1. Seph Rodriguez & Austin Stowell
Circulatory system
Seph Rodriguez & Austin Stowell

2. Basic overview Circulatory system includes Heart Blood cells
Blood vessels/veins/arteries

3. Basic overview cont’d Basic functions include
Internal distribution of materials
i.e. Delivery of O2
Nutrients
Hormones
Removal of carbon dioxide
Ammonia
and other metabolic wastes

4. Blood vessels structure and fucnctions
Contain central Lumen lined with endothelium (single layer of flattened epithelial cells)
Smooth surface of endothelium minimizes resistance to the flow of blood
Surrounding endothelium are layers of tissue that differ among capillaries, arteries, and veins, reflecting their specialized functions

5. Blood vessels structure and fucnctions Cont’d
Capillaries
Smallest blood vessels (diameter only slightly greater than red blood cell)
Have very thin walls consisting only of endothelium and its basal lamina
Facilitates exchange of substances between blood, capillaries, and interstitial fluids

6. Blood vessels structure and fucnctions Cont’d
Veins and Arteries
More complex organization than those of capillaries
Have 2 layers of tissue surrounding endothelium:
outer layer of connective tissue containing elastic fibers, allows vessels to stretch and recoil
middle layer contains smooth muscle and more elastic fibers

7. Differences in arteries and veins
Have wall 3x thicker than vein
Strong walls accommodate high pressure blood pump by the heart
Elastic recoil maintains blood pressure when heart relaxes between heart contractions
Thinner walls bring blood back to heart at lower speeds and pressure
Valves maintain unidirectional flow of blood in these vessels

8. Capillaries, Veins and arteries

9. Capillary functions
5-10% of bodies capillaries have blood flow
However each tissues has many capillaries so every part of the body has constant blood flow
Capillaries in brain, heart, liver, and kidneys are filled to capacity
But other sites’ blood supply varies over time as blood moves from one destination to another

10. Capillary functions Cont’d
Examples include
Blood flow to the skin regulates body temperature
Blood supply to digestive tract increases after a meal

11. Blood composition and function
Blood is a connective tissue whose cells are suspended in a liquid matrix called plasma
Plasma contains dissolved ions referred to as blood electrolytes
Is also 90% water dissolve salts are essential to the blood
Concentration of ions effects the composition of plasma

12. Cellular elements Two types of cells suspended in blood plasma
Red blood cells (erythrocytes)-transport oxygen
White blood cells (leukocytes)-function in defense
Blood contains platelets that are involved in the clotting process

13. Chambers of the heart
The heart has 4 chambers
Two atria (atrium)
Two ventricles
Left and right atria
Right--recieves oxygen-poor blood and pumps it to the right ventricle
Left—receives oxygen-rich blood from the lungs and pumps it to the left ventricle

14. Chambers of the heart cont’d
Left and Right ventricles
Right—receives oxygen-poor blood from the right atrium and pumps it to the lungs
Left—receives oxygen-rich blood from the lungs and pumps it to the rest of the body

15. BP can change from minute to minute with changes in:
Blood Pressure
Blood pressure rises with each heartbeat and lowers whenever the heart relaxes
BP can change from minute to minute with changes in:
Stress, exercise, stress, or sleep
Norm. blood pressure for an adult 20yrs+ should be less than 120/80 mm Hg
Less than 120 systolic and less than 80 diastolic

16. Questionnaire
What are the main components of the circulatory system?
What are the 3 types of blood vessels?
What 2 blood vessels differ in structure/function? List at least 2 differences.
The capillaries of which organs are always filled to capacity?
What are all of the chambers of the heart and their functions?

17. Work cited
AP BIO Textbook chapter 42
heart
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