The Reproductive System Flashcards
1
Q
Male reproductive system functions
A
- Production, maturation and storage of sperm
- Delivery of sperm in semen into the female reproductive tract
- The penis contains the urethra – a passageway for ejaculation of semen and excretion of urine
2
Q
Penis
A
- Penile tip has a triangular structure known as the glans penis
- The foreskin a moveable double layer of skin lies just above the glans
- Penile erection facilitated by stimulation, fills the spongy erectile tissue with blood caused by arteriole dilation and vasoconstriction which increases blood flow into the penis and obstructs outflow
3
Q
Puberty
A
- At puberty gnrh stimulates anterior pituitary secretion of IH and FSH
- IH stimulates leydig cells to produce testosterone – FSH and testosterone initiate spermatogenesis
4
Q
Testosterone
A
- Controls the growth, development and maintenance of sex organs
- Stimulates bone growth, protein anabolism, and sperm maturation
- Stimulates development of male secondary sex characteristics
5
Q
Inhibin
A
- Produced by sertoili cells
- Its inhibition of FSH helps regulate the rate of spermatogenesis
6
Q
Spermatogenesis
A
- Sperm production begins at puberty and continues throughout life under the influence of testosterone
- Sperm produced in the seminiferous tubules of the testes and mature as they pass through the epididymis where they are stored
- Takes makes at 3 degrees below the body temperature
- FSH from the anterior pituitary stimulates sperm production
- Testis are cooled by being positioned outside the abdominal cavity
- A mature sperm has a head, body and long whip like tail used for mobility
- The head is almost completely filled by the nucleus containing DNA
- Its nucleus also contains enzymes required to penetrate the outer layers of ovum to reach and fuse with
- The sperm body is packed with mitochondria to fuel the propelling action of the tail that powers the sperm along the female reproductive tract
7
Q
Ejaculation
A
- Sperm expelled from epididymis pass through deferent duct, ejaculatory duct and the urethra
- Semen propelled by rhythmical contraction of the smooth muscle in the walls of the deferent duct
- Muscle in walls of seminal vesicles and prostate gland also contracts and adds 60% seminal fluid 30% prostatic fluid to 10% sperm
8
Q
Penis has a root and a shaft
A
- Root anchors penis in the perineum
- Shaft is the externally visible, moveable portion of the organ
- 3 cylindrical masses of erectile tissue and smooth msucle
- 2 lateral columns called corpora cavernosa, and column between them which contains the urethra called the corpus spongiiosum
9
Q
Testes
A
- Male reproductive glands suspended in the scrotum by spermatic cords
- Each testis contains 200-300 lobules and each lobule contains 1-4 convoluted loops of seminiferous tubules
- Between tubules are groups pf interstitial cells that secrete testosterone
- Tubules combine at upper pole of testis to form a single 6m long and tightly packed tubule called the epididymis – leaves the scrotum as the deferent duct in the spermatic cord
10
Q
Scrotum
A
- Pouch of pigmented skin, fibrous and connective tissue and smooth muscle, lying behind the penis
- Divided into compartments, each contains a testis, an epididymis and the testicular end of the spermatic cord
11
Q
Spermatic cords
A
- Suspend testes in the scrotum
- The cord, covered in a sheath of smooth muscle, connective tissue and fibrous tissue, extends throughout the inguinal canal and is attached to testis on posterior wall
- Cremaster muscle can contract to pull scrotum towards body for protection
12
Q
Deferent ducts
A
45cm long, passing upwards from testis through inguinal canal towards posterior wall of bladder where it is joined by the duct from the seminal vesicles to form ejaculatory duct
13
Q
Seminal vesicles
A
- Two small fibromuscular pouches lined with columnar epithelium and lying posterior to bladder
- These contract and expel their stored contents, seminal fluid, during ejaculation
14
Q
Ejaculator ducts
A
- Two tubes formed by union of the duct from a seminal vesicles and a deferent duct
- They pass through the prostate gland and join the prostatic urethra, carrying seminal fluid and sperm to the urethra
15
Q
Prostate gland
A
- Lies in the pelvic cavity in front of the rectum and behind the symphysis pubis, completely surrounding the urethra
- Has a fibrous outer covering, the gland progressively enlarges with ages
- Produces thin, milky fluid, making up 30% of semen volume
- Contains a clotting enzyme which thickens the semen in the vagina
16
Q
Disorders
A
- Specific infections caused by STI such as gonorrhoea
- Non specific infections caused by lack of hygiene, spread of infections from urethra, after catheterisation
- Urethritis
- Epididymitis
- Orchiditis
- Prostatitis
- Phimosis – foreskin is tight and doesn’t retract
- Undescended testis
- Benign prostatic enlargement
- Hyperplasia obstructs flow of urine causing urine retention