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Male Reproductive System: Structure & Function

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What is the male reproductive system?

  • The male reproductive system consists of a group of organs that make up the reproductive system and urinary system.
  • The male reproductive system contains internal and external parts. Internal parts are inside your body, and external parts are outside your body.
  • Together, these organs help you pee, have sexual intercourse and make biological children.

1. External – male reproductive parts

Most of the male reproductive system is on the outside of your abdominal cavity or pelvis. The external body parts include your penis, scrotum and testicles. Other names for these parts are genitals or genitalia.

~ Penis:

The penis is the male organ for sexual intercourse.

It contains many sensitive nerve endings, and it has three parts:

1. Root-

  • The root is the base of your penis.
  • It attaches to the wall of your abdomen.


2. Body (shaft)-

  • The body has a shape like a tube or cylinder.
  • It consists of three internal chambers: the two larger chambers are the corpora cavernosa, and the third chamber is the corpus spongiosum.
  • The corpora cavernosa run side by side, while the corpus spongiosum surrounds your urethra.
  • There’s a special, sponge-like erectile tissue inside these chambers. The erectile tissue contains thousands of spaces. During sexual arousal, the spaces fill with blood, and our penis becomes hard and rigid (erection). An erection allows you to have penetrative sex. The skin of our penis is loose and stretchy, which lets it change size when you have an erection.

3. Glans (head)-

  • The glans is the cone-shaped tip of our penis.
  • A loose layer of skin (foreskin) covers your glans.
  • Healthcare providers sometimes surgically remove the foreskin (circumcision).
  • In most people, the opening of the urethra is at the tip of the glans.
  • The urethra transports pee and semen out of your body. Semen contains sperm.
  • You expel (ejaculate) semen through the end of your penis when you reach sexual climax (orgasm).

When our penis is erect, our corpora cavernosa press against the part of our urethra where pee flows. This blocks our pee flow so that only semen ejaculates when we orgasm.

Normal size of the penis-  Studies suggest that the average penis is about 3.5 inches (8.9 cm) when flaccid (soft) and a little more than 5 inches (13 cm) when erect.

~ Scrotum:

  • Our scrotum is the loose, pouch-like sac of skin that hangs behind your penis.
  • It holds your testicles (testes) as well as nerves and blood vessels.
  • Our scrotum protects your testicles and provides a sort of “climate-control system.”
  • For normal sperm development, your testes must be at a temperature that’s slightly cooler than body temperature (between 97 and 99 degrees Fahrenheit or 36 and 37 degrees Celsius).
  • Special muscles in the wall of your scrotum let it contract (tighten) and relax.
  • Our scrotum contracts to move your testicles closer to your body for warmth and protection.
  • It relaxes away from your body to cool them.

~ Testicles: 

  • Our testicles (testes) are oval-shaped organs that lie in your scrotum.
  • They’re about the size of two large olives.
  • The spermatic cord holds your testicles in place and supplies them with blood. Most people have two testicles, on the left and right side of their scrotum.
  • Our testicles make testosterone and produce sperm. Within your testicles are coiled masses of tubes.
  • These are the seminiferous tubules.
  • The seminiferous tubules produce sperm cells through spermatogenesis.

~ Epididymis:

  • Our epididymis is a long, coiled tube that rests on the back of each testicle.
  • It carries and stores the sperm cells that your testicles create.
  • Our epididymis also brings the sperm to maturity — the sperm that emerge from your testicles are immature and incapable of fertilization.
  • During sexual arousal, muscle contractions force the sperm into your vas deferens.
external-male-reproductive-parts
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2. Internal – Male Reproductive Parts:


There are several internal (accessory) organs in the male reproductive system. They include:

~ Vas deferens:

  • Our vas deferens is a long, muscular tube that travels from the epididymis into our pelvic cavity,
  • just behind your urinary bladder.
  • Our vas deferens transports mature sperm to the urethra in preparation for ejaculation.

~ Ejaculatory ducts:

  • Each testicle has a vas deferens that joins with seminal vesicle ducts to form ejaculatory ducts.
  • The ejaculatory ducts move through your prostate, where they collect fluid to add to semen.
  • They empty into your urethra.

~ Urethra:

  • The urethra is the tube that carries pee from your bladder outside of your body.
  • If you have a penis, it also ejaculates semen when you reach orgasm.

~ Seminal vesicles: 

  • Our seminal vesicles are sac-like pouches that attach to our vas deferens near the base of our bladder.
  • Seminal vesicles make up to 80% of your ejaculatory fluid, including fructose.
  • Fructose is an energy source for sperm and helps them move (motility).

~ Prostate gland:

  • Our prostate is a walnut-sized gland that rests below your bladder, in front of your rectum.
  • Our prostate adds additional fluid to ejaculate, which helps nourish sperm. Your urethra runs through the center of your prostate gland.

~ Bulbourethral (Cowper) glands:

  • Our bulbourethral glands are pea-sized structures on the sides of our urethra,
  • just below our prostate.
  • They create a clear, slippery fluid that empties directly into our urethra.
  • This fluid lubricates our urethra and neutralizes any acids that may remain from your pee.

Function

~ What does the urethra do?

The organs that make up the male reproductive system perform the following:

  • Produce, maintain and transport sperm cells and semen.
  • Sperm cells are male reproductive cells. Semen is the protective fluid around sperm.
    Discharge sperm.
  • Produce and secrete male sex hormones.

~ How does the male reproductive system function?

The entire male reproductive system depends on hormones. Hormones are chemicals that stimulate or regulate activity in our cells or organs. The primary hormones that help the male reproductive system function include:

Follicle-stimulating hormone (FSH):

  • Our pituitary gland makes FSH.
  • FSH is necessary to produce sperm (spermatogenesis).

Luteinizing hormone (LH).

  • Our pituitary gland also makes LH.
  • LH is necessary to continue the process of spermatogenesis.

Testosterone:

  • Testosterone is the main male sex hormone.
  • It helps we develop certain characteristics, including muscle mass and strength, fat distribution, bone mass and sex drive (libido).

Disorders & Diseases:

Common conditions that affect the male reproductive system include:

  1. Testicular cancer
  2. Penile cancer
  3. Prostate cancer
  4. Sexually transmitted
  5. infections (STIs)
  6. Premature ejaculation
  7. Male infertility
  8. Erectile dysfunction
  9. Priapism

Reference:

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Saeed Ur Rahman Adademy Port Theme

Female Reproductive System: Structure & Function

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What is the female reproductive system?

The female reproductive system is the female body parts that help us:

  • Have sexual intercourse
  • Reproduce
  • Menstruate

What are the parts of the female reproductive system?

The female reproductive anatomy includes both external and internal parts.

  1. Internal – Reproductive Body Parts
  2. External – Reproductive Body Parts

1. Internal – Reproductive Body Parts

~ Vagina:

  • Our vagina is a muscular canal that joins the cervix (the lower part of uterus) to the outside of the body.
  • It can widen to accommodate a baby during delivery and then shrink back to hold something narrow like a tampon.
  • It’s lined with mucous membranes that help keep it moist.

~ Cervix:

  • Our cervix is the lowest part of your uterus.
  • A hole in the middle allows sperm to enter and menstrual blood to exit.
  • Our cervix opens (dilates) to allow a baby to come out during a vaginal childbirth.
  • Our cervix is what prevents things like tampons from getting lost inside your body.

~ Uterus:

  • Our uterus is a hollow, pear-shaped organ that holds a fetus during pregnancy.
  • Our uterus is divided into two parts: the cervix and the corpus.
  • Our corpus is the larger part of your uterus that expands during pregnancy.

~ Fallopian tubes:

  • These are narrow tubes that are attached to the upper part of your uterus and serve as pathways for our egg (ovum) to travel from your ovaries to your uterus.
  • Fertilization of an egg by sperm normally occurs in the fallopian tubes.
  • The fertilized egg then moves to the uterus, where it implants into your uterine lining.

~ Ovaries:

  • Ovaries are small, oval-shaped glands that are located on either side of your uterus.
  • Our ovaries produce eggs and hormones.
female-reproductive-system

2. External – Reproductive Body

  • The function of your external genitals are to protect the internal parts from infection and allow sperm to enter our vagina.
  • Our vulva is the collective name for all our external genitals. A lot of people mistakenly use the term “vagina” to describe all female reproductive parts. However, your vagina is its own structure located inside your body.
  • The main parts of your vulva or external genitals are:

~ Labia majora:

  • Our labia majora (“large lips”) enclose and protect the other external reproductive organs.
  • During puberty, hair growth occurs on the skin of the labia majora, which also contain sweat and oil-secreting glands.

~ Labia minora:

  • Our labia minora (“small lips”) can have a variety of sizes and shapes.
  • They lie just inside your labia majora, and surround the opening to your vagina (the canal that joins the lower part of your uterus to the outside of your body) and urethra (the tube that carries pee from your bladder to the outside of your body).
  • This skin is very delicate and can become easily irritated and swollen.

~ Clitoris:

  • Our two labia minora meet at your clitoris, a small, sensitive protrusion that’s comparable to a penis.
  • Our clitoris is covered by a fold of skin called the prepuce and is very sensitive to stimulation.

~ Vaginal opening:

  • Our vaginal opening allows menstrual blood and babies to exit your body.
  • Tampons, fingers, sex toys or penises can go inside your vagina through your vaginal opening.

~ Hymen:

  • Our hymen is a piece of tissue covering or surrounding part of your vaginal opening.
  • It’s formed during development and present during birth.

~ Opening to Our urethra.

  • The opening to your urethra is the hole you pee from.
  • The urethra is part of your urinary system.
  • This system is made up of your kidneys, bladder, ureters and urethra.
  • Our kidneys clean your blood and produce urine, a waste product.
  • From your two kidneys, two ureters move the urine to the bladder, where it’s stored until you urinate (pee).
female-reproductive-system

References:

  • Australian Government Department of Health and Aged Care, Healthdirect. Female reproductive system (https://www.healthdirect.gov.au/female-reproductive-system). Accessed 11/28/2022.
  • Merck Manual. Menstrual Cycle (https://www.merckmanuals.com/home/women-s-health-issues/biology-of-the-female-reproductive-system/menstrual-cycle). Accessed 11/28/2022.
  • Planned Parenthood. What are the parts of the female sexual anatomy? (https://www.plannedparenthood.org/learn/health-and-wellness/sexual-and-reproductive-anatomy/what-are-parts-female-sexual-anatomy) Accessed 11/28/2022.
  • The American College of Obstetricians and Gynecologists. Your Changing Body: Puberty in Girls (https://www.acog.org/Patients/FAQs/Your-Changing-Body-Puberty-in-Girls-Especially-for-Teens). Accessed 11/28/2022.
  • US Department of Health and Human Services, Office on Women’s Health. How the female reproductive system works (https://www.girlshealth.gov/body/reproductive/system.html). Accessed 11/28/2022.
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LE Cell Test (Lupus Erythematosus Cell Test)

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Intro:

  • The LE cell test is a hematological test historically used in the diagnosis of Systemic Lupus Erythematosus (SLE).
  • LE cells are a specific type of neutrophil or other phagocyte that has engulfed the denatured nuclear material (homogenized chromatin) of another cell, forming a homogeneous, round body known as an LE body or hematoxylin body.
  • While modern tests like ANA (antinuclear antibody) and anti-dsDNA antibody assays have largely replaced the LE cell test, it still holds historical importance and basic relevance in educational and diagnostic contexts.

About L.E. Cell Test:

LE Cell: A neutrophil or monocyte containing an engulfed, homogenous, smooth, round, purple-staining body (LE body) in its cytoplasm, formed due to phagocytosis of denatured nuclear material coated with autoantibodies.

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Reticulocyte Count

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About Reticulocyte:

  • Reticulocytes are immature red blood cells (RBCs) that are recently released from the bone marrow into the bloodstream.
  • They still contain remnants of ribosomal RNA, which appear as a fine, reticular (mesh-like) network when stained with supravital stains like new methylene blue or brilliant cresyl blue.

Why Reticulocyte Count is Important?

  • Reticulocyte count helps assess bone marrow function.
  • It indicates the rate of RBC production.
  • Used to monitor response to anemia treatment or bone marrow recovery.

 

Normal Reticulocyte Count

  • Adults: 0.5 – 2.5% of RBCs

  • Infants: 2 – 6%

  • Absolute Reticulocyte Count (ARC): 25,000 – 75,000/µL

Clinical Significance or Indication

Condition       Reticulocyte Count
1. Iron deficiency anemia                 Decreased or  normal
2. Hemolytic anemia                  Increased
3. Aplastic anemia                  Decreased
4. After blood loss or therapy                  Increased (reticulocytosis)

Types of Reticulocyte Count

  1. Relative Reticulocyte Count – % of total RBCs.

  2. Absolute Reticulocyte Count – Actual number per µL.

  3. Corrected Reticulocyte Count (CRC) – Adjusted for low hematocrit.

  4. Reticulocyte Production Index (RPI) – Assesses bone marrow response in anemia.

 

Methods of Reticulocyte Count

1. Manual Method (Supravital Staining Method)

Principle:

When blood is mixed with a supravital stain (e.g., new methylene blue), reticulocytes precipitate their residual RNA as dark blue granules or network.

Requirements:

  • Fresh EDTA blood sample

  • Supravital stain (e.g., new methylene blue) – Brilliant Cresyl Blue Stain

  • Microscope

  • Slides and cover slips

Reagent Preparation:

Reagents Needed:

  • Brilliant Cresyl Blue (BCB) – 1 g
  • Sodium Citrate (Na₃C₆H₅O₇) – 0.7 g
  • Sodium Chloride (NaCl) – 0.9 g
  • Distilled Water – up to 100 mL

 

Procedure:

  1. Mix equal parts of blood and stain (usually 2–3 drops).

  2. Incubate at room temperature for 15–20 minutes.

  3. Prepare smears from the mixture.

  4. Allow them to air-dry.

  5. Examine under oil immersion (100x).

  6. Count reticulocytes among 1000 RBCs.

Calculation:

Reticulocyte-count-Estimation-Methods-calculation

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PC – Platelet Count: Methods, Merits & Demerits

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About Platelet:

  • Platelets, also known as thrombocytes, are small, anucleated blood cells essential for blood clotting and maintaining vascular integrity.
  • A platelet count is a part of the Complete Blood Count (CBC) and is vital in diagnosing bleeding disorders, thrombocytopenia, thrombocytosis, and monitoring therapies like chemotherapy or anticoagulant use.

Normal Platelet Count

  • Adults: 1.5 – 4.5 lakh/cu mm (150,000 – 450,000/µL)

  • Newborns: 1.0 – 4.5 lakh/cu mm

  • Critical Values:

    • Below 20,000/µL: Risk of spontaneous bleeding

    • Above 10 lakh/µL: Risk of thrombosis

Functions of Platelets

  • Initiate clot formation (hemostasis)

  • Maintain endothelial integrity

  • Involved in inflammation and wound healing

Methods of Platelet Count Determination

  1. Manual Method (Rees-Ecker Method / Improved Neubauer Chamber Method.
  2. Automated Platelet Count (Hematology Analyzer)

1. Manual Method (Rees-Ecker Method or Improved Neubauer Chamber Method)

Principle:
  • A diluting fluid is used to lyse RBCs and stain platelets.
  • The diluted blood is then charged on a Neubauer counting chamber, and platelets are counted under a microscope.

Rees-Ecker Method (Manual Count)

Reagents:

  • Rees-Ecker diluting fluid:

    • Sodium citrate – prevents clotting

    • Brilliant cresyl blue – stains platelets

    • Formalin – fixes platelets

    • Distilled water – diluent

Procedure:

  1. Mix fresh anticoagulated blood (EDTA) with diluting fluid in a 1:200 dilution.

  2. Fill the Improved Neubauer hemocytometer with the diluted sample.

  3. Allow platelets to settle for 10–15 minutes.

  4. Count platelets in the entire central large square (25 small squares).

  5. Multiply the number of platelets by the dilution factor to get platelet count per µL.

Merits:

  • Inexpensive

  • Does not require automated analyzers

Demerits:

  • Time-consuming

  • Platelets may clump or be confused with debris

  • Needs good microscopy skill

Calculation:
Hemoglobin-Estimation-Methods-05-18-2025_08_16_AM

2. Automated Platelet Count (Hematology Analyzer)


Principle: 
  • Uses electrical impedance or optical flow cytometry.
  • Platelets are counted based on size and internal complexity.
Procedure:


Whole blood is aspirated by the analyzer.

Platelets are distinguished from RBCs and WBCs by size and counted electronically.

Results displayed along with other CBC parameters.

Merits:
  • Accurate, fast, and reproducible
  • No observer bias
  • Can also provide Platelet Distribution Width (PDW) and Mean Platelet Volume (MPV)
Demerits:
  • Expensive equipment
  • May misclassify clumped platelets or large platelets
  • Requires maintenance and electricity

3. Peripheral Blood Smear (Cross-check Method)


Principle:
Estimate platelet count by comparing them with RBCs under oil immersion in a stained smear (Leishman/Wright).

Procedure:
Prepare and stain a thin blood smear.

Under oil immersion (100x), count platelets in 10 fields.

Average number per field × 15,000 = Approximate count per µL.

Merits:

  • Simple
  • Helps detect clumping or morphological abnormalities

Demerits:

  • Rough estimation only.
  • Subjective and not suitable for precise counting

Causes of Abnormal Platelet Count:

Condition Count Examples
Thrombocytopenia             Low (<150,000)                           Dengue, leukemia, bone marrow failure, ITP
Thrombocytosis             High (>450,000)                         Infections, iron deficiency, myeloproliferative disorders

Sources of Error

  • Clotted sample
  • Platelet clumping (EDTA-induced)
  • Misidentification of debris or cells
  • Inadequate mixing of blood before sampling

Precautions

  • Use fresh EDTA blood (<2 hours old)
  • Mix well before testing
  • Avoid hemolysis
  • Clean counting chamber and cover slip

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Hb – Hemoglobin Estimation – Methods, Merits, and Demerits

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Introduction

  • Hemoglobin is a conjugated protein present in red blood cells (RBCs).
  • It consists of a pigment part called heme which contains iron and a protein part called globin and 
  • Hemoglobin plays a vital role in transporting oxygen from the lungs to tissues and returning carbon dioxide from tissues to the lungs.
  • After the normal life span of RBC (over 120 days), the red cells are destroyed by the reticuloendothelial cells (specially in the spleen) and the components of the hemoglobin undergo metabolic degeneration.

Normal Hemoglobin Values

  • Men: 13.5 – 17.5 g/dL

  • Women: 12.0 – 15.5 g/dL

  • Children: 11.0 – 13.0 g/dL

  • Newborns: 14.0 – 24.0 g/dL

Clinical Importance of Hemoglobin Estimation

  • Diagnosis of anemia and polycythemia.

  • Monitoring response to treatment in anemic patients.

  • Evaluation of blood loss.

  • Pre-operative assessment.

  • Nutritional assessment in populations.

Methods of Hemoglobin Estimation

Several methods are available for the estimation of hemoglobin. The most commonly used are:

1. Sahli’s (Acid Hematin) Method

2. Cyanmethemoglobin Method (Drabkin’s Method)

3. Hemoglobin Color Scale (WHO Scale)

4. Automated Hematology Analyzer

5. Tallqvist Method (Historical/Obsolete)

1. Sahli’s (Acid Hematin) Method

Principle:

  • Hemoglobin is converted into brown-colored acid hematin by reacting with hydrochloric acid (N/10 HCl).
  • The color is matched against a standard comparator.

Procedure:

  1. Add 0.1N HCl into the Sahli’s hemoglobinometer tube up to the mark.

  2. Add blood using a pipette (usually 20 µL).

  3. Mix and let it stand for 10 minutes.

  4. Dilute with distilled water till the color matches the standard.

  5. Read the value on the graduated tube.

Merits:

  • Simple and inexpensive.

  • Suitable for fieldwork and small labs.

Demerits:

  • Subjective color matching.

  • Less accurate.

  • Interference by abnormal hemoglobins or lipemia.

2. Cyanmethemoglobin Method (Drabkin’s Method)

Principle:

Blood is mixed with Drabkin’s reagent which contains potassium ferricyanide and potassium cyanide. Hemoglobin is converted into stable cyanmethemoglobin which is measured spectrophotometrically at 540 nm.

Procedure:

  1. Add 20 µL blood to 5 mL Drabkin’s reagent.

  2. Mix and wait for 5–10 minutes.

  3. Measure absorbance at 540 nm.

  4. Compare with standard or calibration curve.

Merits:

  • Highly accurate and reproducible.

  • International reference method.

  • Measures all types of hemoglobin except sulfhemoglobin.

Demerits:

  • Toxic reagents (cyanide).

  • Requires spectrophotometer.

  • Not ideal for field settings.

3. Hemoglobin Color Scale (WHO Scale)

Principle:

Capillary blood is compared with a printed color scale to estimate hemoglobin.

Merits:

  • Inexpensive.

  • Easy to use in remote areas.

Demerits:

  • Highly subjective.

  • Less accurate.

  • Not suitable for clinical diagnosis.

4. Automated Hematology Analyzer

Principle:

Measures hemoglobin through photometric or electrical impedance method. Usually uses cyanmethemoglobin or sodium lauryl sulfate (SLS) method.

Merits:

  • Accurate and fast.

  • Provides complete blood count (CBC) with hemoglobin.

  • Ideal for large laboratories.

Demerits:

  • Expensive instruments.

  • Requires maintenance and electricity.

  • Not suitable for small clinics or field use.

Hemoglobin-Estimation-Methods

5. Tallqvist Method (Historical/Obsolete)

Principle:

Blood on filter paper is compared with a color scale.

Merits:

  • Very simple and portable.

Demerits:

  • Crude and inaccurate.

  • Not used in modern clinical practice.

Conclusion

Hemoglobin estimation is a vital diagnostic procedure. The method chosen depends on the available resources, setting (lab vs. field), and purpose (screening vs. diagnosis). For clinical accuracy, the cyanmethemoglobin method is the most reliable, while Sahli’s method remains a practical tool in limited-resource settings.

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What Is ESR Test?

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What Is ESR Test?

The erythrocyte sedimentation rate (ESR or sed rate) is the rate of sedimentation or settlement of RBCs at which red blood cells in anticoagulated whole blood settled  in a standardized tube or EDTA tube over a period of one hour.

ESR is a common hematology test, and is a non-specific measure of inflammation. 

Clinical Significance

  • The Erythrocyte Sedimentation Rate (ESR) test is a commonly performed in the Hematology laboratory for the prognostic purpose that may indicate and monitor an increase in inflammatory activity within the body caused by one or more conditions such as chronic inflammatory disease, autoimmune disease, anemia, infections, and malignancies.
  • The ESR test is not specific for any single disease but is used in combination with other tests to determine the presence of increased inflammatory activity.
  • The ESR has long been used as a “sickness indicator” due to its reproducibility in both hematological and non hematological.
  • When anticoagulated blood is allowed to stand undisturbed condition for a period of time, the erythrocytes tends to sink to the bottom.
  • Two layers are formed, the upper plasma layer and lower sedimented erythrocyte layer. The rate at which the red cells fall is knows as Erythrocyte Sedimentation Rate (ESR).

Determination of ESR is done by several methods and their Specific Values:

Determination of ESR is done by several methods. These are as follows:

  1. Westergren method.
  2. Wintrobe method
  3. Landu method.

In the developing countries former two methods are used for ESR determination in the laboratory.

Wintrobe’s tube :

  • It is 110 mm long tube with a 3.0 mm internal bore.
  • It is graduated from ‘0’ upto ‘100’ mm (10 cm).
  • The scale with the descending order is used for ESR determination.
  • It is also used for Packed Cell determination.

Westergren’s tube :

  • It is 300 mm long  tube with a 2.5 mm internal bore.
  • It is graduated from ‘0’ upto ‘200’ mm (20 cm).
  • The scale with descending order is used for ESR determination.
  • It is more specific then the Wintrobe’s method and others methods.

Normal value :

  1. By Westergren’s method :
    Male : 0-15 mm/1st hour
    Female : 0-20 mm/ 1st hour
  2. By Wintrobe’s method :
    Male : 0-9 mm/1st hour
    Female : 0-20 mm/ 1st hour

High ESR Test Result (Red blood cells sink faster than normal):

May be caused by inflammation from conditions such as:

  • Giant cell arteritis
  • Arthritis
  • Systemic vasculitis
  • Polymyalgia rheumatica
  • Inflammatory bowel disease
  • Kidney disease
  • Infections
  • Rheumatoid arthritis and other autoimmune diseases
  • Heart disease
  • Certain cancers

Low ESR Test Result (Red blood cells sink slower than normal):

May be caused by conditions such as:

  • Blood disorders:
  • Polycythemia (increased red blood cells)
  • Sickle cell disease (SCD)
  • Leukocytosis (high white blood cell count)
  • Heart failure
  • Certain kidney and liver problems

Additional Notes:

Abnormal ESR results don’t always indicate a medical condition needing treatment.

ESR levels vary based on:

Age and sex

Pregnancy

Menstrual cycle

Aging

Obesity

Alcohol consumption

Exercise

Certain medicines and supplements can affect ESR results.

Determination Of ESR By Westergren’s Method : 


Principle of the Test : 

When anticoagulated blood is allowed to stand undisturbed condition for a period of time, the erythrocytes tends to sink to the bottom. Two layers are formed, the upper plasma layer and lower sedimented erythrocyte layer. The rate at which the red cells fall is knows as Erythrocyte Sedimentation Rate (ESR) and give the result as mm/1st hour.

Specimen :

  • Patient should be fasting for 12 to 16 hours.
  • Collect venous blood.
  • 2.0 ml of blood is collected in a vial containing 0.5 ml of 3.8% Sodium citrate anticoagulant.
  • Fasting EDTA (Ethyl Di-amine Tetra Acetic acid) anticoagulated whole blood is also used for ESR determination.

Requirements :

  • Westergren’s tube with stand.
  • Test tube with test tube rack.
  • 3.8 % Sodium Citrate solution.
  • Stop watch.
  • Blood drawer.

Procedure :

  1. Blood drawer attached with clean and dry Westergren’s tube.
  2. Drawn 3.8% sodium citrate upto ‘150’ mark from ‘200’ mark in a test tube.
  3. Drawn well mixed anticoagulated blood upto ‘0’ mark from ‘200’ mark of the tube and mixed with 3.8% sodium citrate present in the test tube.
  4. Mixed well, filled the Westergren tube exactly upto ‘0’ mark (avoid air bubbles formation in the tube).
  5. Placed the tube upright position in the ESR stand, it should fit evenly into the groove of the stand and it allowed standing undisturbed condition exactly for 1 hour.
  6. Set the time in Stopwatch.
  7. Exactly after 1 hour, note the level to which the red cell column has fallen.
  8. Report the result in terms of mm/1st hour.
Westergren's Tube and Wintrobe Tube
Diagram : Westergren’s Tube and Wintrobe Tube

Determination Of ESR By Wintrobe Method :

Principle of the Test :

When anticoagulated blood is allowed to stand undisturbed condition for a period of time, the erythrocytes tends to sink to the bottom. Two layers are formed, the upper plasma layer and lower sedimented erythrocyte layer. The rate at which the red cells fall is knows as Erythrocyte Sedimentation Rate (ESR) and give the result as mm/1st hour.

Specimen :

Fresh fasting (12 to 16 hours fasting) Ethyl Di-amine Tetra Acetic acid (EDTA) anticoagulated and undiluted whole blood.

Requirement :

  • Wintrobe’s tube with stand.
  • Special Pasteur pipette attached with rubber tied.
  • Stop watch.

Procedure :

  1. Mixed the blood carefully in the vial.
  2. Filled the Wintrobe’s tube to the ‘0’ mark by using a special Pasteur pipette.
  3. Placed the tube in exact vertical position in the stand.
  4. Set the Stop-watch for 1 hour.
  5. At the end of one hour note the level of erythrocyte column and give the result in terms of mm after first one hour (mm/ 1st hour).

Related Questions – Answers

Q1. What is the ESR Test?

Answer: The ESR (Erythrocyte Sedimentation Rate) test measures how quickly red blood cells (RBCs) settle at the bottom of a test tube containing anticoagulated blood over one hour. It’s a common hematology test used as a non-specific marker of inflammation.

Q2. Why is the ESR Test done?

Answer :  The ESR test is used to:

  • Detect and monitor inflammation in the body.

  • Assist in diagnosing conditions like autoimmune diseases, chronic infections, anemia, and some cancers.

  • Track the progress of certain diseases or the effectiveness of treatments.

Q3. Is ESR specific to any disease?

Answer: No, ESR is not specific to a single disease. It is a general indicator of inflammation and should be interpreted alongside other clinical tests and findings.

Q4. How is ESR measured?

Answer: ESR can be determined by several methods:

  • Westergren Method (more commonly used, especially in developed countries)

  • Wintrobe Method

  • Landau Method (less commonly used)

Q5. What is the difference between Westergren and Wintrobe methods?
Feature Westergren Method Wintrobe Method
Tube Length 300 mm 110 mm
Internal Bore 2.5 mm 3.0 mm
Measurement Range 0-200 mm 0-100 mm
Sensitivity More sensitive and preferred Less sensitive
REFERENCES
Practical Hematology, Dacie & Lewis: 12th edition
Clinical Diagnosis & management by laboratory methods, Henry’s: 21st edition
Text Book of Medical Laboratory Technology, Dr. P.B. Godkar & Dr. D.P. Godkar : 5th edition
Practical Medicine, P.J. Mehta’s : 20th edition
growth

The Layers of the Hair Shaft

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Introduction

The hair shaft is a critical structural component of human hair. It is visible above the skin surface and is composed of three distinct layers: Cuticle, Cortex, and Medulla. These layers are integral to the texture, strength, and overall health of hair.

Let’s delve into the anatomy and functions of these layers, their patterns, and their roles in maintaining healthy hair.

1. What is the Hair Shaft?

The hair shaft is the portion of hair visible above the skin’s surface. It is analogous to a pencil’s structure:

  • The outer colored layer of a pencil represents the cuticle.
  • The wooden part corresponds to the cortex.
  • The graphite center mirrors the medulla.

The hair shaft is composed of keratinized (dead) cells that serve aesthetic and protective functions.

2. Layers of the Hair Shaft

The hair shaft consists of three distinct layers, each contributing uniquely to hair’s characteristics.

a. Cuticle Layer

  • Description: The outermost transparent layer made of 5-10 thin, non-pigmented, keratinized cells arranged like roof tiles or fish scales.

  • Function:

    • Shields the cortex and medulla from damage caused by chemicals, pollutants, or physical stress.
    • Controls water content and moisture balance.
    • Reflects light, giving hair a shiny appearance.

  • Patterns:

    • Coronal (crown-like, in rodents and bats).
    • Spinous (petal-like, in seals and cats).
    • Imbricate (flattened scales, typical in humans).

  • Impact of Damage:

    • Healthy Cuticle: Smooth with intact scales, making hair shiny and strong.
    • Damaged Cuticle: Jagged with exposed inner layers, leading to dull, brittle, and frizzy hair.

b. Cortex Layer

  • Description: The thickest intermediate layer, accounting for 90% of the hair shaft. It lies beneath the cuticle and surrounds the medulla.

  • Structure:

    • Composed of cortical cells connected by intercellular lipoproteins.
    • Contains pigment granules that determine hair color (e.g., melanin for black color, absence of melanin for gray/white hair).
    • Encloses macrofibrils and microfibrils made of keratin protein.

  • Functions:

    • Provides hair strength, elasticity, and texture.
    • Determines hair’s natural color and resilience.

  • Special Feature: The hydrogen bonds and disulfide bonds in keratin proteins give the hair its flexibility and tensile strength.

c. Medulla Layer

  • Description: The innermost core of the hair shaft, also called the medullary canal or pith.

  • Structure:

    • Composed of loosely packed, transparent cells and air spaces.
    • May be fragmented, continuous, or interrupted depending on hair type.

  • Presence:

    • Typically found in thick or coarse hair.
    • Absent in finer hair types.

  • Function:

    • Provides minimal structural support.
    • May influence the hair’s insulating properties.

3. Practical Demonstration

Activity: Observing the Hair Shaft Under a Microscope

  1. Materials:
    • Hair strands (different types: straight, curly, thick, fine).
    • Microscope.
  2. Procedure:
    • Examine the outer layer (cuticle) for its scale-like pattern.
    • Observe the cortex for pigmentation and fibril structures.
    • Look for the presence or absence of the medulla in various hair types.

Observation:

  • Discuss how the differences in hair layers influence hair’s appearance and texture.

4. Discussion and FAQs

  1. Why does damaged hair appear dull and frizzy?

    • A damaged cuticle exposes the cortex, leading to moisture loss and rough texture.

  2. What determines hair color?

    • Melanin pigment in the cortex. Variations in its density and type (eumelanin for black/brown, pheomelanin for red) result in different hair colors.

  3. Why is the medulla absent in fine hair?

    • The medulla provides structural support in coarse hair, which is not as necessary for finer hair types.

  4. How can we protect the cuticle layer?

    • Avoid harsh chemicals, excessive heat, and rough brushing.
    • Use conditioners to maintain moisture balance.

Conclusion

The hair shaft’s structure, particularly its layers (cuticle, cortex, and medulla), determines hair’s strength, texture, and appearance. A deeper understanding of these layers aids in maintaining healthy hair and identifying the causes of hair damage. By protecting the cuticle and supporting the cortex, we can enhance the overall health of our hair.

Would you like to explore hair follicle anatomy or the physiology of hair growth next?

Layers-of-hair-shaft

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Sterilization of Glassware Using a Hot Air Oven

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Objective:

To sterilize laboratory glassware (such as test tubes, petri dishes, and pipettes) using a hot air oven and understand its working principle.

Materials Required:

  1. Hot air oven
  2. Glassware (test tubes, petri dishes, flasks, etc.)
  3. Aluminum foil or paper for wrapping
  4. Heat-resistant gloves
  5. Temperature indicator strips (optional)

Principle:

A hot air oven sterilizes objects by applying dry heat. It kills microorganisms by oxidation, destroying proteins and denaturing enzymes. Dry heat is particularly effective for glassware, powders, and instruments that may corrode with moist heat.

Procedure:

  1. Preparation of Glassware:

    • Wash all glassware thoroughly and allow it to dry completely.
    • Wrap test tubes, petri dishes, and other items in aluminum foil or paper to prevent contamination.

  2. Loading the Oven:

    • Arrange the glassware inside the hot air oven in such a way that air can circulate freely around each item.
    • Avoid overcrowding.

  3. Setting the Oven:

    • Close the door securely.
    • Set the temperature to 160–180°C (the standard sterilization temperature for glassware).
    • Set the timer for 2 hours at 160°C or 1 hour at 180°C.

  4. Sterilization:

    • Start the oven and ensure it maintains the set temperature throughout the process.
    • Observe the oven’s indicator light or temperature gauge.

  5. Cooling and Removal:

    • Once the time is up, turn off the oven and allow it to cool down naturally to about 40–50°C before opening the door.
    • Using heat-resistant gloves, remove the sterilized glassware.

  6. Storage:

    • Store the sterilized items in a clean, contamination-free area until use.

Observations:

  • Check the glassware for any visible signs of damage (cracks due to high temperature).
  • If temperature indicator strips are used, confirm that the required temperature was achieved.

Results:

The glassware should be sterile and free from microorganisms, ready for use in experiments.

Precautions:

  1. Ensure all glassware is heat-resistant (e.g., borosilicate).
  2. Do not overload the oven to ensure proper airflow.
  3. Always use gloves to handle hot items.
  4. Avoid opening the oven during sterilization as it can affect the temperature consistency.

Conclusion:

The hot air oven effectively sterilized the glassware at high temperatures, demonstrating the efficiency of dry heat sterilization for non-heat-sensitive materials.

Sterilization of Glassware Using a Hot Air Oven

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