Human Excretory and Reproductive System Functions
Human Excretory System and Kidney Function
Excretion is the process of eliminating waste substances resulting from cell metabolism from the blood.
Components of the Urinary System
- Kidneys: Two organs located in the rear of the abdominal cavity on both sides of the spine.
- Urinary tract: The ducts that carry urine from the kidneys to the outside of the body.
Other Excretory Organs
Besides the urinary system, other organs involved in excretion include the lungs, liver, and sweat glands.
The Nephron and Urine Formation
Nephrons are the functional units responsible for filtering and purifying blood to produce urine. The parts of a nephron include:
- Malpighian glomerulus
- Bowman's capsule
- Renal tubule
- Collecting duct
Urine is formed in two main stages: filtration of substances and reabsorption of substances.
Excretory System Diseases and Prevention
- Nephritic colic: Occurs due to the accumulation of mineral salt stones (calculi).
- Cystitis: Inflammation of the bladder wall or a urinary tract infection caused by certain microorganisms.
Prevention: Maintain proper hygiene, eat suitable food, and drink plenty of water.
Human Reproductive System and Development
The reproductive process involves the following stages:
- Production of gametes: The creation of reproductive cells.
- Fertilization: The union of two gametes inside the female reproductive tract to form a unique cell, the zygote.
- Development of the zygote: Inside the female reproductive tract, the zygote becomes an embryo and then a fetus.
- Birth: The process of delivery.
- Baby's development: The maturation of sexual organs and the transformation into an adult capable of reproducing and producing gametes.
Sperm Production
Sperm are produced continuously in the seminiferous tubules, from where they migrate over several days to the epididymis.
Phases of Childbirth
- Dilation: The cervix dilates and increases in diameter while the muscles of the vagina relax.
- Expulsion: The fetus is pushed to the outside by uterine contractions and the mother's effort using the diaphragm.
- Delivery (Placental stage): Occurring 5 to 15 minutes after expulsion, the placenta is expelled along with the remains of the endometrium.
Complications and Sterility
Common complications of childbirth include bad fetal position, inadequate cervical dilation, umbilical cord pinching, and issues with the uterus or vagina. Sterility is the impossibility of having children; the origin of this problem can be found in the man, the woman, or both.
Pregnancy and Maturity
Pregnancy is the process that starts with fertilization and ends with childbirth. During pregnancy, significant changes occur as the zygote becomes an embryo, then a fetus, and finally a fully formed human being.
- Female Gamete: Egg (Ovum)
- Male Gamete: Sperm
Stages of Life
Human development progresses through childhood, puberty, adolescence, and adulthood.