Phisio experiment

Hematocrit measurement

Procedure

Fill the capillary tube to 2/3 of its length with blood.

Seal one end of the tube with modeling clay.

Place the tube in the centrifuge.

Centrifuge for 5 minutes at 4000 rpm.

After centrifugation, observe the three layers.

Place the capillary tube on the nomogram and read the hematocrit value.

Results Interpretation

• Erythrocytes: ~99% of blood cells → main contributor to hematocrit

• Buffy coat: ~1% (leukocytes + platelets)

Influence of Osmotic Pressure on Erythrocyte Volume

Preparation of solutions

1. Add 1 mL of NaCl solution into each test tube.

2. Add 1 mL of blood to each tube.

3. Mix gently.

Centrifugation

After 2–3 minutes, transfer diluted blood into hematocrit tubes.

Use undiluted blood as a control.

Centrifuge and measure the hematocrit using the nomogram.

Blood pressure measure

Auscultatory Method

Used to measure both systolic and diastolic blood pressure

Equipment

• Sphygmomanometer

• Stethoscope

Technique

• Air is inflated into the cuff until the pulsations of

the radial artery

(anatomical snuffbox) disappear.

• The cuff is then slowly deflated.

• When sounds are first heard, the value read

corresponds to the systolic blood pressure.

• When the sounds disappear, the value read

corresponds to the diastolic blood pressure.

The dosage of the sodium bicarbonate

Experimental Procedure

1. In an Erlenmeyer flask, add:

•1 mL of plasma

• 5 mL of HCl N/100

• 1–2 drops of pH indicator

2. Gently shake to eliminate the CO₂ produced.

3. Titrate the excess acid by adding NaOH N/100 from a burette.

4. Stop titration at the color change (yellow→red).

5. Record the volume of NaOH used

Interpretation of Results

• HCO₃⁻ > 29 mEq/L → Metabolic alkalosis

• HCO₃⁻ < 22 mEq/L → Metabolic acidosis

Identification of Hemoglobine

Method

1. Place one drop of blood on a glass slide.

2. Add a few crystals of sodium chloride.

3. Add 1–2 drops of acetic acid.

4. Cover with a cover slip.

5. Gently heat the slide over a Bunsen burner until boiling.

6. Allow the slide to cool.

7. Observe under the microscope.

Results

• Brown, rhombic crystals appear under the microscope.

• These crystals indicate the presence of hemoglobin.

Interpretation

• Presence of brown crystals → hemoglobin is present → blood confirmed.

• This test identifies blood but does not distinguish human blood from animal blood.

Red blood cell count

Principle

1. - counting Chambre-THOMA

The blood is diluted (1/200 or 1/100) using Hayem solution.

2. The diluted blood is placed in the Thoma chamber.

3.RBCs are counted in 80 small squares (1/20 mm).

4. The formula is used to calculate the number of RBC per mm³

Reticulocytes count

1. Prepare the mixture

• Take blood into the Potain pipette up to mark 0,5

• Aspirate brilliant cresyl blue up to 1.

• Place the mixture onto a watch glass and mix well.

2. Incubation

• Place the watch glass into a humid chamber for

30 minutes.→ During this time, the stain enters the reticulocytes and

colors their RNA blue.

3. Prepare the smear

• Spread a thin blood film on a slide.

• Let it dry.

4. Microscopy

• Examine under oil immersion (100×).

• Reticulocytes appear:

• slightly larger

• blue tint (polychromasia)

• with a blue network/spot inside

5. Counting

You count 1,000 cells (RBCs + reticulocytes)

Blood types

On a clean slide, place:

• A drop of anti-A serum on the left

• A drop of anti-B serum in the middle

• A drop of anti-AB serum on the right

Disinfect fingertip → prick with sterile needle → wipe first blood drop.

Add a small drop of blood (1/10 volume of serum) onto each serum.

Mix each blood + serum drop with a different corner of the slide.

Wait 2 to 3 minutes.

Observe for agglutination (grainy / clumped appearance).

Erythrocytes sedimentation rate

Method

1. Put the blood sample into the plastic container.

2. Insert the Westergren tube through circular

motions until the blood reaches mark 0.

3. Place the tube vertically in the stand.

4. Wait 1 hour.

5. Read the height of the clear plasma

column → this value is the ESR (mm/h)

Bleeding time

Poke finger with sterile needle and start timer

0-5 min normal primary homeostasis

>5min impaired primary homeostasis

>15 min severe impairment of primary homeostasis

Rumple leads compression

Procedure

1. Place a blood pressure cuff on the arm.

2.Inflate to about 100 mmHg (arterial flow maintained).

3.Keep the cuff inflated for 5 minutes.

4.Deflate the cuff and wait 6–10 minutes.

5.Observe and count the petechiae on the forearm.

Results

• Normal: 5–10 petechiae

• Abnormal:

• < 5 → normal

• 10 → capillary fragility

Quick time

Procedure

1. Warm plasma and reagents to 37°C.

2. Put 0.1 mL of plasma in a tube.

3. Add 0.1 mL thromboplastin and 0.1 mL calcium.

4. Start the stopwatch as soon as calcium is added.

5. Gently mix and observe.

6. Stop the stopwatch when the plasma becomes gel-like (clot forms).

Result

• The measured time is the Quick time.

Normal values

• 12–15 seconds

Interpretation

• > 15 seconds → delayed coagulation

• Possible deficiency of clotting factors (II, VII, IX, X)

• Possible use of anticoagulants (vitamin K antagonists)

Howell time

Procedure

1. Warm the plasma and CaCl₂ solution to 37°C.

2. In a tube, mix:

•0.1 mL of plasma

• 0.1 mL of CaCl₂

3. Start the stopwatch immediately.

4. Observe the mixture carefully.

5. Stop the stopwatch when the first fibrin filament appears.

6. Record the time.

Normal Values

• 1 to 2 minutes

Interpretation

• Prolonged Howell time may indicate:

• Treatment with anticoagulants

• Deficiency of coagulation factors

(XII, XI, IX, VIII, X, VII or fibrinogen)