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Organs of the reproductive system
- * Organs produce and maintain sex cells (sperm)
- * Trransports sex cells
- * Secrete sex hormones
- * Primary sex organ
- o Testes
- * Accessory sex organs
- o Epididymis, vasdeferes, ejaculatory ducts, urethra, seminal vesicle prostate gland, and bulbourethral glands
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TESTES
- * Both testes are within a sac called scrotum
- * Covered by a tough fiberous connective tissue that forms 250 lobules
- * Each lobule contains 1-4 long coiled structures called seminiferous tubules
- * Seminiferous tubules form ducts that join to form the epidymus
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Sperm cells
- Sperm cells collect in the lumen of the seminiferous tubles
- Stored the epididymus where they mature
- Sperm cells are made of the head, body, tails
- Head of sperm contains an acrosome that is able to penetrate the egg during fertilization
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vas deferens
- Plural vas deferens
- Know as duct deferens
- Passes throu the inguinal canal
- Outside the bladder, it unites with the duct of the seminal vesicle to form the ejaculatory duct
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Spermatogenises
- Formation of the sperm cells
- Spermatogonoia are undifferentiated cell that havce complete cest of chomasome 46
- Spermatogonium iunder goes cell division primary spermatocytes 46
- At puberty, the primary spermatocyte undergo a first step in cell division and becomes secondary spermatocytes
- The second step od cell division yeilds spermatrids 23
- Spermatid mature into sperm cells 23
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Seminal vesicle
- Convoluted sac like structure
- Attached to the vas deferens near the base of the bladder
- Secretes alkalind fluid to regulate the pH of the tubular contents to provide a safe enviroment for the sperm
- Sevrets fructose that provides energy for sperm
- Secretes prostaglandins which stimulate muscle contraction in the female reproductive organs
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Epididymus
- Plural epididymides
- Tightly coiled about 6ft long
- Emerges from top of the testis
- Immature sperm cells that reach it mature and become moble
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The prostate gland
- A chestnut shape structure that surrounds the proximal portion of the urethre
- Secretes a thin milky fluid with an alkaline pH to neutralize the acidic enviroment around the sperm cell
- Enchances mobility of sperm cell
- Neutrilizes the acidic enviroment of vagina
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The scrotum
- A pouch of skin and subcutaneous tissues
- Has a medial septum that separates it into two chambers
- Protects and help regulate the tempature of the testis by keeping it two degrees lower than the body temapature
- Contains smooth muscles that shrink and raise the testes up during cold so the are closer to the pelvic cavity to absorb heat
- Exposure to heat causes the muscle to relax
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The bulbourethreal gland
- Each about 1 cm in diameter
- Secrete mucus like fluid in response to sexual stimulation
- Lubricates the end of the penis in preparation for sexual intercourse
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The penis
- Cylindrical organ that convey urine and semen through the urethra
- Enlarges and stiffens during erection
- Shaft of the penis contains three columns of erectile tissue: a pair of corpa caverenosa and a single corpus spongiosum
- Corpus spongiosum enlarges distally to form the glans penis
- Glans penis contains the sensory receptors for sexual stimulation
- The prepuce is a fold of skin that covers the glans as a sheath
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How many Sperm cells do males have?
- Semen consists of sperm cells and the fluids secreted from the seminal vesicles, bulbourethral glands, and the prostate gland.
- Volume per ejactualtion varies from 2-5 ml
- There are 120 million sperm cells per ml
- Sperm cells are not motile when stored they begin to swim when mixed with the semen secretion
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Hormonal control
- The pituitary gland is located in the sella turcical of the sphemoid bone
- The size of a pea grain (ball sac)
- Made of two parts:
- Anterior pituitary and posterior pituitary
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Anterior pituitary gland
- Adrenocorticotropi hormone (ACTH): causes the adrenal gland to release its hormone
- Follicle stimulating hormone (FSH): acts on the testes and ovaries
- Lutenizing hormone (LH): acts on the testes and ovaries
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LH and FSH
- LH acts in interstitial cells of the testes to secrete male sex hormones
- FSH stimulates permatogenesis
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Testosterone
- Secretion starts during fetal development till few weeks after birth
- It then ceases during childhood
- Surges at puberty
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Function of testosterone
- *increase growth of body hair
- *Thickening of vocal cords
- *Thickening of skin
- *Increases muscle growth
- *Thickening of bones
- Increases rate of erythrocytes production
- Stimulates sexual ability
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