Embed Size (px)
Citation preview
1
HORMONES & REPRODUCTION Dr. Steinmetz 1
OUTLINE • The Endocrine System • Sexual Reproduction • Hormonal Role in Sexual Differentiation • Gender Differences and Gender Identity • Characterizing Complex Behaviors in the CNS
2
2
OUTLINE • The Endocrine System • Hormonal Control of Female Fertility Cycle • Sexual Reproduction • Hormonal Role in Sexual Differentiation • Gender Differences in the CNS
3
HORMONES ¢ 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)
4
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-brain-barrier
¢ “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
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
http://www.youtube.com/watch?v=STBIjB6xCFc
5
ANTERIOR PITUITARY
¢ Neurons in the hypothalamus stimulate cells in the anterior pituitary gland to release hormones
• Multiple specific hormones are released for each target.
9 9
OUTLINE • The Endocrine System • Sexual Reproduction • Hormonal Role in Sexual Differentiation • Gender Differences and Gender Identity • Characterizing Complex Behaviors in the CNS
10
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
¢ Beginning of the cycle: � anterior pituitary
releases FSH � triggers growth of
follicle and nurturing of ovum
12
Follicle = fluid filled pockets that contain eggs
7
HORMONES & REPRODUCTION
• As the follicle matures it begins to produce estradiol which signals the anterior pituitary to release LH
13
Estradiol LH
• Surge of LH & FSH triggers release of ovum (egg) by follicle (ovulation = maximum fertility)
• LH & FSH affect behavior
• Increased sexual desire during ovulation period
HORMONES & REPRODUCTION 14
8
• Egg travels down fallopian tubes
HORMONES & REPRODUCTION 15
• 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
HORMONES & REPRODUCTION 16
9
HORMONES & REPRODUCTION
¢ 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.
17
PITUITARY / OVARIAN / FOLLICLE COMMUNICATION 18
http://www.youtube.com/watch?v=8qrWlf0bXpU
10
19
Without looking at your notes: 1. Which line is which hormone? 2. Which step in the reproductive process does it trigger?
OUTLINE • The Endocrine System • Sexual Reproduction • Hormonal Role in Sexual Differentiation • Gender Differences and Gender Identity • Characterizing Complex Behaviors in the CNS
20
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.
XX or XY
21
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.
22
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
23
¢ What would happen if testosterone receptors were insensitive?
24
13
OUTLINE • The Endocrine System • Sexual Reproduction • Hormonal Role in Sexual Differentiation • Gender Differences and Gender Identity • Characterizing Complex Behaviors in the CNS
25
LEVAY: INTERSTITIAL NUCLEUS 3 ANTERIOR HYPOTHALAMUS
¢ Twice as large in males ¢ Lesions in animals show relevance to
sexual behavior • Homosexual men more likely to have
smaller INAH 3
26
14
Sexual orientations in adult relatives of a homosexual
The probability of a homosexual orientation is highest among monozygotic twins of a homosexual individual
27
FOR NEXT TIME… ¢ Exam 2 on Tuesday ¢ Data due Tuesday at 3:30; Lab report Intro and Methods due on Wednesday in lab
28
