Quiz 7 Study Guide What are the 4 stages of reproductive behavior Give one or two examples of each Attraction Role of estrogen in females Females sex skin swelling in some primates Males size strength territory Appetitive Behavior motivation Females eye contact proximity Males proximity hurdles Copulation Females receptivity lordosis Males mounts intromissions ejaculation Refractory Phase Ultrasonic song in male rats Coolidge effect Pair bonding in prairie voles What is unusual about copulation in dogs The male intromits and immediately starts to ejaculate His penis swells making it impossible to separate from the female for 5 20 minutes What are pheromones What is the vomeronasal organ Pheromones A chemical signal that is released outside the body of an animal and affects other members of the same species Modulates sexual behavior in mammalian species Vomeronasal organ Collection of specialized receptor cells near to but separate from the olfactory epithelium that detect pheromones and send electrical signals to the accessory olfactory bulb in the brain Why do female rats need repeated vaginal intromissions especially at her preferred pace It is only after repeated mechanical stimulation of the cervix and vagina will the female rat s brain cause the release of hormones to support pregnancy What is the Coolidge effect When a male is presented with a new female the male has renewed sexual interest in the female even if tired from already having copulated What usually happens when prairie voles copulate off and on over a day or two They pair bond Distinguish between the activational and organizational effects of hormones Activational Temporary change in behavior resulting from the administration of a hormone to an adult animal after castration testosterone can restore behavior Organizational Permanently alters behavior Steroids have an organizational effect only when present during a sensitive period in early development Describe the lordosis response in female rats Why is it important The female arches her back so the male rat can successfully intromit Lordosis makes the vaginal opening accessible and the vagina is horizontal What is the most important brain area for female receptive behavior in most species What does estrogen do in this area Ventromedial Hypothalamus Estrogen E implants in VMH restore copulation in ov x females E increases dendritic tree E progesterone P receptors To what downstream area does it project PAG VMH PAg medulla spinal cord lordosis What is the major brain area that controls male sexual behavior What is a major source of input to that area What is a major transmitter there that facilitates male sexual behavior MPOA Medial pre optic area Input Receives input directly or indirectly from all senses Abundant estrogen and androgen receptors VNO olfactory bulb Dopamine What is a major output from that area MPOA ventral midbrain brainstem and spinal cord sends output back to the sources of input How does the parasympathetic system induce penile or clitoral erection Nitric oxide NO from parasympathetic nerves vasodilates arterioles relaxes smooth muscle in corpora cavernosa How do Viagra Levitra Cialis work Prolongs the effects of Nitric Oxide Inhibit the enzyme that breaks down cGMP NO s second messenger What is the SRY gene What does it do Sex determining region of the Y chromosome primitive gonads testes testosterone masculinization No SRY gonads ovaries Determines sex What are Wolffian ducts What is needed for their development What do they develop into Male Wolffian requires T epididymis vas deferens ejaculatory duct seminal vesicles Sertoli cells secrete anti Mullerian hormones AMH What are Mullerian ducts What is needed for their development What do they develop into Female M llerian develops automatically oviducts uterus upper 2 3s of vagina Without T Wolffian ducts atrophy What is antimullerian hormone AMH a k a mullerian inhibiting hormone MIH Causes mullerian ducts to degenerate What is the relationship between testosterone T and dihydrotestosterone DHT Most of T s effects on external genitals are exerted by dihydrotestosterone DHT which is more potent at androgen receptors T is converted to DHT by 5 reductase locally in tissues T is a prohormone It can also be converted by aromatase to estradiol Without 5 reductase less complete masculinization DHT potent masculinizing hormone What tissue in females forms from the same tissue type as the shaft of the penis in males What tissue in females is analogous to the scrotum in males Urethral fold in male Closes Shaft of penis Females Remains separate Inner labia Male scrotum Female outer labia Describe Turner s syndrome cause and symptoms X0 Lack normal ovaries Infertile no puberty deficits in visuospatial skills Treated with GH testosterone for growth and with E P for breast development menstrual cycles and can bear children with donated eggs What is congenital adrenal hyperplasia CAH cause and symptoms Partial masculinization of girls hypermasculin ization of boys Lack of enzyme cortisol therefore decreased feedback excess ACTH adrenal cortex enlarges hyperplasia produces more of whatever it can including androgens Treated with corticosteroids In male differentiation OK but early puberty and cessation of growth In female enlarged clitoris and fused labia Play more with boys toys less interested in motherhood more inclined to male typical activities and careers more likely to be attracted to women but more hetero than lesbian excel in visuospatial tasks What is the result of 5 alpha reductase deficiency What happens at puberty to these individuals Normal internal genitalia testes secrete T AMH causes M llerian ducts to degenerate Lack of DHT leads to inadequate masculinization of external genitalia at birth Testes in labia or abdomen Urethra blind vagina Prostate gland small or absent At puberty lots of T testes descend scrotum darkens phallus enlarges muscular deep voice Describe the cause and appearance of individuals with androgen insensitivity syndrome Due to mutation in gene for androgen receptor on X chromosome Convert T E breast development Do not menstruate or have pubic or underarm hair What is the aromatization hypothesis for rodents Aromatization hypothesis T must be aromatized to E in order to masculinize the brain What is the SDN POA of rats The INAH 3 of humans SDN POA Sexually dimorphic nucleus of the preoptic area Same size in male and female fetuses before day 18 of gestation T surge in