Anat_Semes2_Week_2_CardiovascularSystem_Elisa_GBC_2

• The human heart is a four-chambered muscular organ.
• Three layers of tissue form the heart wall:

The outer layer of the heart wall is the epicardium.

The middle layer is the myocardium.

The inner layer is the endocardium.

IT is a doubled walled sac that the heart is enclosed by.

FIBROUS PERICARDIUM

• 1.  Right ventricle
• 2.  Left ventricle
• Right Atrium
• 4.  Left Atrium

1.  De-oxygenated blood enter Rt. Atrium from Superior and Inferior Vena Cavae   ¯

• 2. From Rt. Atrium blood flows through Rt. Atrioventricular (AV) Valve  to Rt. Ventricle  ¯ 
• 3. Rt. ventricle contraction forces blood through the Pulmonary Semi-lunar Valve into Pulmonary trunk  ¯

4. Blood in Pulmonary trunk flow to Rt. and Lt. Pulmonary arteries   ¯

5. Rt. and Lt. Pulmonary arteries branching from pulmonary trunk carry de-oxygenated blood (blood rich in CO2) to the Rt. and Lt. Lungs  ¯

**BLOOD IS NOW OXYGENATED**

6. Oxygenated blood leaves lung via Rt. and Lt. Pulmonary Veins  ¯

7. Rt. and Lt. Pulmonary Veins empty into Lt. Atrium  ¯

8. Lt. Atrium blood flow INTO the Bicuspid (Lt. AV) Valve into Lt. Ventricle  ¯

9. Lt. Ventricle contraction forces blood via the Aortic Semi-lunar Valve to Ascending Aorta.  ¯

10.  At base of Ascending Aorta O2 rich blood flows via Rt. and Lt. Coronary Arteries to the Heart  ¯

11.  Blood in Ascending Aorta goes to Ascending Arch for Systemic Circulation

• - the umbilical cord contains 3 blood vessels
• - one large umbilical vein
• - two small umbilical ARTERIES
• - The umbilical vein carries blood rich nutrients & oxygen to the fetus.
• - The umbilical arteries carry carbon dioxide & debris-laden blood from the fetus to placenta
• - blood flows superiorly towards the heart of the fetus and bypasses the immature liver.
• - This bypass is done through the DUCTUS VENOSUS and the blood enters the inferior vena cave of the fetus which carries the blood to the RT atrium of the fetus heart

• 1. The veins of the hepatic portal circulation drain the digestive organs, spleen, and pancreas and deliver the blood to the liver via hepatic portal vein.(Roughly 75% of the blood entering the liver is venous blood from the portal vein)
• 2. The remaining 25% of the blood supply to the liver is arterial blood from the hepatic artery.

3.  Terminal branches of the hepatic portal vein and hepatic artery empty together and mix as they enter sinusoids (The liver, spleen and bone marrow contain vessel structures called sinusoids) in the liver.

4. Blood flows through the sinusoids and empties into the central vein of each lobule.

5. Central veins coalesce into hepatic veins, which leave the liver and empty into the vena cava.