Reproductive systems Flashcards
Gonads
Produce gametes (testes and ovaries)
Ducts
Store and transport gametes
Accessory sex glands
Produce substances that protect the gametes and facilitate their movement
Supporting structures
Such as penis and uterus, assist the delivery of gametes
Male reproductive organs
- gonads: testes. Gametes are spermatozoa produced by the seminiferous tubules
- genital ducts: epididymis, ductus deferents, ejaculatory ducts, and urethra
- accessory glands: seminal vesicles, prostate, bulbo urethras gland
- supporting structures: scrotum and penis
Scrotum
Supporting structure for the testes, loose skin suspended from the root of the penis
- scrotal septum divides the scrotum into 2 sacs (externally seen as median ridge Raphe). Made of subcutaneous layer and muscle tissue (Dartos mm)
- cremaster mm: small skeletal mm that is an extension of the internal oblique mm through the spermatic cord to surround the testes
- moves up and down to maintain optimal temp
Testes
Paired oval glands
- each testicles is divided into internal compartments called Lobules (200-300/testicle)
- seminiferous tubules: each lobule contains 2-3. Where sperm are produced
Testosterone
- negative feedback loops control secretin of testosterone and spoermatogenesis
- secreted by interstitial cells between seminiferous tubules
- effects: prenatal development, male sexual characteristics
1. Enlagrgement of male sex organs
2. Secondary sex characteristics: skeletal growth, wide shoulders, facial and chest hair, increased sebaceous oí, enlargement of the larynx
3. Development of sexual function
Epididymus
Site of sperm maturation
- sperm acquire motility and ability to fertilize an ovum
- single, tightly coiled tube enclosed in fibrous casing
- lies along posterior border of each testable
- very small diameter by 20 ft long
- serves as duct through which sperm travel from testis to exterior
- peristaltic contraction of smooth mm propels stern into ductus deferens
Vas deferens / ductus deferens
An extension of the epididymis
- thick, muscular walls
- extends through inguinal canal into abdominal cavity
- ;pp[s over the ureter and passes over side and down posterior surface of bladder
- enlarged terminal portion (ampulla) joins the duct of the seminal visible to form the ejactulatory duct
- ductus deferens Connery’s spree during sexual arousal from the epididymes toward the urethra by peristaltic contractions
Vas deferens
Connects the epeiddiymis with the ejaculatory duct
- one of the excretory ducts fro seminal fluid
- severing or clamping off the vas deferens is known as a vasectomy
Ejactulatory duct
- formed by union of vas deferens with duct from seminal vesicles just superior to the prostate
- passes through the prostate gland, terminating in the urethra
Urethra (males)
Dual function that involves both reproductive system and urinary system
Seminal vesicles
Convoluted pouches on the posterior surface of the bladder
- connects the cas deferens to the ejaculatory duct
- secretes the viscous, nutrient rich part of seminal fluid (60% of semen)
Prostate gland
Lies just below the bladder and is shaped like a donut
- encircles the urethra
- added watery, milky looking secretions to seminal fluid (30%)
Bulbourethral gland
Small, pea-shaped structure with ducts (approx 1 in long) leading into urethra
- lies below the prostate gland
- secretes alkaline fluid that is part of the semen (5-10%)
Penis
Composed of 3 cylindrical masses of erectile tissue, one of which contains the urethra which is the terminal duct for both urinary and reproductive tracts
Spermatic cords
Internal
- fibrous cylinders located in the inguinal canals which enclose the vas deferens, blood vessels, lymphatic, and nerves
Female reproductive organs
- gonads: paired ovaries. Gametes are ova produced by ovaries
- ducts: uterine tubes (fallopian) accessory sex glands (mammary in breast)
- supporting structures: uterus, vagina, vulva (external)
Ovaries
- nodular glands located on each side of the uterus
- in outer cortex are thousands of microspoci structures called ovarian follicles
- ovarian follicles contain the developing female
Functions of ovaries
- produce ova (female gamete)
- oogenesis: process that results in formation of a mature egg from an immature oocyte
- the ovaries are endocrine organs that secrete the female sex hormones (estrogens and progesterone)
- estrogens and progesterone regulate reproductive fucntion in the female
Uterus
Pear-shaped and contains the cervix and body
- located in the pelvis cavity between the urniary bladder and rectum
- bloody of the uterus lies flexed over the bladder
- the cervix points downward and backward, joint the vagina at a right angle
- several ligaments hold the uterus in place but also allow considerable movement
- position of the uterus is altered by age, preganancy, and distensión of related pelvic viscera
Wall of the uterus
- Endometrium: the inner layer, has a rich supply of blood capillaries
- Myometrium: the middle layer, consists of smooth mm fibers and breath strength
- Perímetrium: external layer
Functions of uterus
Permits sperm to ascend toward uterine tubes
- if conception occurs, an offspring develops in the uterus
- of conception does not occur, layers of the endometrium shed during menstruation
- menstruation: cyclical even that allows the endometrium to renew itself
Uterine tubes
Fallopian tubes or oviduct
- attached to the uterus at its upper angles and extend outward toward sides of pelvis
- serve as ptransport channels for ova and as the site of fertilization
Vagina
Tubular organ located between the rectum, urethra, and bladder
- collapsible tube capable of distensión, composed of smooth mm and lined with mucus membrane …
Breasts
Lie over the pectoral mm
- estrogens and progesterone control breast development
- breast size is determined by the amount of fat around glandular tissue
Mammary glands
Alveolus of the mammary gland produce milk, and a system of ducts carries it to the nipple
- lactación
- ovarian hormones make breasts structurally ready to produce milk
- estrogen stimulated development of ducts
- progesterone stimulates development of alveolus, fucntional secretory unit of the mammary gland
Function of the breast
Shedding of placenta results in decrease of estrogen and stimulates prolactin (lactation, alveolus secrete milk)
- suckling of the infant on the nipple stimulates release of prolactin and oxytocin (stimulates milk ejection into ducts)
- lactation proved nutrient rich milk to offspring for up to several years from birth, some advantages are
1. Nutrients
2. Passive natural immunity from antibodies present in colostrum and milk
3. Emotional bonding between mother and child
Female reproductive cycles
Cyclical changes that start with the beginning of meses (menarche) in puberty and ends with menopause
Menstruation cycle
- Menses: menstrual period, days 1-5
- Postmenstrual phase: occurs between the end of menses and beginning of ovulation
- Ovulation: release of the ovum into pelvic cavity; occurs most often 14-16 days prior to menstruation
- Premenstrual (post-ovulation) phase: occurs between ovulation and the onset of menses
Oocyte development
At birth females have the number of oocyte used during her lifetime
- these oocyte are incomplete, meiosis is suspended
- roughly at the start of menstruation, oocytes resume the last phase of meiosis, reducing their chromosomal number sby half (23) in preparation fro fertilization with sperm
- mature oocyte = ovum
Control of reproductive cycles
Hormones control cyclical chagnes
- cyclical chagnes in ovaries result from changes in gonadotropins (FSH and LH) secreted by the anterior pituitary gland
- cyclical chagnes in uterus are caused by changes in estrogen and progesterone
Steps of reproductive cycle
No pregnancy - low levels of FSH and LH - regression of corpus luteum - decrease estrogen and progesterone - sloughing of endometrial lining
