Sexual Physiology

Introduction

There are 3 ways to determine a person’s biologic sex Sex The totality of characteristics of reproductive structure, functions, phenotype, and genotype, differentiating the male from the female organism. Gender Dysphoria:

• Genetic sex Genetic sex Sex Determination: determined by presence of sex chromosomes Sex chromosomes The homologous chromosomes that are dissimilar in the heterogametic sex. There are the X chromosome, the Y chromosome, and the w, z chromosomes (in animals in which the female is the heterogametic sex (the silkworm moth bombyx mori, for example)). In such cases the w chromosome is the female-determining and the male is zz. Basic Terms of Genetics (XX = female, XY = male)
• Gonadal sex Gonadal sex Sex Determination: determined by presence of reproductive structures ( ovaries Ovaries Ovaries are the paired gonads of the female reproductive system that contain haploid gametes known as oocytes. The ovaries are located intraperitoneally in the pelvis, just posterior to the broad ligament, and are connected to the pelvic sidewall and to the uterus by ligaments. These organs function to secrete hormones (estrogen and progesterone) and to produce the female germ cells (oocytes). Ovaries: Anatomy in females, testes Testes Gonadal Hormones in males) 
• Phenotypic sex Phenotypic sex Sex Determination: Human gonads Gonads The gamete-producing glands, ovary or testis. Hormones: Overview and Types produce different hormones Hormones Hormones are messenger molecules that are synthesized in one part of the body and move through the bloodstream to exert specific regulatory effects on another part of the body. Hormones play critical roles in coordinating cellular activities throughout the body in response to the constant changes in both the internal and external environments. Hormones: Overview and Types that determine external phenotype Phenotype The complete genetic complement contained in the DNA of a set of chromosomes in a human. The length of the human genome is about 3 billion base pairs. Basic Terms of Genetics.

Terms

• Gender Gender Gender Dysphoria identity: 
  • Represents individual’s inner sense of maleness or femaleness
  • Usually established by age 3
• Gender Gender Gender Dysphoria role or behavior:
  • Represents behaviors exhibited by or expected from an individual
  • Can be congruent or incongruent with individual’s gender Gender Gender Dysphoria identity 
• Sexual orientation Orientation Awareness of oneself in relation to time, place and person. Psychiatric Assessment:
  • Individual’s pattern of physical and emotional arousal
  • An individual assessment of one’s sexual orientation Orientation Awareness of oneself in relation to time, place and person. Psychiatric Assessment is termed sexual identity. 
  • Examples:
    • Homosexuality: attraction to those with same gender Gender Gender Dysphoria identity
    • Heterosexuality: attraction to those with opposite gender Gender Gender Dysphoria identity
    • Bisexuality: attraction to either gender Gender Gender Dysphoria identity
    • Asexuality: attraction to neither gender Gender Gender Dysphoria identity
  • Coming out: defined as individual acknowledging their sexual orientation Orientation Awareness of oneself in relation to time, place and person. Psychiatric Assessment 
• Gender Gender Gender Dysphoria dysphoria:
  • Emotional discomfort arising from misalignment between gender Gender Gender Dysphoria identity and sexual identity 
  • Seen in boys more frequently than in girls

Behaviors during sexual development

Appropriate:

• During early childhood years:
  • Showing interest in exploring one’s own or other’s genitals
  • Undressing self or others
  • Masturbatory movements
  • Asking reproductive or sexual questions
  • Increased interest in sex Sex The totality of characteristics of reproductive structure, functions, phenotype, and genotype, differentiating the male from the female organism. Gender Dysphoria words or play
  • Masturbation is considered a normal behavior at all ages and occurs equally in both genders (it is pathological only when it interferes with normal functioning).
• Exploring human sexuality is normal, especially during teenage years, with different- or same-sex partners.

Abnormal:

• Repeated insertion of objects into vagina Vagina The vagina is the female genital canal, extending from the vulva externally to the cervix uteri internally. The structures have sexual, reproductive, and urinary functions and a rich blood supply, mainly arising from the internal iliac artery. Vagina, Vulva, and Pelvic Floor: Anatomy or anus
• Inappropriate sex Sex The totality of characteristics of reproductive structure, functions, phenotype, and genotype, differentiating the male from the female organism. Gender Dysphoria play (simulating genital–genital, oral–genital, or anal–genital sexual intercourse)
• Use of force in sex Sex The totality of characteristics of reproductive structure, functions, phenotype, and genotype, differentiating the male from the female organism. Gender Dysphoria play
• Age-inappropriate sexual knowledge

Tanner Stages

The Tanner stages is a scale Scale Dermatologic Examination that measures physical/sexual development in children, adolescents, and adults. It involves genitalia in males, breast in females, and pubic hair in both.

Sexual Response Cycle

Sexual dysfunctions (in males or females) arise from problems involving any stage of the sexual response cycle.

Normal Sexual Changes with Aging

Healthy sexual behavior and desire persist into elderly adulthood.

Pharmacotherapy exists to facilitate sexual behavior:

• Sildenafil Sildenafil A phosphodiesterase type-5 inhibitor; vasodilator agent and urological agent that is used in the treatment of erectile dysfunction and primary pulmonary hypertension. Phosphodiesterase Inhibitors: to assist erection Erection The state of the penis when the erectile tissue becomes filled or swollen (tumid) with blood and causes the penis to become rigid and elevated. It is a complex process involving central nervous system; peripheral nervous systems; hormones; smooth muscles; and vascular functions. Penis: Anatomy in men
• Hormonal creams/pills: to counteract vaginal atrophy Atrophy Decrease in the size of a cell, tissue, organ, or multiple organs, associated with a variety of pathological conditions such as abnormal cellular changes, ischemia, malnutrition, or hormonal changes. Cellular Adaptation in women

Clinical Relevance

• Gender Gender Gender Dysphoria dysphoria: also known as gender Gender Gender Dysphoria identity disorder. Individuals with gender Gender Gender Dysphoria dysphoria have difficulties reconciling the incongruence between their expressed gender Gender Gender Dysphoria and assigned gender Gender Gender Dysphoria (continuous inner conflict between gender Gender Gender Dysphoria identity and sexual identity). The 1st signs of cross-gender behaviors begin around age 3, the time when gender Gender Gender Dysphoria identity is established.
• Female sexual dysfunction Female sexual dysfunction Female sexual dysfunction represents a variety of disorders in any part of the sexual response cycle, including desire disorders, arousal disorders, orgasmic disorders, and pain disorders. The condition may result from stresses and interpersonal conflicts as well as physical illness or medication/substance use. Female Sexual Dysfunction: disorder in any part of the female sexual response cycle. This group of disorders includes desire disorders, arousal disorders, orgasmic disorders, and pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways disorders. The dysfunction might result from stresses and interpersonal conflicts, as well as from physical illness or medication/substance use. These disorders cause significant distress to the patient.
• Male sexual dysfunction Male sexual dysfunction Male sexual dysfunction is any disorder that interferes with the male sexual response cycle and includes desire disorders, erectile disorders, and ejaculatory disorders. Sexual dysfunction has a varied etiology and may be due to psychological causes, endocrine diseases, neurogenic dysfunction, chronic medical illness, or medication/substance abuse. Male Sexual Dysfunction: disorder in any part of the male sexual response cycle. This group of disorders includes desire disorders, arousal disorders, and orgasmic disorders. The dysfunction may be caused by psychological disorders, endocrine diseases, neurogenic dysfunction, chronic medical illness, or medication/substance use disorder.