HORMONES & REPRODUCTION OUTLINE

Transcription

1 1 HORMONES & REPRODUCTION Dr. Steinmetz OUTLINE 2 The Endocrine System Sexual Reproduction Hormonal Role in Sexual Differentiation Gender Differences and Gender Identity Characterizing Complex Behaviors in the CNS 1

2 OUTLINE 3 The Endocrine System Hormonal Control of Female Fertility Cycle Sexual Reproduction Hormonal Role in Sexual Differentiation Gender Differences in the CNS HORMONES 4 Hormone = chemical secreted a gland or neuron that is carried through the blood to its target (organ or neuron). Hormones have widespread effects (whole body) Neurotransmitters have localized effects (synapse) 2

3 ENDOCRINE SYSTEM Neurons located in the hypothalamus in the brain Pituitary Gland Other peripheral glands such as the liver, pancreas (digestion), thyroid (growth), ovaries / testes (reproduction) 5 5 PITUITARY GLAND Outside of the blood-brainbarrier Master Gland - regulates the output of other glands Divided into 2 parts - anterior & posterior Difference in the hormones that released and how they are released 6 6 3

4 POSTERIOR PITUITARY Neurons located in the hypothalamus release: oxytocin (sexual and parental behaviors) vasopressin (antidiuretic and vasocontriction) into the blood supply in the posterior pituitary 7 OXYTOCIN 8 4

5 ANTERIOR PITUITARY 9 9 Neurons in the hypothalamus stimulate cells in the anterior pituitary gland to release hormones Multiple specific hormones are released for each target. OUTLINE 10 The Endocrine System Sexual Reproduction Hormonal Role in Sexual Differentiation Gender Differences and Gender Identity Characterizing Complex Behaviors in the CNS 5

6 REPRODUCTIVE CYCLE HORMONES FSH - follicle-stimulating hormone (released by anterior pituitary) LH - luteinizing hormone (released by anterior pituitary) Estradiol - type of estrogen hormone (released by the follicle to act on the hypothalamus) Progesterone - hormone that has effects on peripheral tissue (uterine lining) and the hypothalamus 11 HORMONES & REPRODUCTION 12 Beginning of the cycle: anterior pituitary releases FSH triggers growth of follicle and nurturing of ovum Follicle = fluid filled pockets that contain eggs 6

7 HORMONES & REPRODUCTION 13 As the follicle matures it begins to produce estradiol which signals the anterior pituitary to release LH Estradiol LH HORMONES & REPRODUCTION 14 Surge of LH & FSH triggers release of ovum (egg) by follicle (ovulation = maximum fertility) LH & FSH affect behavior Increased sexual desire during ovulation period 7

8 15 HORMONES & REPRODUCTION Egg travels down fallopian tubes 16 HORMONES & REPRODUCTION Follicle now releases progesterone which thickens uterine lining & inhibits LH & FSH At the end of the cycle if ovum is unfertilized, then all levels decrease and the cycle restarts 8

9 HORMONES & REPRODUCTION 17 If ovum is fertilized, (pregnancy) progesterone and estradiol remain high inhibiting LH and FSH Most birth control pills / medications trick the hormone system into thinking it is pregnant by providing artificial high levels of estrogen and progesterone. PITUITARY / OVARIAN / FOLLICLE COMMUNICATION

10 19 Without looking at your notes: 1. Which line is which hormone? 2. Which step in the reproductive process does it trigger? OUTLINE 20 The Endocrine System Sexual Reproduction Hormonal Role in Sexual Differentiation Gender Differences and Gender Identity Characterizing Complex Behaviors in the CNS 10

11 WHAT DETERMINES THE SEX OF YOUR CHILD? What determines the sex of a child? 1 sex chromosome is contributed by the egg and 1 sex chromosome is contributed by the sperm. 21 XX or XY SEXUAL DEVELOPMENT Gonads (reproductive organs) are derived from identical tissue. Y chromosome (males) contains a gene, SRY causes the gonads to develop into testes Testes release testosterone which facilitates the male differentiation of the rest of the reproductive organs and tissue

12 NATURE S IMPULSE IS TO CREATE A FEMALE Lack of testosterone results in female development Differentiation occurs during a sensitive period around 3-4 months of pregnancy What would happen if testosterone receptors were insensitive? 12

13 OUTLINE 25 The Endocrine System Sexual Reproduction Hormonal Role in Sexual Differentiation Gender Differences and Gender Identity Characterizing Complex Behaviors in the CNS LEVAY: INTERSTITIAL NUCLEUS 3 ANTERIOR HYPOTHALAMUS 26 Twice as large in males Lesions in animals show relevance to sexual behavior Homosexual men more likely to have smaller INAH 3 13

14 Sexual orientations in adult relatives of a homosexual 27 The probability of a homosexual orientation is highest among monozygotic twins of a homosexual individual FOR NEXT TIME Exam 2 on Tuesday Data due Tuesday at 3:30; Lab report Intro and Methods due on Wednesday in lab 28 14