Gurnick lecture 16

Notes

Blood -

Blood is more than a body fluid

4 components of blood

* Blood plasma
* Red blood cells ( RBC’s ) - Erythrocytes
* White blood cells ( WBC’S ) Leukocytes and Lymphocytes
* Platelets - Thrombocytes

Blood stream

Blood stream is used as the transportation system

* blood vessels are like the streets and highways of the body and the blood flowing in them is like the traffic flow through those streets and highways

White blood cells

White blood cells get to work and fight off the invaders

7\.35

Blood ph lower than 7.35 results in acidosis

7\.45

Blood ph above 7.45 result in alkalosis

Buffer

A buffer is a substance that can partially neutralize either an acid or a base in order to resist the changes in ph of the body

Hypothalamus

The part of the brain that controls most homeostatic functions

Hypothalamus

The internal thermostat of the body

Average body contains

4-5 liters of blood total depending on size of the body

How much blood can a person lose and still live ?

40% of the volume or greater is usually considered the maximum amount

Blood plasma

Comprises about 55% of the volume of blood

Plasma proteins include

* clotting factors
* Enzymes
* Transport proteins
* Lipoproteins
* Hormones

Plasma - yellowish fluid

Which is mainly

* water with salts
* Sugars
* Vitamins
* Minerals
* And proteins suspended in it

Plasma

91% water

9% nutrients , Metabolites , and plasma proteins

Specific transport proteins

* transport only specific molecules

Non-specific transport proteins

Transport a variety of different molecules

* one such non-specific transport protein in blood plasma is albumin it is the most abundant protein in the blood

Albumin levels are 3.5 - 5.0 g/dl

A low albumin level is referred to as hypoalbuminemia

Indicates -

Poor protein intake

Protein malnutrition

Poor liver function

Albumin - made by the liver

High albumin level

* sign of dehydration
* Liver never makes more albumin than necessary

Albumin has two functions in the blood

1. transport molecule : transport is albumins primary function it is a non specific transporter
2. Attracts water by osmosis to keep it in the blood ie , to maintain colloidal pressure

Colloidal pressure

Helps flowing between compartments

Interstitial space

* the space between cells in tissues

3 major compartments where fluids can be located ?

1. In the blood
2. Inside the cells
3. Between the cells in the interstitial space This fluid is called the interstitial fluid

Sodium ( Na )

Is the CD most abundant extra cellular electrolyte and the most abundant electrolyte in blood plasma

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Normal serum sodium should range between- 135 and 145 mMol/L

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* sodium always has a very important role in the control of osmotic water movements between blood and interstitial fluid

Blood pressure

The pressure of the blood against blood vessel walls

* high blood pressure of blood against the blood pressure walls causes high tension in the blood vessel walls called ( hypertension ) - high blood pressure

2 major particles that control the osmotic movement of water in and out of the blood

* Albumin : the major plasma transport protein
* Sodium : the major plasma electrolyte

Three major types of blood vessels

* arteries
* Veins
* Capillaries

Arteries

Are the blood vessels that carry blood away from the heart toward the tissues

Veins

Are the blood vessels that carry blood back to the heart from the tissues

Capillaries or ( capillary beds

Are the tiny blood vessels in the tissues that allow molecules to move between the blood and the tissue cells

Arteries walls

* the inner most layer - Intima
* The outermost layer - Adventitia
* The middle layer is the layer of smooth muscle tissue - tunica media
* Which is responsible for vasoconstriction and vasodilation

larger arteries branch out into smaller ones which branch out into tiny arteries called

* arterioles
* Arterioles - bring blood to the capillary beds , where exchange of molecules happens

Tiny veins - venules

Which join larger veins on the way back to the heart