Physiology - Fertilization, placenta, amniotic fluid, labor and lactation

Question 1

What are the three erectile bodies of the penis?

Answer 1

Two corpora cavernosa and one corpus spongiosum.

Question 2

In short, how is male erection possible.

Answer 2

The cavernosus nerve gives rise to a release of NO.
NO relaxes vascular smooth muscle cells through activation of guanylyl cyclase increasing cGMP. Dilatation of blood vessels increases blood flow into sinusoidal cavernous spaces until the collapse of venous return.
Contraction of muscles at the base of the penis further promotes the erection.

Question 3

What are commonly referred to as “accessory sex glands” in males? Which of the glands contributes to the majority of the seminal volume?

Answer 3

The prostate, seminal glands, bolourethral and paraurethral glands.
The seminal glands is responsible for 60 % of the seminal volume.

Question 4

Is orgasm a sympathetic or parasympathetic response?

Answer 4

Sympathetic.

Question 5

What are erogenous zones specific to males?

Answer 5

Glans, corona, lower part of the penis.

Question 6

What are erogenous zones specific to females?

Answer 6

Clitoris, labia minora, lower part of the vagina.

Question 7

How many sperm cells may one ejaculation (2-5 ml.) contain?

Answer 7

40-500 million.

Question 8

What are the components of a sperm cell?

Answer 8

A head (with nucleus and enzymes) and acrosome (cap).
A centre bit (with mitochondria).
A tale (or flagellum).

Question 9

What happens to the sperm because of capacitation?

Answer 9

The sperm obtains …
Ability to undergo acrosome reaction.
Ability to bind to zona pellucisa.
Acqusition of hypermotility.

Question 10

Along with the oocyte, what else is released into the peritoneal cavity?

Answer 10

The zona pellucida and corona radiata (granulosa cells).

Question 11

What are the effects of estrogen and progesterone on the cilia in the Fallopian tubes?

Answer 11

Estrogen increases the number of cilia.

Progesterone increases mobility.

Question 12

How is the ovum transported from the ovary and through the Fallopian tube?

Answer 12

Infundium moves toward the ovary at ovulation.
Fimbriae capture the ovum.
Fluid passes from peritoneal cavity to uterine tubes.
Muscle contractions and cilia moves the ovum down toward the uterus.

Question 13

What are the 8 steps of fertilization?

Answer 13

1. Sperm cells weaves through corona radiata and binds to zona pellucida.
2. Exocytosis of the acrosome (containing hydrolytic enzymes).
3. The zona pellucida disolves and the sperm cell reach the oocyte membrane.
4. Fusion of the two membranes. The content of the sperm cell empties into the oocyte.
5. Hardening of the zona pellucida, preventing entry of other sperm cells.
6. The ooctye completes meiosis 2.
7. The head of the sperm cell enlargens and becomes the male pronucleus.
8. Fusion of male and female pronucleus.