Reproductive system Flashcards
List the functions of the male and female reproductive systems.
- Production of gametes
- Fertilization
- Development and nourishment
of a new individual - Production of reproductive
hormones
Describe the function of meiosis in the formation of sperm cells and oocytes
- a special type of cell division that
leads to formation of gametes - Haploid cells
Describe the scrotum and its role in regulating the temperature of the testes.
- Must be kept outside the body cavity
- Muscles (cremaster, dartos) alter
how near or far they are from the
body wall - Spermatogenesis occurs at a lower
temperature
Testes produce sperm inside
seminiferous tubules
interstitial cells
secrete testosterone
Germ cells
cells that sperm cells arise from. Go through meiosis to produce sperm cells
sustentacular cells
nourish germ cell and produce hormones
Sperm cells
Head: contain a nucleus and DNA
Midpiece: contain mitochondria
Tail: flagellum for movement
Epididymis
Where seminiferous tubules
empty the new sperm
Ductus (Vas) Deferens
Connects the epididymis to the
urethra
Prostate
- Surrounds urethra
- Size of walnut
- Enlargement occurs with age or
cancer and can block urethra making
it difficult to urinate - Secretes 30% of seminal fluid
seminal vesicle
Secretes 60% of seminal fluid
* Merges with the ductus deferens
as it enters the urethra
Bulbourethral gland
5% of seminal fluid
* Neutralizes acidity of male urethra
Penis
- corpus cavernosum, corpus
spongiosum, spongy urethra are
3 columns of erectile tissue which
fill with blood for erection - Releases sperm from male
- Excretes urine
- distal end of the penis forms a
cap, the glans penis. - Urethra opens to the exterior as
the external urethral orifice
Describe the functions of the male reproductive hormones
- Gonadotropin-releasing hormone (GnRH) is produced in the hypothalamus and stimulates
secretion of LH and FSH. - Luteinizing Hormone (LH) is produced in the
anterior pituitary and stimulates secretion of
testosterone from the interstitial cells. - Follicle-stimulating hormone (FSH) is produced
in the anterior pituitary and prompts
spermatogenesis in the seminiferous tubules
Describe the changes that occur in males during puberty.
begins at 12 to 14 and ends around 18.
Testosterone is major male hormone
* secondary sexual characteristics develop: skin texture, fat distribution, hair growth, skeletal muscle growth, and larynx
changes
* Irreversible changes in body shape and voice
male sex act
- The male sex act is a complex series of reflexes that result in erection of the
penis, emission, and ejaculation. - Erection Neural stimuli cause the penis to enlarge and become firm.
- Parasympathetic nerves cause the arteries that supply blood to the erectile tissues to dilate.
- Blood then fills the erectile tissue and compresses the veins, which reduces blood flow from
the penis. - Emission is the movement of sperm cells, and seminal fluids into urethra.
- Ejaculation is the forceful expulsion of the secretions that have accumulated in
the urethra - Sympathetic nerves cause the contraction of smooth muscle in the wall of the urethra and
skeletal muscles surrounding the base of the penis.
Path of sperm
- Sperm develop in seminiferous
tubules (testes) - Epididymis (mature)
- Ductus deferens
- Receive secretions from
seminal vesicles, prostate
gland, and bulbourethral gland - Urethra where semen (sperm)
exits body
Female reproductive organs consist of
2 ovaries, 2 uterine, 1 uterus, 1 vagina, external genitalia, and mammary glands.
ovaries
primary female reproductive organ , produces oocytes and sex hormones, one on both sides of uterus and anchored by ligaments
ovarian follicle
groups of cells in ovaries that contain oocytes
oogenesis
the process of gamete production in females
oogonia
the ovaries contain 5 million oogonia which are the cells from which oocytes develop.
uterine tube
Part of uterus which extends
toward ovaries and receive oocytes
Fimbriae
are fringe-like structures around opening of uterine tubes that help sweep oocyte into uterine tubes
ampulla
fertilization usually occur
Uterus
- Functions: receive, retain, and provide nourishment for fertilized oocyte, where embryo resides and develops
- Body: main part
- Fundus: the part of the uterus superior to the entrance of the uterine tubes
- Cervix: narrow region that leads to vagina, must dilate for vaginal childbirth
- Checked for precancerous cells with pap smear
walls of uterus
- perimetrium (serous): outermost layer
- myometrium (muscular): middle layer, composed of smooth muscle
- endometrium: innermost layer that is sloughed off during menstruation
Vagina
contains very muscular walls and a
mucous membrane
* Maintains an acidic environment to keep unhealthy bacteria out, has a balanced microbiome
Mammary Gland
organs of milk production in breast. Modified sweat glands. Lobes, ducts, lobules are altered
during lactation to expel milk
Describe the changes that occur in females during puberty
Vagina, uterus, uterine tubes, and external genitalia enlarge and fat
is deposited in breasts and hips. Elevated levels of estrogen and progesterone are secreted by ovaries. (Begin at 11-13 end at 16)
Menses
time when endometrium is shed
from uterus. Estrogen and progesterone are low
* Follicles begin to mature in the
ovary. (Day 1-5)
Proliferative Phase
Endometrial lining thickens and becomes vascular
* Estrogen levels increase
* Progesterone levels stay low
* Follicles mature
(Day 6-13)
Ovulation
- Oocytes is released from ovary
- LH and FSH peak
- Estrogen levels are high
- Progesterone levels start to rise
- Cervical mucus thins
(Day 14ish)
Secretory Phase
- Endometrium is prepared for
implantation - Estrogen levels decrease
- Progesterone levels are high
Gonadotropin-releasing (GnRH)
- produced in the hypothalamus
- stimulates secretion of LH and
FSH
Follicle-stimulating hormone
(FSH)
- produced in the anterior pituitary
- prompts follicles in the ovaries to
begin development.
Luteinizing Hormone (LH)
- produced in the anterior pituitary
- causes ovulation.
Estrogen
- proliferation of endometrial cells
- control of LH and FSH secretion
- development and maintenance of secondary sex characteristics
Progesterone
- enlargement of endometrial cells
and secretion of fluid from uterine glands - maintenance of pregnancy state
- control of estrogen, FSH, and LH
secretion - development of secondary sex
characteristics
Menopause
The menstrual cycle slows and eventually stops
* Ovaries secrete less hormones
* Follicles are low
* Side effects – fatigue, temperature dysregulation, vaginal dryness (Age 50)
Female sexual act
- During sexual excitement,
erectile tissue within the clitoris
and around the vaginal opening
becomes engorged with blood. - The glands within the vestibule
secrete mucus - Stimulation of the female’s
genitals and psychological
stimuli can trigger an orgasm, or
climax
Female sexual act (2)
The vaginal and uterine smooth
muscle, as well as the
surrounding skeletal muscles,
contract rhythmically, and
muscle tension increases
throughout much of the body
