the head and neck.

10. Major Arteries and Systemic Circulation
Left Subclavian Artery: third branch of aortic arch
Vertebral Artery: serves part of the brain
Axillary Artery: serves the axilla
Brachial Artery: serves the arm
Radial and Ulnar arteries: serves the forearm

11. Major Arteries and Systemic Circulation
Thoracic Aorta: moves downward through the thorax following the spine
Intercostal arteries: 10 pairs serving the ribs
Bronchial arteries: serve bronchioles of lungs
Esophageal Arteries: serve esophagus
Phrenic arteries: serve diaphragm

12. Major Arteries and Systemic Circulation
Abdominal Aorta: moves through diaphragm into the abdominopelvic cavity.
Celiac Trunk:
Left gastric artery: supplies the stomach
Splenic Artery: serve the spleen
Common hepatic artery: serves part of colon
Superior Mesentrick artery: supplies most of the smaller intestine and the first part of the large.
Renal Arteries: serve the kidneys
Gonadal Arteries:
Ovarian: serve ovaries in females
Testicular: serve testes in males

13. Major Arteries and Systemic Circulation
Lumbar arteries: pairs of arteries which serve the muscles of the abdomen and trunk.
Inferior mesentric artery: serves second half of the large intestine.
Common Iliac Arteries: final branches of the abdominal aorta.
Internal iliac artery: supplies pelvic organs
External iliac artery: enters the thigh and becomes…
Femoral artery: serves thigh and becomes …
Popliteal artery: splits into …
Anterior and Posterior tibial arteries: supply leg and foot
Dorsalis Pedis artery: supplies bottom of foot

14. Major veins of Systemic circulation
Superior Vena cava: veins coming from the head and armpits
Radial & Ulnar Veins: deep veins draining the forearm and they come together to form the:
Brachial Vein: drains the arm
Axillary vein: drains the axillary region
Cephalic Vein: superficial drainage of the lateral arm & empties into the axillary vein
Basilic Vein: Superficial vein drains the medial aspect of the arm and empties into the brachial vein
Medial Cubital vein: the joining of the cephalic and basilic veins. Major site of blood draws

15. Major veins of Systemic circulation
Subclavian vein: receives blood from the axillary vein, skin and muscles of head through the jugular vein.
Vertebral vein: drains posterior head
Internal Jugular vein: drains dural sinuses of brain
Brachiocephalic veins: right and left drain from the subclavian, vertebral and internal jugular veins. The join to form the …
Superior vena cava: where blood enters the heart

16. Major veins of Systemic circulation
Azygos vein: single vein draining the thorax and enters into the superior vena cava
Inferior Vena cava: veins draining from the lower body
Anterior and Posterior tibial veins: drain the calf and foot.
Peroneal vein: drains the calf and foot
Popliteal vein: posterior tibial vein that becomes
Femoral vein: drains the thigh and becomes the
External Iliac vein: where blood drains from the pelvis

17. Major veins of Systemic circulation
Great Saphenous vein: longest veins in the body. Receives drainage from the leg. Begins at the foot and goes to the thigh.
Common iliac vein: right and left are formed by the external and internal iliac veins and drain the pelvis
Right gonadal vein: drain the right ovary and right testicle
Left gonadal vein: drain the left ovary and left testicle.

18. Major veins of Systemic circulation
Renal Veins: drain the kidneys
Hepatic portal vein: single vein which drains the digestive tract organs
Hepatic veins: drain the liver

19. Arterial Supply of the Brain
The brain is supplied by two pairs of arteries
Internal carotid:
Run through the neck and enter the skull through the temporal bone and then divide into the…
Anterior and Middle cerebral arteries: supply most of cerebrum
Vertebral artery:
Paired arteries running upward from the subclavian arteries at the base of the neck. In the skull they join to form the …
Basilar arteries: serve the brain stem and cerebellum. At the base of the cerebellum they divide into the …
Posterior Cerebral Arteries: supply the posterior cerebrum

20. Circle Of Willis
The circle of Willis is where the anterior and posterior blood supplies unite by small communicating arterial branches.
They form a complete circle around the base of the brain of connecting blood vessels.

21. Hepatic Portal Circulation
Veins of hepatic circulation drain the digestive system, the spleen and pancreas and deliver blood to the liver through…
Hepatic portal vein: blood contained here contains large amounts of nutrients and ensures that the liver processes these nutrients before entering systemic circulation.
Inferior mesentric vein: drains part of the large intestine and drains into the …
Splenic vein: drains the spleen, pancreas and left side of the stomach

22. Hepatic Portal Circulation
Superior Mesentric vein: joins with the splenic vein to form the hepatic portal vein
Left gastric vein: drains the right side of the stomach directly into the hepatic portal vein.

23. Fetal Circulation
In the fetus the lungs and digestive system are not functioning so all nutrients and gas exchange go through the placenta.
Umbilical cord: contains three blood vessels
Umbilical vein: one vein carries blood rich in nutrients and oxygen to the fetus
Umbilical arteries: two arteries carrying carbon dioxide and debris from the fetus to the placenta
Ductus Venousus: bypass for blood to go towards the heart and bypass the liver which is non functioning.

24. Fetal Lungs
In the fetus the lungs are non-functional and are collapsed.
Shunts: there are two shunts which make sure the lungs are bypassed.
Foramen Ovale: blood entering the right atrium is shunted directly to the left atrium through this opening in the internal septum. It closes after birth
Ductus Arteriosus: short vessel connecting the aorta and pulmonary trunk. At birth it collapses and becomes the …
Ligamentum Arteriosum: fibrous tissue completing the circulatory system of an adult.