BIOL 460 1nd Edition Lecture 10Outline of Last Lecture I. Thyroid Gland (begins Exam Three Material)a. Composition b. Hormonesi. T3 ii. T34c. DiseasesOutline of Current Lecture I. Parathyroid GlandII. Pancreasa. Islets of Langerhansi. Alpha cellsii. Beta cellsiii. Delta cellsIII. Pineal Glanda. MelatoninIV. ThymusV. Reproductive Systema. Maleb. FemaleCurrent LectureThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.Parathyroid Gland1. Four small masses around thyroid gland2. Release parathormone (parathyroid hormone) 3. Regulates Ca2+ levels (antagonists for calcitonin)4. Acts on kidneys- reabsorption of Ca2+5. Causes osteoclasts to degrade bone matrix6. Intestine absorb more Ca2+Pancreas 1. Exocrine and endocrine gland2. Islets of Langerhans make up endocrine parta. Humans have about 1 million isletsb. Three cell typesi. Alpha1. Secretes glucagon2. Secreted between meals and during periods of fasting (when glucose levels are low)3. Raises amount of glucose in blood triggering glycogenolysis by cells of liver4. Stimulates lipolysis 5. Causes gluconeogenesisii. Beta1. Secretes insulin 2. Insulin is released during a period of increased glucose level in blood 3. Promote entry of glucose into cell (GLUT transporters)4. Glycogenogeneis 5. Lipogenesis iii. Delta- somatostatin1. Inhibit action of alimentary canal and alpha and beta cellsPineal Gland1. Communicates info about environmental lighting to body2. Primitive vertebrates had a pineal eye 3. Light strikes retina→ a signal goes to pineal gland4. Causes pineal gland to produce melatonin when there is no light 5. Light inhibits secretion of melatonin 6. Secretes melatonin in lack of light 7. Entrain circadian rhythms a. About a dayb. All eukaryotes have circadian rhythmc. Rhythm of activity is about 24 hours in length d. Sunrise → melatonin levels drop, tells organism that it is morning8. Photoperiodisma. Physiological response to change in dayb. Tells organism length of night→ depends on how long melatonin is secreted 9. Melatonin- antigonadotropina. Inhibits secretion of FSH and LHb. No eggs produced10. Melatonin supplementsa. Sleep b. Jet lagThymus 1. Large in fetus 2. Atrophies into adulthood 3. Secretes thymopoeitin 4. Site of maturation of T lymphocytes 5. As lymphocytes mature, thymus becomes less necessary and atrophies 6. T-cells- cell-mediated immunity, releases chemical to destroy abdominal cellsReproductive System 1. Male Reproductive Systema. Male gonads- testes b. Contains seminiferous tubulesc. Contain spermatogonia (stem cells) that go through meiosis to make spermd. Closet to wall of tissue- immature spermatogonia e. Between seminiferous tubules- interstitial cells of Leydig- produces testosteronef. Figure in Chapter 20i. Hypothalamus→ gonadotropin RH→ adenohypophysis→ gonadotropins→ FSH, LH→ seminiferous tubules and interstitial cells→ spermatogenesis and testosterone release ii. Testosterone and inhibin cause negative feedback (testosterone goes to hypothalamus, both go to adenohypophysis)g. Testosteronei. Integrity of male genitalsii. Male secondary sexual characteristics iii. Negative feedback in hypothalamus and adenohypophysis 2. Female Reproductive System a. Estrogens and progesterone (corpus luteum)b. Estrogensi. Main – estradiol 17 betaii. Pregnancy – estriol (produced by placenta)iii. Menopause – estrone (adipose tissue)c. Ovariesi. Fallopian tubes/uterine tubesii. Ovary contains folliclesiii. Follicles produce eggsiv. Immature follicle1. Stem cells – ovogonia2. Surrounded by single layer of follicle cells3. FSH released, follicles stimulated, they begin to mature4. Follicle cells (granulosa) undergo mitosis5. Follicle cells synthesize mRNAs, passed into ovogonium via pinocytosis6. Stored in ovogonium, affecting early embryonic development7. Mom’s genome establishes axes of embryov. Mature follicle – bursts, egg is released into body cavity, pulled towards uterine tubevi. Egg fertilized in upper third of uterine tubed. Uterusi. Walls composed of three layersii. Epimetriumiii. Myometrium – smooth muscleiv. Endometrium – two layersv. Deeper layer – stratum basalisvi. Upper layer – stratum functionalise. Early embryoi. Embryonic stem cells (in intercell mass) are totipotentii. Trophoblasts releases enzymes that break down cellular adhesion molecules (CAMs) in functionalis, intercell mass embeds itself in functionalisiii. Trophoblast – embryo part of placentaiv. Stratum functionalis – mother’s part of