Monday, May 16, 2011
First topic: Circulation
What's the purpose of the circulatory system?
1. Maintains the exchange of materials in/out of our bodies
2. Efficient internal transport system of blood and other substances
3. Allows diffusion to occur by giving cells the resources they need
-Oxygen from the lungs go to blood, then to tissue
-Carbon Dioxide from tissue go to blood, then to the lungs
-Basically, the circulatory system gets rid of waste in our bodies (Carbon Dioxide, urine, feces)
There are two types!
-OPEN circulatory system:
--Blood is pumped through open blood vessels and flows among cells
--Invertebrates (no backbone), mollusks (snail), arthropods (insects)
-CLOSED circulatory system:
--Blood pumps within a secluded blood vessel amongst itself
--vertebrates (backbone), earthworm, octopus
Comparative Anatomy: Hearts
-Amphibian (Frog): 3
-Reptile (Lizard): 3-4
-Bird/Mammal (Crow/You): 4
The cardiovascular system is a fascinatingly complex one that uniquely comprises primarily (but not exclusively (unless the discussion's basis revolves around the idea of simplistic measures)) of the hard-working heart and the efficiently excellent blood vessels, which are (needless to mention) inevitably teamed up (or forced to work) with the rigorous, colossal player in the soccer stadium, the motivated student in the school, the Lithium-ion 700 Milliamp battery in the Samsung Galaxy S phone, blood (or sangre, in Spanish).
Cardiovascular system=heart+blood vessels+blood!
Atrium=heart chamber that RECEIVES BLOOD
Ventricle=heart chamber that KICKS OUT BLOOD
Blood vessels: arteries, then arterioles, then capillaries, then venules, then veins.
DIFFUSION OCCURS IN THE CAPILLARIES.
SO...... where does blood travel?
1. Right ventricle
3. Pulmonary valve
4. Capillaries (oxy diffuses into blood)
5. Pulmonary veins
6. Left Atrium (oxy rich!)
7. Bicuspid valve
8. Left ventricle
9. Aortic valve
11. Capillaries (O2 diffuses into tissues, CO2 diffuses into blood)
12. Superior Vena Cava
13. Inferior Vena Cava
14. Right Atrium
15. Tricuspid Valve
16. Dispersed to supply arteries!
How does the heart work?
-Atria has thin walls, pumps blood to VENTRICLE
-Ventricle has THICK walls, pumps blood to BODY
-Valves make sure blood doesn't come back inside
-4 chambers make it easy to separate oxy rich and oxy poor blood!
-Definition: rhythmic contraction and relaxation of the heart
Two phases of this cycle!
Homework: Read chapter 23 pages 503-514.
Late arrival tomorrow!