Physiology Flashcards
Apparatus used in determining hemoglobin content
Sahli which has 2 readings (gram/100 or % of normal)
Sahli is used in
Determination of Hb content
Material/principle used in determining hemoglobin content
0.1 HCl to 10% in Sahli tube + 0.02 ml anti-coagulated blood using pipette
Add distilled H2O to acid hematin and match colors
What is the role of HCl in the hemoglobin content experiment
Blood + diluted HCl (hypotonic) ——> Repture of RBC’s (hemolysis) + formation of acid hematin (dark brown color)
Intensity of color alpha Hb content
Can HCL be replaced with sulphuric acid (H2SO4)?
No, gives another color
Precautions in determining Hb content
Sterilization, No air bubbles in blood column, avoid compression of finger
Normal value of Hb content for males?
15-16 gm/100ml
Normal Hb value for females?
13-14 gm/100 ml
Why is Hb content lower in females?
male androgen (increases erythropoietin) in males. Also females have periods
As one ages, Hb content…….
decreases
State the variation in Hb% could happen due
Chronic bleeding: ↓due to iron loss—> microcytic hypochromic anemia
Newborn: ↑due to relative intra-uterine hypoxia—-> stimulate erythropoietin release—–> ↑ RBC’s
High altitude: ↑ due to hypoxia—>stimulate erythropoietin release—> ↑RBC’s
Renal failure: anemia (↓ erythropoietin)
Hb above physiological level is called
polcythemia
Functions of Hb
gas transport, buffer (maintaining PH at 7.4)
blood ph?
7.4
Each 1 gm of Hb carries _____ml of O2
1.34 ml
Apparatus used in ESR
Westergren tube
Clinical significance of ESR?
Prognostic not diagnostic test (used in follow up)
Materials used in ESR
Anticoagulant = (0.5 ml Na citrate → Deionization of ca++ ion) + 2ml blood (ratio 1:4) in tube to 0
Read plasma on top of RBCs after 1 & 2 hours
ESR possible mechanism
- Plasma proteins neutralize charges on RBCs →↓ repulsion forces→ favors adhesion, sedimentation.
- specific gravity of RBC’s 1090 > plasma 1030
Rate of sedimentation depends on…..
number of RBC’s, repulsion force between RBC’s, specific gravity of RBC’s, plasma
ESR normal values for male and females at 1st hour and 2nd hour
Factors that increase ESR
Pregnancy, menstruation, infection, inflammation, malignant and anemia
Factors that decrease ESR
Afibrinogenemia and Polycythemia
Why ESR is increased in inflammatory conditions:
↑ plasma antibodies (proteins) neutralize charges on RBCs→↓ repulsion forces→ favors adhesion, sedimentation.