47
Today : and
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.
