Module 2 Section 4 (Sex B/w Males & Females)

Question 1

Describe the male sex act.

Answer 1

The male sex act involves two components: erection and ejaculation.

Question 2

Describe the female sexual cycle.

Answer 2

1) Excitement:
Excitatory stimuli can be both psychological or physical stimuli.
- Stimulation of the clitoris and the surrounding area -> activates a spinal reflex that activates the parasympathetic system to dilate the arterioles throughout the vagina and external genitalia.
- The nipples also become erect and there is an increase blood supply to the skin.
- Dilation of arterioles in the vaginal walls causes vasocongestion of the capillaries, which forces
fluid out of the vessels and into the vagina.
• This fluid, along with secretions from Bartholin’s gland,
serves as the primary lubricant for intercourse.

2) Plateau
- During the plateau phase, the uterus raises upward, lifting the cervix and enlarging the upper portion of the vagina.
- This tenting effect creates space for ejaculated semen.
- Breathing, HR, and BP of the female also continue to incr.

3) Orgasm:
If erotic stimulation continues, the sexual response culminates in orgasm, as sympathetic impulses lead to rhythmic contractions of the pelvic musculature.
- There is no female equivalent to ejaculation.

4) Resolution:
- After orgasm, HR, BP, and breathing return to normal.
- This phase is marked by a general sense of well-being, enhanced intimacy, and, often, fatigue.
- Some women are capable of a rapid return to the plateau phase with further sexual stimulation

Question 3

Explain the erection reflex and the process of ejaculation.

Answer 3

Thoughts about sex or stimulation of mechanoreceptors in the glans penis (the sensitive bulbous structure at the end of the human penis; i.e., the head of the penis) initiate the erection reflex.

This is a spinal reflex and the erection generating centre lies in the lower spinal cord.
Activation of the erection reflex has three main actions:
1) Inhibiting the sympathetic supply to the penile arterioles. This removes the tonic vasoconstrictor actions of the sympathetic system.
2) Activates the parasympathetic supply to the penile arterioles to cause vasodilation via a NO-mediated mechanism.
3) Activates the parasympathetic supply to the bulbourethral glands to secrete mucus for lubrication.

Question 4

What must happen for sexual reproduction to occur?

Answer 4

Sexual reproduction in humans requires the delivery of sperm into the female vagina through the sex act (sexual intercourse, coitus, or copulation).

Question 5

** Know the location of the structures **

Answer 5

Check slide 2

Question 6

What is the purpose of an erection?

Answer 6

Erection: it’s when the penile tissue fills with blood allowing the penis to become rigid and permit its entry into the vagina.

• The erectile tissue of the penis is made up of 3 columns of sponge-like vascular spaces. These columns = the corpora cavernosa.
• During arousal, the arterioles that supply these vascular spaces dilate. The result = the penis enlarges and becomes rigid.
• *check chart on slide 4**

Question 7

What is erectile dysfunction (impotence)?

Answer 7

It’s referred to as the inability to obtain and maintain an erection rigid enough for sex. If erectile dysfunction is an ongoing issue, it could be a sign of an underlying health condition that requires treatment.

Question 8

What are the 2 stages of ejaculation?

Answer 8

It’s also the result of a spinal reflex, and is mediated by the same tactile and psychological
stimuli that cause an erection.

Step 1: Emission:
- Increased sympathetic activity -> smooth muscle contractions in the prostate, reproductive ducts,
and seminal vesicles.
- The timing is coordinated such that prostatic fluid, then sperm, then seminal
vesicle fluid is delivered into the urethra. Collectively, this mixture = semen.
- The sphincter at the neck of the bladder is also contracted to prevent urine release.

Step 2: Expulsion:

• The filling of the urethra with semen triggers the activation of skeletal muscles at the base of the penis.
• This incr the pressure and forcibly expels the semen.
• This changes the pressure within the urethra and forcibly expels the semen.

Question 9

Describe the male sexual response cycle?

Answer 9

1) The excitement phase: this includes a heightened sexual awareness and erection.
2) The plateau phase: this has more generalized responses (incr HR, BP, and RR).
3) The orgasmic phase: this includes ejaculation as well as other physical and emotional responses.
4) The resolution phase: the return of the body to its pre-arousal stage.

Once ejaculation has occurred, a temporary refractory period occurs in which further sexual
stimulation cannot trigger another erection

Question 10

There are several events which occur from arousal to ejaculation during the male sexual response. Using what you have learned from this section, order the events of the male sexual response from arousal -> ejaculation:

• Bulbourethral glands secrete lubricating mucus
• Parasympathetic stimulation and sympathetic inhibition of penile arterioles
• Semen collects in the urethra
• Semen is forcibly expelled
• Skeletal muscles at the base of the penis contract
• Smooth muscle contraction in prostrate
• Smooth muscle contraction in reproductive ducts
• Smooth muscle contraction in seminal vesicles

Answer 10

1) Parasympathetic stimulation and sympathetic inhibition of penile arterioles
2) Smooth muscle contraction in seminal vesicles
3) Bulbourethral glands secrete lubricating mucus
4) Semen collects in the urethra
5) Smooth muscle contraction in prostrate
6) Skeletal muscles at the base of the penis contract
7) Smooth muscle contraction in reproductive ducts
8) Semen is forcibly expelled

Question 11

There are several events which occur from arousal -> ejaculation during the male sexual response.
Using what you have learned from this section, order the events of the female sexual response from arousal to orgasm:
- Fluid from Bartholin’s gland is released
- Nipples and clitoris become erect
- Parasympathetic activity dilates the arterioles throughout the vagina and external genitalia.
- The arterioles in the vaginal walls cause vasocongestion of the capillaries
- The uterus raises upwards and the vagina expands
- Uterus and muscles of the vagina contract
- Vasocongestion causes fluid to be forced into the vagina

Answer 11

1) Parasympathetic activity dilates the arterioles throughout the vagina and external genitalia.
2) Nipples and clitoris become erect
3) The arterioles in the vaginal walls cause vasocongestion of the capillaries
4) Vasocongestion causes fluid to be forced into the vagina
5) Fluid from Bartholin’s gland is released
6) The uterus raises upwards and the vagina expands
7) Uterus and muscles of the vagina contract