Chapter 28 (Male)

What are gametes made of?

What are gametes made of?

• sperm

• 2nd oocyte

Structures in the male reproductive system

• testes

• system of ducts

• accessory sex glands

• supporting structures like the penis

Scrotum

cutaneous out pouching of the abdomen that supports the testes

Cremaster muscle

• elevates testes on exposure to colds and during arousal

• warmth reverses process

Testes

• paired oval glands

• surrounded by dense white capsule called tunica albuginea

• each filled with 2 or 3 seminiferous tubules where sperm are formed

Sertoli Cells

• form blood testis barrier

• support developing sperm

• produce fluid and control release of sperm

Spermiogenesis

maturation of spermatids into haploid sperm cells

spermiation

release of sperm cell from a sertoli cell

Sperm morphology

• head contains DNA and acrosome

• midpiece contains mitochondria to form ATP

• tail is flagellum used for locomotion

GnRH in males

stimulates anterior pituitary secretion of follicle, stimulating hormone (FSH) and luteinizing hormone (LH)

LH in males

assists spermatogenesis and stimulates production of testosterone

FSH in males

initiates spermatogenesis

What happens if testosterone gets too high?

Sertoli cells produce inhibin

Puberty

• hypothalamus increases its stimulation of anterior pituitary with releasing hormones (GnRH)

• anterior pituitary increases secretion LH and FSH

Testosterone

• controls the growth, development, functioning, and maintenance of sex organs

• stimulates growth, protein anabolism, and sperm maturation

• stimulates development of male secondary sex production

• negative feedback systems regulate testosterone production

Sexual characteristics during puberty in men

• sexual behavior and libido

• male metabolism

• deepening of the voice

Pathway of sperm flow

• seminiferous tubules

• straight tubules

• rete testis

• efferent ducts

• ductus epididymis

• ductus deferens

Epididymis

• 1.5in ling along posterior border of each testis

• head, body and tail region

Spermatic Cord

• All structures passing to and from the testes

  • testicular artery

  • pampiniform plexus of veins

  • autonomic nerves

  • lymphatic vessels

  • ductus deferens

  • cremaster muscle

Inguinal canal

2in long tunnel through the 3 muscles of the anterior abdominal wall

Hernia

a rupture or separation of a portion of the abdominal wall resulting in a protrusion of a part of an organ

Seminal vesicles

• pair of pouchlike organs found posterior to the base of the bladder

• alkaline, viscous fluid

Cowpers Glands

• paired, pea sized gland within the urogenital diaphragm

• alkaline mucous

• connected to spongy urethra

• mucous for lubrication and an alkaline substances that neutralizes acid within urethra

Semen

mixture of sperm and seminal fluid

Erection

• caused by parasympathetic reflex

• sexual stimulation causes dilation of arteries supplying the penis

• veins become compresses and blood is trapped

Ejaculation

• sympathetic reflex

• muscle contractions close sphincter at base of bladder

• peristaltic contractions in the ductus deferens, seminal vesicles, ejaculatory ducts and prostate propel semen into the penile portion of the spongy urethra