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.