BIO183 Exam 4

• How many sperm cells are produced from spermatogenesis?

  4
• How many eggs are produced in oogenesis?

  1
• What are the structures involved in spermatogenesis?

  • Seminiferous tubules: The earliest stages of spermatogenesis occur closest to the lumen of the seminiferous tubules.
  • Testes: Sperm are produced in testes, which are suspended outside the body in the scrotum.
  • Internal accessory glands: Ducts connect the testes to internal accessory glands.
  • Penis: Ducts connect the testes to the penis.
• What are the structures involved in oogenesis?

  • Ovaries: Eggs are produced in the ovaries and upon fertilization develop in the uterus.
  • Uterus: Upon fertilization, eggs develop in the uterus.
  • Oviducts: The oviducts transport the egg from the ovary to the uterus.
• What is the process of spermatogenesis?

  Spermatogenesis: Mitosis of a stem cell gives rise to one cell that remains a stem cell and one cell that becomes a spermatogonium. Spermatogonium undergoes mitosis and forms two primary spermatocytes, which each undergo meiosis and form four total secondary spermatocytes; each of these undergo meiosis and form a total of 8 spermatids, which develop into 8 mature sperm.
• What is the process of oogenesis?

  Diploid primary oocyte goes to one haploid polar body and one haploid secondary oocyte. The secondary oocyte completes meiosis 2 (a second polar body is formed) and is fertilized by a mature sperm, resulting in the fertilized egg.
• Reproductive structures of males

  Male external reproductive structures include the penis and scrotum. Male reproductive internal organs are the gonads which produce sperm and hormones, accessory glands that secrete products needed for sperm movement, and ducts that carry sperm and glandular secretions.
• Hormonal Control of Human Sperm Production

  The production of sperm in human males is regulated by hormones. Specifically follicle-stimulating hormone (FSH) and luteinizing hormone (LH). FSH stimulates the Sertoli cells in the testis, which nourish developing sperm. LH stimulates the production of androgens, mainly testosterone, which in turn stimulate sperm production. The concentration of testosterone in the blood is roughly ten times higher in males than in females. The gonads are the major source of sex hormones, but the adrenal glands also secrete sex hormones in small amounts.
• (Part 1) Human ovulation involves two phases: the follicular phase and the luteal phase. The follicular phase begins on day 1 of the menstrual cycle and lasts until ovulation, which typically occurs on day 14. During this phase, the follicle grows and matures, and the endometrium of the uterus thickens in preparation for a potential pregnancy. The follicle produces estrogen, which stimulates the growth of the endometrium and inhibits the production of follicle-stimulating hormone (FSH) and luteinizing hormone (LH).
• (Pt2) At the end of the follicular phase, a surge in LH triggers ovulation, which is the release of a mature egg from the ovary. The luteal phase begins after ovulation and lasts until the start of the next menstrual cycle. During this phase, the ruptured follicle forms a corpus luteum. These hormones prepare the endometrium for implantation of a fertilized egg and inhibit the production of FSH and LH. If fertilization does not occur, the corpus luteum degenerates, and the levels of progesterone and estrogen decrease, leading to the shedding of the endometrium and starts a new menstrual cycle.
• Hormonal control of ovula. involves FSH, LH, estrogen, and progesterone. FSH and LH are produced by the anterior pituitary gland and stimulate the growth and maturation of the follicle and the production of estrogen. LH also triggers ovulation. After ovulation, the corpus luteum produces progesterone and some estrogen, which prepare the endometrium for implantation and inhibit the production of FSH and LH. If fertilization doesn't occur, the corpus luteum degenerates, and levels of progesterone and estrogen decrease, leading to the shedding of the endometrium and starts a new menstrual cycle.
• What is Corpus Leuteum?

  The corpus luteum is a secreting tissue in the ovary that forms from the collapsed follicle after ovulation and produces progesterone. It is a temporary endocrine structure that develops from the ruptured follicle after the release of the egg. The corpus luteum produces progesterone, which is essential for the maintenance of pregnancy. If pregnancy does not occur, the corpus luteum degenerates and is replaced by scar tissue. The corpus luteum is regulated by LH and FSH produced by the pituitary gland.
• What hormone is detected in pregnancy tests?

  hCG
• What is the placenta?

  The placenta is an organ that develops in the uterus during pregnancy. It is formed from the outer layer of cells of the blastocyst, called the trophoblast, and maternal tissues. The placenta is responsible for providing oxygen and nutrients to the developing fetus and removing waste products. It also produces hormones that help maintain the pregnancy and prepare the mother's body for childbirth.
• Describe the structure of the human lungs.

  Human lungs are the primary organs of the respiratory system, responsible for the exchange of gasses between the body and the environment. The lungs are located in the thoracic cavity, protected by the rib cage, and separated from the abdominal cavity by the diaphragm. The right lung has 3 lobes, while the left has two to accommodate the position of the heart.
• Anatomy of the Lungs

  • The trachea, or windpipe, carries air from the mouth and nose to the lungs.
  • The bronchi are the two branches of the trachea that enter the lungs and divide into smaller bronchioles.
  • The bronchioles further divide into tiny air sacs called alveoli, where gas exchange occurs.
  • The lungs are surrounded by a double-layered membrane called the pleura, which helps to protect and lubricate the lungs during breathing.
• Where does gas exchange occur in the lungs?

  The alveoli
• The countercurrent exchange system is where the blood flows in the opposite direction to the water passing over the gills. In fish gills, more than 80% of the O2 dissolved in the water is removed as water passes over the respiratory rate. Fish die from lack of oxygen when taken out of the water because there is not enough surface area.
• Isoosmotic solutions have the same solute concentration, while hyperosmotic solutions have a higher solute concentration. Hypoosmotic solutions have a lower solute concentration.
• Marine bony fishes, such as cod, constantly lose water by osmosis and balance water loss by drinking a lot of seawater. The excess salts ingested with seawater are eliminated through the gills and kidneys. Freshwater fish gain water and some ions in food and uptake salt ions by the gills, as well as osmotic water gain through gills and other parts of the body surface. They excrete large amounts of very dilute urine and drink almost no water to balance the uptake of water by osmosis.