Chapter 18 Male Reproductive System

Functions of the Male Reproductive System 1. Produce and Store Sperm 2. Produce male sex hormone testosterone

Physical Changes Male growth spurt growth spurt acne acne deeper voice deeper voice facial and body hair develops facial and body hair develops broader shoulders broader shoulders muscles get larger muscles get larger perspiration increases perspiration increases 1st ejaculation occurs 1st ejaculation occurs

External Structures Penis Penis Male sex organ Male sex organ Incase urethra Incase urethra Penis

External Structures Scrotum Scrotum Incase testes Incase testes Control temperature of testes Control temperature of testes Scrotum

Internal Structures Testes Testes Make Sperm (50,000 sperm every minute) Make Sperm (50,000 sperm every minute) Produce the male sex hormone testosterone Produce the male sex hormone testosterone Necessary for sperm production and development of the male sex characteristics.Necessary for sperm production and development of the male sex characteristics. Testes

Internal Structures Epididymis (on top of each testicle) Epididymis (on top of each testicle) Sperm are stored and mature here Sperm are stored and mature here Epididymis

Internal Structures Vas Deferens Vas Deferens Sperm travel through here Sperm travel through here Tubes that lead to the urethra Tubes that lead to the urethra Vas Deferens

Internal Structures Urethra Urethra Semen travels through here and out the end of the penis Semen travels through here and out the end of the penis Urine flows through here and out the end of the penis Urine flows through here and out the end of the penis Urethra

Internal Structures Seminal Vesicle Seminal Vesicle Supplies fluid to sperm Supplies fluid to sperm Nourishes sperm (sugar) Nourishes sperm (sugar) Seminal Vesicle

Internal Structures Prostate Gland Prostate Gland Supplies fluid to protect the sperm Supplies fluid to protect the sperm Prostate Gland

Prostate Cancer Most common cancer among American males Most common cancer among American males 2 nd leading cause of death among U.S. men 2 nd leading cause of death among U.S. men Cause: unknown Cause: unknown

Prostate Cancer Continued Symptoms: difficulty urinating, frequent urination, painful or burning urination Symptoms: difficulty urinating, frequent urination, painful or burning urination Treatment: radiation therapy, chemotherapy, surgery Treatment: radiation therapy, chemotherapy, surgery

Internal Structures Cowper’s Gland Cowper’s Gland Bulbourethral Gland Bulbourethral Gland Supplies fluid to sperm to help with mobility Supplies fluid to sperm to help with mobility Cowper’s Gland

Male Reproductive System Seminal vesicle Prostate gland Bulbourethral gland/Cowpers Gland Side View Scrotum Urinary bladder Vas deferens Urethra Penis Epididymis Testes Foreskin Glans Anus Ejaculatory Duct

Male Reproductive System Seminal vesicle Prostate gland Bulbourethral gland/Cowpers Gland Front View Urinary bladder Vas deferens Urethra Penis Epididymis Testes

4 Parts of Semen Sperm (300 to 400 million) Sperm (300 to 400 million) Seminal Fluid – Nutrients (sugar) Seminal Fluid – Nutrients (sugar) Prostate Fluid – Protection Prostate Fluid – Protection Cowper’s Fluid – Mobility/Neutralize Cowper’s Fluid – Mobility/Neutralize

Vocabulary Terms

Sperm Structure Composed of a head, mid-piece, tail Composed of a head, mid-piece, tail Millions produced daily Millions produced daily Head contains genetic information Head contains genetic information X or Y chromosomeX or Y chromosome 23 chromosomes23 chromosomes

Sperm Head, Mid-piece, Tail

Lots of Sperm

Seminal vesicle Prostate gland Bulbourethral/ Cowper’s Gland Vas deferens Urethra Penis Testes The Pathway of Sperm Epididymis

Erection Penis becomes larger and stiffer as blood chambers in the penis become filled with blood Penis becomes larger and stiffer as blood chambers in the penis become filled with blood

Ejaculation Ejection of semen from the penis Ejection of semen from the penis Contractions occur at the base of the bladder, forcing semen through the urethra Contractions occur at the base of the bladder, forcing semen through the urethra 1 ejaculation = million sperm 1 ejaculation = million sperm

Nocturnal Emissions “Wet Dreams” “Wet Dreams” Ejaculation during sleep Ejaculation during sleep They are normal and may occur frequently or it is normal if they never occur They are normal and may occur frequently or it is normal if they never occur