14 Sexual Reponse Lect (3)-1

8/13/2019 14 Sexual Reponse Lect (3)-1

http://slidepdf.com/reader/full/14-sexual-reponse-lect-3-1 1/22

The Sexual Response Cycle



It starts in your brain:

nucleus accumbens



nucleusaccumbens



Autonomic Nervous System (ANS)

Sympathetic NS Parasympathetic NS

• “Fight or Flight”

• Increases respiration

• Increases heart rate

• Decreases salivation

• Decreases digestion

• Decreases hearing

• “Tunnel vision”

• Decreases sexual desire

• Constricts arteries, bloodflow to non-essentials

• No erections

• “Rest and Digest”

• “Feed and F#%@”

• Relaxes arteries

• Increases blood flow todigestive system, reprod.system

• Promotes digestion

• Better peripheral vision,

hearing• Pathway for sexual arousal

• Erections encouraged



Sex works better when we are relaxed

and safe.

NO! YES!

(or at least

“maybe”)







Sexual Response Cycle: Male



Sexual Response Cycle: Female



Desire Phase

(early “Excitement Phase”)

It starts up:• Sight

• Sound

• Touch

• Smell

• Memories/associations

• The brain takes in signals, clues; tells the body

to start gearing up for sex.

• Similar for both sexes.



Erogenous Zones







Midsagittal image of the anatomy of sexual intercourse envisaged by R L Dickinson anddrawn by R S Kendall3.

Schultz W W et al. BMJ 1999;319:1596-1600

©1999 by British Medical Journal Publishing Group



Excitement Phase:

• Vaginal lubrication

• Vagina length and width increase

(“tenting”), inner diameter

increases

• Uterus ascends, increases in size• Vaginal walls, labia minora,

clitoris engorge with blood.

• Nipples erect, breasts enlarge,

areolas darken

• Labia majora retract frommidline.

• Muscle tension

• “Sex flush”

• Erection begins and progresses

• Scrotum skin tightens, testes

elevate

• Heart rate, respiration, blood

pressure increase

• Nipples may become erect

• Muscle tension

• “Sex flush” possible



Plateau Phase

• Lower 1/3 of vagina more

engorged, inner space

decreases

• Clitoris shortens and

retracts

• Uterus rises more

• Sex flush increases

•Heart rate, respiration,

blood pressure increase

• Muscle tension increases

• Glans size increases

• Cowper’s glands release

fluid

•Testes further elevated,

increase in size

• Prostate enlarges

• Sex flush increases

• Heart rate, respiration,blood pressure increase

further

• Muscle tension increases



Orgasmic Phase

• Takes 10-20 minutes onaverage

• Muscular contraction oflower 1/3 of vagina,expansion of inner 2/3

• Rhythmic contractionsof uterus

• Sex flush, heart rate,blood pressure peak

• Time varies widely

• Smooth musclecontractions of ductsand glands, movingsperm and semen along

• Contractions of penisand muscle at base,

ejaculation• Sex flush, heart rate,blood pressure peak



Resolution phase:

• Everything back to

original, resting state

• Lowered BP, respiration,

heart rate, muscletension

• Sympathetic NS takes

control, blood drains

• Sleepy

• Everything back to

original, resting state

• Lowered BP, respiration,

heart rate, muscletension

• Sympathetic NS takes

control, blood drains

• Sleepy



Sexual Response Cycle: Male



Sexual Response Cycle: Female





Documents

14 Sexual Reponse Lect (3)-1