HUMAN REPRODUCTIONBIOLOGY 269
Recall:
Female Reproductive System1) Produce estrogen and
progesterone for sexual characteristics
2) Produce and release one large oocyte at regular intervals
3) Sexual intercourse, receive semen
4) Produce hormones to prepare endometrium for pregnancy each cycle; shed functional layer by menstruation
5) Protect/nourish embryo/fetus; expel it during childbirth
6) Produce milk to nourish newborn
Male Reproductive System:
1) .
2) .
3) .
4) .
Testis:
Approximately 4cm x 2 cm x 2 cm
Outside body cavity in scrotum
Divided into + 20 compartments;
Each compartment
Hundreds of millions of sperm produced per day
Spermatogenesis is initiated and stimulated by
secreted by the
FSH is the same hormone that stimulates oogenesis in the ovary.
However, secretion of FSH in women rises and falls each cycle, resulting in the production of just one oocyte;
Secretion of FSH in men remains relatively steady so spermatogenesis is continuously stimulated and sperm are continuously produced.
The pituitary gland also secretes
in male.
LH stimulates formation of the corpus luteum and production of progesterone in the ovary.
In the testicle, LH stimulates
, which are located
Unlike oogenesis, in which the developing oocyte is surrounded and protected by a follicle, sperm are not produced within follicles
However: developing sperm are protected and supported by a special cell called a
Sperm leaving the testis next enter a long (>6 meters) coiled tube called the
Also located in scrotum, behind the testis
From the epididymis, sperm are transported through the which passes upward into the abdominal cavity..
As it passes from the scrotum to the abdominal cavity, the vas deferens is accompanied by the artery, veins, and nerves supplying the testis.
All of these are surrounded by a thick covering of connective tissue,
The spermatic cord passes through a tunnel called the inguinal canal
Within the abdomen, the vas deferens on each side curves backward, then downward and forward, along the side of the bladder.
The end of the vas deferens, called its , is enlarged. .
Male Accessory Glands:
Paired, posterior to bladder. Ducts join vas deferens to form .
Produce
Contains nutrients for sperm.
Contains chemicals to
Male Accessory Glands:
: Inferior to bladder, ejaculatory ducts embedded within it.
Surrounds proximal part of urethra as it leaves the bladder
Produces.
Contains chemicals to:
- ;
- ;
- .
During ejaculation: a) Sperm from the b) Fluid from the c) Fluid from theAll enter the urethra as it passes through the prostate
The urethra then passes through the penis to its tip.
Penis:
: Embedded in perineum; + 50% of total length
: Outside, covered with skin
: Tip, not covered with skin
Penis:
Three erectile bodies:
- Two
- One
Fill with blood during erection, causing shaft to line up with root of penis
When blood leaves erectile bodies, shaft of penis droops down into normal position
Semen:
Mixture of sperm, seminal vesicle fluid, prostate fluid
Normal ejaculate:
Semen clots immediately after ejaculation to hold it in vagina, then liquifies gradually over 5 to 10 minutes to release sperm
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