Lecture 15 & 16: Hormones and Sexual Behavior Flashcards
Define Organs
Body Parts
What is the difference between glands and non-glands?
Glands secrete things and non-glands do not.
What is the difference between exocrine and endocrine glands?
Exocrine glands secrete stuff locally (usually through ducts) whereas endocrine glands secrete hormones into the blood.
What are some examples of exocrine glands?
Sweat, saliva, breastmilk
What do hormones do?
Influence cell activity (ex. metabolic rate)
What are the difference between hormones and neurotransmitters?
Hormones have global, long lasting effects and NT have local short lived effects.
Can hormones be NT? If so, give some examples.
Adrenaline (Epinephrine) and Noradrenaline (Norepinephrine)
Function of Hypothalamus
Send signals to pituitary gland
Function of Pituitary Gland
Master endocrine gland
What are 2 major types of hormones?
Steroid and Non-Steroid
How do steroid hormones work?
- Diffuse across membrane
- Attach to R in cytoplasm
- R-hormone complex enters nucleus
- Triggers gene expression (very long lasting)
How do Non-steroid hormones work?
- Attach to R on membrane
- Activate 2nd messenger system inside cell
- Alters metabolism (minutes/hours)
What are the two types of steroid hormones?
Cortisol (adrenal cortex) and Sex (gonads and other body parts)
What are the 2 main types of sex hormones?
- Androgens –> TTT
- Estrogens —> Estradiol
Define Gonads
Endocrine glands that are a part of reproductive organs
How do gonads work?
- Secrete Sex Hormones
- produce / release gametes
What are male gonads called and how do they work?
A. Testes
B. 1. Secrete TTT
2. Produce Sperm (male gamete)
What are female gonads and how do they work?
A. Ovaries
B. 1. Estradiol
2. Produce ovum (egg) (female gamete)
Define genitalia.
non-endocrine parts of the reproductive organs
Define Genetic Gender.
Dictates gonads
What Chromosome contains the gene to form the Testes?
Y
What is the genotype if you are male? Female?
Male: XY
Female: XX
Define Gender Phenotype.
How an organ/organism appears.
What are the 2 gender phenotype anomalies?
Female Masculinization and Testicular Feminization
What is Female Masculinization?
It is when a fetus is genetically female but exposed to TTT in utero by either the adrenal cortex (excess TTT) or anti-miscarriage drug (mimics TTT). Genitalia are intermediate but have female gonads. Usually made into phenotypic females.
What is Testicular Feminization?
Genetically male, but insensitive to TTT in utero because lacking/dysfunctional TTT receptors so TTT cannot activate genes inside cells. Genitalia and appearance are female but have male gonads.
Does homosexuality arise from nature or nurture?
Yes!
What does the Sexually Dimorphic Nuclei in the hypothalamus indicate?
Levay study in 1993:
16 hetero male: 0.12 mm^2
6 hetero female: 0.056 mm^2
19 homo male: 0.051 mm^2
What are some of the confounds of the Levay study?
That the smaller nuclei could have been caused by AIDS or HIV.
When does puberty being in humans?
12-14 y/o.
What happens during puberty?
TTT and estradiol start being produced AGAIN by testes and ovaries. Controlled by the hypothalamus which releases luteinizing hormone.
What happens to females during puberty?
Larger hips, chest, pubic and underarm hair. Menstrual cycle starts.
What happens to males during puberty?
Beard, broader shoulders, myofibrillar proteins (muscles), pubic and underarm hair. Continual sperm production.
What happens during the menstrual cycle?
Involves the hypothalamus, pituitary, and gonads. In the middle of the cycle estradiol increases and results in the release of an egg.
What is the animal equivalent of ovulation?
Estrus
Define Luteal phase.
Gets uterine lining ready for fertilized egg with vasculature. If no vasculature, then bleeding.
Primates and humans’ sexual behavior are not governed by sex hormones. Explain.
Not entirely as sex is throughout cycle. HOWEVER, human females initiate sexual activity more often at ovulation. Maybe because estradiol?
What does the Pudendal nerve do?
Area surrounding vagina that sends pleasure signals to the brain.
How do sex hormones affect animals?
Some animals only mate when TTT is high (ex. birds in spring and summers)
How does sex hormones affect males?
TTT = key for sexual activity.
How does castration affect men?
Lack off TTT can lead to losing their sex drive (EUNICS). Low TTT can lead to impotence. Sexual Prime 15-25 y/o.
