Reproduction Prelims

• Sperm undergoes second meiosis division to form four spermatids with 23 single-stranded chromosomes.
• First meiosis division results in two secondary spermatocytes, each with 23 chromosomes that become double-stranded.
• Primary spermatocytes have 2n=46 chromosomes.
• Spermatogonium with 2n=46 chromosomes multiply by mitosis.
• Sperm morphology includes a head containing DNA and acrosome, a midpiece with mitochondria for ATP production, and a tail for locomotion.
• Male glands include seminal vesicles, prostate, and Cowper's glands, which secrete seminal fluid.
• Semen is a mixture of sperm and seminal fluid, with substances such as fructose, coagulation proteins, enzymes, and prostaglandins.
• Hormonal control of male physiology involves the hypothalamus secreting GnRH, anterior pituitary secreting FSH and LH, and testosterone stimulating spermatogenesis.
• Puberty in males is characterized by reproductive system maturation, elevated FSH and LH levels, and the development of secondary sexual characteristics.
• Effects of testosterone include spermatogenesis, development of secondary male sexual characteristics, and sensory impulses for sexual response.
• Emission and ejaculation involve muscle contractions, propulsion of fluids through reproductive ducts, and the release of prostatic fluid.
• Erection is initiated by sexual stimulation and involves the dilation of arterioles supplying the penis.
• The nervous, endocrine, skeletal, muscular, cardiovascular, integumentary, and lymphatic systems all have effects on the reproductive system and are influenced by sex hormones.
• Respiratory system: Provides oxygen and removes carbon dioxide. Sexual arousal increases respiration. Helps maintain the body's pH.
• Digestive system: Provides nutrients. Developing fetus crowds digestive organs.
• Urinary system: Removes waste production. Developing fetus compresses the urinary bladder. Helps maintain the body's pH, ions, and water balance. Urethra is a common passageway for sperm cells and urine in males.
• Sex: Refers to distinct biological differences between male and female. Determined by genitals and chromosomes. Begins at conception.
• Gender: Characterizes how a person presents oneself in a culture (gender role) and identifies oneself based on mental awareness (gender identity). Sex and gender are not always aligned. Intersex refers to a person who does not exhibit typical definitions of male or female.
• Libido or sex drive: Ensures the continuation of the species. Triggers desire, physiological changes, and nurturing instincts.
• Sexual act: Physical union of male and female through which human beings procreate. Characterized by penetration or insertion of the penis into the vagina.
• Attitude towards sex and sexual activity: Should be protected, rational, responsible, respectful, and consensual. Good sex happens at the right time, with the right person, and for the right reason.
• Prenatal development: Begins when a sperm fertilizes an egg. Oogenesis refers to the development of a mature egg. Spermatogenesis refers to the maturation of immature sperm. Fertilization occurs when a sperm meets an egg.
• Fertilization of an egg by a sperm results in a zygote with 46 chromosomes (23 from each parent)
• Twins can form as monozygotic (identical) or dizygotic (fraternal)
• Implantation occurs approximately a week after fertilization, with the zygote taking the form of a blastocyst
• The placenta is formed and acts as a life support system for the developing fetus
• The period of the embryo is from the 4th to 8th week of development, where body parts are formed
• The period of the fetus is from 9 weeks after conception to birth, with an increase in size and functioning systems
• Embryonic development progresses from the first month to the ninth month, with various milestones reached such as heartbeat and movement
• The mother may experience symptoms such as fatigue, nausea, and cravings during pregnancy.
• Movement of the baby from the 4th to the 5th month can cause heaviness, swollen legs, constipation, pelvic pains, frequent urination, and uterine contractions in the mother.
• General Risk Factors include nutrition, stress, and the mother's age.
• Teratogens, such as diseases, drugs, and environmental hazards, can harm the developing fetus and result in birth defects.
• Teratogens can influence prenatal development by harming specific structures at particular points in development.
• Prenatal diagnosis methods include ultrasound, amniocentesis, and chorionic villus sampling.
• Childbirth classes provide information about pregnancy and childbirth, teach pain control techniques, and can lead to less medication use during labor and a more positive experience for the mother.