6.6 Hormones, Homeostasis & Reproduction modified from Stephen Taylor i-Biology.net

The Endocrine System Key endocrine glands: A stimulus is received and processed. Hormones are secreted directly into the blood. They are carried to the target tissues (the place of intended action). The action of the hormone changes the condition of the tissue. This change in monitored through feedback. Most hormonal change results in negative feedback. Key endocrine glands: Pineal gland Pituitary gland Thyroid gland Thymus Adrenal gland Pancreas Ovary (female) Testes (male) Endocrine glands from: http://en.wikipedia.org/wiki/Endocrine_gland

The Endocrine System Key endocrine glands: A stimulus is received and processed. Hormones are secreted directly into the blood. They are carried to the target tissues (the place of intended action). The action of the hormone changes the condition of the tissue. This change in monitored through feedback. Most hormonal change results in negative feedback. Key endocrine glands: Endocrine glands from: http://en.wikipedia.org/wiki/Endocrine_gland

Male Reproductive System 6.6 S.1 Annotate diagrams of the male and female reproductive system to show names of structures and their functions Male Reproductive System

Male Reproductive System: 6.6 S.1 Annotate diagrams of the male and female reproductive system to show names of structures and their functions Male Reproductive System: 1. Epididymus: Large coiled tube (23 ft. long) that surrounds testes. Stores sperm (about 20 days). During ejaculation, about 400 million sperm cells are propelled from epididymis.

3. Ejaculatory (Sperm) Duct: 2. Vas Deferens: Long muscular ducts from scrotum to back of bladder. During ejaculation, the sperm pass from epididymis into these two ducts. *Vasectomy: Each vas deferens is cut to prevent sperm from entering urethra. 3. Ejaculatory (Sperm) Duct: Short duct after two vas deferens ducts unite. 4. Urethra: Deliver sperm to the exterior. In males, urine and sperm pass through the urethra. 5. Scrotum maintains temperature (lower than body) that sperm require for normal development

6.6 U.1 A gene on the Y chromosome causes embryonic gonads to develop as testes and secrete testosterone. Initially the development of the embryo is the same in all embryos and embryonic gonads could develop into testis of ovaries. The developmental pathway for the gonads depends on presence or absence of one gene When SRY is present the gonads develop into testes. SRY codes for a DNA binding protein called TDF (testis determining factor). TDF stimulates the expression of other genes that cause the development of the testis

Side View of Female Reproductive System 6.6 U.3 Estrogen and progesterone cause pre-natal development of female reproductive organs and female secondary sexual characteristics during puberty Side View of Female Reproductive System

1. Ovaries: Produce ova (egg) and sex hormones. 6.6 S1 Annotate diagrams of the male and female reproductive system to show names of structures and their functions. Major Organs of Female Reproductive System: 1. Ovaries: Produce ova (egg) and sex hormones. Size and shape of large almond. *Follicles: A single egg with surrounding cells that nourish and protect it. Women are born with all of their follicles (40,000 to 400,000).

Major Organs of Female Reproductive System: 2. Oviducts (Fallopian Tubes): Transport the egg from the ovary to the uterus. Fertilization occurs here. 3. Uterus Has thick walls of smooth muscle responsible for uterine contractions and cramps. Inner mucous lining, which thickens each month in preparation for pregnancy. If fertilization does not occur, breaks down and is discharged during menstruation. If fertilization occurs, the egg implants and helps support growth until the placenta develops.

5. Vagina: Thin walled, muscular chamber. 4. Cervix: Lower portion of the uterus, which projects into the vagina. 5. Vagina: Thin walled, muscular chamber. Receives the sperm and penis Acid pH kills bacteria and sperm cells Part of birth canal

6.6 U.4 The menstrual cycle is controlled by negative and positive feedback mechanisms involving ovarian and pituitary hormones. Feedback Regulation of Oogenesis feedback regulation of female reproductive cycle is negative and positive leads to female cycles hypothalamus and pituitary control ovaries ovarian hormones control uterus

Ethical Issues with in vitro fertilization Advantages of IVF: there are as many reasons for this treatment as there are people seeking this treatment. As examples •Over comes infertility •Allow families for people who must be sterilized e.g.. radiography/chemo therapy cancer patients Disadvantages of IVF: •What happens to unwanted embryo's •What happens to orphaned embryo's •Should infertility be by-passed

6.6 A.2 William Harvey’s investigation of sexual reproduction in deer Embryogenesis an early theory of egg development proposed by Aristotle. His idea called the Seed and soil theory, believed that males produce seed, females form an egg which mixes with menstrual blood to develop into a fetus inside the mother William Harvey tested this idea by shooting deer during mating season He discovered that it took months for the fertilized egg to develop in the uterus. This help debunk the idea of Spontaneous generation and lead to a better understanding of embryology. (1578-1657)

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