Today: and F 4/10 no class. M 4/13 class + movie at 7pm in WEL 1.308
Fig B-cells, T- cells, antibodies, nutrients, waste, O 2, CO 2, water, minerals, etc must be transported throughout the body
Fig Mammals have two ciculatory circuits: pulmonary and systemic
Fig Blood flows from arteries to capillaries to veins
Capillaries provide the large surface area required for these exchanges to take place.
Fig Blood pressure changes as the blood moves from arteries to capillaries
Fig This change in pressure causes fluid to leak out of the capillaries
High pressure, Fluid forced out Blood in vein, More viscous Interstitial fluid, Recovered by…
Fig Not all of the fluid (~15%) is reabsorbed on the venous side. This interstitial fluid is collected by the lymphatic system.
Lymphatic system
Fig Because of the low pressure in veins and lymph vessels, movement of these fluids comes from skeletal muscles movements.
The mammalian circulatory system is both open and closed Fig 44.3
Nutrients, Waste, O 2, CO 2, Water, Minerals, etc must be transported throughout the body
Fig Gases move by diffusion: Only from high to low concentration
Fig hemoglobin Hb is carried inside red blood cells Hemoglobin (a protein) carries oxygen in the blood
Fig The Respiratory System: large surface area to maximize gas exchange ~100m 2 in humans
Fig Gas exchange occurs in alveoli
In the lungs, O 2 diffuses into the blood, and CO 2 diffuses out into the lungs.
Fig 44.1 How is oxygen delivered to where it is needed?
By adjusting blood flow…
Fig By changes in blood pH
Cell Blood Lung CO2 O2 Cellular Respiration Hb in RBC CO2 O2 Hb in RBC Low CO2 High O2 Fig O2
Cell Blood Lung CO2 O2 Cellular Respiration Hb in RBC CO2 O2 Hb in RBC Low CO2 High O2 CO2+H2O =H2CO3 (carbonic acid) (less carbonic acid) Fig O2
Cell Blood Lung CO2 O2 Cellular Respiration Hb releases O2 at lower pH CO2 O2 Hb can bind O2 Low CO2 High O2 CO2+H2O =H2CO3 (carbonic acid) (less carbonic acid) Fig O2
Next week: Nutrition and Digestion F 4/10 no class. M 4/13 class + movie at 7pm in WEL 1.308