Course: Animal Production Unit Title: Hormones TEKS: 130.3 (C)(6)(A) Instructor: Ms. Hutchinson Objectives: After completing this unit of instruction, students will be able to: A. Define what hormones are; B. Compare and contrast the male and female hormones; C. Explain what each hormone in the mail reproductive system does; D. Describe what the hypothalamus gland secretes; E. Describe what the pituitary gland secretes; F. Write which hormones are specific to females; G. Identify the difference between estrous and estrus; H. Outline the estrous cycle for a cow; and I. Explain what happens during estrus.
Interest Approach: Hormones in Livestock CommonGround YouTube video http://www.youtube.com/watch?v=np0wfu_mgzo Curriculum Hormones: Chemicals secreted by an animal that affect other parts of the organism. Hormones in Male Reproduction: Gonadotropic Releasing Hormone (GnRH) hormone that stimulates the gonads Follicle Stimulating Hormone (FSH) Causes production of sperm cells Luteinizing Hormone (LH) Causes endocrine cells in the tests to produce the male hormone Testosterone Testosterone Steroid hormone responsible for the growth and development of secondary sex characteristics in a male such as growth and maintenance of male sex organs and the production of sperm Hormones are Secreted from Glands: Hypothalamus Area of the brain directly above the pituitary that produces one of the hormones which control reproduction GnRH Pituitary gland situated beneath and stimulated by the hyphalamus releases FSH and LH which serve such functions as stimulating production of sperm & testosterone in males Use a $10,000 Pyramid Moment to review concepts. Hand out a set of cards to a group of three students. This means you may have to make several sets using the terms above for the hormones and glands. Take 3 x 5 note cards and put the terms above on them for each group. Game Show Rules: There are three roles in this activity the Player, the Clue Giver, and the Teleprompter. The Player sits facing the Clue Giver and with his or her back toward the Teleprompter. The Player guesses the facts through clues given by the Clue Giver. The Clue Giver faces the Player and the Teleprompter. He or she will receive the facts from the Teleprompter and give clues to the Player. The Teleprompter stands behind the Player and faces the Clue Giver. He or she will reveal the fact cards one at Instruction PPT Slide 4 What is a hormone? PPT Slide 5-7 What does GnRH do? What does FSH do? What is the function of LH? What is testosterone? What are the 2 glands that secrete hormones? Where are these glands located? What does the hypothalamus produce? What does the pituitary produce? 3 x5 note cards with terms on each of them. Timer
a time to the Clue Giver. Each student is to play each role. Each round is 60 seconds long. At the end of 60 seconds have them count how many cards they made it through or how many times they made it through. This activity will probably last for 5 minutes total. Hormones in Male Reproduction 1. Gonadotropic Releasing Hormone (GnRH) Hormone that stimulates the gonads. Works like a light switch turning LH and FSH on and off. 2. Follicle Stimulating Hormone (FSH) Causes production of sperm cells. 3. Luteinizing Hormone (LH) Causes endocrine cells in the testes to produce the male hormone testosterone. Hormones are secreted from glands. 1. Hypothalamus Area of the brain directly above the pituitary that produces one of the hormones which control reproduction. Gonadotropic Releasing Hormone (GnRH). 2. Pituitary Gland situated beneath and stimulated by the hypothalamus, releases follicle stimulating hormone (FSH) and Leutinizing hormone (LH), which serve such functions as stimulating production of sperm and testosterone in males. As you return to your seats, think about how the female reproductive hormones might differ from the male hormones we covered yesterday. What do you think will be similar? Take responses. What do you think will be different? Take responses. These are some great thoughts! Let s take a closer look at the hormones that effect females and learn about the estrus cycle in cattle. Keep an eye out for connections in the hormones we learned about in the males. Female Hormones: GnRH stimulates the gonads Acts as a light switch turning FSH and LH on and off Released by? Follicle Stimulating Hormone (FSH) Signals the follicle on the ovary to begin production of an egg Released by? PPT Slide 8-17 What does GnRH act as? What is GnRH released by?
Luteinizing Hormone (LH) causes follicles to undergo changes which lead to egg release Released by? Estrogen As the follicle grows larger, it begins to secrete more and more estrogen. Affects the nervous system causing restlessness, the desire to mount other animals. Causes the signs of heat and it causes the female to accept service from the male. (Released by the follicle) Progesterone yellow body secretes this hormone Hormone that maintains pregnancy Prepares the uterus for pregnancy and prevents the heat cycle Brain Splash! On large post-its around the room write the different hormones and glands. Divide the class into 5 groups and have each group write under the piece of paper what they know about the hormone or gland they have been given. Estrous vs Estrus: Estrous series of events occurring in the ovaries and other female reproductive organs Average cow heat estrous cycle 21 days Estrus Portion of the female reproductive cycle when cows and heifers are sexually active, receptive and fertile. Cattle estrus lasts about 18 hours The Estrous Cycle: Day 1: Estrus Day the heifer is sexually receptive to the male and fertilization of the egg may occur Estrogen production is high at this point Day 2-6: Developing Corpus Luteum replaces the follicle, secretes progesterone and some estrogen, and prepares the uterus for pregnancy and prevents heat Day 7-16: Developed Corpus Lueteum Will stay in this stage if pregnant, secreting progesterone and some estrogen to prevent heat and maintain pregnancy Day 17-21: Regressing CL Stage CL regresses size and produces less progesterone Follicle begins to grow and mature releasing more estrogen Growth of follicle happens due to the Anterior What does FSH do? Where is FSH released from? What does LH do? Where is LH released from? Describe estrogen. What is progesterone? What secretes progesterone? What is another name for the yellow body? What is estrous? What is estrus? What happens on day 1 of the What happens on days 2-6 of the What happens on days 7-16 of the What happens on days 17-21 of the
pituitary producing FSH and LH (Follicular Phase) Estrus (Day 1): Period of time the cow will accept service Ovulation actually occurs after this period of time. Ovulation actual release of the mature egg from the follicle. occurs about 10 to 14 hours after the end of heat. We will breed at 12 hours after the sight of standing heat, and then 12 hours later. A sharp increase in Luteinizing Hormone causes the follicle to rupture and the egg to release It also stimulates the corpus luteum to develop from the ruptured follicle so progesterone can be produced to help maintain pregnancy, if it occurs. Actual fertilization does not occur until after heat; however the male was accepted during heat. What day will the cow accept service? What is ovulation? When does ovulation occur? What happens when there is a sharp increase of LH? What stimulates the corpus luteum to develop? What produces progesterone? What does fertilization actually occur?
Review & Instruction: Objectives will be reviewed before examinations. Exams will be developed based on objectives as taught in class. Instructional Support: A. References B. Teaching Aids & Equipment: a. PowerPoint (Hormones) b. Post-Its c. Question Flash Cards d. C. Facilities: a. Agriculture classroom