Reproductive system

Fundamental purpose of reproductive system is to

create gametes and to form a zygote

Gametes

sex cells that merge to form zygote

male gametes are

sperm cells

female gametes are

oocytes

Fertilization refers to

creation of zygote once a sperm cell and oocyte have merged

reproductive system consists of:

• gonads (testes/ovaries) —→ produce gametes and endocrine hormones

• reproductive tract

• accessory glands

• external genitalia

Male reproductive system:

• scrotum

  • testis

  • epididymis

• Ductus deferens

• Urethra — transports urine and seminal fluid

• glands

  • seminal gland

  • prostate gland

  • bulbo-urethral gland

• penis

3 parts of male urethra

• prostatic

• membranous

• spongy

During in ureto development, the testes actually form ____. As in ureto development progresses, the testes slowly drop from ____ and descend into the ____

inside the abdominal cavity ; the abdomen ; scrotal sac

what develop at body temperature

testes

Sperm development takes place at

slightly below body temp (around 93-95F)

Spermatic cord connects directly to _____

testis

Contents of spermatic cord:

blood vessels, ductus deferens, nerves

Cremaster muscle

wraps around the spermatic cord and testis to which the cord is connected.

Cremasteric reflex

involves rubbing the skin of the inner thigh and seeing a reflexive elevation of the ipsilateral testis

the seminiferous tubules are:

the coils found within the testes. Sperm are created in the tubules

In between the seminiferous tubules are

special endocrine cells that produce testosterone

Another key structure of the male reproductive tract is the

epididymis

It has a comma shape and it sits on a testis.

A key process that occurs in the epididymis is

the maturation of sperm cells — a process called capacitation.

Spermatozoa must be biochemically modified here so that they are eventually able to penetrate an oocyte.

Male reproductive tract:

• epididymis

  • capacitation

• ductus deferens (vas deferens)

• urethra

Structures that contribute to composition of seminal fluid

seminal vesicles, prostate gland, bulbo-urethral gland, epididymis

Semen is comprised of

sperm cells, seminal fluid and enzymes

Internal structure of penile tissue :

• Two posterior corpora cavernosa

• One anterior corpus spongiosum

parasympathetic & sympathetic nerves act upon on penile tissue

Erection of penis -

• parasympathetic nerves are activated

• Smooth muscles in the arterial walls relax

• Arterial vessels and within the corpora cavernosa and corpus spongiosum become engorged w blood

• erection occurs

Semen release and ejaculation

• sympathetic activity

  • emission

  • Ejaculation

    • contractions of ischiocavernosus and bulbospongiosus

Main female reproductive structures

• ovaries

• uterine tubes (fallopian tubes)

  • fimbriae

• Uterus

  • cervix

• vagina

• external genitalia

  • labia minora/majora, clitoris

• breasts

Broad ligament

attaches to lateral edges of the uterus

ligament is an important stabilizing structure for the uterus, especially during the expansion of uterus during pregnancy

• Fimbriae are adjacent to, but not attached to, the ovary

3 processes occurring in female reproductive tract

1. oogenesis (creation of oocytes)

2. ovarian cycle

3. uterine cycle

Ovulation occurs when

oocyte is released by the ovary

uterus consists of

• body

• fundus

• uterine cavity

• isthmus

• internal os

• cervix

  • cervical canal

• External os

Menstrual cycle

process that occurs in female body to prepare body for potential pregnancy. inner lining of uterus is built up. in case a release oocyte is not fertilized, the inner lining of uterus is shed (period)

Process of menstruation is regulated by

hormones

Ovulation occurs at day 14

A surge of luteinizing hormone stimulates this event

On avg, menstrual cycle takes place over course of 28 days

3 phases of menstrual cycle: in the order they are:

1. menstrual phase

2. proliferative phase

3. secretory phase

Uterine lining is shed during these first 7 days

External genitalia

• mons pubis

• clitoris

• cestibule

• labia minora

• hymen

• labia majora

Breast tissue is part of female reproductive system

Which hormone stimulates milk ejection from breast

oxytocin (released by pituitary gland)

Female climacteric (menopause)

• decline in estrogen levels results in:

  • reduced size of uterus

  • reduced size of breasts

  • thinning of vaginal walls

  • weakening of supportive tissues of reproductive organs

  • osteoporosis

  • hot flashes

• Typically occurs at age 45-55

Male Climacteric

• testosterone levels begin to decline (not as rapidly as estrogen however)

• occurs gradually between ages 50-60

• reduction in sexual activity