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SEM I (2011)

FACULTY OF VETERINARY MEDICINEUNIVERSITI MALAYSIA KELANTAN

Week V Lecture (9 October 2011)

Course Coordinator: DR. ERKIHUN AKLILU W.G. (Course Coordinator)

ANIMAL PHYSIOLOGY I

Week V Lecture

PLASMA PROTEINS AND HOMEOSTASIS

Plasma proteins and Homeostasis Introduction A human body is Split Into three Solution-

Filled Compartments

Body 60-80% water by weight 70 kg man has ~ 49 kg water = ~49 litres 3 Main compartments:

Intracellular (inside cells) = ~ 34 liters Interstitial (outside cells) = ~ 13 liters Blood plasma = ~3 liters

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Body FluidsBlood plasma 40% of blood is red blood cells

(RBCs)

Plasma is similar to interstitial fluid, but contains plasma proteins

Serum = plasma with clotting proteins removed

Intracellular fluid is very different from interstitial fluid (high K concentration instead of high Na concentration, for example)

BLOOD

PLASMAComposition of Plasma

Water 90%

Organic substance 9%

Plasma proteins 7% (albumin, globulin, firinogen)

Other organic substance 2% metabolic products urea creatinine,

nutritive substance like Glucose & Amino Acids, Enzymes, hormones,vitamines

Inorganic substance 1% Na, K, Ca, Cl

Respiratory gases O2, CO2

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PLASMA

Plasma ProteinPlasma Protein Functions

Blood coagulation: fibrinogen & prothrombin.

Blood viscosity: 2 times more than water & maintain diastolic bl. Pressure.

Production of an effective osmotic pressure maintaining body fluid

Buffering action.

Defence action. Antibodies are gamma globulins

Carriage of CO2

Regulation of capillary permeability.

Carrier functions: vitamins, Iron, copper, cholesterol, phospholipids, hormones e.g. Thyroxin, cortisol.

Protein metabolism.

HOMEOSTASISHomeostasis

Is the maintenance of a stable internal environment

Describes the physical and chemical parameters that an organism must maintain to allow proper functioning of its component cells, tissues, organs, and organ systems

Enzymes function best when within a certain range of temperature and pH

Cells must strive to maintain a balance between having too much or too little water in relation to their external environment

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HOMEOSTASISThe Internal Environment

There are two types of extracellular fluids in animals:

The extracellular fluid that surrounds and bathes cells

Plasma, the liquid component of the blood.

HOMEOSTASISInternal components of

homeostasis:

Concentration of oxygen and carbon dioxide

pH of the internal environment

Concentration of nutrients and waste products

Concentration of salt and other electrolytes

Volume and pressure of extracellular fluid

HOMEOSTASIS

Stages in homeostasis

Detection: A receptordetects the changes from the stable state

Counteraction: An effector counteracts the changes from the stable state

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HOMEOSTASIS

Three (3) main components:

a. Receptor (receives a stimuli: detection)

b. Integrator (processes the information from the stimuli) --"regulatory centre“

c. Effector (carries out a response to the stimuli: counteraction)

HOMEOSTASISMechanisms of homeostasis

Two (2) different mechanisms (body responses):

Negative feedback: cancels or counteracts original stimuluse.g., blood sugar balance, blood pH balance, blood pressure balance, body temperature

Positive feedback: increases original stimulus [e.g. child birth (labor), sexual reproduction (orgasm)]

Most homeostatic mechanisms operate by negative feedback

Blood GlucoseBlood Glucose The amount of glucose in the

blood is carefully controlled

It is under the hormonal controlsystem

The hormones responsible forregulating blood glucose areproduced in the pancreas inparticular, islets of Langerhans

Blood ion concentrations slightlytoo high or too low can be lethal

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Blood Glucose

Exercise

Glucose is being used up

Alpha cells will produce glucagon

Release of an enzyme that breaks glycogen to glucose

(glycogenolysis)

Blood GlucoseMeal

The blood glucose levels will begin to rise

Pancreatic beta cells, will produce more insulin

Insulin then binds to receptor proteins in cell membranes

(Liver)

More channels open so that more glucose can enter the

cell

Encourages enzymes toconvert glucose to glycogen(glycogenesis) for storage

Blood Glucose

Blood Glucose

Regulation

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HOMEOSTASIS

HOMEOSTASIS

New folder\Homeostasis.mp4

New folder\Homeostasis And Negative Feedback.flv

New folder\Positive and Negative Feedback Loops.mp4