LQB185 Chapter Notes - Chapter 28: Dense Irregular Connective Tissue, Tunica Vaginalis, Male Accessory Gland
25 May 2018
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Chapter 28- Reproductive System
28.1 Male Reproductive System
➢ Include Testes, system of ducts, accessory sex glands and several
supporting structures (scrotum and penis)
➢ Testes
- Produce sperm and secrete hormones
➢ Duct system
- Transports and stores sperm, assists in their maturation and conveys
them to the exterior.
➢ Penis
- Delivers sperm into female reproductive tract
➢ Scrotum
- Supports the testes
- Consists of loose skin, underlying subcutaneous layer and muscle
tissue called the Dartos Muscle (smooth muscle fibres)
- Scrotal Septum: divides the scrotum into 2 sacs
- Each testis has the Cremaster Muscle- series of small bands of
skeletal muscle
- Contraction of Scrotum muscle regulate temperature of testes
- Sperm production requires temp 2-3C lower than body temp
➢ Testes
- Oval glands, developed near the kidneys.
- Tunica Vaginalis: serous membrane that partially covers the testes
- Hydrocele: serous fluid in the tunica vaginalis
- Tunica Albuginea: deeper than vaginalis, white fibrous capsule of
dense irregular connective tissue. Divides testis into internal
compartments called Lobules
- Each lobule contains 1-3 tubules called Seminiferous tubules: sperm
are developed here
- Seminiferous Tubules contain 2 cell types: Spermatogenesis cells and
Sustentacular cells
- Spaces between seminiferous tubules are clusters of cells called
interstitial cells: secret testosterone (androgen) that promotes
masculine characteristics and sexual drive
- Spermatogenesis
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➢ Sperm
- Head and Tail, nucleus with 23 condensed chromosomes
- Testosterone and Dihydrotestosterone both binned to the same
androgen receptor.
- Androgen produces:
1. Prenatal Development
2. Development of male sexual characteristics
3. Development of sexual function
4. Stimulation of anabolism- protein synthesis
➢ Reproductive System Ducts in Males
- Pressure from fluid secreted by Sustentacular cells pushes sperm and
fluid along the lumen of seminiferous tubules and into ducts called
Straight Tubules.
- Straight tubules -> rete testis -> efferent ducts -> ductus epididymis
- Epididymis: comma-shaped organ consists of tightly coiled ducts
epididymis (pseudostratified columnar epithelium and smooth
muscle)
- Epididymis is the site of sperm maturation (sperm acquire motility
and ability to fertilize)
➢ Accessory Sex Glands
- Seminal Vesicles: secrete alkaline, viscous fluid that contains fructose,
prostaglandins and clotting proteins.
- Prostate: secretes milky, slightly acidic fluid that contains substances
1. Citric acid in prostatic fluid- used by sperm for ATP production via
the Krebs cycle
2. Several proteolytic enzymes- eventually breaks down the clotting
proteins from the seminal vesicles
3. The function of the acid phosphatase secreted by the prostate is
unknown
4. Seminal plasmin- prostatic fluid that is an antibiotic that destroys
bacteria.
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Include testes, system of ducts, accessory sex glands and several supporting structures (scrotum and penis) Transports and stores sperm, assists in their maturation and conveys them to the exterior. Consists of loose skin, underlying subcutaneous layer and muscle tissue called the dartos muscle (smooth muscle fibres) Scrotal septum: divides the scrotum into 2 sacs. Each testis has the cremaster muscle- series of small bands of skeletal muscle. Contraction of scrotum muscle regulate temperature of testes. Sperm production requires temp 2-3c lower than body temp. Tunica vaginalis: serous membrane that partially covers the testes. Hydrocele: serous fluid in the tunica vaginalis. Tunica albuginea: deeper than vaginalis, white fibrous capsule of dense irregular connective tissue. Each lobule contains 1-3 tubules called seminiferous tubules: sperm are developed here. Seminiferous tubules contain 2 cell types: spermatogenesis cells and. Spaces between seminiferous tubules are clusters of cells called interstitial cells: secret testosterone (androgen) that promotes masculine characteristics and sexual drive.
