Today:

and

F 4/10 no class.M 4/13 class +

movie at 7pm in WEL 1.308

Fig 44.25

B-cells, T-cells, antibodies, nutrients, waste, O2, CO2, water, minerals, etc must be transported throughout the body

Fig 44.24+.25

Mammals have two ciculatory circuits: pulmonary and systemic

Fig44.22

Blood flows from arteries to capillaries to veins

Capillaries provide the large surface area required for these exchanges to take place.

Fig 44.30

Blood pressure changes as the blood moves from arteries to capillaries

Fig 44.23

This change in pressure causes fluid to leak out of the capillaries

Highpressure,Fluid forced out

Blood in vein,More viscous

Interstitial fluid,Recovered by…

Fig 44.23

Not all of the fluid (~15%) is reabsorbed on the venous side. This interstitial fluid is collected by the lymphatic system.

Lymphatic system

Fig 44.30

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, O2, CO2, Water, Minerals, etc must be transported throughout the body

Fig 44.11

Gases move by diffusion:Only from high to low concentration

Fig 44.15

hemoglobin

Hb is carriedinside red blood cells Hemoglobin

(a protein) carries oxygen in the blood

Fig 44.11

The Respiratory System:large surface area to maximize gas exchange

~100m2 in humans

Fig 44.11

Gas exchange occurs in alveoli

In the lungs, O2 diffuses into the blood, and CO2 diffuses out into the lungs.

Fig 44.1

How is oxygen delivered to where it is needed?

By adjusting blood flow…

Fig 44.20By changes in blood pH

CellBlood

Lung

CO2

O2CellularRespiration

Hb in RBC

CO2

O2

Hb in RBC

Low CO2High O2

Fig 44.20

O2

O2

CellBlood

Lung

CO2

O2CellularRespiration

Hb in RBC

CO2

O2

Hb in RBC

Low CO2High O2

CO2+H2O=H2CO3(carbonic acid)

(lesscarbonic acid)

Fig 44.20

O2

O2

CellBlood

Lung

CO2

O2CellularRespiration

Hb releasesO2 at lower pH

CO2

O2Hb canbind O2

Low CO2High O2

CO2+H2O=H2CO3(carbonic acid)

(lesscarbonic acid)

Fig 44.20

O2

O2

Next week: Nutrition and DigestionF 4/10 no class.

M 4/13 class + movie at 7pm in WEL

1.308