Download Circulatory System Part 1

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CIRCULATORY SYSTEM
Composed of cardiovascular and lymphatic systems
Heart –pumps blood
Blood Vessels –passageways for blood
Lymphatic System –returns leaked plasma to blood vessels after removing bacteria, etc.
THE BLOOD
I. Blood – only fluid tissue in the body (5-6 L “1.5 gallons” in adult
males, 4-5 L in adult females) Blood cells originate in the red bone
marrow
1. Blood is a Specialized Connective Tissue: living formed elements
(cells) suspended in nonliving fluid matrix (plasma)
a) pH 7.35 – 7.45
b) 100.4°F
2. Functions of Blood
a) Deliver oxygen from lungs and nutrients from digestive
tract
b) Transport metabolic waste from cells to elimination sites
(CO2 to lungs and Nitrogen wastes to kidneys)
c) Transport hormones from endocrine glands to target
organs
d) Maintain body temperature by absorbing and distributing heat throughout body
e) Maintain pH = reservoir for HCO3- (bicarbonate)
f) Use salts and blood proteins to prevent fluid loss from bloodstream to tissue
g) Prevent blood loss- platelets and blood proteins clot blood
h) Prevent infection – antibodies, proteins, and white blood cells found in blood
3. Erythrocytes = red blood cells
a) Carry oxygen to cells by use of the red
pigment hemoglobin
b) Are composed of 97% hemoglobin
c) Carry CO2 back to lungs
d) 45% of total blood volume
e) Not true cells, because they have no
nuclei or organelles (Anucleate) Lose
nucleus Day 4 of RBC development
f) 2.5 trillion RBCs in an adult human (more = thicker blood, less = thinner blood)
g) Live up to 4 months
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4. Leukocytes = white blood cells (protect the body in various ways) less than 1% of blood
volume
a) Live several days up to many months depending on the type
b) 5 types: neutrophils (phagocytize bacteria), basophils (unknown function),
eosinophils (allergic reactions), lymphocytes (make antibodies), monocytes
(phagocytize bacteria)
5. Platelets = Not true cells, but are cell fragments that stop bleeding
a) Live only 9 days or so
(Aspirin is an anticoagulant and works on platelets to make them less
effective at sticking together. Platelets live 7-10 day and will remain
ineffective once altered by aspirin. Some foods act similar to this – e.g.
grape juice and red wine.)
6. Plasma – 90% water; >100 dissolved solutes, 55% of blood volume
a) Nutrients, gases, hormones, wastes, electrolytes and proteins = dissolved solutes
b) Albumin (most abundant solute in blood)
i. Acts as a carrier to shuttle lipid molecules through circulation
ii. Acts as a blood buffer
iii. Major contributor to maintenance of plasma osmotic pressure (pressure
that keeps water in the bloodstream)
c) Globulin – helps with immune response - antibodies
d) Fibrinogen – helps platelets clot blood
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II. Blood types
1. ABO – Discovered in 1901
a) Type A
1. contain A Antigens
2. may contain B antibodies
b) Type B
1. contain B Antigens
2. may contain A antibodies
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c) Type AB
1. contains both A and B Antigens
2. will NOT contain A or B antibodies
3. Universal Acceptor
d) Type O
1. RBC does NOT contain either A or B Antigens
2. may contain A and/or B antibodies
3. Universal Donor
2. Rh factor – Discovered in 1937
a) Rh positive
1. contains Rh Antigens
2. will NOT contain Rh antibodies
b) Rh negative
1. will NOT contain Rh Antigens
2. may contain Rh antibodies
3. Rh- women must be aware of this when giving birth to a Rh+ child
Rh- women are given medication after childbirth so mother
won’t make antibodies that could attack the next child during
gestation
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