Today: and. CB 42.5 Mammals have two ciculatory circuits: pulmonary and systemic.

Today:

and

CB 42.5

Mammals have two ciculatory circuits: pulmonary and systemic

CB42.9

Blood flows from arteries to capillaries to veins

CB 42.11

Blood pressure changes as the blood moves from arteries to capillaries

CB 42.14

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…

CB 42.14

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 42.10

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

CB 42.27

Gases move by diffusion:Only from high to low concentration

CB 42.28

hemoglobin

Hb is carriedinside red blood cells Hemoglobin

(a protein) carries oxygen in the blood

CB 42.23

The Respiratory System:large surface area to maximize gas exchange

~100m2 in humans

CB 42.23

Gas exchange occurs in alveoli

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

CB 42.27

How is oxygen delivered to where it is needed?

By adjusting blood flow…CB 42.13

CB 42.30By changes in blood pH

CellBlood

Lung

CO2

O2CellularRespiration

Hb in RBC

CO2

O2

Hb in RBC

Low CO2High O2

CB 42.30

CellBlood

Lung

CO2

O2CellularRespiration

Hb in RBC

CO2

O2

Hb in RBC

Low CO2High O2

CO2+H2O=H2CO3(carbonic acid)

(lesscarbonic acid)

CB 42.30

CellBlood

Lung

CO2

O2CellularRespiration

Hb releasesO2 at lower pH

CO2

O2Hb canbind O2

Low CO2High O2

CO2+H2O=H2CO3(carbonic acid)

(lesscarbonic 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

Which is male?

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

0

20

40

60

80

100

120

140

160

180

200

height (in.) weight (lbs.)

malefemale

Average height/weight by sex in U.S.

0

0.5

1

1.5

2

2.5

Grizzly Bear Gorilla Orangutan Bonobo Chimpanzee Human

Ratio of Weight Male/Female

M/F

Bonobos

Primates have different reproductive stratagies

0

0.5

1

1.5

2

2.5

Grizzly Bear Gorilla Orangutan Bonobo Chimpanzee Human

Ratio of Weight Male/Female

M/F

0

0.005

0.01

0.015

0.02

0.025

0.03

0.035

0.04

0.045

gorilla orangutan human chimpanzee

Testes Compared to Overall WeightT

esti

cle

size

(oz

) pe

r bo

dy w

eigh

t (lb

s)

Pipefish: related to seahorses

Pregnant Male:Males care for developing eggs

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, 45:874–884Adam G. Jones, Gunilla Rosenqvist, Anders Berglund, and John C. Avise

Jones et al. Fig. 1

freq

uenc

y

number of mates

When there are more females than males, many females cannot mate.

freq

uenc

y

number of matesJones et al. Fig. 1

When the sex ratio is even, most males and females mate.

freq

uenc

y

number of matesJones 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.

num

ber

of in

divi

dual

s

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)

num

ber

of in

divi

dual

s

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.