Lecture 47 Flashcards
What are the male genital reflexes?
The genital reflexes of the male sexual act include: the erection of penis, mucus secretion into the urethra, emission (release of sperm) and ejaculation.
What leads to the erection of the penis? Do women have a similar feature?
The 3 cylindrical erectile tissues (2 corpora cavernosa, 1 corpus spongiosum, containing urethra), the blood supply travels from the abdominal aorta to the common iliac artery to the internal iliac to the internal pudendal artery (the main artery of the perineum), during erection the blood supply increases significantly, leading to cavities within the erectile tissues to expand. Females also contain erectile tissues in the clitoris (containing more blood and nerves than male).
What do genital sexual reflexes involve?
Genital sexual reflexes involve coordination of the sympathetic, parasympathetic and somatic nervous system. It occurs via a reciprocal loop, efferent signals come from the cerebral cortex/limbic system, these are activated by psychological stimuli via the pelvic nerves. Parasympathetic helps erection, sympathetic is the normal and stops it, afferent signals from the penis will also be sent.
What does ejaculation involve (phases?
Ejaculation is the process of expulsion of the semen from the penis. It has two phases (sympathetic as male must then take a break): emission (sperm and fluid from the accessory glands move to the urethra in response to peristaltic contractions) and expulsion (strong spasmodic contractions of urethral smooth muscles that eject the semen). The pelvic floor smooth muscles will contract in response to pudendal nerve stimulation.
What is erectile disfunction? How does itt occur??
Erectile disfunction (impotence) is a consistent inability to attain or maintain an erection. Possible causes include: tears in corpus carnosa capsule, obstructions in penile arteries, diabetes and alcohol, drugs or smoking.
What is the female response to autonomic stimulation?
The corpora of the clitoris, labia and vagina become engorged in response to autonomic stimulation, lubrication fluid will move through the baginal wall via secretion of mucus into vestibule and blood flow is increased to the vagina, this increases width and lenth of vagina in response to tactile stimlation, leading to the uterus moving upwards. Rhythmic contraction of the pelvic floor muscles in response to pudendal nerve stimulation will help move sperm. The afferent and efferent signals are the same as for males.
What are some methods of contraception?
Contraception has many methods: natural ones like the rhythm method, withdrawel method, douching and urination (washing out after intercourse), lactational infertility, these have the problem of still having risk and not protecting against STIs. There are also artificial control methods like surgical sterilization (cutting vas deferens, cut uterine tubes, entire uterus removal(ectopic pregnancys can till occur if this is only partial)), contraception via drugs, barriers and intrauterine devices and pregnancy termination.
What are some examples of drug, barrier and intrauterine device contraception?
(caps, diaphragms (an imperfect barrier, needs to remain at least 6 hrs and only used by a few women) or condoms, intrauterine devices (produce low grade local inflammation, reduces sperm transport, oocyte and sygote viability, impairs implantation and decidualization.) Steroidal contraceptives contain progestind and sometime estrogens, at low doses these act by thickening cervical mucus and reducing sperm transport, oocyte viability and uterine receptivity to the embryo. At high dose the estrogens suppress ovulation, regular menstruation can occur if combined pills are taken. Male pills are typically not acceptable unless anrogens are replaced, the progestagen plus androgen can reduce the sperm conentration heavily but may promote prostate hyperplasia (growth in prostate glane) and other problems.
