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Midterm

PSYC 211 Study Guide - Midterm Guide: Posterior Pituitary, Defeminization, Coolidge Effect


Department
Psychology
Course Code
PSYC 211
Professor
Yogita Chudasama
Study Guide
Midterm

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Sexual&behavior&in&male&rats&depends&on&testosterone&released&by&testes.&&
o A&castrated&male&rat&will&cease&sexual&activity&which&can&be&reinstated&with&an&injection&
of&testosterone&&
Sexual&behavior&in&female&rats&depends&on&estradiol&and&progesterone&released&by&ovaries&&
o Ovariectomised&rats&are&not&sexually&receptive&but&can&be&produced&by&administering&
estradiol&followed&by&progesterone.&&
&
Sexual&Behavior&in&Female&Laboratory&Animals&
When&she&is&receptive,&the&female&rat&arches&her&back&which&elevates&her&hindquarters&(lordosis)&&
Although&a&passive&participant,&she&is&active&in&initiating&copulation&she&may&entice&him&by&sniffing&
and&nuzzling&the&male’s&genitals&and&make&quick,&short&hopping&movements&with&rapid&ear&
wiggles.&&
NEED&ESTRADIOL&(first)&AND&PROGESTERONE&(second),&they&must&have&estrogen&and&
progesterone&receptors,&has&three&effects;&it&increases:&&
o Receptivity:&ability&and&willingness&to&copulate&&
o Proceptivity:&eagerness&to&copulate,&seek&out&a&male&&
o Attractiveness:&physiological&and&behavioral&changes&that&affect&the&male&
Male&rats&are&most&responsive&to&a&female&rat&on&“heat”,&in&estrus&&
Males&will&ignore&females&whose&ovaries&have&been&removed&but&injections&of&estradiol&and&
progesterone&will&increase&her&attractiveness&&
&
&
Sexual&Behavior&in&male&laboratory&animals:&&
Intromission&(entry&of&penis&into&female&vagina),&pelvic&thrusting&(rhythmic&movement&of&the&
hindquarters)&and&ejaculation&(semen&discharge)&are&characteristics&of&all&male&mammals.&&
When&a&male&rat&encounters&a&receptive&female,&he&will&spend&more&time&sniffing,&nuzzling&and&
licking&her&genitals,&as&well&as&mount&her&an&engage&in&pelvic&thrusting&&
He&will&mount&her&several&times&and&intromit&on&most&occasions&but&will&ejaculate&only&after&
about&8]15&intromissions&&
After&a&refractory&period,&the&male&will&return&to&copulate&again&&
If&the&male&is&exhausted&by&repeated&copulation&with&the&same&female,&he&will&respond&more&
quickly&if&presented&with&a&new&female.&&
Successive&introductions&with&new&females&keeps&up&his&performance&for&long&periods&of&time&&
&
Coolidge&Effect:&the&restorative&effect&of&introducing&a&new&female&sex&partner&to&a&male&that&has&
apparently&become&“exhausted”&by&sexual&activity&
Oxytocin:&a&hormone&secreted&by&the&posterior&pituitary&gland,&causes&contraction&of&the&smooth&muscle&
of&the&milk&ducts,&the&uterus,&and&the&male&ejaculatory&system;&also&serves&as&neurotransmitter&in&the&
brain&&
&
Behavioral&Defeminization&
Androgens'are'male'sex'steroid'hormones'which'stimulate'the'development'of'the'male'sex'
organs,'they'suppress'the'development'of'neural'circuits'controlling'female'sexual'behavior'''
Androgens&have&a&defeminizing&effect;&they&inhibit&the&later&development&of&anatomical&or&
behavioral&female&characteristics&&
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