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Ch. 19 Reproductive System. Male Reproductive SystemOrgans classified as essential or accessoryEssential organs are testes that produce sperm.Accessory organsDucts passageways that carries sperm from testes to exteriorSex glands produce protective and nutrient solution for spermExternal ge
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1. Ch. 19 Reproductive System Common Structural Characteristics
Can be identified between sexes
Systems are adapted for development of sperm and egg
Sex hormones in both sexes are important in development of secondary sexual characteristics & normal reproductive activity
2. Ch. 19 Reproductive System Male Reproductive System
Organs classified as essential or accessory
Essential organs are testes that produce sperm.
Accessory organs
Ducts – passageways that carries sperm from testes to exterior
Sex glands – produce protective and nutrient solution for sperm
External genitals
3. Ch. 19 Reproductive System Testes – gonads of men
Structure and location
Testes in scrotum for lower than body temperature
Covered by tunica albuginea, which divided testes into lobules containing seminiferous tubules
Interstitial cells produce testosterone
Functions
Spermatogenesis is process of sperm production
Sperm precursors called spermatogonia
Meiosis produces primary spermatocyte which forms 4 spermatids containing 23 chromosomes.
4. Ch. 19 Reproductive System Spermatoza – highly specialized cell
Head contains genetic material
Acrosome contains enzymes to assist sperm in penetration of ovum
Mitochondria provide energy for movement
5. Ch. 19 Reproductive System Production of testosterone by interstitial cells
Testosterone “masculinizes” and promotes male accessory organs.
Stimulates protein anabolism and development of muscle strength
6. Ch. 19 Reproductive System Reproductive ducts – ducts through which sperm pass after exiting testes until the exit the body
Epididymis – single tube 6 m long; lies on top and behind testes
Sperm mature and develop capacity for motility as they pass through epididymis
7. Ch. 19 Reproductive System Ductus (vas) deferens – receives sperm from epididymis and transports them from scrotal sac through the abdominal cavity
Passes through inguinal canal
Joins duct of seminal vesicle to for ejaculatory duct.
8. Ch. 19 Reproductive System
9. Ch. 19 Reproductive System Accessory sex glands – semen: Mixture of sperm and secretions of accessory sex glands. 3-5 ml per ejaculation, with each ml = 100 million sperm.
Seminal vesicles
Pouch like glands produce 60% of fluid volume
Secretion is yellowish, thick and rich in fructose to provide energy needed by sperm for motility.
10. Ch. 19 Reproductive System Prostate gland
Shaped like doughnut, located below the bladder.
Urethra passes through the gland.
Secretion represents 30% of seminal fluid volume, thin and milk-colored.
Activate sperm and is needed for ongoing sperm motility
11. Ch. 19 Reproductive System Bulbourethral (Cowper’s) glands
Shape and size of a pea.
Secrets mucus like fluid, constituting less than 5% of seminal fluid volume.
External genitals
Penis and scrotum called genitalia
Penis has 3 columns of erectile tissue, 2 dorsal called corpora cavernisa and 1 ventral corpora spongiosum
Glans penis covered by foreskin
Surgical removal of foreskin called circumcision
12. Ch. 19 Reproductive System Female reproductive system
Structural plan
Essential organs are gonads (ovaries) produce ova (sex cells)
Accessory organs
Ducts – oviducts, uterus, and vagina
Sex glands including those in the breasts
External genitals
13. Ch. 19 Reproductive System Ovaries
Structure & function
Paired glands weighing 3 grams each
Resemble large almonds
Attached to ligaments in pelvic cavity alongside uterus
14. Ch. 19 Reproductive System Microscopic structure
Ovarian follicles – contain oocyte which is immature sex cell (1,000,0000 at birth)
Primary follicles = 400,000 at puberty covered with granulosa cells
350-500 mature follicles ovulate during reproductive lifetime
Secondary follicles have hollow chamber called antrum.
Corpus luteum forms after ovulation.
15. Ch. 19 Reproductive System Functions
Oogenesis – meiotic cell division produces daughter cells with 23 chromosomes
Production of estrogen and progesterone
Granulosa cells surrounding oocyte produce estrogen
Corpus luteum produces progesterone
Estrogen causes development and maintenance of secondary sex characteristics.
Progesterone stimulates secretory activity of uterine epithelium and assists in starting menses
16. Ch. 19 Reproductive System Reproductive ducts
Uterine (fallopian) tubes
Extend 10 cm from uterus to abdominal cavity
Extended distal end surrounded by fimbriae
Mucosal lining is directly continuous with abdominal cavity.
17. Ch. 19 Reproductive System Uterus
Lies in pelvic cavity behind bladder
Myometrium is the muscle layer.
Endometrium is lost in menstruation.
Menopause – end of repetitive menstrual cycles at 45-50 years of age.
18. Ch. 19 Reproductive System Vagina
Distendable tube about 10 cm long
Located between bladder and rectum in pelvic cavity
Receives penis during sexual intercourse and is birth canal for normal delivery of baby.
19. Ch. 19 Reproductive System Accessory and supportive sex glands
Bartholin’s - (greater vestibular) glands
Secretes mucus like lubricating fluid
Ducts open between labia minora
Breasts –
Located outside pectoral muscles
Size determined by fat quantity
Lactiferous ducts drain at the nipple
Lymphatic drainage important in spread of cancer cells to other body areas
20. Ch. 19 Reproductive System External genitals
Mons pubis
Clitoris
Orifice of urethra
Bartholin’s gland
Vagina
Labia minora & majora
Hymen
Perineum – area between vagina & anus
Episiotomy surgical cut during child birth
21. Ch. 19 Reproductive System Menstrual cycle – many monthly changes in uterus, ovaries vagina & breasts
Length – about 28 days (can vary from month to month even with same individual)
Phases
Menses – first 4-5 days; sloughing of endometrium (uterine lining)
Proliferative phase – usually between day 5-13, varies with individual. Characterized by repair of endometrium
22. Ch. 19 Reproductive System Secretory phase – days between ovulation and next menses, usually between days 14 – 28. Characterized by thickening of endometrium in preparation of implantation of fertilized ovum. High FSH and LH caused ovulation; sudden sharp decrease in estrogen and progesterone will bring on menstruation.
23. Ch. 19 Reproductive System