Density-dependent factors affect population size in relation to the population’s density.

Density-dependent factors down into two categories. 

Negative density dependence 

Positive density dependence (inverse density dependence

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#Unit 7. System Physiology – Animal

The normal total circulating blood volume is about 8% of the body weight (5600 mL in a 70-kg man).  About 55% of this volume is plasma (3500 mL in a 70-kg man).

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#Unit 7. System Physiology – Animal

Most capillary walls are relatively impermeable to the proteins in plasma, and the proteins exert an osmotic force of about 25 mm Hg across the capillary wall (oncotic pressure) that pulls water into the blood.

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#Unit 7. System Physiology – Animal

The plasma proteins are also responsible for 15% of the buffering capacity of the blood because of the weak ionization of their substituent COOH and NH2 groups.

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#Id: 5177

#Unit 7. System Physiology – Animal

Plasma proteins have:  Specific functions

(antibodies & blood clotting proteins)

Nonspecific functions (carriers for various hormones, solutes, and drugs)

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#Id: 5178

#Unit 7. System Physiology – Animal

Most of the plasma proteins are synthesized in the liver only circulating antibodies are manufactured by lymphocytes

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#Id: 5179

#Unit 7. System Physiology – Animal

Serum has essentially the same composition as plasma, except that its fibrinogen and clotting factors II, V, & VIII have been removed.