psych study group compiled

psych study group compiled - Section 1 Section 1: Hormones,...

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Section 1 Section 1: Hormones, their control and cycles (p.65-66, 325-326, 331-334) Hormone : chemical messenger, secreted by a gland, travels in the blood, where it goes to a target tissue where it has effect. [Ex: Melatonin- helps to regulate body clock; rennin, angiotensin] o Chart of 15 important hormones and functions on page 64!! o Particularly useful for coordinating long-lasting changes in multiple parts of the body [ex: birds release a hormone that changes their eating and digestion to store energy to migrate ] o Two types of hormones that are composed of chains of amino acids Protein hormones: longer chains Peptide hormones: short chains Sex hormones o Steroid hormones: derived from cholesterol o Exert their effects in 3 ways Bind to the membrane receptors, like neurotransmitters Enter cells and activate certain kinds of proteins in the cytoplasm Bind to chromosomes where they activate or inactivate certain genes o The "Sex Hormones": special category of steroids released mostly by the gonads and to a lesser extent by the adrenal glands Androgens: a group that includes testosterone and several others, "male hormones" b/c men have higher levels Estrogens: includes estradiol and others, "female hormones" Androgens and estrogens are CATEGORIES of chemicals, NOT chemicals themselves ** Progesterone : another predominantly female hormone, prepares the uterus for the implantation of a fertilized ovum and promotes the maintenance of pregnancy o Sex-limited genes- genes that androgens and estrogens activate Control most of the differences b/w male and female animals Humans: breast development, facial hair Animals: antlers Increase or decrease apoptosis (cell death) in the brain, causing certain areas of the male brain to be slightly larger May be accredited to the Y chromosome behavioral consequence? Activating Effects of Sex Hormones : sex hormones do not CAUSE sexual behavior activates brain to respond a certain way to stimuli o Rodents: Remove male testes decline in sex drive; testosterone injections bring it back. Estrogen injections in females increase sensitivity of the pudendal nerve (transmits stimulation from pubic area to brain) o Sex hormones also bind to receptors increase responses to hypothalamus Part of the anterior hypothalamus area: sexually dimorphic nucleus (SDN ) larger in males than females
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Testosterone and estradiol prime the MPOA (medial preoptic area) to release dopamine strongly during sexual activity o Humans Men: Low testosterone = low sex drive. BUT impotence (inability to get erection) does NOT equal low testosterone Drugs used on sex offenders to lower testosterone levels: cyproterone (blocks the binding of testosterone to receptors); medroxyprogesterone (inhibits the hormone that stimulates testosterone production) drugs aren't always effective; bad side effects BUT new drug : triptorelin like med. Seems promising. Women: Menstrual cycle- periodic variation in hormones and fertility
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psych study group compiled - Section 1 Section 1: Hormones,...

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