Human Biology: Male Reproductive System

Male Reproductive System

• The male reproductive system consists of the male gonads (testicles), genital tract, accessory glands, and penis.
• The penis is responsible for depositing sperm in the vagina and consists of erectile tissue, with three regions: two corpora cavernosa and one corpus spongiosum.

Penis

• Corpus spongiosum surrounds the urethra, keeping it open at all times, and widens at the end to form the glans.
• The glans is a very sensitive area protected by a fold of skin called the foreskin.
• When the penis is erect, the foreskin retracts to leave the glans uncovered.

Testicles

• The testicles are two oval-shaped organs inside a sack of skin called the scrotum, which hangs outside the abdominal cavity.
• Each testicle is made up of millions of semiiferous tubules containing sperm precursor cells that make the male gametes.
• The temperature of the testicles is about 3 °C lower than body temperature, essential for sperm maturation.
• Endocrine cells between the seminiferous tubules produce testosterone, responsible for male secondary sexual characteristics.

Genital Tract

• The genital tract consists of the ducts that take sperm to the outside of the body: the epididymis, vas deferens, and urethra.
• The epididymis is a long, coiled tube attached to the top of each testicle, where sperm is stored while it matures.
• The urethra is a shared duct with the excretory system, expelling semen and urine from the body.
• The vas deferens passes through the prostate and empties into the urethra, carrying sperm cells from the epididymis to the urethra.

Accessory Glands

• The accessory glands secrete substances that mix with sperm to form semen, including the seminal vesicles, prostate gland, and Cowper's glands.
• The seminal vesicles produce seminal fluid, rich in fructose, the main energy source of sperm.
• The prostate gland produces prostatic fluid, which activates sperm and neutralizes the acidity of female mucous secretions.
• The Cowper's glands secrete a lubricating fluid that neutralizes the acidity of the urethra before semen passes through it.

Female Reproductive System

• Consists of ovaries, genital tract, and external genitalia

Ovaries

• Almond-sized and almond-shaped
• Suspended in the abdominal cavity by small ligaments
• Produce oestrogen and progesterone, responsible for female secondary sexual characteristics and preparing the body for possible pregnancy
• Composed of medulla (inner part) and cortex (outer part)
• Cortex contains numerous follicles that contain immature eggs (oocytes)

Genital Tract

• Consists of fallopian tubes, uterus, and vagina
• Fallopian tubes connect ovaries to the uterus, collecting eggs through the infundibulum
• Uterus is a hollow, muscular, upside-down pear-shaped organ
• Cervix is the narrow section at the bottom of the uterus
• Uterus wall is composed of myometrium (smooth muscle layer) and endometrium (epithelial cell layer)
• Vagina is an elastic duct connecting the cervix to the outside of the body, with lubricant-secreting glands on its walls

External Genitalia

• Combines to form the vulva
• Labia majora are two outer folds of skin that cover the labia minora (two thinner folds)
• Clitoris is an organ near the top junction of the labia minora, equivalent to the male glans

Menstruation

• Dysmenorrhea (menstrual cramps) is caused by uterine contractions during the menstrual period
• Common and causes pain in the stomach, hips, and back

Female Reproductive System

• Consists of ovaries, genital tract, and external genitalia

Ovaries

• Almond-sized and almond-shaped
• Suspended in the abdominal cavity by small ligaments
• Produce oestrogen and progesterone, responsible for female secondary sexual characteristics and preparing the body for possible pregnancy
• Composed of medulla (inner part) and cortex (outer part)
• Cortex contains numerous follicles that contain immature eggs (oocytes)

Genital Tract

• Consists of fallopian tubes, uterus, and vagina
• Fallopian tubes connect ovaries to the uterus, collecting eggs through the infundibulum
• Uterus is a hollow, muscular, upside-down pear-shaped organ
• Cervix is the narrow section at the bottom of the uterus
• Uterus wall is composed of myometrium (smooth muscle layer) and endometrium (epithelial cell layer)
• Vagina is an elastic duct connecting the cervix to the outside of the body, with lubricant-secreting glands on its walls

External Genitalia

• Combines to form the vulva
• Labia majora are two outer folds of skin that cover the labia minora (two thinner folds)
• Clitoris is an organ near the top junction of the labia minora, equivalent to the male glans

Menstruation

• Dysmenorrhea (menstrual cramps) is caused by uterine contractions during the menstrual period
• Common and causes pain in the stomach, hips, and back

Female Reproductive System

• Consists of ovaries, genital tract, and external genitalia

Ovaries

• Almond-sized and almond-shaped
• Suspended in the abdominal cavity by small ligaments
• Produce oestrogen and progesterone, responsible for female secondary sexual characteristics and preparing the body for possible pregnancy
• Composed of medulla (inner part) and cortex (outer part)
• Cortex contains numerous follicles that contain immature eggs (oocytes)

Genital Tract

• Consists of fallopian tubes, uterus, and vagina
• Fallopian tubes connect ovaries to the uterus, collecting eggs through the infundibulum
• Uterus is a hollow, muscular, upside-down pear-shaped organ
• Cervix is the narrow section at the bottom of the uterus
• Uterus wall is composed of myometrium (smooth muscle layer) and endometrium (epithelial cell layer)
• Vagina is an elastic duct connecting the cervix to the outside of the body, with lubricant-secreting glands on its walls

External Genitalia

• Combines to form the vulva
• Labia majora are two outer folds of skin that cover the labia minora (two thinner folds)
• Clitoris is an organ near the top junction of the labia minora, equivalent to the male glans

Menstruation

• Dysmenorrhea (menstrual cramps) is caused by uterine contractions during the menstrual period
• Common and causes pain in the stomach, hips, and back

Female Reproductive System

• Consists of ovaries, genital tract, and external genitalia

Ovaries

• Almond-sized and almond-shaped
• Suspended in the abdominal cavity by small ligaments
• Produce oestrogen and progesterone, responsible for female secondary sexual characteristics and preparing the body for possible pregnancy
• Composed of medulla (inner part) and cortex (outer part)
• Cortex contains numerous follicles that contain immature eggs (oocytes)

Genital Tract

• Consists of fallopian tubes, uterus, and vagina
• Fallopian tubes connect ovaries to the uterus, collecting eggs through the infundibulum
• Uterus is a hollow, muscular, upside-down pear-shaped organ
• Cervix is the narrow section at the bottom of the uterus
• Uterus wall is composed of myometrium (smooth muscle layer) and endometrium (epithelial cell layer)
• Vagina is an elastic duct connecting the cervix to the outside of the body, with lubricant-secreting glands on its walls

External Genitalia

• Combines to form the vulva
• Labia majora are two outer folds of skin that cover the labia minora (two thinner folds)
• Clitoris is an organ near the top junction of the labia minora, equivalent to the male glans

Menstruation

• Dysmenorrhea (menstrual cramps) is caused by uterine contractions during the menstrual period
• Common and causes pain in the stomach, hips, and back