MALE REPRODUCTIVE SYSTEM

• STAGES OF ANIMAL DEVELOPMENT

  1. Gametogenesis

  2. Fertilization

  3. Cleavage

  4. Gastrulation

  5. Organogenesis

  6. Differentiation and Growth
• Spermatogenesis


  The process of sperm production
• Oogenesis


  The process of egg production

  
• Internal fertilization


  Fusion of sperm and egg takes place within the female parent
• External fertilization


  Fusion of sperm and egg takes place outside the female parent
• Parthenogenesis


  A form of reproduction in which an egg can develop into an embryo without being fertilized by a sperm
• Cleavage


  A series of mitotic divisions whereby the enormous volume of egg cytoplasm is divided into numerous smaller, nucleated cells
• Gastrulation


  Formation of three germ layers: ectoderm, mesoderm, and endoderm
• Germ layers


  • Ectoderm
  • Mesoderm
  • Endoderm
• Ectoderm


  Outer, external layer that goes on to form epidermis, hair, nails, brain, spinal cord, peripheral nervous system
• Mesoderm


  Middle layer that goes on to form muscle, bone, connective tissue, notochord, kidney, gonads, circulatory system
• Endoderm


  Inner layer that goes on to form epithelial lining of digestive tract, stomach, colon, liver, pancreas, bladder, lung
• Organogenesis


  The process of formation of organs from three germ layers
• Monozygotic twins


  Twins conceived from one egg and one sperm, also called identical

  
• Dizygotic twins


  Twins conceived from two separate eggs (ova) fertilised by two separate sperm, also called fraternal

  
• Functions of the male reproductive organ


  • Produce, maintain, and transport sperm cells and semen
  • Discharge sperm
  • Produce and secrete male sex hormones
• Male reproductive hormones

  • Follicle-stimulating hormone (FSH)
  • Luteinizing hormone (LH)
  • Testosterone
• Vas deferens


  A long, muscular tube that transports mature sperm to the urethra in preparation for ejaculation
• Penis


  The male organ for sexual intercourse, containing many sensitive nerve endings and having three parts
• Urethra


  The tube that carries urine from the bladder outside the body, and also ejaculates semen during orgasm
• Scrotum


  The loose, pouch-like sac of skin that hangs behind the penis, holding the testicles
• Testicles


  Oval-shaped organs in the scrotum that produce testosterone and sperm through spermatogenesis
• Prostate gland


  A walnut-sized gland below the bladder that adds fluid to ejaculate to help nourish sperm
• Seminal vesicles


  Sac-like pouches that attach to the vas deferens and make up to 80% of ejaculatory fluid, including fructose to provide energy for sperm
• Bulbourethral glands


  Pea-sized structures on the sides of the urethra that create a clear, slippery fluid to lubricate the urethra and neutralize acids
• Conditions and disorders of the male reproductive system

  • Cancer (testicular, penile, prostate)
  • Sexually transmitted infections
  • Male infertility
  • Priapism
• Low-flow (ischemic) priapism


  A long-lasting erection caused by blood remaining in the erection chambers and unable to drain out
• Recurrent (stuttering) priapism


  A type of low-flow priapism where a long-lasting erection repeatedly goes away and comes back, growing more painful each time
• High-flow (nonischemic) priapism


  A rarer type of priapism caused by an injury that leads to uncontrolled blood flow into the penile tissues, causing a long-lasting erection
• The epididymis is where sperm mature and are stored.
• The scrotum is the sac that contains the testes.
• The vas deferens carries sperm from the epididymis to the urethra during ejaculation.