- What is the Bulbourethral Gland? Pea-sized glands inferior to the prostate, produces thick - clear mucus prior to ejaculation.
- What does the mucus produced by the bulbourethral gland do? Lubricates the glans penis and neutralizes traces of acidic urine in the urethra.
- What is Semen? Mixture of Sperm and accessory gland secretions.
- What does Semen contain? Nutrients (fructose), protects and activates sperm, and facilitates their movement (e.g. relax - produced by prostate).
- What is the purpose of Prostaglandins? Decreases the viscosity of mucus in the cervix, stimulate reverse peristalsis in the uterus.
- What effect does the sperm being alkaline have on the reproductive system? Neutralizes the acid in the male urethra and female vagina.
- What do the Antibiotic chemicals of semen cause? Destroys certain bacteria.
- Why does the clotting factors cause? Coagulate semen just after ejaculation, and then fibrinolysin liquefies it
- How many mL of semen are ejaculated? 2- 5 ml.
- How much sperm is ejaculated? 20 - 150 million sperm/ml
- What is an Erection? Enlargement and stiffening of the penis from engorgement of erectile tissue with blood.
- What initiates an erection? Sexual stimuli (Touch and mechanical stimulation of the penis, erotic sights, sounds, and smells). Can be induced or inhibited by emotions or higher mental activity
- What is the physiology of an erection? The parasympathetic reflex promote release of nitric Oxide which causes erectile tissue to fill with blood. The copora cavernosa expands compressing drainage veins and maintains engorgement; while corpus spongiosum keeps the urethra open.
- What is impotence? The inability to attain erection
- What is Ejaculation? Propulsion of semen from the male duct system and initiates a sympathetic spinal reflex
- What does the Sympathetic spinal reflex cause? Ducts and accessory glands to contract and empty their contents, bladder sphincter muscle to constrict, preventing the expulsion of urine, bulbospongiosus muscle to undergo a rapid series of contractions.
- What is Spermatogenesis? Sequence of events that produces sperm in the seminiferous tubules of the testes.
- What are most body cells? Diploid 2n.
- What do most body cells contain? Two sets of chromosomes (one maternal, one paternal), 23 pairs of homologous chromosomes.
- What are Gametes? Haploid (n).
- What do Gametes contain? 23 Chromosomes.
- What does gamete formation involve? Meiosis
- Describe Meiosis of gametes : Nuclear division in the gonads in which the number of chromosomes is halved (from 2n to n); two consecutive cell divisions (meiosis I and II) following one round of DNA replication; produces 4 daughter cells, and introduces genetic variation
- What is the difference in the number of divisions in mitosis and meiosis? Mitosis is one division (consisting of prophase, metaphase, anaphase, and telophase); while meiosis is two divisions (each consisting of prophase, metaphase, anaphase, and telophase. DNA replication does not occur between the two nuclear divisions.
- What is the difference in the synapsis of homologous chromosomes in mitosis and meiosis? It does not occur in mitosis. Whereas, in meiosis it occurs during mitosis I; tetrads formed, allowing crossover
- What is the difference in the daughter cell number and genetic composition in mitosis and meiosis? Mitosis: has 2. Each diploid (2n) cell is identical to the mother cell; Meiosis: has 4. Each haploid (n) cell contains half as many chromosomes as the mother cell and is genetically different from the mother cell
- What is the difference in the roles in the body in mitosis and meiosis? Mitosis: Fro development of multicellular adult from zygote. Produces cells for growth and tissue repair. Ensures constancy of genetic makeup of all body cells. Meiosis: Produces cells for reproduction (gametes). Introduces genetic variability in the gametes and reduced chromosomal number by half so that when fertilization occurs, the normal diploid chromosomal number is restored (in humans, 2n = 46)
- What is spermatogenesis? Spermatic cells give rise to sperm
- What happens during Mitosis of Spermatogenesis? Spermatogonia form Spermatocytes.
- What happens during Meiosis of Spermatogenesis? Spermatocytes form spermatids.
- What happens during Spermiogenesis? Spermatids become sperm.
- What occurs in Meiosis I? Primary spermatocyte (2n) gives way to 2 secondary spermatocytes (n)
- What occurs during Meiosis II? Each secondary spermocyte (n) gives way to 2 spermatids (n)
- What is a spermatid? Small non-motile cell close to the lumen of the tubule
- What are the major regions of sperm? The head, mid-piece, and tail
- What is the head of sperm? Genetic region; nucleus and heletlike acrosome containing hydrolytic enzymes that enable the sperm to penetrate an egg
- What is the mid-piece of sperm? Metabolic region; contains mitochondria (energy)
- What is the tail of sperm? Locomotor region; flagellum
- How are the hormones of the male reproductive system function regulated? The place where a sequence of hormonal regulatory events involving the hypothalamus, anterior pituitary gland, and the testes (hypothalamic-pituitary-gonadal (HPG) axis)
- What happens in the hypothalamic-pituitary-gonadal (HPG) axis? (1)Hypothalamus release Gonadotropin releasing hormone (GnRH); which stimulates the anterior pituitary to secrete FSH and LH. The FSH causes sustentacular cells to release androgen-binding protein (ABP), which makes permatogenic cell receptive to testosterone (enhances spermatogenesis). The LH stimulates interstitial cells to release testosterone; which is the final trigger for spermatogenesis. Until finally the hypothalamus and pituitary are inhibited by feedback mechanism (rising levels of testosterone, inhibin (released when sperm count is high))
- What is testosterone synthesized from? Cholesterol
- Why is testosterone transformed? To exert its effects on some target cells
- What are the target cells in which testosterone has to be transformed for? Dihydrotestosterone (DHT) in the prostate and Estrogen in some neurons in the brain
- What prompts spermatogenesis? Testosterone
- What does testosterone target? All accessory organs
- What does a deficiency of testosterone lead to? Atrophy
- What has multiple anabolic effects throughout the body? Testosterone
- What is the basis of the sex drive (libido) in males? Testosterone
- What are secondary sex characteristics induced by testosterone? Appearance of pubic, axillary, and facial hair, enhanced growth of the chest and deepening of the voice, skin thickens and becomes oily; bones grow and increase in density, and skeletal muscles increases in size and mass
- What are the ovaries? Female gonads.
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