Human Blood and Reproduction: A Comprehensive Overview
Human Blood: Composition and Function
Blood is a vital red liquid circulating throughout the body’s blood vessels. The human body contains approximately five liters of blood. Its key functions include transporting substances and protecting against diseases.
Red Blood Cells (Erythrocytes)
These disc-shaped, red cells carry oxygen and carbon dioxide. They are small, biconcave cells lacking a nucleus; they are elastic and deformable. Hemoglobin is a red protein within these cells.
White Blood Cells (Leukocytes)
Irregularly shaped and nearly transparent, white blood cells combat infections from microorganisms like influenza. Larger than erythrocytes and containing nuclei, there are five types: neutrophils, eosinophils, basophils, monocytes, and lymphocytes.
Platelets (Thrombocytes)
Round-shaped platelets are responsible for blood clotting when a cut occurs. They are cellular fragments originating from giant bone marrow cells.
The Placenta
The placenta is a temporary organ in placental mammals (and some marsupials and sharks). It develops during pregnancy, supporting fetal respiration, nutrition, and excretion. It originates from the same stem cells as the embryo and has two components: a fetal portion (chorion) and a maternal portion (decidua).
Human Reproductive System
The reproductive system comprises various internal and external organs, differing between males and females. It produces gametes (reproductive cells), which, upon fertilization, create a new individual.
Musculoskeletal System
Composed of the muscular (muscles) and skeletal (bones) systems, it enables locomotion and voluntary body movements.
Circulatory System
The systemic circulation (heart to organs) is longer than the pulmonary circuit.
Menstruation
Menstruation is part of the female maturation process, enabling potential childbearing.
Assisted Reproductive Technologies
Artificial Insemination
Artificial insemination (AI) is used to treat infertility or enable pregnancy without a partner (using a sperm donor). In the latter case, the mother is the genetic parent, and the donor is the genetic father.
In Vitro Fertilization (IVF)
IVF involves fertilizing an oocyte with sperm outside the mother’s body. It’s a primary infertility treatment when other assisted reproduction methods fail.
Major Organs
Examples of major organs include the kidneys, lungs, and liver.
Stages of Childbirth
The Expansion Period
The expansion period, part of the first stage of labor, is divided into latent and active phases. The latent phase ends when the cervix is dilated to 2 cm. The active phase (2–10 cm dilation) follows, ending when the cervix is fully dilated.
Amniotic fluid may be released spontaneously or intentionally. The genital area is shaved, and an enema may be administered.
The latent phase averages 9 hours for first-time mothers and 5 hours for subsequent births. The active phase lasts approximately 2 and 5 hours, respectively.
Contractions are stronger and more frequent during the active phase (every 5 minutes).
Breathing exercises are recommended. The mother should be at the clinic during this period.
The Expulsion Period
The expulsion period, the second stage of labor, begins with complete cervical dilation and ends with the baby’s delivery. Uterine contractions reach maximum power and frequency. The mother may experience involuntary stomach muscle contractions (pujo).
This period lasts less than an hour for first-time mothers and a few minutes for subsequent births.
The Placental Period (Lighting)
After the baby and amniotic fluid are expelled, uterine contractions lessen, and the placenta is expelled. Uterine height drops. The contracted uterus prevents bleeding.
Proper assistance is crucial to prevent complications. Post-delivery checks include bladder emptying, pulse and blood pressure monitoring, and ensuring uterine contraction.
The mother may feel exhausted, cold, or sweaty after childbirth.
Postpartum care includes resting and allowing time for bonding with the baby.