Download MBBS Physiology Presentations 63 Plasma Proteins Lecture Notes

Download MBBS (Bachelor of Medicine, Bachelor of Surgery) 1st Year, 2nd Year, 3rd Year and Final year Physiology 63 Plasma Proteins PPT-Powerpoint Presentations and lecture notes




Plasma Proteins

Learning Objectives:

At the end of this lecture student should be able to discuss-

Types of plasma proteins

Characteristics of plasma proteins

Functions of plasma proteins

Hypoproteinemia and oedema


Plasma proteins

Plasma contains ~ 7% protein,

Normal total plasma protein is about 6.3- 8.4 g/dl

Classes of Plasma Proteins

Albumins - 60%

Globulins (, , ) - 35%
Fibrinogen - 4%

Other proteins - 1%
Site of synthesis of Plasma Proteins

Liver - 90% plasma proteins

Plasma cel (B lymphocytes) - globulin

Peptide hormones ? Endocrine glands

Liver dysfunction - plasma proteins

A:G ratio (normal): 0.8-2.0., Decreased in liver

dysfunction and chronic inflammatory conditions.

Plasma protein - Albumin

? Forms - 55%-60% of total plasma proteins

? Normal value - 3.5-5.0 g/dl

? Molecular Weight (MW)- 66,500 D (lightest)

Structure - a single peptide chain of 585 amino acids
Plasma protein - Albumin
? Major function: Plasma Col oid Osmotic Pressure

? Carrier

Hypo-albuminemia

Liver disease,

Malnutrition

Chronic infection

.

Plasma protein - Globulin

? Forms ? 35% of total plasma proteins

? Normal value - 2-3 g/dl; ? Molecular Weight (MW)-90,000-150000 D

? Type - Three types of globulin have been identified -- alpha, beta, & gamma.


Fibrinogen

? Forms ? 4%-6% of total plasma proteins

? Normal value - 0.3-0.4 g/dl; .? Molecular Weight (MW)-4,00,000-500000 D

? It is a plasma clotting factor, important for blood coagulation as can be

converted into insoluble fibrin Molecules form clots, Produce long, insoluble

strands of fibrin

? It also contributes to the viscosity of blood.

Other Plasma Proteins

1% of plasma proteins:

Regulatory proteins (cel ular products) (1%):

Hormones,

Enzymes, and

Prohormones
Methods of plasma protein separation

Common methods of protein separation into:

albumin, globulins (alpha, beta & gamma) and fibrinogen by ?

Electrophoresis

Salting out

Ultracentrifugation

Affinity chromatography

Fractional precipitation method

Immune electrophoresis

Hypo-proteinemia

? Liver failure

? Nephrotic syndrome

? Malnutrition

? Malabsorption

? Severe burns

? Infection (catabolism)

? Genetic
Functions of plasma proteins

1. Col oid osmotic pressure in blood

2. Viscosity of blood

3. Buffer action

4. Clotting and fibrinolysis

5. Defense function body

6. Transport function

7. Plasma proteolytic enzyme system

8. Plasma protease inhibitor system

9. Nutritional reserve

Colloid osmotic pressure (oncotic pressure)

80% of plasma oncotic pressure is maintained by albumin.

It is the opposing force to hydrostatic pressure.


Col oid osmotic pressure (oncotic pressure) and filtration of fluid

Edema

Due to disturbance in hydrostatic and/or oncotic pressure between

intra-capillary and interstitial component.


Organ specific

? Brain: Cerebral edema

? Lung: Intra-alveolar=pulmonary edema,

intra-pleural=pleural effusion

? Peritoneum=ascites

? Severe generalized edema=anasarca

? Leg edema- deep venous thrombosis

Facial oedema

EdemaPitting Non pitting

Clinical y

Pitting Non pitting
Clinical Problem Based Question
A previously wel 9 year old girl presents to your office
with the chief complaint of facial puffiness. Her mother
noticed this a few days ago and it seems to be worsening. She
has no other symptoms, but about two weeks ago had "a bad
cold." On examination HR 90/min, RR 20/min, BP 92/55 mm of
Hg. Abdomen is soft, non-tender. Her face shows moderate
puffiness and periorbital edema. The dorsal surfaces of his
hands and feet also have mild pitting edema. Urinalysis shows
4+ protein, Blood -protein of 2 g/dL, serum albumin of 1.4 g/dL
Que.1 What is the provisional diagnosis?
Que.2 What is the cause of facial puffiness and feet edema?

Fill in Blanks

? Reduced plasma osmotic pressure leads to a net movement of fluid into the --------

------------ subsequent -----------------plasma volume.

? ------------------capil aries permeability results in increased capil ary hydrostatic

pressure, causing------------------.

? Patients having acute cardiac failure do not show oedema, because

1.The plasma oncotic pressure is high

2.There is renal compensation

3.There is an increase in cardiac output

4.There is a fal in the systemic capil ary hydrostatic pressure

This post was last modified on 08 April 2022