1. Unit J - Circulation and Blood .

2. Overview 1. 5 types of blood vessels 2. ID major blood vessels
3. Pulmonary vs. Systemic Circulation
4. Fetal circulation
5. Lymphatic System

4. Intro…
When you are unicellular there is no need for a transport system…
However when you are trillions of cells a system to transport nutrients (glucose, amino acids) and remove wastes (carbon dioxide, ammonia) is required….

5. Circulatory System
Blood = the medium of transport (will carry nutrients & wastes)
Blood vessels = pathway for blood
Heart = pump that will move blood through vessels

8. 5 type of blood vessels Arteries – arterioles (smaller version)
Veins – venules (smaller version)
Capillaries – smallest!!!

9. Arteries (10% of blood) Carry blood AWAY from heart
Thick walls to withstand blood pressure
Elastic muscle fibers to withstand blood pressure
Highest blood Pressure
Smooth muscle can regulate size

10. Arterioles Connects to arteries and capillaries Smaller than arteries
Can dilate or constrict which regulates blood pressure

11. Veins (70% of blood) Carry blood Back to heart Thinner walls
Contain Valves to prevent back flow
Lowest blood pressure

13. Venules
Connect veins to capillaries
Very thin walls

14. Capillaries (20% of blood)
Narrow, microscopic tubes, blood cells will pass through single file!
Site of nutrient / waste exchange
Thin walls allow for diffusion
Large surface area allows for greater exchange of gases and nutrients
Largest cross sectional area

15. The blood flow across the capillary bed is regulated by a sphincter muscle on the arteriole side.

16. Over 99 percent of the blood vessels in the body are capillaries,even though they only hold 20 percent of the body’s blood.

17. Capillary Bed

18. Blood vessels - compared

20. Capillary Bed

21. Capillary Fluid Exchange

22. Capillary Fluid Exchange
1. Arteriole Side - blood pressure (40 mm Hg) is higher than the osmotic pressure (25 mm Hg.).
Fluid with oxygen & nutrients exit out of the blood (the walls of the capillaries) into the surrounding tissues.
Blood proteins and blood cells are too big and remain in the capillaries.

23. Capillary Fluid Exchange
2. Middle - Oxygen, glucose and amino acids in the fluid diffuse into the cells. (PASSIVE TRANSPORT)
CO2 and ammonia produced in the tissue cells diffuse out of the tissues. (PASSIVE TRANSPORT)

25. Capillary Fluid Exchange
3. Venule Side- blood pressure is now reduced (10 mm Hg.), and is less than osmotic pressure (25mm Hg.). Fluid (containing wastes) is now is moved by osmotic pressure back into the blood vessels. (PASSIVE TRANSPORT)

27. Capillary Fluid Exchange
The remaining fluid enters lymph vessels carried back to the circulatory system…

28. Pulmonary vs. Systemic Pulmonary = Lungs Systemic = Body
2 circuits with 2 functions
Pulmonary – from heart to lungs and back to heart…. Function ???
Return deoxygenated blood to capillaries in lungs
(CO2 diffuses out, O2 diffuses in)
Return oxygen rich blood to heart (the pump for oxygenated blood)

29. Systemic
Systemic – from heart to EVERY cell of body and back to heart ….. Function????
Oxygenated blood delivered to cells
(O2 diffuses out of blood, CO2 diffuses into blood)
Deoxygenated blood return to heart (heart is the pump for blood)

32. Fetal Circulation
Different - Why???

34. Fetal Circulation
The fetus does not use pulmonary circuit
Why???

36. Fetal Circulation
Placenta - organ responsible for delivery of nutrients, removal of waste products and delivery of oxygenated blood to the fetus via diffusion and active transport mechanisms. 

38. Fetal Circulation – 4 differences AKA: The Fetal Four
Umbilical cord
Umbilical vein (1)- A vessel which delivers oxygenated and nutrient rich blood from the placenta to the fetus.
Umbilical arteries (2) vessels that carries deoxygenated blood from iliac arteries out to the placenta.
2. Venous duct - receives blood from the umbilical vein and directs it to the posterior/inferior vena cava. This venous duct acts as a liver bypass and moves blood into the fetal systemic circulation.
Function – to bypass the liver Why bypass the liver??

40. Fetal Circulation
3. Foramen Ovale - an opening between the right atrium and left atrium of the heart
Function – to bypass the lungs
Why bypass the lungs??

41. Fetal Circulation
Ductus Arteriosus - A vessel that connects the pulmonary artery to the aorta.
Function – to bypass pulmonary circuit.

45. Lymph System Is a one way transport system (tissues to blood)
Takes excess fluid from capillary beds of body and returns it to the blood
CONSISTS of lymph veins (have valves) and capillaries
Fluid is called lymph
Joins blood at subclavian vein

46. Main Functions of Lymphatic System
Take up excess tissue fluid
Transport fatty acids (from LACTEAL)
Fight infection (lymphocytes)
lymph system

47. Parts of Lymphatic System
1. LACTEAL: dead ends of lymph vessels in villi of the small intestine.
2. LYMPH NODES - small oval structures that produce and store lymphocytes, filter the lymph of damaged cells and debris.
SPLEEN: stores blood.
THYMUS GLAND -production and maturation of some lymphocytes.

50. PATH OF A BLOOD CELL THROUGH THE BODY
Start in the Left Ventricle and go through the Circulatory System