Lecture 38: COITUS, FERTILIZATION AND CONTRACEPTION Flashcards
What is coitus?
Sexual intercourse/copulation
When does coitus occur?
When the erect penis is introduced to the vagina (intromission)
What is insemination?
Semen released into upper part of vagins
What can happen because of insemination?
Sperm can travel to the appropriate site for fertilisation (ampulla of uterine tube)
What are the stages of the male sexual act?
Erection, ejaculation and resolution
What type of action is erection?
Parasympathetic
What also happens during erection?
Mucus from bulbourethral gland is secreted into the urethra
What are the parts of ejaculation?
Emission and expulsion which are both sympathetic
What are erectile tissues surrounded by?
Different layers of fascia
What are the corpora cavernous and corpus spongiosum surrounded by?
Separate tunica albuginea
What surrounds the tunica albuginea?
Deep fascia
What surrounds the deep fascia?
Superficial fascia
What is within the erectile tissue?
Smooth muscle fibres (trabecular) surrounding lacunae
What do the structure of the clitoris and penis share?
Developmental origins
Are the tissues of the clitoris erectile?
Yes
What is the path of blood supply to the penis?
Abdominal aorta > common iliac artery > internal iliac artery > internal pudenal artery
Where does the gonadal artery branch from?
High from the abdominal aorta as the testes develop quite high
What does the internal pudenal artery do?
Feeds the perineum and external genitalia, including penis
What do branches to the penis include?
artery to bulb, urethral artery, dorsal artery, deep (cavernosal) artery
What are the veins of the penis?
deep dorsal, superficial dorsal and subtunical
When does blood supply to the penis increase?
During erection, filling the lacunae
What is the penis richly innervated with?
Sensory and motor neurons
What does the nerve supply of the penis include?
Sensory fibres responsive to touch, pressure and temperature
What does the pudenal nerve supply?
Sensory and somatic motor innervation to perineum and external genitalia, including penis (dorsal nerve)
What is autonomic innervation to the penis dervied from?
Pelvic plexus (parasympathetic and sympathetic)
What does erection stimulate?
Production of nitric oxide (NO)- a vasodilator by deep arteries of the penis
What do deep arteries do during erection?
Dilate and fill lacunae in corpora cavernosa with blood
What control is ejaculation under?
Sympathetic and somatic
What sympathetic processes happen during ejaculation?
Stimulates contraction of smooth muscle, reproductive glands and accessory glands
What is the somatic actions during ejaculation?
Stimulates contraction of skeletal muscle around the bulb of the penis