Endocrine & Reproductive Systems Chapter 34 Biology

34.1 The Endocrine System Hormones and Glands o Chemicals that are released in one part of the body and travel to other parts. o Hormones act on specific cells called target cells or the message is ignored. o Over 40 glands exist in our bodies o Ex: gland: pancreas hormone: insulin target cells: liver, muscles

GlandLocationJobHormones Released Hypothalamus Brain-Master control -signals pituitary Sends Releasing Hormone to pituitary Pituitary BrainControls hormone secretion of glands ADH, oxytocin, growth hormones PinealBrainControl sleep/wake cycles Melatonin Thyroid Neck (at trachea) Maintains metabolism -thyroxine- metabolism rates -calcitonin- reduce blood Ca levels Parathyroid Next to thyroidRegulate calciumParathyroid hormone- increase blood Ca levels Pancreas Abdomen near stomach Maintains blood sugar level -insulin- decreases blood sugar levels -glucagon- increases blood sugar levels ThymusChestImmune responsethymosin Adrenal Above kidneysResponds to stress epinephrine (also called adrenaline) Norepinehprine

Exocrine Glands o Tube-like structures (ducts) that secrete directly out of body or into digestive system. Ex: tear ducts, bile duct, sweat glands Endocrine Glands o Release hormones directly into blood Ex: pituitary, adrenal, thyroid Prostaglandins o Small hormone-like substances secreted by cells o “local hormones” Steroid v non-steroid hormones

34.2 Glands of the Endocrine System How is the Endocrine System Controlled? o The HYPOTHALAMUS o Regulated by negative feedback o Maintaining water balance (ADH) keeps levels of many hormones in check. o Controlling metabolism also affects many hormones o Body temperature is another method of regulation

34.3 The Reproductive System How Hormones Relate to the Reproductive System HormoneSourceFunction Releasing Hormone Hypothalamus Stimulates pituitary Follicle Stimulating Hormone (FSH) Pituitary Stimulates sperm production or Stimulates follicle and oocyte development in ovary Luteinizing Hormone (LH) Pituitary Stimulates testes to produce testosterone or in females causes follicle to mature and break open Estrogen Follicle and corpus luteum Causes endometrium to thicken; development of secondary sex traits Progesterone Corpus luteum Causes and maintains endometrial thickening; controls menstrual cycle. Testosterone Testes Stimulates sperm production; development of secondary sex traits

Male Reproductive System o Testes (2) produce sperm and sex hormones. (equivalent to ovaries) contained in scrotum maintain temperature suitable for sperm o Epididymis (2) sperm maturation site coiled duct from testes. o Vas deferens (2) tube for mature sperm to travel from epididymis to ejaculatory duct. o Ejaculatory duct (2) conduct sperm to penis. o Urethra- dual purpose duct for sperm or urine. o Penis- organ for sexual intercourse and expels semen

o Accessory Glands Seminal vesicle secretes fructose and prostaglandin Prostate gland secretes buffer Bulbourethral gland secretes mucus

Female Reproductive System o Ovaries (2) oocyte production and maturation sex hormone production o Oviducts (2) fallopian tubes connecting tube between ovaries and uterus fertilization occurs here. o Uterus chamber for embryonic growth and development. endometrium - inner lining necessary for embryo myometrium - muscle layers for contractions.

o Cervix secretes mucus to enhance sperm mobility into uterus. mucus helps reduce embryonic infection. o Vagina organ for intercourse and childbirth o Clitoris external organ sensitive to sexual stimulation. o Vulva external fat padded skin

Sperm and Egg Production o For every immature sperm, 4 mature sperm are produced o For every immature egg, 1 mature egg is produced o Sperm consist of a head with DNA, mid-piece with mitochondria and a flagellum. o Eggs contain all of the cytoplasm and organelles needed once fertilized

Ovarian and Menstrual Cycles o Assume this to be a 28 day cycle, but it does vary in reality. PhaseEvents# of Days Follicular Phase (includes two parts) Menstruation; endometrium breaks down Follicle matures; endometrium rebuilds Ovulation Egg released from ovary 14 Luteal Phase Corpus luteum forms & secretes progesterone; endometrium thickens 15-28

Fertilization and Embryonic Development o Gamete formation o Fertilization Sperm + egg = zygote 2 haploid cells become 1 diploid o Implantation Burrow into uterus as blastocyst o Gastrulation Ectoderm, mesoderm, endoderm o Neurulation o 8 weeks = fetus o 4-6 mo: complex and specialized cells/tissues o 7-9 mo: organ systems mature; size and mass changes of fetus o 40 weeks is full term pregnancy