Chapter 13 – Blood
Chapter 22 – Fetal Circulation
Chapter 22 pages 458 - 459
Blood
• Blood is made up of two parts
1. Formed Elements
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Red blood cells
White blood cells
Platelets
2. Plasma
Formed Elements
• Red Blood Cells
– Also called erythrocytes
– No nucleus
– Made in the Marrow of Bones (the middle of
bones)
– Contains the protein Hemoglobin. This allows the
cell to carry oxygen.
– If arterial blood is carrying low amounts of oxygen
then the kidney produces a hormone called
erythropoietin. This tells the body to produce
more red blood cells
Red Blood Cells
•Double Concave
•No nucleus
•Protein Hemoglobin
•Made in Bone Marrow
White Blood Cells
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Called Leukocytes
Many different types of white blood cells
Made in the marrow of bones
Use a combination of special proteins,
enzymes, and phagocytosis to kill infections
Platelets
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Also called Thrombocytes
Made in the Marrow of bones
Involved with blood clotting
No Nucleus
Platelet
No Nucleus
Smaller than RBC
Forms Blood Clots
Where do blood cells come from
• There are a type of stem cell found in the
marrow of bones
• These stem cells can create any type of blood
cell including
– Platelets
– Red Blood cells
– All types of White blood cells
• Page 251
Plasma
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Mostly made up of water
Transports dissolved gases  CO2, O2
Transports nutrients  Amino acids, glucose
Transports wastes  Urea, Uric Acid
Transports hormones  Insulin, epinephrine
Has Plasma Proteins
– Fibrinogen, prothrombin  These proteins help
create blood clots
Capillary Exchange
• On the arterial end of capillaries the blood
pressure pushing into cells is greater than the
osmotic pressure pushing out of cells.
– The result is that materials move into cells
• On the Venous end of capillaries the blood
pressure pushing into cells is lesser than the
osmotic pressure pushing out of cells.
– The result is that materials move out of cells
Review
• Page 260 -261
• Testing yourself
– Questions 1- 12
Blood Circulation in a Fetus
• A fetus does not use its lungs for gas exchange
– Instead it relies on the mother for gas exchange
• The fetus has a whole in the heart that
connects the right atrium to the left atrium
called the oval opening
– Most of the blood coming into the right atrium
goes to the left atrium
• Any blood that goes into the Right Ventricle
goes up through the pulmonary trunk and is
diverted and enters the aorta via the arterial
duct
• The Fetus does its gas and nutrient exchange
through the placenta.
• Oxygenated blood going to the fetus heart
goes through the umbilical vein
• The umbilical vein enters the liver and then
joins with the venous duct, which then enters
the heart via the inferior vena cava
• When blood leaves the heart it goes to the
body and deoxygenated blood goes back to
the placenta through the umbilical artery