Lec18 Reproduction

Lec18 Reproduction - Biology 115: The Reproductive System...

Info iconThis preview shows pages 1–15. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Biology 115: The Reproductive System Fig. 16.1 Male anatomy 1. Scrotum (1) 2. Testes (2) 3. Epididymis (2) 4. Vas deferens (2) 5. Urethra (1) 6. 3 glands 7. Penis (1) Male anatomy: Scrotum and testes Scrotum : Sacs that hold the testes Help regulate the temperature of the testes Testes: Paired organs that produce sperm and male sex hormones- testosterone Composed of seminiferous tubules where sperm are being produced Epididymis: Sperm mature and are stored here Male anatomy: Scrotum and testes Male anatomy: Vas deferens and urethra Vas deferens Transports sperm to the urethra First section stores mature sperm Second part transfer tube to urethra Urethra Conducts sperm through penis Penis Enables sexual intercourse Male anatomy: 3 glands that contribute to semen Seminal vesicles produce a sugary fluid that provide energy for the sperm Prostate gland produces an alkaline fluid to help buffer the acidic pH in the vagina Bulbourethral glands produce mucus that acts as a lubricant in the urethra Male anatomy: Penis Penis: organ used for sexual intercourse and urination Glans penis : Intensely sensitive tip of the penis usually covered by foreskin Circumcision is the removal of all or part of the foreskin Erectile dysfunction (impotency) occurs when the erectile tissue does not expand enough to compress the veins Semen and sperm Semen is slightly basic (pH 7.5), Contains fructose for energy & prostaglandins that cause uterus to contract; May help sperm move along Sperm consists of a flagellar tail, middle section full of mitochondria, head containing 23 chromosomes, & an acrosome : Type of lysosome containing enzymes to penetrate the zona pellucida , the muco-protein covering of the egg. Sperm anatomy 3 parts: Head : covered by a cap called the acrosome which stores enzymes needed to penetrate the egg Middle piece : contain mitochondria to make energy (ATP) Tail: provides movement for the sperm Path of Sperm to Fertilization Erection : Impulses from parasympathetic system cause blood to accumulate in sinuses of the penis Movement of Sperm : Sperm stored in the vas deferens combine with other components of semen from the seminal vesicles, prostate, Cowper's gland move to the urethra Ejaculation: Urethral wall muscles undergo peristalsis causing ejaculation from the urethral opening in the glans penis Path of Sperm to Fertilization Ejaculation Usually about 400 -600 million sperm/ 3.5 ml ejaculation Low sperm count typically 35-50 million sperm ---> infertility Some concern that environmental pollution is lowering sperm counts Relaxation and refractory period : Refractory period increases with age. Regulation of Male Sex Hormones Hypothalamus: secretes GnRH "Gonadotropic Releasing Hormone" Anterior Pituitary : Releases two gonadotropic hormones: FSH (follicle stimulating hormone): As FSH rises, so does spermatogenesis in the...
View Full Document

This note was uploaded on 04/07/2009 for the course BIOL 115 taught by Professor Irving during the Spring '08 term at Illinois Tech.

Page1 / 72

Lec18 Reproduction - Biology 115: The Reproductive System...

This preview shows document pages 1 - 15. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online