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CB 42.5 Mammals have two ciculatory circuits: pulmonary and systemic

CB 42.9 Blood flows from arteries to capillaries to veins

CB Blood pressure changes as the blood moves from arteries to capillaries

CB 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…

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

CB 43.5 Lymphatic system

CB 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

CB 42.5 Nutrients, Waste, O 2, CO 2, Water, Minerals, etc must be transported throughout the body

CB Gases move by diffusion: Only from high to low concentration

CB hemoglobin Hb is carried inside red blood cells Hemoglobin (a protein) carries oxygen in the blood

CB The Respiratory System: large surface area to maximize gas exchange ~100m 2 in humans

CB Gas exchange occurs in alveoli

In the lungs, O 2 diffuses into the blood, and CO 2 diffuses out into the lungs.

CB How is oxygen delivered to where it is needed?

By adjusting blood flow… CB 42.13

CB By changes in blood pH

Cell Blood Lung CO2 O2 Cellular Respiration Hb in RBC CO2 O2 Hb in RBC Low CO2 High O2 CB 42.30

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) CB 42.30

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) CB 42.30

I hope Pat likes my feathers because I am tired of dragging them around everywhere.

1 2 Which is male?

1 2

Female grizzly bears cannot reproduce while lactating. Therefore they can only reproduce every once every 3 years…

…this leads to competition between males

Sexual Dimporphism: differences between males and females

Average height/weight by sex in U.S.

Ratio of Weight Male/Female M/F

Bonobos

Primates have different reproductive stratagies

Ratio of Weight Male/Female M/F

Testes Compared to Overall Weight Testicle size (oz) per body weight (lbs)

Pipefish: related to seahorses

Pregnant Male: Males care for developing eggs

The Measurement of Sexual Selection Using Bateman’s Principles: An Experimental Test in the Sex-Role-Reversed Pipefish Syngnathus typhle (2005) Integrative and Comparative Biology, 45:874–884 Adam G. Jones, Gunilla Rosenqvist, Anders Berglund, and John C. Avise

Jones et al. Fig. 1 frequency number of mates When there are more females than males, many females cannot mate.

frequency number of mates Jones et al. Fig. 1 When the sex ratio is even, most males and females mate.

frequency number of mates Jones et al. Fig. 1 When there are more males than females, most males can mate.

Jones et al. Fig. 1 The sex ratio affects who will successfully reproduce. Pipefish females are more affected by competition.

number of individuals body length (mm) Jones et al. Fig. 4 Excess females: only medium size females can mate (This is some additional info about pipefish that was NOT covered in class)

number of individuals body length (mm) Jones et al. Fig. 4 Excess males: many different size males can mate (This is some additional info about pipefish that was NOT covered in class)

Jones et al. Fig. 4 medium sized female pipefish are most successful at reproducing while size is less critical for male pipefish (This is some additional info about pipefish that was NOT covered in class)

Different reproductive strategies lead to differences in sexual dimorphism.